I did some LSA head testing!
I went to a local shop to get some independent results. The shop I use is Forrest and Forrest-these guys have been around my area for long time and do alot of old school SBC, BBC stuff and are super knowledgeable.
I wanted there opinion and right away they were impressed with the castings-especially the chamber. For and as-cast head-it's impressive.
The chambers came in at 68.5 to 69cc's.
These were flowed on a 4" bore with a 1.75" pipe on the exhaust.


Now realize-every flow bench is different-let's not get hung up on numbers. I wanted a baseline-and will reflow them after Charlie@RPM motors does his CNC port program on the heads.
I will then do a valve job and reflow them-to see how much a good valve job is worth.
I have nice cam in mind for these heads already-something that will have nice street manners but make big power.
This?
They are "roto-cast" which from what ive told are supposed to be stronger castings, so, assuming thats correct, id say that is probably worth something.
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If some people really want a definitive answer on deck thickness, put some skin in the game and I will cut one in half. The bare cores are $170.00.

Just like that one!!!
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I've had no issues with 243 or 317 heads and these are a much stronger casting than those.
I think the issues most folks were having was with the earlier L92 castings-the LSA's are much stronger than those.
I wanted to see for myself what these heads were all about. I did a few cams for 08 and up C6's and with a tiny 226 intake lobe these cars went from 400 rwhp to 450 rwhp-with no CAI.
Add 8-9 psi and they go to 675 rwhp with ease.
I wanted to see what these heads flowed and looked like. Even with the wing in the intake port there still pretty impressive. It doesn't even look like it would take much effort to knock that wing out.
Ill post them after the new year. The Thread posted above is where I posted my info.
As far as the deck thickness I am almost certain they are thicker than L92/LS3 heads. They are made of better grade aluminium and are rotocast (spun) as they are cooling. The wing serves some function of fuel mixture suspension and even distribution across the combustion chamber under pressure as well. You may find some more flow by removing it but these seem to make very useable power as is I would hate to even touch them. I am sure alot of GM money and time was spent developing that wing.
They also have no casting # in the usual spot so people dont necessarily know what you are running which is cool.
I know alot of the hardcore cathedral guys will poopoo on rectangular port heads saying they dont rev blah blah blah. The big valve may be shrouded. Or they have no velocity. My response is. May have a slight point N.A but how can you mess with a 260cc as cast intake runner pressurized? It flat out moves more air.
Last edited by 1sick-Z; Dec 30, 2012 at 01:27 PM.
The Stage 3 is a 230/242 and it's had some real good results. But I think this head will work better with a tighter spit and still carry the rpm up top.
I'm leaning towards a 230/238.
I got a really good deal on some CNC porting so it will be nice to see what and where the improvements in flow will be.
I'm actually going to flow them after the CNC port-then again after the valve job-this way we can see gains a good valve job offers as well.
I got a really good deal on some CNC porting so it will be nice to see what and where the improvements in flow will be.
I'm actually going to flow them after the CNC port-then again after the valve job-this way we can see gains a good valve job offers as well.









