Small chamber raceheads/dish piston/pump gas

ChrisU · Post by **ChrisU** » Thu Apr 21, 2005 1:21 pm

I've bought that head from Ron.

The majority of my cylinder heads come from Tony Bischoff at BES. Does great work.

Tonys port, and Rons port seem to be pretty close in almost every aspect... pretty much do the same thing on the flow bench, and the dyno.

shawn · Post by **shawn** » Thu Apr 21, 2005 1:50 pm

We used lot's of heads from Ron's and CFE on our comp. stuff. Always seem to be really good products from both.
shawn

67RS502 · Post by **67RS502** » Thu Apr 21, 2005 5:43 pm

I guess what I'd like to do with this "work truck motor" is build it like
the engine master did... Their 235dur. hyd. roller 360" SBs made 600hp
on pump gas (Joe Sherman), so I figured - since I aint smart enough to
figure out where their gettin that last 50hp, I'd build something similar
just with more cubes and better heads, and with some luck I may get
600hp out of a mild pump gas street motor. Plus I like grinding on heads
so I figured it would be fun to clean up a set of 14deg. heads for it.

shawn · Post by **shawn** » Thu Apr 21, 2005 6:02 pm

I'm not sure what RHS is going to do to the intake flange on those 14* heads, but it you want a cast alum. intake for the older style ones, this is a smokin' deal-

http://www.castheads.com/used_parts.php#used

shawn

jdeleon · Post by **jdeleon** » Thu Apr 21, 2005 10:21 pm

ChrisU
I'm seriously IMPRESSED ....Thats a ton of HP for a 23deg. How 'bout sharing some engine data. At what rpm did you peak tq/hp, what manifold? etc. Not asking for secrets, just some basics.
Thanks

ChrisU · Post by **ChrisU** » Fri Apr 22, 2005 7:23 am

The engine makes peak hp at between 83-8500, and the peak torque is 640 lb/ft at 6500. 3.75 stroke x 4.195 bore. Compression is around 18:1.

Bar none, the best and only two manifolds out there for a max effort deal are the 2971 Dom flg, and the 2968, both for a 4150 23 degree head application. Dont bother with any other manifolds. Granted they don't look like anything they originally did when they're finished. Usually I tell people this and it doesn't seem to stick.... The manifold choice, and work is extremely important and overlooked by many folks for this 23 degree stuff.

cboggs · Post by **cboggs** » Fri Apr 22, 2005 10:06 am

Chris,

Did you say 18:1 !! ( yikes )

That's a little high on compression isn't it?

I've been watching these threads on 400" small blocks as I might
build one for a Super Comp / Bracket dragster for my self.
I really don't want a big block in the seas of big blocks, .. and want
to move over into comp C/ED later.

The All Pro head is VERY impressive.

Chris, have you built a drag engine based on a 3.28" crank and 4.030" bore? I'm thinking about this for a bracket engine with a 15º head
and sheet metal intake with a single dominator.

Curtis

dbusch · Post by **dbusch** » Fri Apr 22, 2005 12:25 pm

for a single 4 cast manifold engine, i dont think there is a limit to how much compression you can run...well, maybe it is 18.1...LOL! Depending on the manifold, too, the more compression the better since the manifold restricts how well the cylinder fills at higher rpm, say above 8500 rpm. It helps the motor come on power sooner and keeps it going longer after the manifold cant supply the air anymore. In my 398 Ford engine, the more compression i run the faster i go, although i would try to keep plunge cuts in the piston limited to .050" deep and no more than a .200" dome...

Sheet metal single 4s with large dominator probably backs up with more than 16.0 compression since it fills better at ultra high rpm, though i am sure someone out there has run more than this and seen gains. The 2X4 stuff supposedly is held around 15.0 since it fills the cyl. so well...

ChrisU · Post by **ChrisU** » Fri Apr 22, 2005 4:34 pm

Well, with a spec fuel of C25 for the class, the 18:1 is probably a bit excessive as she is a detonating pain in the rear(timing requirements are insane for this kind of engine, and when the wind changes direction the tuneup needs addressed), but this is something we have developed and slowly come up to over time and this is how she likes to run best.... in destruction mode..... unfortunately. Maybe a little detonation is good?? Don't know all I know is I haven't found the point where the engine falls off yet with compression. Maybe 19:1 would be better?? I don't think I can get it there with a 55cc chamber. This piston is plunge cut and ugly, and again the engine is cranky but it's a heads up no break out class and this is what we have to live with.

I think the compression requirement(as I call it) also has something to do with the inefficient chamber/dome resultant to the 23 degree valve angle, relative to something like a 12 or 13 degree chamber. One has to ask the question in that are we developing the same kind of heat in the charge with 55cc 23 degree chamber with a given compression, as what you would with a 30cc chamber with a good shape to it, with the same static and dynamic compression.....

I'm not claiming to know it all, this is just my own project and my own ideas.... I really hate 23 degree headed engines and this one does not improve the relationship

BES(Tony Bischoff) does the head and manifold work and I believe that is really what makes this engine what it has become.

Curtis, I haven't built any kind of Comp type engine with a small bore like that. I've built a few short stroke large bore combinations but not a 4.030".... why the small bore requirement?

SStrokerAce · Post by **SStrokerAce** » Sat Apr 23, 2005 4:53 pm

67RS502,

I like the ideas you are going with here on a motor like this.

You should look at the 18X heads from Brodix.

http://www.brodix.com/18STDX&18SPX.html

They will give you the larger chamber you are looking for and with a off the shelf flat top and those chambers you get 11.7:1. Which is not a issue on pump gas.... That's partly where the Engine Masters small blocks made the extra power. Sherman was 11.4:1 on his winner the first year and Kaase has been as high as 13.2:1. Your cam choice will be important but 230-250 duration cams for a motor like this will easily put your dynamic compression in a safe range with 11.5-12.0:1 compression. your not going to have to go to a crazy revearse dome and small chamber setup like on Kaases high compression pump gas engine masters motors.

http://popularhotrodding.com/enginemast ... c_13_s.jpg

As for the ports on the 18X, well they would be equal to about a 220cc 23deg head so don't get too worried about the size of the runners. You could run these things on a street 358 cube motor (7,000rpm) without too much issue. Min Cross Section is in the 2.2-2.3 range as a bare port and you really could get away with some minor work on them to get them ready to rock.

There are some good pics of a set I have in the shop .....

http://community.webshots.com/album/327970687pQqHNE

And here are some good comparison pics of them vs. some comparable 15* heads.

18x vs 15º exhaust port
http://community.webshots.com/photo/328 ... 1140KvASVh

18X vs 15º combustion chambers
http://community.webshots.com/photo/328 ... 5080sceNgL

18X vs 15º intake port
http://community.webshots.com/photo/171 ... 5565NJhezy

18X vs GM 18* intake port
http://community.webshots.com/photo/171 ... 7114AGcqqF

The 15* heads are on a really strong 383 (650+ at the flywheel and 550+ at the tires) and re in the 220-230cc range in volume and 330cfm in flow.

The nice thing with these heads is that you could run a hyd roller cam, you could get away with this on a standard shallow angle head but there would be some pushrod angularity and I'm not sure how many issues you would run into with that on hyd roller motors. Plus since you are looking at a hyd roller, no real need for shaft mounts etc... and the 18X use standard 23* valvetrain parts.

With all of this you could see 600-650hp, and that's with a good amount of idle vacuum and a 260-265cc final head port volume in the 18X's. In something like a 23* STD head that would equal 235-240cc which is not that much on 434 cubes. Hell thats equal to a 190-195cc runner on a 355.

I'd also think about EFI on something like this... it's going to take more to tune but the drivabilty will be there and the need for a big amount of air on this motor would only be fed by a Dominator without the carb being a restriction.

Bret

67RS502 · Post by **67RS502** » Sun Apr 24, 2005 12:24 am

Ace
Links for the 15deg. heads dont work.
Thank for the help, I'm still undecided as to what I'm gonna do on the 400sb, but I wanna keep the cam real mild around 230-235dur.
I have 3 - 400SB options:
1. Use the TFS215R heads that are on the 383 now, (home ported) 301/236cfm, didnt cc them but guessing they are around 220cc, which would be decent for a 400sb.
2. I have a set of TFS G1 Twisted Wedge heads on my bench which I need to port, these usually have killer low/mid #, great chambers, and make good power. I'll throw these on my 383 and see how much it picks up, if its a lot then I could run them on the 400sb, but they are kinda small.

3. Build the 400sb with an exotic head (14deg. being my preference), but would consider an 18. I have a friend that may build a pump gas 400sb with the 18Xs so I could see how that works out for him.
The other thing I'd like to do is do a tunnel ram, which I could do on both of the standard TFS heads I have, but not on the exotic heads. I'd love to be able to get an honest 550+hp out of this 400sb with a smoooth idle cam, because my Luv is kinda a sleeper... plane jane gray work truck, so people dont thing it runs 11s with a smooth idle quiet 383 now (and gets 22mpg

) . I think I can get it to run low 11s with this mellow 383, but not sure if it will go high 10s. Thats why I'd like to build something with more power, but still keep a realy mild cam in it. A 400sb with 14deg. heads should put it deep in the 10s even with a puny cam - right? I may do 2 cams, one around 225-230dur. (smooth idle) and another one with around 250-255dur. and see how big a diff. it makes. A small street tunner ram should be good on the street, as they have killer throttle response and will make more power across the board.

SStrokerAce · Post by **SStrokerAce** » Sun Apr 24, 2005 7:12 pm

links are fixed....

I agree man, I really enjoy pump gas street motors that are terrors as well. It's basically about pushing the limits and building "race" motors that just work at a low and very wide operating range.

Bret

Jay Allen · Post by **Jay Allen** » Sun Apr 24, 2005 8:32 pm

ChrisU wrote:I'm not claiming to know it all, this is just my own project and my own ideas.... I really hate 23 degree headed engines and this one does not improve the relationship

How's about that cam!

ChrisU · Post by **ChrisU** » Mon Apr 25, 2005 1:33 pm

Yes yes it has a cam designed by Jay Allen at Camshaft Innovations... and he done good!!!

Don Terrill’s Speed-Talk

Small chamber raceheads/dish piston/pump gas

off the topic, but...