After looking at different options, I wondered about having my stock casting LT4 heads CNCed by the above folks.

They don't have much info on there website and haven't heard much about them on this forum, but do know that they are popular with the magazines (just not LT4 that I have seen).

Anyone try them? Results? Flow numbers, etc.

After adding up costs for AFR LT4 195's with spring upgrade, studs, etc and the fact that they are only ~10 cfm better out of the box than what I got...I wonder.

Thanks

:)

 

they are one of the best, hands down, however, they are also one of the most expensive.

 

try trevor johnson cylinder heads, tjcylinderheads.com He ported my stock LT1 castings and installed 2.0/1.55 Fererra SS valves and they flow 260 cfm. LT4's should flow near 300 when ported.

 

i am also looking for a place to have my heads p&p. i checked the websites and it seems like a pricey game. i have purchased new lt4 heads and most places have an exchange where you lose your new castings.if you take the price of new complete lt4 heads from GM and then sending them somewhere only to get heads that may have been run for 100k , sure you can rebuild them but there has to be some fatigue somwhere. might be time to fire up the ole die grinder. i know equipment and r&d can be expensive but $1300 to remove about 1oz of metal(of course in the right places) seems a bit high....

 

its not the actual removing of the castings that costs that much, its the cnc programs behind them. hand 3-angle vavle jobs costs a few hundred, versus the thousand dollar cnc job.

 

I can only tell you how happy I am with my L98 CNC Cylinder heads. mine don't flow as much as their new program, as Tommy Morrison's shop hand-ported the bowls on these heads. I got them as part of my lawsuit settlement with Morrison.

They ONLY flow 218 CFM, but with the other parts of the package crank out nearly 400 HP and 500 lb/ft of torque. They really know what they are doing, and you really do pay for their experience when you have them do a job for you.

The difference here is that you COULD pick up a die-grinder and absolutely ruin a set of LT4 heads in a flash. The L98 package last year cost around $2300 from them, which included the CNC work, new valves, springs, retainers etc. They come to you ready to drop in. I got the pricing from them just for comparisons between them and Lingenfelter. If you want a stealthy look it is the only way to go. From outside my motor shows nothing off. Inside is another story :lol:

 

cnc cyl heads should be doing a 5 angle valve job & have flow figures for all there work. didn't they tell you anything when you called them & spoke to there techs? i can't imagine you'd shell out cash without some detailed talking on there end.

 

If you mean CNC in Pinellas Park FL. I'll vouch for them. ;)

 

Yes I'm referring to the folks in Florida...seemed like they were one of the originals...

Unfortunately, I haven't contacted them by phone, but will do so when able.

Having the original castings has got to be worth something...everything fits, stock look, etc. Although I'm sure they are limitation when you start looking for some BIG numbers (not in the cards).

Thanks

:)

 

I am thinking about sending my stock LT1 heads to them to have ported. I have been doing alot of research on differnet CNC porters and have found some good info on these guys. I also call Ed Wright at Fastchip and he said that the ported heads that are coming from CNC Cylinder Heads are putting out the highest HP numbers that he's seen. Their Flow numbers look real good.Check out the links below.
http://u2.netgate.net/~jshapiro/heads http://www.malcams.com/legacy/misc/headflow.htm http://www.corvettemagazine.com/1999/oct99/lt1/ltp1.asp

 

I had my LT1 heads done by them. They worked with More Performance
to supply a top end package for my '93. The car really runs great. I've
got about 80k miles on the package & have had no problems.

I'm currently considering a 383 stroker package & will use both CNC &
More Performance again.

 

Trevor Johnson in Rockwall, TX did my heads and I was very happy. The only thing he does is cylinder heads mostly by word of mouth in the Dallas racing community. No, he does not have the "big" name, but he was recommended to me by a local Dyno shop. He said he does heads for other big name shops, including a very well known Viper tuner in Houston.

When I was there, he had a set of head fresh from a CNC machine that he had to finish out by had anyway. Call him and at least find out what he will do and for how much.

He does not use a CNC machine because it does not save that much time vs. hand porting. He said all the top head porters still do it by hand, so CNC does not gurantee the best performance.

I visited his shop last year and was impressed with what he had to say. He did not try to sell me on a high priced job. He was suprisingly very price competitive.

He is not a big name operator with lots of guys working on a per-hour basis and lots of overhead. If you want something special, I am sure he will try to do it.

My heads looked great when I got them back. I picked up 22 hp on my LT4 just from a basic Stage I porting. I would happily use him again.


[Modified by Mez, 8:50 PM 6/20/2002]

 

cnc should be able to get close to 300 intake cfm out of a LT4 casting, short of pro action you really getting up there in head flow. the AFR 210 has a more potential than the LT4 casting but is it available in rev flow cooling? same with the pro action stuff? most of it i've seen is gen 1. by the way how crazy are you getting, 300cfm at .600 lift is killer as SBC stuff goes

 

Trevor Johnson ported my heads and I'm pushing over 400 HP at the flywheel. He does an excellent job and a reasonable price.

 

reasonable price does mean quite a bit, cnc tech costs a fortuine but they flow like mad also. unless he came from a NASCAR team not many head porters can match what they can do. 400hp is extremely easy to get from a lt1 casting, necked valves, a 3 angle job, bowl hogging and some smoothing of the runners will easily get 220+ intake cfm and make 400hp. i had a set of the latest zz4 castings and with good valves and some bowl work, intake smoothing not much else 400hp is quite possible.

 

Check out Norris Motorsports. He's a CNC dealer.

My stock short block LT1 with Norris/CNC stage 3 heads, CC305 cam, 30lb injectors, and longtubes is putting out 360 at the rear wheels. Now figure in the drivetrain losses with the 3000 stall converter and 3.45 D44 etc. at around ~18% and that puts it at 425-435hp at the crank. :yesnod:

But dyno numbers mean nothing compared to timeslips. :D

 

gtsyellow:
I don't think you caught the gist of my post...I didn't shell out the cash for my heads as they were a settlement in a lawsuit against Tommy Morrison. Morrison just had them do the basic CNC work, and he came in and had his guy do the bowl work to get it the way they wanted it. Their techs were very helpful and answered all the questions I had about the combination we were doing for the motor. I did do a lot of asking and major research before I got to the rebuild stage on my motor.

CNC's new program for L98's flows 227 CFM with a 5-angle valve-job, titanium keepers and all the other goodies they provide. They also changed the type of springs they use since mine were first done.

mez:
While CNC work does not guarantee the best performance, what it does do is minimize minor differences between the chambers. Because every chamber is EXACTLY the same shape & size, there are less differences in the way the combustion process happens in those individual cylinders. It makes it a lot easier to tune the engine this way.

I agree that the top head guys still do hand-port work a lot...but that work is done WAY down behind the bowls where a CNC mill can't get. They mostly do the clean-up and blending work to give you the extra .4 or so horsepower out of the heads.


[Modified by Joe90, 10:46 PM 6/20/2002]

 

Actually I surfed on the C5 forum a bit and came across him...already received an email from him:)

Looks like the CNC Cylinder Head process bumps up the flow to 285-290 @.550 lift. That is pretty good to me. I don't expect this engine, when complete, will have anything more than a .600 lift cam so not too wild.

Still looking at options, but maintaining stock castings is a big plus to me.

Also AFR LT4 heads are offered in 195 and 210 cc intake sizes...but they don't seem to flow much better then stock LT4's. Ok better yes but not as good as I would expect:)

Thanks for the help.

:)

 

Joe90,
What happened with Morrison that resulted in a lawsuit?
Just curious,
Robert

 

I contracted with him to build a motor. He took the deposit and 6 months later I was still waiting for an engine. Since it didn't look like he was going to send me an engine, we sued him.

I ended up getting a default judgement against him for $12k. They sent me the engine in pieces in a crate.

I've since met someone who worked for him, and this was apparantly a fairly typical thing for Morrison to do. He takes the deposit from your engine to finish up the engine in front of you. Bad money management is what I call it. The Texas courts called it fraud and awarded me 3x the damages. I'll never see the money, but I got an engine in parts. It is what I've been racing for the last year.

Bottom line is, I wouldn't send him any money ever. If you do business with him, do it face-to-face and walk away with what you came there for. I wouldn't trust him any further than I could throw him.




[Modified by Joe90, 8:20 AM 6/24/2002]