I was going to get these LSA castings flowed and the chambers CC'd before getting them CNC ported.

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.

 

Kinda surprised on the intake to exhaust ratio. I thought these were very similar to l92's?

 

Wow...at 600 lift the ratio is 90%. That's crazy

 

I have been reading a lot on these heads but cant get a good answer. Are the decks on these heads thicker than LS3/L92?

 

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.

 

there is no answer to that question on this site. If there is its in a cranny somewhere far far gone. I am positive its not 3/4 or we'd all be running em.

 

From my understanding they aren't thicker, just a stronger casting. They are have spots in the head reinforced unlike the ls3/l92 heads.

 

I will be running a set of these soon, just need to send them to Arun to get ported first. Going to run his cam most likely as well. I do not believe the head is any thicker but is definitly better cast. The appearance of the head is night and day from any of the other factory heads other then the ls9 head.

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!!!

 

I currently have these heads, but I haven't really had a chance to push them. I'm having such a hard time deciding on a cam/cam designer for my new combo.

 

Search big boost with rectangle port heads

 

https://ls1tech.com/forums/forced-in...ep-inside.html

 

I doubt these heads will have any issues keeping clamped down at a 1000 whp.

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.

 

Impressive numbers for stock, any updates Arun?

What cam is going with these ported heads? What would you use for a cam with these stock? maybe your stg 3?

 

I never posted the pics of the LSAs I cut apart, but there is significant improvements, mainly the material.

Ill post them after the new year. The Thread posted above is where I posted my info.

 

From what i understand, someone who has had the work done said that wing was not hard at all to remove.

 

You guys are letting the cat out of the bag on these heads lol. I been running them on a turbo setup all year and they make killer power. IMO for the $$ there is not a better boost head. I see these replacing the 317 castings for budget 6.0 builds very soon. Square port motors spool turbos extremley hard too.

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.

 

The heads just shipped last week to get CNC ported. Just collecting parts on the motor. Picked up a fresh LS2 block and some Wiseco's. K1 is sending me some of there H-beam rods and 4340 stock stroke crank.

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.

 

These are my thoughts exactly. I was not even going to port the runner because I do agree with you that GM put it there for a reason.

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.

 

Very interested in the results of that. Think the valve job will gain more than the porting?

 

The deck is the same thickness. .400"