...One thing that I forgot to mention: The car will definitely be a cruiser with air conditioning. SM

 

....and the rear gear ratio is undecided at this point, suggestions on that would also be welcome. SM

 

Well...instead of "Chevelle Tech"...looks like this thread would have been more productive if I had seen/posted in the "Engine" section under the "Mechanical" header.

Can one of the "moderators" move this please?
Thanks...Stan M.

 

Stan,
To be honest with you if you are going to keep the Q-jet and want this to be a nice driver, I would just leave it alone and plug it in. If you are going to change cams you will have to do valve springs too and that probably requires doing away with the valve rotators too. Not sure how much cam you can put in those without having to do machine work on the heads. Not sure that a cam change will really gain you anything without doing other things too.

Just my opinion,

 

Stan,
To be honest with you if you are going to keep the Q-jet and want this to be a nice driver, I would just leave it alone and plug it in. If you are going to change cams you will have to do valve springs too and that probably requires doing away with the valve rotators too. Not sure how much cam you can put in those without having to do machine work on the heads. Not sure that a cam change will really gain you anything without doing other things too.

Just my opinion,

That may be right Bill....and thanks for the post.

....and hello to everyone who's kicked in their 2 cents, I'm just getting in from a long day.

Bill (and/or anyone)...What other things do you think would be the minimum requirement in your opinion? It's a great engine as is..for what it is. I was just thinking it could use "some" help... The pretty much original ragged old 69 Malibu, and is a straight almost rust free car...just don't want to get buried in it like all my others.

I have a set of 290 heads left over from an old 396 project that might work pretty good with the low compression this thing has. But I was hoping trying not to get that far into the engine unless I have too. I know I'd probably rebuild the whole thing if I go that far.

...and could someone tell what the purpose of the rotators is,,,can't say I've had to deal with them before (unless I just thought they were shims of some kind).

 

I agree with Bill. Given your stated goals, clean it up, paint it and drop it in as-is.

BTW - That didn't directly answer your question. So, to answer your question, I would recommend the cam that is in it and the intake that is on it.

 

I think the weiand would be perfect! Had good luck with the big oval version of that intake in my 509cid peanut engine. Dont know much about camshaft, but isky mega 264 could be the one.

 

Keep in mind that engine will have dish pistons and open chamber head - about 7.3:1 compression. Cams designed in the 1980's to help these low compression engines would be really what you are looking for to juice it up a little - Comp Cams High Energy series, Isky Mega Cams, Engle Cams. I would keep the intake duration (@ .050) around 210* to 215* and lift around .500", this would require a spring upgrade and rotator eliminators as mentioned. As for an intake, either the Wieand Street Warrior or the Edelbrock Performer 2-0 (which is also a peanut port intake) would work for what you are looking for.

My experience with the stock peanut port 454 is the cam and heads give up too soon - around 3500 RPM. The second design TBI cam that came out in the 1994 models did improve the upper end and would improve the earlier Mark IV engines as the 156 heads that came on the Gen V engines was the smallest of the peanut port heads, the earlier peanut port heads were better.

 

This cam works well, while it does not have a lot of lope to it I ran the Melling version (same specs) years ago in my '74 GMC 454 and the truck flat out would pull to a clean 5500 rpm making power all the way. I had headers and an 800 Holley Spread-bore carb on it.

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Free Shipping - Summit Racing™ Classic Camshafts with qualifying orders of $99. Shop Camshafts at Summit Racing.

www.summitracing.com

 

Back in the early 90's I bought a 1980 3/4 ton camper special with a tired 454. It had a couple burnt valves and low oil pressure. I got a stock rebuild kit (low compression) rebuild kit, had the crank turned as it was out of spec, a weiand action plus dual plane spread bore intake, 290 closed chamber heads (helps the compression), basic port clean up, Rhoads RV cam and lifter combo, Holley/ motorcraft 800 cfm spreadbore cheap summit headers. Drove it until the body fell off. Pulled like a freight train to a little over 5K. Great towing, torque motor. It had a capital 14 locker with 410 gears.

Point is that you have a great motor and with a few pieces it will be a great cruiser motor.

I wish I could find another one !

 

Back in the early 90's I bought a 1980 3/4 ton camper special with a tired 454. It had a couple burnt valves and low oil pressure. I got a stock rebuild kit (low compression) rebuild kit, had the crank turned as it was out of spec, a weiand action plus dual plane spread bore intake, 290 closed chamber heads (helps the compression), basic port clean up, Rhoads RV cam and lifter combo, Holley/ motorcraft 800 cfm spreadbore cheap summit headers. Drove it until the body fell off. Pulled like a freight train to a little over 5K. Great towing, torque motor. It had a capital 14 locker with 410 gears.

Point is that you have a great motor and with a few pieces it will be a great cruiser motor.

I wish I could find another one !

10-4 on that, they are getting fewer a farther in between these days. I think there's a good bit of potential in any of these engines....and I always had big blocks back in the day.
Was there flat top or recessed pistons in your 80 model truck, if you recall? Compression is what is bothering me the most...but I'm not sure what this one has without a tear down..

 

Stan,
I just noticed that your post title says GenV but then you say this is a 1988 engine ? I dont think 88 would be a GenV engine ? Are you sure that you have PP heads ? How about a casting number off the block or even an engine code stamping to be sure.

 

Dang,,,you are right Bill it's a Mark IV I believe...(just typed it wrong.)

Here's the numbers anyway:

Block: 14015445 (0288)
Heads: 14092360
Front ID pad: CJ3330277
Above timing cover pad: T053PLC

Carbuerator #: 17085212
1168 HPA

Some of the above I can decipher, and some I can't find anything on.
Thanks...Stan

 

I would try and get those closed chamber 290 heads on that engine, it would make a pretty big difference in power. Make sure you have the heads chamber CC'd so you know what your dealing with, unless you know for sure they have not been milled. Hopefully you do not have domed pistons. I have those heads on my LS5 Chevelle and they kick ass. Tons of low end and midrange torque and throttle response, pulls like a freight train. Then you can use a regular oval port dual plane. And based on that, you can select a cam to complement the heads and final compression. Make sure that piston to valve and piston to head clearances are checked when changing heads and cams. If your pistons are flat top or dished, you don't have to worry about piston to head clearance. If you do all that, I would consider a roller cam too. Do this while the engine is still out of the car, way easier. Good luck!

 

The 290 heads would bring your compression up to around 8.5:1, the Summit Cam suggested by 68Chevelle would work well with that combo, a good dual plane Large Oval Port intake and it would be a fun street cruiser. The carb is a Heavy Duty Truck - Motorhome carb, should help with "fuel economy" (sarcasm meant)

 

He could get the 290 heads milled down to gain some compression. I purchased a set of those about 10 yrs ago on ebay, they had been milled to yield a 90 cc chamber. Only downside they are heavy. Have to watch how much camshaft lift with those stock flat tops.

 

Stan,
I am going to disagree with the others. If all you want is a cruiser with AC to drive around in I would leave it alone and put it in the car. I am only saying that because i know if you decide to do a head swap its just going to go further and further ........ If you want to do an intake swap to lose a few pounds I guess that wont hurt if somebody makes a dual plane for the PP heads that the Q-jet will bolt to.

By the way, I might be wrong but I dont think that Chevy ever had an 800 cfm Q-jet. Certainly not on a truck. Only some big Caddys and maybe Olds and a few Pontiacs.

 

Stan,
I am going to disagree with the others. If all you want is a cruiser with AC to drive around in I would leave it alone and put it in the car. I am only saying that because i know if you decide to do a head swap its just going to go further and further ........ If you want to do an intake swap to lose a few pounds I guess that wont hurt if somebody makes a dual plane for the PP heads that the Q-jet will bolt to.

By the way, I might be wrong but I dont think that Chevy ever had an 800 cfm Q-jet. Certainly not on a truck. Only some big Caddys and maybe Olds and a few Pontiacs.

I agree with Bill (again.) This is how multi-year frame-off restorations happen. "I think I'll just change the oil, and then, and then, and then . . ."

Just drop it in and run it...

 

Thanks to all who posted..
Decisions decisions...lol!

I wish I knew more about the compression and pistons on this motor without tearing it down. It's clean as a new engine under the valve cover...doesn't even have any dark residue on the valve cover! It's still totally untarnished!!

I found a list of carb id numbers a few days back...but I cant find that list again for some reason. Does anyone have a link to quadrajet identification numbers? I've slept since then...but I'm almost positive it ID'd as a 800 cfm carb and I would like to recheck that list (or one similar) again.

 

Thanks to all who posted..
Decisions decisions...lol!

I wish I knew more about the compression and pistons on this motor without tearing it down. It's clean as a new engine under the valve cover...doesn't even have any dark residue on the valve cover! It's still totally untarnished!!

I found a list of carb id numbers a few days back...but I cant find that list again for some reason. Does anyone have a link to quadrajet identification numbers? I've slept since then...but I'm almost positive it ID'd as a 800 cfm carb and I would like to recheck that list (or one similar) again.

If you have this small bump in the primary side, it is large bore.

 

There are more 800 CFM Q-jets out there then you think.
Common on 80' and newer 454 truck and most 454 motorhomes.

 

I wonder how the RV 800's compare to non RV carbs, especially if the heads and cams are ramped up to another level??

I'm also wondering about the Turbo 475 transmissions...and how they would be on a street car??

 

I wonder how the RV 800's compare to non RV carbs, especially if the heads and cams are ramped up to another level??

Someone will correct me if I am wrong, but my understanding is the primaries are slightly larger so you run longer in the 2-bbl mode increasing throttle response and economy (if you can say economy and 454 in the same sentence). When my 1986 K30 was still running it would get around 11 mpg (TH400 - 3.73 gears) empty or full

 

I’m running what was an original peanut port motor. Stock bottom end but I put some GM oval port heads, comp cams 268xe cam kit, a cheap chinesium dual plane from procomp, and a 600cfm holley(a little small but I’m not racing so I live with it) . Has great vacuum for my power brakes and does as much damage on the street as I need it to do. Can’t keep my tires from spinning. I’m sure you’d get similar results with the same cam keeping the peanut ports and intake you have. A lot of companies have cams in that range so pick your poison. Take what I say with a grain of salt but this combo works from my personal experience

 

Thanks Mike..
What oval ports heads did you use if you know...and do you happen to have a/c with the 268 XE . I've had several 268 HE cams in the past...and am sure I'd like the 268 XE with later motors.

 

No AC but I do have future plans for that. They’re 820 heads with some port work done by previous owner. From what I’ve read they flow almost on par with 781/049s though definitely not as desirable I got them for 200 bucks. I’ve also read guys using 396 closed chamber heads to bump the compression up with these flat top 454s. That might be something to look into

 

10-4 Mike. I I have a set of 290 heads that I think are off a 396...at least that's what they were on when I got them some years back. It had a bad piston...and was in the trunk of the Malibu I'm fixing up.

 

My wagon came with a 445 block 454 in it. The short block had never been apart. Somone had put in a Comp xe262 cam, RPM Airgap, 1972 292 /820 heads Wdelbrock 800 avs, hei and a set of headers. It ran great and got almost 18mpg on higway.

It was leaking so pulled it out. It was a 4 bolt main block, dished pistons etc. Ended up turning it into a mild 489 and reused the topend. I should have some pics of the pistons somewhere.

That XE262 would be a good cam for cruising with a/c.

 

Hmmm,...445 same block as mine. 18 mpg wow! I've never seen 18 mpg with a big block and I've had a ton of them (wreckers).
I would like to see pics of the pistons if they are convenient. I don't have a clue what RV pistons look like, recessed dish I suppose...
Thanks for tehecam info I'll take a look at that XE262

 

Hmmm,...445 same block as mine. 18 mpg wow! I've never seen 18 mpg with a big block and I've had a ton of them (wreckers).
I would like to see pics of the pistons if they are convenient. I don't have a clue what RV pistons look like, recessed dish I suppose...
Thanks for tehecam info I'll take a look at that XE262

I did a quick search of smog 454 pistons and came up with this picture from the corvette
forums

Not sure if this is what yours look like but likely

Good luck
J

 

Corvettte forum.. Is this a truck motor?

 

In the 1970's the HD emission pickup trucks got the dish piston, while the 1/2-tons with the 454 and all Suburbans got flat-top pistons - they were rated 10 HP more. By the end of the 1970's all trucks including Suburbans got the dish pistons on the 454. I have a 1977 C20 Suburban engine that had flat-tops and my 1978 C20 has dish pistons as does my 1979 C35 Dualy. The flat-top were the advertised 7.8:1 compression while the dish pistons engines were an actual 7.3:1 even though advertised as 7.8:1

 

That's a lot of good information Tom. Thanks very much. Did they continue 7.3:1 all the rest of the
way on teh 454s? Mine is a 1988 I think.

 

That is a heck of an idea Joe!!
I don't know why that never occurred to me?
Duh...senior lapse I guess...thanks for the great idea!!!