Cut through the BS..are max effort LT4 heads worth it over lt1s?

I've heard that when the porting starts that a lt4 setup isn't worth it from some people and some others say that they are. What do you guys think with my setup. I have a 12:1 355 with 2.0 1.56 lt1 heads. Cam motion Solid roller 255/263 @ 50 656/628 lift on a 110 LS. Would a max effort LT4 head and intake be worth it in my situation. Ive been told that .2 to .3 could be picked up just by switching(of course bigger valves etc.) What do you guys think. Could 20-30 hp be picked up by switching over to lt4s. Maybe a AFR lt4 setup? Anxously awating your opinions.

Thanks,
Tim

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95 firebird Blueprinted and ballanced 355, ported lt1 heads, custom cam motion solid roller,Moser 9" with 4.57's and a locker just to name a few.
11.23@122.25 1.579 60'

2001 NFRA LT1 NA Winner

More on www.geocities.com/herrint (http://www.geocities.com/herrint)

Depends on how good your lt1 heads flow now. Bigger valves "should" help flow #'s, the raised runner helps. I think I would look at the AFR heads. Be a spendy 15-20 hp, but your at that point, no cheap hp to be had.

well I would like to do the AFR 215 RRs but with the cost associated with converting its kind aut of the question at this point.

I don't have any flow numbers on my heads. They seem to be doing pretty good. I hope to squeeze into the 10.9 range when the good air returns. My 11.2 at 122 was spinning and with some "problems" that i have found and corrected since then.

but your are right on one thing. Seems for me to go faster I'm gonna have to spend some money.

Anyone else?

Tim

[This message has been edited by 95Bird (edited July 17, 2002).]

Tim I really think you would see more going to a FAST ECM, then you can really start to make power http://web.camaross.com/bb/smile.gif We had seen .25 and 3 mph on my car when we switch over. Over the winter we had switch my bother Mustang from stock to FAST and the car went from 10.78 @ 124 to 10.42 @ 127, and when the air gets good again I feel we'll be in the 10.teens.

For the money I feel FAST is the way to go, if you do end up going this way I would be more then willing to help you out. The wide band o2 is a must.

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Steve Quinn
95' Z 350 NA auto
1.44 60'
10.543 @ 127.04

Stock block, pistons, rods and crank.

New NA motor coming soon....

www.norushracing.com

So use stock un touched LT1 heads and a fast system and run 10s? I AM IN!! http://web.camaross.com/bb/wink.gif http://web.camaross.com/bb/wink.gif

I will bet you are going to want me to gut the car though http://web.camaross.com/bb/wink.gif Sorry not going to happen http://web.camaross.com/bb/wink.gif

If you compare LT1 heads and LT4 heads both ported to there limits LT4 heads are going to cone out on top all things being equal. Sounds like you need to go to a better head then that though. Me? I plan on running low 10s high 9s on my crappy LT4 heads and over 3,600 race weight http://web.camaross.com/bb/biggrin.gif

Good luck!

BTW I was kidding on the FAST, just the way you guys changed subjects on a dime http://web.camaross.com/bb/wink.gif

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Ellis
Team Captain
Team North West F-Body
www.teamnwfbody.org (http://www.teamnwfbody.org)

I think the important thing is that if you have what you are feeling is a nice set of LT1 castings, then its probably not worth your time. A decent outlay of $$ for a marginal gain.....

A Large cc AFR though might be up for the call though? However to take advantage of a larger head/larger cam (more RPM), you'll be needing the FAST Steve mentioned. http://web.camaross.com/bb/smile.gif

Kurtis "FAST Equipped" Tamez

Where do you get stock un touched LT1 heads? http://web.camaross.com/bb/smile.gif

Heads are far from stock, car is far from gutted, but yet everyone has there own feeling on what gutted is.

The reason I would look to a FAST ECM is the stock pcm limits you too only 7000 rpm before it cuts out. With Tim's sold roller I would think its just starting to make power at 7k. As my little hyd roller 240/251 108cl, made peak at 7000 and was still making good power at 7500. Power was 581@7000 550@7500, this was a 350 lt1, crankshaft power.

And like I tried to mention. Where did that come into the head question http://web.camaross.com/bb/wink.gif

My car has FULL interior and ALL the creature stuff http://web.camaross.com/bb/wink.gif

Good luck all!

Ellis

Great idea Steve. I guess I just need to save my duckies and go for the fast system. Was that .25 and mph change with no other changes in the same weather? What exactly do you gain over lt1 edit etec. I'm very interested in this setup. I'm pretty sure that my heads are choking this cam down so I could pick up some with a 215 setup..but like someone else stated I would need the fast system to utilize the new powerband etc. I know it pulles all the way to when it start to cut our or hit my rev limiter...I can't really tell which it is. Limiter is set at 7200 now. Hey, do you get away totally from the opti setup? Do you use a crank triger at that point. Is there somewhere I could read about this system.

I was also thinking of the 210 AFRs if I did make the change without going to the 215 setup. I think both would give me the ability to make power in the mid to upper 7000 range. But then we are back to the pcm stuff. Man, this could start to get expensive...:P

Thanks again for the help guys.

Tim

[This message has been edited by 95Bird (edited July 17, 2002).]

<font face="Verdana, Arial" size="2">Originally posted by OneFlyn95z28:


My car has FULL interior and ALL the creature stuff http://web.camaross.com/bb/wink.gif
</font>

It should be noted that these cars are running in the 10 second range w/ no spray. http://web.camaross.com/bb/wink.gif Little bit different scenario.....


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Kurtis Tamez
LT4-396.com (http://www.lt4-396.com)
97 Z28 LT4-396
94 Firehawk LT1-396
Team NW F-Body (http://www.teamnwfbody.org)

I well under stand that big boy http://web.camaross.com/bb/wink.gif I am not running tens yet either. and when I do? I will still have all this stuff in my car http://web.camaross.com/bb/biggrin.gif

Street cars are no fun with out all that stuff http://web.camaross.com/bb/biggrin.gif

Squinn is fast and I respect that. Then again we went from a heads discussion to a ECM discussion and no answers were really given.

I may never run 9s or 10s BUT if I do you can be damn sure I will be coming down the return road with the A/C on http://web.camaross.com/bb/wink.gif

Like it or not http://web.camaross.com/bb/biggrin.gif

Now we are even further from the subject then we started.

So you Big dogs have fun and us Puppies will stay in the corner because we are not good enough http://web.camaross.com/bb/biggrin.gif

Ellis"who cares what the subject was'

<font face="Verdana, Arial" size="2">Originally posted by OneFlyn95z28:
I may never run 9s or 10s BUT if I do you can be damn sure I will be coming down the return road with the A/C on http://web.camaross.com/bb/wink.gif
</font>

Preach it brotha http://web.camaross.com/bb/smile.gif

AC is for winmps http://web.camaross.com/bb/wink.gif


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94 Formula M6
Last year 10.98 @ 126
355 stock heads, P600

In the works:
383 worked heads, D1, th400

Sorry Bud just tryin to get you to compare Apples to Apples, instead of Apples to Oranges. If I build a Pratt and Whitney Jet Powered Limo, is it better then your car cuz its got a cocktail bar and goes 6s? http://web.camaross.com/bb/tongue.gif

Sorry for the lack of content Tim. http://web.camaross.com/bb/smile.gif

For what its worth you have a great running car, and depending on just how nice your LT1 castings are, its probably not worth swapping heads unless you get into those AFR 210s or better. For your Situation/Setup, I think Steve is definetly a guy I'd hold some regard in what to do though. http://web.camaross.com/bb/smile.gif I only hope my stroker with 396 more cubes can keep up with his 350. Suppose I could make excuses.... http://web.camaross.com/bb/tongue.gif

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Kurtis Tamez
LT4-396.com (http://www.lt4-396.com)
97 Z28 LT4-396
94 Firehawk LT1-396
Team NW F-Body (http://www.teamnwfbody.org)

Well Tim for starters you can spin it past 7k http://web.camaross.com/bb/smile.gif I've never programmed with LT1 edit, was not out when I went to FAST. On the fly programing, real time wide band o2, you can set it up to run off the o2 to correct at WOT. I find FAST very easy to program, but yet I've been playing with for 4 years now. You can run without a crank trigger, but for high rpm its a must. I run a Holly hal effect crank trigger, some fabbing is required, if you need to see pic I can send you some.

As for my gains it was cool out when I had done my base line, and hotter out when I ran the fast system. After changing gear, stall, tire size, a few odds and end, lots of flogging on the program I had drop 1.05 sec off my ET.

As for your LT1 heads I think there is still more in them, You might look at getting a ASM monoblade to get more are flow. I' hope to let you know what the limits of the stock heads are after I get my solid roller motor together.

Steve

Here is a link to FAST

http://www.fuelairspark.com/

I've always wondered about this too...the original question http://web.camaross.com/bb/tongue.gif http://web.camaross.com/bb/biggrin.gif.

I haven't seen (in internetville) too many guys actually stay with the LT1 heads, though. I'd hate to learn I'd have to lay down a lot more $$$ to get to the 'next level.' (just restating what Kurtis said http://web.camaross.com/bb/smile.gif)

How about this: Sticking with the stock pcm, can you make good power with the stock heads (500rwhp NA)?

Ryan

[This message has been edited by 96-speed (edited July 18, 2002).]

You're talking about 620 crank HP out of stock ported aluminum LT1 heads? If you could do that, you could make a mint http://web.camaross.com/bb/smile.gif

Sorry, but I believe the effort necesary to do this would far outweigh the cost of larger aftermarket heads. But to give you some perspective, let me give you an illustration from Impala land http://web.camaross.com/bb/smile.gif:

My stock Impala iron heads, stock 1.94 valves, hand ported = 250/185 cfm @ 0.500" lift.

My buddy's Impala, with LT4 heads, CNC ported and 2.02 valves = 278/202 @ 0.500" lift.

The porting cost me $650. My buddy spent over 2500 bucks on his LT4s, since he had to get a new intake also. So there you have it, 1800 bucks more for an extra 28cfm. Whether this is worth it or not, only you can answer.

By the way, he has a 396 stroker, while mine is a stock bottom 350, which of course makes some difference.


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SSMOKEM

1995 Impala SS "Cherry Bomb"
Best ETs: faster than my '65 pickup
Mods: 93% stock

My Super Impala SS Website (http://www.cadwiz.net/cherrybomb/)

[This message has been edited by George Debski (edited July 18, 2002).]

If the he's only making 360rwhp w/ LT4's that flow 310cfm @ .600" and a CC306, then his tune is MOST DEFINITELY wrong. Either that or something else is choking/hurting it. I have seen too many people make 415rwhp with heads that flow less on a stock bottom end.

<font face="Verdana, Arial" size="2">Originally posted by bunker:
Lets put it this way, my buddy got LT4 heads that flow 293/230 cfm at .550 & around 309 on intake at .600 lift, has a cc306 cam, rear end, etc... & he can't beat my other friend's cc305 cam & stock ported LT1 heads on both having 350's. Why? I personally think he has too much flow & bad port velocity, he also has 2.05 intake valves as apposted to my other friend who has 2.0 valves, so there you have it, he switched to LT4 heads & about 15rwhp from stock heads & a bigger cam, this is out of the so called awesome stage 4 GTP/MTI heads that were flowed in 2 different places at those incrediable numbers & make no power. He also has 12:1 compression, no detonation, ok tune etc... So its all about having the right heads for the right setup, & those heads prolly need a 396 or something, not a 350, he's pretty pissed off getting 360rwhp out of that setup, & being sliced & diced by a cc305 & stock ported LT1 heads stage II local port job http://web.camaross.com/bb/smile.gif</font>


yeah yeah .. that poor bastard is me http://web.camaross.com/bb/frown.gif
its sad .. very sad . .i ran almost as fast on shorty headers / cc305 / stock LT1s .. now i got ported LT4s / FLPs / CC306 / 3.73s and the car only keeps up to my friends car (As mentioned by bunker) with a cc305 / small ported LT1s and 3.42s http://web.camaross.com/bb/frown.gif


I think i'll get rid of my POS FLP Y pipe first .. then do more tuning on the dyno .. if i dont hit 400+ RWHP ... heads for sale, cam for sale .. WTB T-Trim

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Black '94 Z28, M6

Heads. Cam. Traction.

Speed Kills. Drive a Ford, Live Forever!
Pics of the beast (http://communities.msn.com/GMsFbody/sideways.msnw)
Hear it idle thru the muffler (http://members.shaw.ca/payam/REC00001.WAV)

British Columbia - Team F-Body
www.bctfb.com (http://www.bctfb.com)

if your heads flow that well, and you can't get the velocity you need, i'm assuming you dont' haev enough cubes/rpm's or the cam is mismatched, correct?

If you dont' get what you want, and plan on getting a supercharger, why not keep those on there? Wrong ratio intake to exhaust for forced induction?