Anyone put a 292 truck L-6 in a Chevelle? I know one motor mount is different (from the 230/250) and the whole thing is about 2" taller.

Just wondering if it fits under the hood...

I don't see why it wouldn't fit. You may just have to use a lower profile air cleaner.

IMO I would install a modified 250 in place of the 292. Between the two engines, the 250 properly done was a much smoother engine and made equivalent if not more power. The 292's were tough on cranshaft vibrations and flywheels/harmonic balancers especially if they were running in higher than stock RPM bands. One of the nicest 250's that I saw was a Canadian 250 block marked with Canada on it. They cylinder walls were extra thick compared to the US cast block and could be easily bored out to a true 4.00 inches. IMO the 292 blocks need to be sonic checked for boring, we did several at .060 and the cylinder walls thinned out up at top of the bore. The later model 250's that used the integrated head are not the hot ticket. You want the separate head and intake (clifford) and the 250 crankshaft (lighter) from a middle eighties engine. Cylinder heads work well with larger valves installed about the same as the 283 V-8 with 1.94 intakes and 1.6 exhausts.

Which intake would you pick for the street? Four barrel (which presumably could be converted back to two barrel if necessary with adapter plate)? Two barrel? Dual two barrels? Three two barrels? TBI (probably not going here)?

Which intake would you pick for the street? Four barrel (which presumably could be converted back to two barrel if necessary with adapter plate)? Two barrel? Dual two barrels? Three two barrels? TBI (probably not going here)?

If you what a cool induction system for your 6, contact tlowe on this forum. He has a turbo FI system that he built, that is very cool, fast and dependable.

Thanks for the feedback everybody. I am doing research for some sort of L-6 build for my 300.

That is such an absolutely cool car! :thumbsup:

I was checking out your Car Domain page. That 300 6 cyl was a really neat find.

I wouldn't do very much to it appearance-wise. Maybe some mild engine hop-ups, but I'd keep the appearance just like it is. Even the Granada Gold paint, which I personally like ( I have three cars the same color!).

Very nice car


Randy

That is such an absolutely cool car! :thumbsup:

I was checking out your Car Domain page. That 300 6 cyl was a really neat find.

I wouldn't do very much to it appearance-wise. Maybe some mild engine hop-ups, but I'd keep the appearance just like it is. Even the Granada Gold paint, which I personally like ( I have three cars the same color!).

Very nice car


Randy

Hey thanks! I like it alot and am having great fun with it. I am right there with you on the appearance (beyond the wheels and tires). I don't plan to do anything to the outside (except I do have one rust spot I will have to deal with soon) and I don't want to paint it anytime soon.

I was planning a 327 build but was still struggling with how far to stray from stock. I got some comments on the (ugly but cool) 230 six in there now and saw pictures of a really nice 250 with dual exhaust and cool intake etc and new that that was what I needed to do with my car.

Pete,

Your 230 block is the same as the 250 block. If you can find a late model 250 crankshaft with the smaller counterweights and change pistons appropriate for the correct pin height, you should be good to go. You can even re-use the connecting rods as they are the correct length as well. See if Sissell automotive out on the West Coast is still going, they had some really nice equipment to get that engine going.

Rich

Pete,

I almost forgot, for dress up accessories such as tappet covers, valve covers check out Clifford performance and also look out for Mercruiser engines at the marine shops. They used the same engines for marine and had some nice cast aluminum tappet/valve covers made for that engine.
I had a Clifford valve cover that was wrinkle black orignally and we stripped it and had it polished along with the Clifford manifold. It really looked nice. I did have a cast timing gear cover that I bought once, but I never used it as there were issues using it with the factory balancer. The cover was thicker and caused problems with the timing tag and aligning the belts on the water pump pulley. If you run any kind of performance camshaft, IMO run the Cloyes gears and make sure that you either use a set screw or bolt drilled and tapped into that gear to make sure it doesn't walk off the nose of that camshaft. If it does, you'll notice that a timing check will show the timing always retarded. Resetting it will last only a short time until other bad things eventually happen.

Rich

i recently picked up a 69 300, has a bent frame, but was a low milage car with a 230 six, w/power steering-i had a half azz idea of reusing the 6, change to a 350 trans, make the rest of the car look like its fast(but i'll prob put my 540/4l80e in it) but i thought it would be cool to have something like that to ride in style(quite, comfort-lol)

I am impressed with the advice Rich Till is giving :thumbsup:. I say that you keep your 230 block and drop a 250 crank into it. The 250s were gone after '84 and the changes to make the crank lighter may have happened in '80 (last year for the L6 in the car lines was '79; CAFE standards went up a notch on the light trucks in '80).

The separate head & intake was last used on the 250 in '74 but continued on the 292 through until the end (1988). A trick would be to use a head from a 194 six because of the smaller combustion chambers. That has the effect of yeilding a higher compression when used on a larger displacement. Boring out a 250 can give you a 255 to 262.

In Super Chevy back around '91/'92 there were 2 nice articles concerning straight sixes. I don't have it at my fingertips, but they spoke of the advantage of machining your block for zero deck hieght. They also made some modifications that involved adding metal into the ports and machining them (I think it may have been the Sissel Lump Port head).

Your car has the 3-speed column shift. Be carefull of clearance between the linkage and the headers. I wouldn't want to cut the tunnel on your nice original Chevelle 300 just to throw in a floor shift. As an alternative to individual tube headers, you might also condsider cast iron headers. Those might not have the same issues with clearance and potential leakage (headers sometimes need numerous rounds of re-torquing so they don't leak around the flanges). A picture is worth a thousand words: http://www.stoveboltengineco.com/acartpro/

In my opinion you would be best running one of those little Holley 4-barrel carbs that are around 450-500 cfm. Multiple carbs look cool but you can run into linkage and syncronization issues. Pontiac actually ran with a Quadrajet on their high output OHC-6 (that engine shares the same bore spacing with the Chevy, and may have even shared the intake with the Chevy for the 1-barrel versions (they sure look identical).

About a month ago a neighbor offered me a free 1975 250 that was sitting at Alex Irvine Chevrolet here in Toronto. When I spoke with him several days later I found out it was scrapped :sad: because the dealership is moving to a neigboring town shortly. I didn't need the engine but a guy in our local club wants a 250 to replace the flathead six under the hood of an old Packard. He wants MY '67 250 :noway:. I'm keeping my six, thank you.

Cam,

Thanks for the kind words! See if you can find Pete one of those cast in Canada blocks with the extra thick bores that will bore 4.00". Your advice is right on! I actually ran the 194 cylinder head for the increased compression but because the combustion chambers were smaller, there wasn't adequate room for the larger valves and the subsequent shrouding problem. Later on we worked with the larger chambered 250 head and larger valves and found that they actually flowed better and ran better even with the lower compression. Something similar to what the GM engineers discovered when they went over from the closed chamber BBC heads to the open BBC heads. Anyway I also ran the Sissell lump port head during the middle 1980's. It was based on a "mecho in mexico" 250 head (separate intake/head design) with extensive brasing inside. For what it was at the time, it flat got it done. If Pete really wants multiple carbs, then go look at the Duggan head (Austrailian, but marketed here) made from aluminum and ready for side draft webers. It is really not that pricey and is IMO the best performance head around for this type of engine. Kay Sissell passed away several years back (rip) but he was very nice to talk to and understood these engines extremely well.
Rich

Wow! Thanks for all the great discussion! All of this is just planning because I just deployed for six months yesterday and nothing will happen (except planning and parts buying) until the Spring.

I was (am) looking to pick up a 250 just because my car is so original. I had hoped to find a 250 (twenty free cubes without swapping cranks) for next to nothing so I could work on it for as long as necessary and then just swap it out for the 230 and keep it stored in case I needed to put it back to original condition. Plus I get to drive it longer this way:hurray:.

I asked about the 292 because alot of the discussion in the Santucci book and here http://www.67-72chevytrucks.com/ go on about how much more torque a long stroke 292 can make. I have decided to stick with the 250 for simplicity.

I definitely want to keep the three speed. I have been looking at clifford intakes and stovebolt headers. I can't exactly tell for sure, but the stovebolt website says their headers clear the clutch linkage (no more detail). I agree with the comment on the 4 barrel intake. This is all basically to look cool and provide a bit more power (and sound good). Multiple carbs will just be more work and may sacrifice driveability. Offenhauser has intakes too... My decision may hinge on a matching intake, valve cover, and side covers. The picture in my mind has an orange block and head and matte aluminum finned valve and side covers with black paint between the fins.

Alot of this was brought on by this car on Cardomain:

http://memimage.cardomain.net/member_images/2/web/2102000-2102999/2102753_21_full.jpg

After some searching, I have determined that the father of the owner of this car (who helped build it) is/was a member of TC.

I won't have the budget to go all the way to a lump port head and will have to look closely at either a 194 head (to increase compression ratio) or larger valves in a 230/250 head. It will all depend on what I find and how much machine work is required for the head and block.

Don't bother replying about a 350 being cheaper and more powerful. A 350 in my car would be a step back in my opinion. It happened to me again this past Saturday when I opened the hood and somebody said "Wow! A straight six. I haven't seen one of those in a LONG time!"

I plan to keep refining the plan while deployed, and I will certainly take into consideration all your excellent feedback. I will keep posting updates so you can evaluate my decision making.

I would have never guessed I could get this excited about a base model 300 with a straight six and no options. I guess it is because it is different and you don't see them around. I dare say my car got more attention than the (rough) 66 SS I parked next to on Saturday:D.

Thanks for all your help!

[quote=Cam;1495986]Pontiac actually ran with a Quadrajet on their high output OHC-6 (that engine shares the same bore spacing with the Chevy, and may have even shared the intake with the Chevy for the 1-barrel versions (they sure look identical).

quote]

There is a guy at the local drive in with a 67 LeMans Sprint with the OHC 230. I spent a long time talking to him Saturday about his intake and Quadrajet. He says it is a special (hard to find) Quadrajet but that intake/exhaust setup sure does look like it would bolt right on my Chevy. The stock exhaust on the Sprint engine has 3 into 1 headers but then combines into a single collector just below that.

Pete,

I ran a model 4412 Holley 2 bbl on my 250 six cylinder and I also ran a model Holley 6895
390 cfm 4 bbl on it as well from time to time. Both had great idle circuits and street manners and the top end performance was actually quite even. We ran solid flat tappet camshafts built by Reed Cams from Atlanta and occasionally ran a solid roller from them as well. The roller was naturally more expensive and labor intensive to run, of course this was back almost 20+ years ago before they had the really nice pressure fed roller lifters. The offenhauser manifold in that picture you had was not very impressive compared to the Clifford model in terms of performance. There was also another company from Waxhaw, North carolina that sold a "bolt in" lump design for the stock type head to better improve the flow direction. I did not test it but it was definitely priced right compared to Sissell's lump port head. Good luck with your deployment and may God protect you in the process.

Rich

stick with the 6 it will turn more heads! tom

I guess its senseless to ask , has anyone gotten into the sbc head mods of cutting and welding up two v8 heads to fit on these motors with v8 domed pistons? Going too far?

I guess its senseless to ask , has anyone gotten into the sbc head mods of cutting and welding up two v8 heads to fit on these motors with v8 domed pistons? Going too far?

It has been done in the past with cast iron SBC heads, the previously mentioned book (I think it's that book) has a very detailed section about doing that exact same thing. I would think that today with the availability of Aluminum SBC heads, this should now be even easier (easier to find a place willing to do the welding the heads, maybe cheaper too). There are plenty of used Aluminum heads on the market that may not be the most high-tech, best flowing heads for the hot rodding SBC crowd, but more than enough to feed a little 250. Any set of heads that'll feed a hot little 350 will be more than enough to feed a 250-based engine (250ci x 1.33 = 332.5).

I love seeing a hipo 6 in a Chevy. Everyone has a V8 and it is great to see something different. I ran across this site while looking for a local machine shop. http://www.customdesignperformance.com/leo/leo.html. I can't vouch for the machine shop but there is a lot of Chevy 6 cylinder info here. I can't wait to see how it turns out.

I love seeing a hipo 6 in a Chevy. Everyone has a V8 and it is great to see something different. I ran across this site while looking for a local machine shop. http://www.customdesignperformance.com/leo/leo.html. I can't vouch for the machine shop but there is a lot of Chevy 6 cylinder info here. I can't wait to see how it turns out.

This is the man who wrote the bible on Chevy sixes. Leo Santucci.

I guess its senseless to ask , has anyone gotten into the sbc head mods of cutting and welding up two v8 heads to fit on these motors with v8 domed pistons? Going too far?

Here is a link to a 292 (http://www.chevelles.com/showroom/showphoto.php/photo/1426/cat/500/ppuser/335)that had a pair of sectioned LHS small-block heads brazed together. Because the bore spacing is the same as the small-block V8 you can actually make it work. I'm not sure what happens with the pushrods; they might end up being exposed above the deck.

If I was to do this head sectioning thing like we are talking about, I would check and see what early '50's, MOPAR Hemi heads would come close to the bore spacing of our engines and use them!!

Go to this much trouble, I'd use a HEMI-Head to start w/!!!!!!!!!!!!

pdq67

the sbc head has a different bolt pattern. when doing this with sbc heads it really is no longer a street engine and the deck is weakened.
just turbo it! tom

Pete, I knew a guy here in Phx that was a real manual transmission geek. He had a 66 Chevy pickup with 4 on the tree. He used a Saginaw 4-spd and fiddled the linkage a little, he said it was trivial. On those trannies the reverse is in the tailhousing, he ran a cable from under the seat to to the reverse lever. It was cool, you couldn't see it at all. All he did was put the column shifter in neutral and pull the cable, it was like a manual choke cable.

Later I found out he had done the old mod to add the Saginaw overdrive that came on Sag 3-spds. It can be used on Sag 4-spds with a little minor machining. What a cool deal.

The Sag 4 spds are cool because the first gear is lower than a Muncie. Give better performance off the line, get up to freeway speed and slide it on into OD, very cool.

If you're interested in this deal let me know, I'll see what I can dig up.

And yeah, the 292s are sort of a pain to deal with.

There's lots of hot rod parts out there for a 6, just have to look around a little more. I've built a number of Holley 1850 4 bbls for them.

Straight 6 guys are cool, more of a fraternity.

Tom,

Please post ALL the info on the Sag you have b/c I'm definately interested in it too.

As for 6-bangers, I'm not too sure that the old GMC 302" engines can't be made bigger easier than the 292??

pdq67

Pete, I knew a guy here in Phx that was a real manual transmission geek. He had a 66 Chevy pickup with 4 on the tree. He used a Saginaw 4-spd and fiddled the linkage a little, he said it was trivial. On those trannies the reverse is in the tailhousing, he ran a cable from under the seat to to the reverse lever. It was cool, you couldn't see it at all. All he did was put the column shifter in neutral and pull the cable, it was like a manual choke cable.

Later I found out he had done the old mod to add the Saginaw overdrive that came on Sag 3-spds. It can be used on Sag 4-spds with a little minor machining. What a cool deal.

The Sag 4 spds are cool because the first gear is lower than a Muncie. Give better performance off the line, get up to freeway speed and slide it on into OD, very cool.

If you're interested in this deal let me know, I'll see what I can dig up.

And yeah, the 292s are sort of a pain to deal with.

There's lots of hot rod parts out there for a 6, just have to look around a little more. I've built a number of Holley 1850 4 bbls for them.

Straight 6 guys are cool, more of a fraternity.

All of this sounds very cool. My plan so far is this: Find a decent (preferably low miles or rebuilt and recently running) 250. Build the 250 (the extent of this effort is still TBD depending on the shape of the donor engine and wife's understanding of budget) and bolt it to the stock 3 sp.

I'm sure having the engine out will push me to think about rebuilding the front end and brakes...but will definitely need lots of detailing of engine compartment.

Then I can think about that 4sp OD on the column. That would blow people away. I'd definitely like to see the details but that would be way down the road. I am just getting started and will need to beef up my wrenching skills...

I wonder what the shift pattern on the column was for a four speed? Best would be to put first in the (3sp) reverse position and go from there. Not sure how the linkages would work...

Keep this discussion going, I like it. I hope to join that fraternity of straight six guys. Thanks Tom.

I'll look around for that Sag OD stuff. I don't know where it is right now, it might be on a CD, I rolled a bunch of stuff off to CD awhile back.

here's a start:

http://www.chevytrucks.org/tech/overdrive.htm

http://www.dandltransmission.com/saginaw.html for some info on the ratios available for the Sag 4-spd

that Chevytrucks.org article seems to be linked to from all over the place. It's not the article I had that I'm having trouble finding, it was longer and more detailed.

Thanks Tom for sharing!

Fwiw, Packard had a fully sync'd 3-speed stick and I think it had an OD on it. I mention it b/c it had to be big to handle a Packard Straight-8's torque so it should be a lot stronger than the Sag. OD conversion..

And the best Sag is the 2.54 1st geared tranny!

Somewhere I read that SOME P/U's had 4-speed column shifts STOCK!! But, I've NEVER seen one..

Now back to the head. You can make a little wing cross-section "air-foil" that a head-bolt goes through to split the siamesed ports if you want to go to the trouble. Somewhere there is an old article on 6-bangers and it has a pic of how to make this! (If you are really interested, PM me and I will try to find my copy...)...

It may do better than the "lump-head" deal for the money spent??

Guys used to take the exhaust manifold and cut it either just in front of or just back of the middle, plug both ends and then hole the short piece and braze a short 2" or 2.5" pipe nipple w/ a homemade exhaust manifold gasket plate on it to create real split manifolds way back there b/c split headers were hard to come by, plus pricey for us kids!!

And guys did the same thing w/ the intake by brazing on center flanges on each end so three carb's, be them 3x2's or 3x1's could be ran!! And alotta time's they ran a custom intake w/ 2x2's or 2x1's(??)..

This is "old-school" to say the least!!

You plane the head to up the CR. to whatever gas would stand back then, I'm thinking 11.5 to 1 CR., add a 5/8th's to a 3/4 race cam, (even a full race cam), and a 4-speed w/ something like 4.56's for the 1/4 or 5.13's for the 1/8th and a good set of slicks and you wiill kick some V-8 tail!!

And don't get me started here about the cams b/c the old-timers will know just EXACTLY what grinds I am talking about!!

pdq67

Guys,

Great discussion, but if its a production Chevrolet 6 cylinder head about .080 off is about all its going to take if you lean on it with gasoline. On alcohol, about 14.1 compression static is all the head gasket is going to take with o-ringing the block before its done.

Remember there are only 4 headbolts per cylinder on this model and they are woefully inadequate for performance usage. If you turbo it, at some point this will show up as a weakness. These blocks and heads are light cast pieces compared to the Studebaker engines that were artificially aspirated. Duggan (Austrailia) already makes a superior (imo) aluminum cross flow head that uses 3 Weber carburetors for these engines.
They were available at one time from Sissell Automotive in California.

Methanol really works well on these engines!

Rich

How did the Stude engines get in here??

I love the little "REAL" V-8 Stude engines just about as much as I love the little short-stroke Chevy V-8's!! Flathead Stude 6-bangers suck!!


Bttt, if I was serious about this, I'd de-deck the block, come back and weld full the top so that when a new head-bolt pattern was used, it would be ready to take ALL the power that a NEW head bolt-pattern will put out!!

This is why I mentioned using the old Hemi-heads here!! They were AND still are SOTA head-wise in my book!!

pdq67

Just a random thought here about the comparison between the Pontiac 230 and the Chevrolet. If you are curious about interchangeability, try looking up the intake manifold gasket for both engines online at Autozone or Checker. If they share the same part number gasket, then maybe the interchange thing could work.

I'm having a discussion with a guy who has a Clifford intake and headers and an old 292 head he is looking to get rid of. As best I understand it, the 230/250/292 heads are pretty much the same so I am not too worked up about his particular head. Here are two questions I have that maybe you all can shed some light on:

1. He suggests the larger valve treatment (and has new valves, guides, and springs) on the head which seems pretty standard and is discussed in detail in the Santucci book. But he also suggests milling the head about 0.060" for an increased CR of about 9.0 or 9.5 to 1. Does this sound about right (or even advisable)? I know the deal with the 194 head (smaller combustion chamber but also less room for larger valves) but haven't heard about milling the 230/250/292 head as much. It seems this might allow for bigger valves and higher CR.

2. He has a Clifford intake but it doesn't look like it is plumbed for heat. Emails with Cliffordperformance tech indicates the new ones come plumbed and ready to go to hook up the heat. Did the earlier manifolds not have heat? Do they have the water channels but just not the fittings?

Thanks,
Pete

Pete,

The .050-.060 for cutting the head is a good number to follow. As I remember there were several sizes of combustion chambers on these heads just as the big and small block heads depending on the year and application. The last head that I had with larger valves installed was a late eighties 250 Gm replacement head (mexican cast) with the larger combustion chamber compared to a 194,215,230 head. It had 1.94 intakes and 1.68 exhausts in it. Oddly enough Kay Sissell prepared this head and I remember him saying that these engines were more exhaust sensitive than you think given the fact that the heads are not cross flow and share exhaust runners.

The Clifford intake that I had did not have any heat provisions for it (late eighties) and it hauled butt with the Holley 4412 we had on it. It had lots of throttle response and bottom end. We ran several different camshafts, flat tappet and solid roller, along with Shoenfeld crossover headers connected to a 3 inch exhaust.

go to www.inliners.org then to the bulletin board. much more info there and guys that like them. tom

Picked this up yesterday:

http://memimage.cardomain.net/member_images/1/web/2653000-2653999/2653024_57_full.jpg

It is a 50k mile 250 from a 74 C10. With 3 speed still attached.

Now the fun begins!

Inline 6 have quite a following. My Dad would rather have that then a SBC for a Nova.

Whats the plan??

1. Leave the bottom end alone if possible.
2. Send the head out for some mild work. 1.8 intake and 1.6 exhaust valves for better flow but not too big. Hardend valve seats. Mill for increased CR (around 9.0:1?). Mild porting (no lump ports or anything that crazy). Still not really smart about this part (which is the most important and expensive of the whole plan.)
3. Offenhauser 4bbl intake with Holley 390. Water heat adapted. I was set on the Clifford but the inliner.org guys seem to think the Offy is better for street use (which is what this car is about). Somebody over there also recommended an Edelbrock 500cfm vice the Holley 390.
4. Langdon's Stovebolt cast manifolds. (Will need advice on exhaust system behind them. Want to do true dual exhaust, but a little bit apprehensive about the sound of the "buzzin half dozen." Not sure this is what I am looking for.)
5. Not sure about cam. If I leave the whole bottom end alone I could just leave it. But I have seen several posts recommending the "RV" cam to liven things up a bit. Got a recommendation on a Comp Cams 260H kit that comes with an aluminum timing gear and lifters.
6. HEI conversion for the stock sized distributor.
7. I will pretty up the whole package. I want to paint the block and head red. I love the aluminum finned Offy valve covers too. But they too are expensive (got advice to look for a Mercruiser). I love the look of a finned aluminum valve cover with color (red) between the fins. Something cool with the side covers and air cleaner.
8. It has a bunch of smog stuff on it that I plan to remove. There is a line going into the head above each exhaust port that will need to be filled.

Thoughts? Feedback?

This a WAY TOO COOL thread imho!

To heck w/ everything, hang a 144 supercharger off it's side and go!

pdq67

i would tell you to put the exhaust pipes both on the same side. if they are on oposing sides, it will sound sic/bad. believe me the rap when getting on it is music. tom

i would tell you to put the exhaust pipes both on the same side. if they are on oposing sides, it will sound sic/bad. believe me the rap when getting on it is music. tom

You mean like with both exhausts exiting on one side behind the rear wheel? That would look different, but could be ok. What about mufflers? What kind and I read something about how far forward or aft affecting the sound?

in the chevelle you are stuck putting them in one spot. i had 2" pipes on mine , both on one side and it sounded mean. now i have one 3" w/the turbo and no muffler. loudest is at idle.
i used a glass pack w/duals also. they fit better. tom

Pete,

PLease inspect those rod bearings carefully when inspecting the bottom end on that engine, especially the #1 rod bearing as it gets oiled up last and will show wear and abuse long before the others. Same thing applies to the #1 main bearing as well. If they look reasonably good, the chances are excellent that the others could possibly be fine.
Schoenfeld headers makes some cross-over headers (behind the block) for that engine and they really work well, but I don't think you would have the room in between the firewall for that set-up.

You ain't lived until you have followed out of town one evening a hopped up 261 Gimmy w/ splits and true duals w/ "Smitties"!!

Sucker will put goose bumps on the back of your neck! You will NEVER forget the sound it make's going up and down through the gears!!

Make's a V-10 MOPAR truck sound terrible, imho.

pdq67

Thanks for the feedback. I'll check out those bearings Rich.

I guess I hadn't focused on it, and I just assumed I could run the split exhaust back like any V8 exhaust. I just never thought it through how one pipe would cross over to the other side. And now I see that there isn't any clean way to do it. Hmmm. Got some more thinking to do.

Still somewhat apprehensive about the exhaust sound. I'm pretty sure I don't want people to never forget what my car sounds like. I've got feedback on how to make it loud, but none on how to make it not so loud.

the cackle is only when you really get into it, like running it thru the gears at wide open throttle. a good set of glasspacs will give it a ggod tone at idle and part throttle. do not go too big (over 2") with the pipes or the mufflers will be worthless. ask guy's w/v8's and 3" exhaust systems. tom

"SMITTIES"!!!!!!!!!!!!!!

Patriot Smithy glasspacks and Summit sell's them. 2" in and out!

You will NEVER forget the sound of a healthy 6-banger w/ splits and smitties on it, GUARANTEED!

And I haven't TO THIS DAY!!!!!!

pdq67

Love this thread. What is the best street intake I am torn between the Clifford and the Offy for my 71 wagon with the 250. It already has the clifford headers on it with true duals 2" I believe all the way out the back exiting on oppoiste sides. The motor has an HEI but other than that nothing else. I want to put a 4bbl. on it and put the OD behind it.

the offy is the better street version intake. they all need to be water heated for smooth operation. the offy's i have seen do not have this provision. tom

If compression is a problem to come up w/, I would use the 194 head and plunge cut unshroud the larger valves IF Santucci say's it's OK to do this w/o weakening the head?

pdq67

Langdon's sells a heat kit for the Offy intake. Not sure if all the Offy's are the same or if it is only the later models you can adapt for heat. You can put the heat plate on the new Offy 4bbl intake. This is the route I plan to go. There haven't been any Offy 4bbls on ebay for a while, will have to get a new one probably.

here's one. sorry ends soon.
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ih=003&sspagename=STRK%3AMEWA%3AIT&viewitem=&item=130208720703&rd=1

tom

I missed it. Could almost buy a new one for that type of money anyway.

Wow, $196 for straight six Offy manifold? Yiokes, maybe I'd better go check the old storage shed.

i would recomend getting one from tom langdon. http://www.stoveboltengineco.com/ . he has great service and knowledge of what it takes to get it done right the 1st time. tom

Yep. Planning on getting his exhaust manifolds and fastener kit so might as well throw in the Offy and heat plate too. Big bills coming...

Easy way to up the compression is to get the propane pistons for it. The propane pistons have a smaller dish. Not sure what the dish is on a 250 but on a 292 the stock dish is 0.3" deep and the propane pistons have a 0.15" dish. Speaking from recollection the stock 250 had an 8.5:1 compression ratio and the 292 an 8.0:1. Pretty measley, but great for turbocharging. For my 292 I went with propane pistons, had them thermal and friction coated from Swain-tech, had custom tapered Crower rods built, and found one of the stronger/lighter-weight cranks.

Only thing I would say about straight-6s is if you want to make some power out of them, be prepared to pay some money. Everything is more expensive.

We used to take and cut the carb flanges off (2) or (3) stock 235/230 intakes depending on motor's and braze them onto the intake we wanted to use to get it done way back in the early '60's!!

Then hand split the stock lower exhaust manifold's so we could braze on flanges to create 6-banger "split exhaust manifolds".

pdq67

Started tearing into the 250 last weekend. Small potatoes to you guys, but new ground for me. Lots of fun. Please give feedback where you see fit, I'm just charging into this with little real planning.
Started by making these pins for removing the tranny:
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bb1cbd58f00000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bb7a354d400000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bb7b154c600000026109IZMWTVw0I
Pretty nasty looking inside:
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bb7a6d5e100000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bb487955900000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bcb5b541200000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bcbced5b700000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bcb9354da00000026109IZMWTVw0I
This was weird. Anybody know what's going on here with the flywheel teeth?
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bca41149000000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bb55dd51b00000026109IZMWTVw0I
.

So if the flywheel's toast, and I have to get a new one, does that mean all the internals have to come out to get balanced with the new flywheel? The 250 is internally balanced. You can see holes drilled in the backside of the flywheel here.
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bc889956900000026109IZMWTVw0I
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bc932547a00000026109IZMWTVw0I
Up on the stand:
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bc98654ce00000026109IZMWTVw0I
A dolly I threw together. The tranny is still tied to my floor jack. Once I can get back out into the garage I'll put it on here. It's based on plans I found here (http://www.stovebolt.com/techtips/engine_dolly.html).
http://im1.shutterfly.com/procserv/47b8da22b3127cceb77bce1c95ff00000026109IZMWTVw0I
Hope to get back out there this weekend to start tearing off the accessories.

Why would the flywheel be toast? You can replace the starter teeth. Was there a dowel in the end of the crank for the flywheel? I didn't see it.

A note about using Langdon's headers, and exhaust sound.

If you run the exhaust out behind the rear wheel wells, it will sound rough.
If you run big tailpipes, they sound rough.
If you run too short of glasspacs, they'll be LOUD.
If you run a turbo muffler, they'll sound ROUGH
If you turn the pipes to the ground, under the car, it'll be the worse drone you've ever encountered, especially with turbo style muffs.

Best sound comes from 2 1/2" exhaust pipes to 36" glasspacs, with 2" tail pipes, exiting in the same direction as in: straight out under back bumper either together on one side or as you would do an eight with one on each side if you chose to exit straight back. This gives the listener the sound of both pipes and it will be a very smooth sound as each pipe will carry the sound of three cylinders equally spaced. There will be some "chop" at idle, and with a stick, some backrap during the shift.

Pete,

The ring gear on that flywheel is replaceable and any good auto parts store should be able to get that item for you. I believe based on the shape of the bellhousing where the starter is located that it is a 153 tooth version. Cheverolet make a lighter nodular iron version (about 12 lbs or less) that you might be able to source that would really help in the performance aspect. The nodular iron flywheel fits all of the internally balanced small blocks and comes set up to run the smaller clutch assembly. I don't think any of the 230's and 250's came with the dowel pin located in the back of the crankshaft that I have seen, conversely the 292's just about all had them and they had some vibration issues as well. Be sure and have the freeze plug side of the block checked for cracks around the freeze plug areas and check the #1 cylinder headbolt area (driver side) as it goes in to the water jacket/waterpump area and it can develop a crack externally that is very difficult to fix.

Rich

pete, is that motor a 292? it looks to be a 250. show a pic of the pass side of engine. the side covers on a 292 are 6" tall and on a 250 are 4" tall. the ring gear is replacable as said before. it can be ordered at any parts store. tom

A 292 has a 10.875" deck height vs a 9.100" for the 250 and on down engines.

pdq67

pete, is that motor a 292? it looks to be a 250. show a pic of the pass side of engine. the side covers on a 292 are 6" tall and on a 250 are 4" tall. the ring gear is replacable as said before. it can be ordered at any parts store. tom

It's a 250. I started the thread a long time ago thinking about a 292, but then bought a 250. Maybe I should change the title of the thread.

It didn't have a dowel pin in the crank.

Any more info on that head? Inliners.org has been down hard for a while now.

Pete,

The ring gear on that flywheel is replaceable and any good auto parts store should be able to get that item for you. I believe based on the shape of the bellhousing where the starter is located that it is a 153 tooth version. Cheverolet make a lighter nodular iron version (about 12 lbs or less) that you might be able to source that would really help in the performance aspect. The nodular iron flywheel fits all of the internally balanced small blocks and comes set up to run the smaller clutch assembly. I don't think any of the 230's and 250's came with the dowel pin located in the back of the crankshaft that I have seen, conversely the 292's just about all had them and they had some vibration issues as well. Be sure and have the freeze plug side of the block checked for cracks around the freeze plug areas and check the #1 cylinder headbolt area (driver side) as it goes in to the water jacket/waterpump area and it can develop a crack externally that is very difficult to fix.

Rich

Thanks guys, didn't know about the starter teeth. This is the kind of feedback I need. Can you get one of the nodular iron flywheels new? Or do I have to find one in a junkyard or something?

Pete,

That flywheel (nodular iron) is available through Chevrolet GMPP and listed in with the small block parts (2 piece main seal). Try Scoggin Dickey's website. IF you end up rebuilding that 250 and buying pistons, there is a flat top 2 eyebrow piston (TRW/Speedpro) that will fit that 3.875 bore with a real sporty ring package,lighter in weight and forged. There is also a 4 eyebrow version that is forged and not very performance oriented.

Rich

Pete,

That flywheel (nodular iron) is available through Chevrolet GMPP and listed in with the small block parts (2 piece main seal). Try Scoggin Dickey's website. IF you end up rebuilding that 250 and buying pistons, there is a flat top 2 eyebrow piston (TRW/Speedpro) that will fit that 3.875 bore with a real sporty ring package,lighter in weight and forged. There is also a 4 eyebrow version that is forged and not very performance oriented.

Rich

Thanks for all the help so far. If I replace the flywheel, does the whole rotating assembly have to come out of the block to get re-balanced?

I'm still trying to figure out if I can get away with not completely rebuilding the bottom end. I noticed the current flywheel has holes drilled in it and from what I've seen on TV, balancing involves mounting the crank in some device and spinning it around with weights etc...

the flywheel you buy should allready be neutral balanced. so no further balancing required for you. keep in mind the nodular lite weight flywheel weighs 15 lbs , the one you have is around 30 lbs. it will have less momentem off the line, esp at normal take off rpms. i would tell you to stay with the 30 lb wheel. tom

Had to dredge this up from the archives, but I figured I'd report out on how things went. It is hard to believe this started over three years ago, but with work and two moves in between, this takes time. I'll let the short video clip speak for itself, but I'll give a quick summary of what happened.

YouTube - ‪Chevy inline 250 dual exhaust‬‏

74 C10 250 bored .040 with stock replacement pistons. Block was decked "a little." Lump-port head by board member Tlowe with 1.84/1.60 valves. 260H Comp Cam. Offy intake with 500cfm Edelbrock carb. Langdon's split manifolds with 2" exhaust and 24" Cherry Bomb glasspacks. I have an HEI that I haven't installed yet. Stock 3 on the tree remains in place (new clutch and plate.)

It drives and sounds fantastic! Thanks for the advice in this thread, which was helpful.:thumbsup:

Too dog-gone-cool! Sounded good, real good. Its great to see the unusual. Apparently took plenty of perseverance & help from The TC gurus'. And thanks for your Service.

Sounds really good Pete!!! Nice job, I like that you did put the 2 exhaust pipes on one side!!! Color of car is great too!!

i thought this was a 292 thread...why did you build a 250? What isthe estimated HP?

pretty cool-i just finished a 65 post, took out the 230 6 cyl, 3 speed stick
i was looking at another 65 post body, thought about a 6 cyl with a 4 sp, could be a neat driver-is there some good info around on swapping stuff bet a 230 and 250
years ago i had an old pickup with the 292, it was a taller engine, lots of torq

i thought this was a 292 thread...why did you build a 250? What isthe estimated HP?

Way back when I asked the question I was thinking about a 292 but ended up buying a 250 and running with that. I never found out if the taller deck 292 would fit under the stock hood.

The experts over at inliners.org estimate 230-250 HP.

pretty cool-i just finished a 65 post, took out the 230 6 cyl, 3 speed stick
i was looking at another 65 post body, thought about a 6 cyl with a 4 sp, could be a neat driver-is there some good info around on swapping stuff bet a 230 and 250
years ago i had an old pickup with the 292, it was a taller engine, lots of torq

The 230 and 250 share an identical block (and bore) but the 250 stroke is longer so everything is a direct swap except crank and maybe rods/pistons.

First of all, nice work Pete! It looks and sounds great. I'm sure you will really enjoy it.


I have a low deck 250 that is running a 292 crank. It is not a very cost effective way of doing it since custom rods & pistons are needed, plus a lot of clearancing. Why did I go that route? Because the 292 block is taller. The additional height is not a problem if you run side draft carbs like Webers (or a turbo like Tlowe) but I wanted the old school down draft carbs. I have a new Offy intake with water heating provisions and I have a pair of new staged 2-barrel carbs. The head is modified with the long headbolts replaced with stubby bolts so that they don't go through the intake ports (more flow). It also has the bolt-in version of the Sissel lump port design. I went with larger valves and had some porting done. My cam is the one that Tom Langdon recommended, basically like an RV grind (actually a marine cam). Roller rockers & screw-in rocker studs will add a little efficiency and durability. Tom also custom made a mini HEI ignition for me with a small body distributor. Since the 67s still used the linkage type throttle I will have a little fun trying to make it work with twin carbs (or perhaps Lokar will supply me a cable type throttle). I really don't want to go too far with modifications since I also appreciate the stock setup.


Did you ever wonder why the motor mount & fuel pump are in different positions on a 292? After dropping the 292 crank in my 250 block we saw firsthand why. There is no clearance for the fuel pump excentric. I will be running an electric fuel pump, something I was not crazy about doing. I am trying to get up on the learning curve regarding fuel pumps, regulators and lines before finalizing my configuration.


Since the motor was put together I really felt that a better damper is needed for the 4.125" stroke crank. Despite what is said by the manufacturers, getting a proper damper for my application will entail some engineering fees to ATI since they don't actually have a correct damper for my application (a SBC damper will fit, but getting it keyed properly and having the timing marks actually useable means some engineering needs to be done). An inline six has a long crank and therefore more accumulated torsional twist along its length. Combine the long 4.125" stroke, potentially extreme rod angles (due to the low deck height) with a higher than intended RPM range plus higher compression and it become clear to me why a better damper is a good idea. My crank is an uncommon 1964-66 292 crank with 6 counterweights (rather than 12) for lighter weight and therefore hopefully faster acceleration. I don't want to break that sucker!

http://www.chevelles.com/showroom/data/500/medium/Feb2010_010.jpg