So who mucks about with Iron Heads

Anybody mess around with Iron heads?

Seems like an aggressive 355 with Iron heads could be fun.

How big of a cam do you think you would need to run 64cc chambers with flat-tops?

Can't get the squeeze without pinging/detonation from what I hear...9.5 is absolute max....with cam....

early castings are fine 993? 88x? something, but later casting are supposedly thin and not worth crap....

IMO spend ~200 bux on a pair of #113 L98 aluminum heads, and for the buxs it's what's on my engine now...and totally happy....

assuming a 350 displacement.....at 10.5 ratio...

after that I"d say Edel heads....pick up a used set off Craigslist....

out of you local head shop maybe....:shocking:

How am I supposed to rebel against orthodoxy that way?

:lol:

This could be a good budget build for those that did not want to step up to a 383. To be fair what fuel are you planning on using, what trans/gear, what kind of 64cc heads do you have, and how do you define aggresive? Also, are you thinking that the cam will let you get by with more static comp. by lowering your cylinder pressure? I would hate to say somthing using my idea of an E-85 fueled solid roller 7000rpm aggresive street engine when you were thinking 87 fuel and 6250.

World Products 012250-2 - World Products SB-Chevy Sportsman-II Heads Details
SB-Chevy Sportsman II Cast Iron Cylinder Heads - 72cc Combustion Chambers, Straight Plug

Applications: World has tested Sportsman-II heads in many applications including 375Hp 9:1 street engines; 450HP 9.8:1 street /strip engines; all the way to 940HP blown alcohol drag race engines.
Typical Application Street: 274 Cam: 230/236° .487''/.490'', Dart II Sportsman #955-061010 dual plane intake; 750 cfm carb, 1-3/4'' header. 430HP on 9.8:1 355; 480HP on 383 10.5:1 (varies with displacement and compression ratio).
Typical Application Drag Race: Modified 750 cfm carb, 276/284° roller cam, single plane plenum intake, 1-3/4''-plus header. MUST Upgrade to 1.550'' roller valve springs and 10° hardware. Up to 650HP normally aspirated depending on displacement and CR and porting.

Click to expand...

So with the 9.8:1 compression and the XE274, that supposedly worked according to them. To keep a similiar DCR I would need an intake closure point of 70 ATDC to use 64cc chambers and 5cc flattops.

The goal is 460hp (355 * 1.3hp/cube) Iron heads, Hooker sidemount exhaust, OE hydraulic roller.

Muncie M21 and 3.36 rearend, 6500rpm or so will do it.

BTW check out the chambers on the new sportsman 2s.

guru said:

How am I supposed to rebel against orthodoxy that way?

:lol:

Click to expand...

Protestant.....


:crutches:

Damn Straight.

460 hp out of 355 is going to be LOUD one time.....


I just think it's a bit ambitious with iron heads....

:fishing:

They are getting 430hp out of a pretty mild cam.

Here is a 10:1 iron head motor (Combo 9)

http://www.ryanscarpage.50megs.com/combos2.html

There was an article in Popular Hot Rodding where they took a junk yard core 350 and made around 450 hp with replacement iron heads. If memory serves me they milled the heads due to the fact that they re-used the factory dished pistons. They also used a tighter LSA than 110° which I am very much a fan of. I like the sportsmans for a 383; but on a 350 they have a little bit more port area than I would run on a mild 6500 rpm street 350. In years past I would have told you that Pro heads were the way to go in iron; but now I can not say. I have not seen a set of the R.H.S. heads to know if they are the same. Unless you are just wanting to pack the extra weight, have you ever considered Patriot's aluminum head? I know that the iron head should make more power; but it is hard to argue with the effects of removing weight from the front of and almost 50/50 weight bias vehicle. $895 for a aluminum 190cc runner assy. By the way when was this "new" Sportsman II chamber introduced?

I dont know. I can only operate from their sales propoganda.

I have some Pro topline torquers with 76cc chambers and an old school chamber. No fast burn there.

RHS is now part of Compcams anyway. I consider the hot-rodding axis of evil to be AFR, Compcams, and Edelbrock.

Patton read Rommel's book, so thusly I read the RHS tech page
http://www.racingheadservice.com/Information/Technical/RacerFAQ/CylinderHeadRunnerVolume.asp

They seem to think 200cc would be appropriate.

AFR says their 195cc heads for 2000-6500rpm.

You might check with Joe Sherman. I dug out an old article where he made 539hp@6100 and 523lb-ft@4600 with a 383. It used the RHS Vortec 906 replacement heads. Cam was a comp hyd roller 236/242 with 106°LCA. Comp. Ratio was 10:1 and cranking PSI was 200psi. Heads were milled .030" to raise the ratio due to using dished pistons. This combo with your 3.48" stroke might work well. As far as the 200cc heads go. I always look for the head with the highest ave. flow and least CC runner. I think that a 3.36 rear will like the smaller runner where as 4.88:1 might not care as much not to mention it looks like Sherman made some decent power:wink:.

I can probably chill out on the top end and get less aggressive, and knock that down to 6000rpm top.

That gives me a topspeed of 145mph and I an hit 65 in first gear with the muncie.

I think there is nothing wrong with iron heads, other than weight. The air fuel mixture will not know if it's flowing through aluminium or iron pipe. Straight from the box aluminium ones might be better, with better quality cast, maybe also CNC machined...

I have Sportsman II heads that are well ported by my friend. Topped with flat pistons (.03 oversize). Compression is about 10.3, it's not checked so this is approximate value. Cam is CompCam roller (300BR-6) with 1.6 rockers. Engine was dynoed with Victory Junior intake (ported also) and Holley 750 double bumber carb. Figures are: 487hp @ 6800rpm and 444ft/lbs @ 4400 rpm.

I got these heads when my buddy changed to RHS iron heads. Now he has 600+hp out of 355 (.03 oversize 350). I think compression is now about 11 sharp. He is running about 8000rpms at the moment. So, it is possible to get some nice numbers out from iron heads too, but they need a bit more work than aluminium ones. :drink:

this is the smallest cam I would run.

http://www.cranecams.com/index.php?show=browseParts&action=partSpec&partNumber=109831&lvl=2&prt=5

I have been checking around and most mild iron headed motors run around 7.9:1 dynamic compression. So this cam would leave me with a nice 7.7:1 dynamic compression with flat tops, a 0 deck, and 64cc chambers.

Dart Iron Eagle Platinum 200s flow better than AFR 195 without the competition porting. (288cfm at .5 lift)

I don't think that that cam would get you to your goal. I would keep the lobe seperation around 108° and bump up the @.050 numbers by about 10°. If you don't trust what I am telling you, call up Joe Sherman and ask him. I would rather have more power that I expected rather than less when it comes dyno time. If you are concerned about the drive factor, I would just stop looking for a magic number and be happy with what I ended up with. The cam you are looking at is larger than the one used in the ZZ430.

The zz430 seems like a damn fine motor too.

If I could find some used fastburn heads i would be all about it.