With a single plane, BIG HR cam and 227s or 210s on a forged 383 what do you guys think is doable? My car is a weekend car and thats my next step. Or switch to s SR cam but would like to know?

I do agree some good ported stockers will exceed MOST peoples goals.

 

One of the members here linked me to this thread....

A 227 on a 383 isnt too large provided your running a solid roller cam so the engine will take advantage of the higher lift airflow and the RPM potential the larger, higher flowing runner will provide.

IMO, camshaft selection (and usable RPM range) is the largest deciding factor concerning the OP's decision whether to go 210 or 227.....a 210 is the perfect choice for a 65-6700 RPM 383 which will RPM limited more from valvetrain limitations (assuming hydraulic roller) than head choice, but with a small street mechanical roller, even the 210 heads would buzz cleanly to 7000 RPM or so assuming the right cam profile.

The larger head combo (a 227 with a mechanical roller) could spin into the low/mid 7000 range and make more peak power obviously but it will be softer under 4000 RPM than a similar combo with the 210 heads.

If its more of Friday night street toy and your cool with some RPM and some occasional valve adjustment with a solid, go for the larger 227 head and have at it. If your looking for a no maintenance hydraulic set-up, I would go with the smaller head thats better suited (or should I say better optimized and more ideal) for less cam lift and less RPM. You can run the larger head with that also but you will soften the bottom/midrange some and not have enough headroom upstairs to justify the swap IMO.

Combination is KING and a more optimized combo with a slightly smaller head can perform just as well as a less optimized combo with a larger head and be alot more responsive on the street where these engines obviously still spend a good deal of time. OR....bite the bullet and go big (227) but do it properly with the right camshaft and be prepared to turn it higher in the RPM range where the larger head/solid roller combo will naturally shine.

Both are good choices.....the right choice is more a personal one based on the type of combination you would like to own and maintain.

-Tony

 

Well said...especially the last sentence .

I didn't link you, but glad you dropped in. A lot of misconceptions about AFR heads on this site for some reason. Most of the more "hardcore" sites like YB and speedtalk love them...but they do cater to a different demographic then the mostly pure street cars of 'Tech.

 

I ran some ported 210s on my 396 (242/248 comp solid) ... unreal torque and plenty on the big end
I'm sure I left a few hp behind, but I did that with the smaller cam choice as well

Tony's advice is spot on

good luck with your build!

 

My new HR cam in the 383 is a 244/254 608/608 110 LSA, patriot gold springs and comp stainless steel promags, Manely hardened CM push rods I dont mind RPM and will take it to the PCMs limit. My car is more set up to race than cruise, so Tony what would you use?

Oh with that said Ill prob end up with a SR set up and aftermarket computer system down the road.

 

Your heavy rockers will probably start to float the valves at about 64-6500 RPM or so....consider swapping to a lighter aluminum body rocker. Even still I would look at the 210's for sure....its still enough head for the usable RPM range you will have even with lighter rockers and slightly more RPM potential (you might see 6700 RPM or so).

With only 383 cubes, a 227 head is only a good choice with an RPM friendly solid roller set-up (72-7500 RPM's).

-Tony

 

this 3rd page has some of the most valuable info i've EVER read in this section of ls1tech. thanks for chiming in tony

 

So are my 210,s a little small then for a s.r 383 with a jesel setup and a .648 lift cam ?

 

Bet there will be some comp ss rockers for sale somewhere soon. Tony, thanks for taking time to give us some useful info.

 

wow...

 

Thanks for the response!!
Interesting though, I spun it to 6800 on my 355 with no signs of float. Well at least none that the dyno saw or at the track. It made 415 peak HP at 6400 and I would shift around 6800. This was on Stock ported LE2 heads. Are AFRs worth the upgrade before I go with a SR cam and fast or BS3 set up?

 

Seems like AC would be better off to keep his SS rockers and add one of AFR's HydraRev kits to get the best of both to me? What do ya'll think?

 

^ I hope you are not serious

 

It depends on the severity of the valve float. If its not a lot power would just tapper of early.

 

Yes and no. the costs are similar but the rockers would be much easier to do.

 

No. Seriously if you're looking into a real cylinder head you will look elsewhere than AFR and have it converted over. I'd recommend a dart or profiler casting with a proven porting program applied. There's a huge world outside of ls1tech, AFR, Ai, etc. but people here wouldn't make money with you finding it. If you'd like some cylinder head direction shoot me a PM and I'll link you to some alternatives.

 

steel rockers = valve float ???

the guy just said he doesn't based on his dyno and track experiences. just because sponsor makes a generalization (incorrect) everyone who doesn't have a clue has to pipe up? roller rockers and rev kits...

 

I ran steel rockers and didn't have any problems , or seam like I had any .

 

Im not floating the valves hence the question.

 

My post was meant to be more a question (for Tony M) than a statement. In fact it was meant as a question towards correcting valve float with the hydrarev versus going to lighter rockers and I only brought it up because it's AFR's own product. I have zero first-hand experience with that set-up. I've only read a little about it and it seems like a good idea since it's added pressure is not put on the lifter plunger itself, but the body of the lifter.
I doubt I will every have an LT1 that is serious enough to need more than ported stock heads and common valvetrain parts as I'm not trying to make 500rwhp like the OP is shooting for. I do plan on having 3 or 4 budget LT1's that make between 330 & 430 rwhp within the next year though. lol