Cut through the BS..are max effort LT4 heads worth it over lt1s?
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Joined: Jan 2001
Posts: 296
From: Clawson, MI
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Joined: Dec 1999
Posts: 2,248
From: Houston, TX
I've always wondered about this too...the original question 
.
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 $$$ to get to the 'next level.' (just restating what Kurtis said
)
How about this: Sticking with the stock pcm, can you make good power with the stock heads (500rwhp NA)?
Ryan
[This message has been edited by 96-speed (edited July 18, 2002).]
.I haven't seen (in internetville) too many guys actually stay with the LT1 heads, though. I'd hate to learn I'd have to lay down a lot more $$$ to get to the 'next level.' (just restating what Kurtis said
)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).]
Registered User
Joined: Sep 1998
Posts: 98
From: Ormond Beach, FL
You're talking about 620 crank HP out of stock ported aluminum LT1 heads? If you could do that, you could make a mint
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:
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
[This message has been edited by George Debski (edited July 18, 2002).]
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
: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
[This message has been edited by George Debski (edited July 18, 2002).]
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Joined: Jan 2001
Posts: 368
From: Indianapolis, IN
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.
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Joined: Feb 2001
Posts: 3,842
From: BC, Canada
<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</font>
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
</font>
yeah yeah .. that poor bastard is me
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
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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Registered User
Joined: Feb 2002
Posts: 8
From: Hagerstown, MD
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?
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?
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