Have any interest in it? Just out of my own curiousity, I've looked into them and it seems, again, seems, that parts are readily available over the counter and it's easy to put a combination together without having to visit the machine shop a half a dozen times. Thoughts?

I went that route on my last 427" tall deck SBC. I used the Dart castings. The problem with 18's is that you have to use offset lifters which are super expensive. You have to run an special 18 degree intake, and you have to use shaft mounted rockers. Here is a breakdown of what I went through with my setup with new parts!

-Castings $1200
-Machine work $500(Seats, guides, and pushrod holes)
-Valves $300
-Springs $200
-Shaft Rockers $700-1200
-Offset Lifters $450
-Intake $250
-18 degree pistons for the larger valves and changed valve angles with cam lift over .500 lift $800

You can see that if you convert from an already roller cammed SBC to 18's, this could cost close to $5000!
My opinion is to stick with cnc'd 23 degree heads unless you need 400 cfm if airflow for some reason. A cnc'd 23 degree head can be had fairly cheap now and will flow the came as an 18 degree head out of the box. If you want ported 18's, that is another $2000. Bodix 18's are cheaper, but are a far more inferior head and more close to a 23 degree head then a real 18 degree head.


Another problem I had with this engine, is that it was street driven with a.700 lift roller. I had to change valvesprings, Lifters, and rocker bearing EVERY year. With the high offsets and massive spring pressures needed to take advantage of the high flow numbers at .700 lift, you need strong springs. They just tear stuff up!

Hope this helps with your thoughts.

P.S. What ever happend with the P.M.'s you sent me a while back???????

Scott, whats up bud, this is exactly what I wanted to hear. And I haven't forgotten about you, I'll e-mail you a little bit later...anyhow, regarding the 18-degree stufff....the reason I was wondering is because, Brodix offers a head that uses all conventional 23-degree valvetrain. Another friend of mine chimed in and said that it'll do well and generate killer power, but it wouldn't compare to the newer LSX stuff....well, maybe, maybe not. That's what I want to find out. :)

Brodix offers a head that uses all conventional 23-degree valvetrain. Another friend of mine chimed in and said that it'll do well and generate killer power, but it wouldn't compare to the newer LSX stuff....

You're referring to the Brodix 18X head. For the straight scoop with no poop on this head, PM Jason Gore (DragRacer) on this site. He can give you all the ups/down and ins/outs.

I can tell you that too!
Brodix heads use a standard valvetrain setup like you said. Because of this the intake port is not as wide. The reason the normal 18 degree stuff requires offset lifters and rockers is to clear the slightly moved and widened intake ports. What this means is Brodix 18's will never make as much max power as a standard 18 degree head but you can use the same valvetrain.
The downside is you still need 18 degree pistons so the valve impressions match the heads or you will have clearance issues with pretty much any decent cam. Valvetrain reliability will be very good compared to regular 18 degree stuff because the standard straight up style alignment puts less pressure on all the little needle bearings.

My new LSX stuff is amazing! My Mildly ported factory casting LS1 heads flow more air then my out of the box, trick as could be, 18 degree setup did!! Plus they were 1/4 the cost!! An LSX motor will always make much more power then a SBC both using all factory parts. With all aftermarket parts it will be a wash, but the fuel injected LSX will be more driveable. My whole new motor/turbo setup cost WAY less then an 18 degree SBC, AND, I now make 1000 hp on 93 octane!! Lets talk turbos!!

Oh ya, how does everyone get those little smiley faces in there posts??

Hope this helps on you search for info.

I can tell you that too!
Brodix heads use a standard valvetrain setup like you said. Because of this the intake port is not as wide. The reason the normal 18 degree stuff requires offset lifters and rockers is to clear the slightly moved and widened intake ports. What this means is Brodix 18's will never make as much max power as a standard 18 degree head but you can use the same valvetrain.
The downside is you still need 18 degree pistons so the valve impressions match the heads or you will have clearance issues with pretty much any decent cam. Valvetrain reliability will be very good compared to regular 18 degree stuff because the standard straight up style alignment puts less pressure on all the little needle bearings.


Hopefully Jason will see this post and offer his experience with the geometry problems of these heads and standard 23dg hardware. FWIW, Brodix also makes a true 18dg head which is what I run.

Did the 18 X stuff have any problems with direct bolt on beside the pistons??

A question along the same line is. Can you build a milder but big inch small block (ie 427+) that could still take advantage of the extra air flow of a 18 degree head, and still be streetable. Using a small street roller that wouldn't be so hard on parts.

Mine like Johns motor was a 427" sbc. It was a tall deck which brought a world of other problem, but I won't get into that!

The problem is that the 18's do not flow well untill .700 lift, you could run a small cam, but that would defeat most of the purpose of having such a high flow head. f you went that route, youd be FAR better off staying with a 23 degree head. Either way, you'd spend about $5000 bucks for the swap. Real 18's are more suitable for a race motor that needs MAX power with limited use.

Scotty, I sent Jason an email to get him to chime in when he gets free. The basic answer is yes, they will bolt up, but the rocker geometry was crap.

Mike, I believe you can get a pump gas 18dg combo to work, its just a matter of getting the cross section and camshaft correct. Probably worth about 50hp over a comparable 23dg pump gas setup.

OK.. So if you need all of that flow and have to do all of that machine work.. Why not run 15 Degree stuff?

The problem is that the 18's do not flow well untill .700 lift, you could run a small cam, but that would defeat most of the purpose of having such a high flow head. f you went that route, youd be FAR better off staying with a 23 degree head. Either way, you'd spend about $5000 bucks for the swap. Real 18's are more suitable for a race motor that needs MAX power with limited use.

Here's a link to some smallish 238cc BMF 18dg heads. These would be killer on a mild pump gas 427. ~300cfm@.400" lift is pretty stout for any SBC head.

http://www.bmfracing.com/sbc_flow_238.htm

Seems a shame with the 18 degree heads better valve placement and better port design that there isn't one offered that makes sense for a street car. I liked the idea of having something different, as you rarely see them used at the cruise nights.

Thanks for the link John. They look pretty killer. Are you planning on taking the 67 out again soon?

You're referring to the Brodix 18X head. For the straight scoop with no poop on this head, PM Jason Gore (DragRacer) on this site. He can give you all the ups/down and ins/outs.

Thanks John, can't wait to hear his thoughts!

I can tell you that too!
Brodix heads use a standard valvetrain setup like you said. Because of this the intake port is not as wide. The reason the normal 18 degree stuff requires offset lifters and rockers is to clear the slightly moved and widened intake ports. What this means is Brodix 18's will never make as much max power as a standard 18 degree head but you can use the same valvetrain.
The downside is you still need 18 degree pistons so the valve impressions match the heads or you will have clearance issues with pretty much any decent cam. Valvetrain reliability will be very good compared to regular 18 degree stuff because the standard straight up style alignment puts less pressure on all the little needle bearings.

My new LSX stuff is amazing! My Mildly ported factory casting LS1 heads flow more air then my out of the box, trick as could be, 18 degree setup did!! Plus they were 1/4 the cost!! An LSX motor will always make much more power then a SBC both using all factory parts. With all aftermarket parts it will be a wash, but the fuel injected LSX will be more driveable. My whole new motor/turbo setup cost WAY less then an 18 degree SBC, AND, I now make 1000 hp on 93 octane!! Lets talk turbos!!

Oh ya, how does everyone get those little smiley faces in there posts??

Hope this helps on you search for info.

Here's the thing, I have a local manufac, who's about to offer over the counter pistons for it. Come on, you have to admit, that's trick! :)

Here's a link to some smallish 238cc BMF 18dg heads. These would be killer on a mild pump gas 427. ~300cfm@.400" lift is pretty stout for any SBC head.

http://www.bmfracing.com/sbc_flow_238.htm

Oh man, BMF is something else! I'm currently working on a set of 405 BB heads from them, and holy wow...they are incredible. 24.5-degrees, but I swear, if you saw them...the inline valves look pretty canted and man are they beautiful!

Thanks for the link John. They look pretty killer. Are you planning on taking the 67 out again soon?

Mike, probably not for a couple weeks. The car should go in late next week to have the cage finished and I need to finish the air pan. Maybe early Oct??????? I have to admit, not having a car that is all one color (new hood) is really bugging me. I may get it back and make a few more test passes then send it to the body shop.

Henry, be sure to read this thread:

http://speedtalk.com/forum/viewtopic.php?t=3316&postdays=0&postorder=asc&highlight=18x&start=0

Henry, I think JE makes some over the counter pistons in a few select sizes if I remember correctly. By far the cheapest place to get pistons is ebay from the nascar leftovers. You can find new sets of 10 for $300-500 bucks! The only bad thing is they are for some oddball engine sizes, youd have to build the motor around the pistons!

Hopefully we will some better weather here soon, can't wait to see some 9.50s.

Henry, be sure to read this thread:

http://speedtalk.com/forum/viewtopic.php?t=3316&postdays=0&postorder=asc&highlight=18x&start=0

Thats a great thread and thank you for pointing it out to me. My thing is, before I pursue this particular story - it's fairly obvious that several people are interested in this....my thing is, I want one person to state, "yes", and tell me what they want to see and I'll move fwd with it. If not....it was a great question and I thank those that responded. :)

OK here's the full scoop on Brodix 18X heads.

1.)
The 18X uses a 40/60 valve spacing vs. the 58/107 spacing that a standard 18 degree head uses. The pushrod pinch is the same as any 23 deg. head with 40/60 valve spacing to allow room for the pushrod to pass through. As such the cross section can only be opened up to around 2.66 sq. in. at the pinch which is considerably smaller than the throat area which should be around 2.9 sq. in. for a 2.15 intake valve. Ask any professional head porter and he will tell you this is good way to kill big power. You never want the highest velocity point in the port to be upstream of the throat area for a multitude of reasons. This winter I will be welding up the pushrod pinch and moving it out to match a standard 18 degree head.

2.) When I assembled the top end of the engine, I put two intake rockers on and quit, went in the house and ordered a set of shaft rockers. The valve geometry is absolutely aweful with standard rockers. Yes you could run it, but it is not right and WILL NOT last on a street driven car. Same goes for the AFR 220 and 227. You can do it, but it is not right. On the exhaust side several pushrods hit the head and would have required clearancing. I orderded the shaft rockers with .100" offset and problem solved.

3.) The 18X uses a 10 deg. intake face like a 23 deg. head, but uses a raised port location like a standard 18 deg. head. That leaves you with running an 1800 series Brodix/HVH intake, which are crap in my opinion. John proved this point on the dyno by losing 20HP/20 lb-ft of TQ. A standard 18 degree head uses a 5 degree intake face angle.

If I could go back and do it again, I would have a set of standard 15 or 18 degree heads on my engine. The 18X only makes marginally more power than a 23 degree head. Maybe 20 HP or so. I have heard the same from at least one professional engine builder that has used a couple of sets of the 18X heads. Forget the flow numbers. Mine go 351 cfm @ .700 lift on Reher-Morrison's bench. Low lift flow is well below a standard 18 degree head because of the pushrod pinch. Flow numbers do not guarantee HP. Port design and shape are far more critical.

If you are going to buy the headers, pistons, and other associated components to go 18 degree, do it right and go with the shaft rockers.

For the cost, don't overlook the Trick Flow 18 degree head to get your foot in the door if cost is a concern. Have them ported later on and make some good power.

If you are looking at the power that is advertised on the Brodix website for the 18X heads. Forget it. WAY WAY bogus numbers or someone let two bottles of N2O go in the dyno room before the pull.

More info on my 445 SBC:

http://hometown.aol.com/jgchevelle/engine.html

Hebry, best bang for buck for any normal rodder, would be to deeply investigate modern CNC porting on a popular aftermarket head. For instance, an AFR 220 or Brodix track one head can flow 330-350 cfm with good porting
!
All it would cost is porting, with no change in valvetrain, it would be cheapest and most reliable setup especially if you are already running those heads or a simialar head.

OK here's the full scoop on Brodix 18X heads.

1.)
The 18X uses a 40/60 valve spacing vs. the 58/107 spacing that a standard 18 degree head uses. The pushrod pinch is the same as any 23 deg. head with 40/60 valve spacing to allow room for the pushrod to pass through. As such the cross section can only be opened up to around 2.66 sq. in. at the pinch which is considerably smaller than the throat area which should be around 2.9 sq. in. for a 2.15 intake valve. Ask any professional head porter and he will tell you this is good way to kill big power. You never want the highest velocity point in the port to be upstream of the throat area for a multitude of reasons. This winter I will be welding up the pushrod pinch and moving it out to match a standard 18 degree head.

2.) When I assembled the top end of the engine, I put two intake rockers on and quit, went in the house and ordered a set of shaft rockers. The valve geometry is absolutely aweful with standard rockers. Yes you could run it, but it is not right and WILL NOT last on a street driven car. Same goes for the AFR 220 and 227. You can do it, but it is not right. On the exhaust side several pushrods hit the head and would have required clearancing. I orderded the shaft rockers with .100" offset and problem solved.

3.) The 18X uses a 10 deg. intake face like a 23 deg. head, but uses a raised port location like a standard 18 deg. head. That leaves you with running an 1800 series Brodix/HVH intake, which are crap in my opinion. John proved this point on the dyno by losing 20HP/20 lb-ft of TQ. A standard 18 degree head uses a 5 degree intake face angle.

If I could go back and do it again, I would have a set of standard 15 or 18 degree heads on my engine. The 18X only makes marginally more power than a 23 degree head. Maybe 20 HP or so. I have heard the same from at least one professional engine builder that has used a couple of sets of the 18X heads. Forget the flow numbers. Mine go 351 cfm @ .700 lift on Reher-Morrison's bench. Low lift flow is well below a standard 18 degree head because of the pushrod pinch. Flow numbers do not guarantee HP. Port design and shape are far more critical.

If you are going to buy the headers, pistons, and other associated components to go 18 degree, do it right and go with the shaft rockers.

For the cost, don't overlook the Trick Flow 18 degree head to get your foot in the door if cost is a concern. Have them ported later on and make some good power.

If you are looking at the power that is advertised on the Brodix website for the 18X heads. Forget it. WAY WAY bogus numbers or someone let two bottles of N2O go in the dyno room before the pull.

More info on my 445 SBC:

http://hometown.aol.com/jgchevelle/engine.html

Jason, you are the man! Very detailed and very open with your thoughts with little influence. I like that. I did look into TFS and you can get a complete set of heads for around $2,300....which was another option I looked into. Regardless of the heads I pick, do me a favor and e-mail me at chp.editor@gmail.com. I would like to push this convo and get your thoughts on which direction to go.

I really would like to pursue this story, but hey, I'm still waiting on one person to say, "yes", do it! :)

What are you looking for in a story? Just the swap? 18's on the street? 18's on a daily driver? 18's vs. standard head? I did not notice what direction you want this to go.

What are you looking for in a story? Just the swap? 18's on the street? 18's on a daily driver? 18's vs. standard head? I did not notice what direction you want this to go.

Put it this way, the LS stuff is freakin amazing in my head...we, well, those who are familiar with it can appreciate the valvetrain and what's available. For the longest time, I refused to move from the conventional 23-degree stuff, because I felt it was overly complicated. I'm slowly starting to realize, that its not, and considering it's something we haven't showcased, I'm debating whether or not to show it.

Oh, and Scott, you'll love the upcoming Jan issue. I compared a LS2 stroker to a conventional 406 mouse. The results are rather interesting and as for the price....yeah, that, too. :)

Also don't confuse the Brodix 18X head with the 18C head that Brodix offers. Brodix makes a very nice "standard" or "clone" head in the 18C. Do a search on Ron's porting service and Weld Tech for CNC ported versions.

Scotty,

With all due respect, an AFR 220 will not go 330-350 cfm on an honest flowbench with a reasonable SBC bore size. They also use a relocated intake valve that REQUIRES offset shaft rockers for CORRECT valvetrain geometry. Yes you can physically install a standard stud rocker, but that does not make it correct. I think even the AFR literature now says that shaft rockers are required for street or endurance use when using the 220 or 227 AFR heads.

I did not know that on an AFR 220. Too much stuff to know and be on top of the game. I made the switch to the darkside (lsx) and have been forgetting all my previously unused useless SBC knowledge I had in my cluttered head!!

I did not know that on an AFR 220. Too much stuff to know and be on top of the game. I made the switch to the darkside (lsx) and have been forgetting all my previously unused useless SBC knowledge I had in my cluttered head!!


Okay, that cracked me up. LOL

Geez big dawgs....I'm still sitting here, waiting to hear a response! ;)

I would do it. But go all out. Show a typical performance small block with sonny's fully ported 18 degree Dart heads. They are the best castings and will cost some bucks. They flow about 400 cfm! Nobody ports these heads like Sonny's. That would make a 10.5:1 pumpgas 750 hp "street/strip" motor for an article.

To try to push 18's as a street driver head would be the wrong thing to do in my opinion. But I would like to see an all out setup like I mentioned.

I had the misfortune of having a 67 C10 with a 5.7 LS1 follow me on the Dynojet one day. All he had done was a cam, programmer and headers and he had 60 hp on my old vortec setup. At least I had 30-60 ftlbs on him in the normal driving range. But that got me fired up based on how little work it took to make that HP with an LS1. And I'd just spent all that cash on the 383.
The only way I found to even hope to come close to the LSx was with 18* heads or add a turbo. And the turbo would cost about the same as the heads but with more torque.
A used 6.0 LSx installed would cost me about the same as my current 383. I'd just need to track down the timing signals the LSx uses so I could fix/swap to an earlier computer and not need to spend all that cash on a programer.
Some careful ebay shopping might make for a better combo if time allowed.
I'd looked at the 18x heads but I wouldn't consider it now after reading the above. I'd imagine a used set of road course 18* heads might be the best bet for a 406 or so motor.
I'd still like to see a "cheap" 18* setup done. Since it's not my money!

I had the misfortune of having a 67 C10 with a 5.7 LS1 follow me on the Dynojet one day. All he had done was a cam, programmer and headers and he had 60 hp on my old vortec setup. At least I had 30-60 ftlbs on him in the normal driving range. But that got me fired up based on how little work it took to make that HP with an LS1. And I'd just spent all that cash on the 383.
The only way I found to even hope to come close to the LSx was with 18* heads or add a turbo. And the turbo would cost about the same as the heads but with more torque.
A used 6.0 LSx installed would cost me about the same as my current 383. I'd just need to track down the timing signals the LSx uses so I could fix/swap to an earlier computer and not need to spend all that cash on a programer.
Some careful ebay shopping might make for a better combo if time allowed.
I'd looked at the 18x heads but I wouldn't consider it now after reading the above. I'd imagine a used set of road course 18* heads might be the best bet for a 406 or so motor.
I'd still like to see a "cheap" 18* setup done. Since it's not my money!

Great points, I'm def looking into the cost factor, and want to get a better idea of what you all think before I move fwd with it.

Thanks for your input!

H

How about this:

Ross makes a piston that has both 23 and 18 degree valve reliefs cut. Build a medium inch short block(406-421?) around 11:1 and put a set of heads PROPERLY suited for the combination along with a well matched cam and intake. Line it out on the dyno and note the results.

Swap on the 18 deg. optimized heads, cam, intake, and headers and line it out as far as jetting and timing.

Report the results.

Increase compression to 14.5:1 and repeat the above.

That being said, I would like to see a consultant on the project that knows what makes this stuff tick. Someone like Joe Sherman, Mike Lewis, Larry Meaux, Tony Bischoff, or Chris Uratchko. Better yet have one of these guys (or similar) pick and prepare both induction combinations.

That is something I would not mind seeing although I have more than a pretty good idea of the results ;)

Chris U is the man, and I would love to get him involved. That said, I think I have something to keep me busy for the next month or so. :) Thank you all!

Henry - Not to appear negative, but I see the 18° stuff as no man's land. If you are going to spend the money on new valvetrain and induction, why not look at the assortment of 10° - 15° stuff that is available? The replacement cost is approximately the same. If you are going to do a story, show what can be done with "out of the box" 10° - 15° heads and provide a base for significant performance improvements downstream.

Before I would ever invest the time and money to switch to either 18 or 15 degree stuff, and this is just another opinion, unless I had a class that dictated the limitations, I wouldnt even consider running another head. If a guy is doing one from the ground up.......sure , pick a good head and build...........but knowing what I know now, with my current head, without making any major changes........I would switch to NOS, good rods and the peripherals to compliment the fuel system with the timing retard and blow all the normally aspirated 15 and 18 degree stuff right over the guard rail ( unless they're running NOS too LOL). I would think 8.80s would be no problem..........bring it on naysayers!

Bad, bad, bad!

Imho, He, He!!

"DARK SIDE" = BB!!!

AND again, imho, at LEAST a 496 jobber!!

Bttt,

Yes, how do the 10 degree Buick/Chevy type heads stack up here??

But, I guess if I was after the ultimate head, I would order an aftermarket block with undrilled decks and figure out how to put a pair of Hemi-Head's on top of it....

Sorry, I'm getting carried away as usual...

Please carry-on and pay me no-mind...

EXCELLENT THREAD!!!!!!!!!!!!!!!!!!

pdq67