LT1 to LT4 conversion Kit ???
Thread Starter
Melting Slicks
Joined: Oct 2000
Posts: 2,156
Likes: 3
From: La Mesa CA
LT1 to LT4 conversion Kit ???
In the Summit racing catalog, they have a LT1 to LT4 conversion kit.
Is it worth $2300. They say it will make a proven 425+ HP will it or
is it bull. Also need to make mods to computer what mods would have to be made. One more thing if this kit makes 425+ HP for my LT! why dose the
LT4 only make 330HP.
:confused:
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Re: LT1 to LT4 conversion Kit ??? (94TR)
It was documented in CHP magazine a couple years ago when the LT4 first came out. GM then introduced the LT4 hotcam and that was what made the difference for the LT4 making the reported 425 Hp or there abouts. But if I remember right that reported number was on a LT4 engine that had a carburetor on it, but I can't say for sure.
The LT4 was never delivered with a HOT cam installed its strictly an aftermarket cam that came out after the LT4 was introduced and it is not CARB approved, but with tuning it can be made to pass emissions easily.
The LT4 was never delivered with a HOT cam installed its strictly an aftermarket cam that came out after the LT4 was introduced and it is not CARB approved, but with tuning it can be made to pass emissions easily.
Team Owner
Joined: Sep 2001
Posts: 62,126
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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Re: LT1 to LT4 conversion Kit ??? (94TR)
I would just do the LT4 hotcam, 1.6rr, and have the stock heads ported.
You should come out cheaper, and be faster. (with exhaust)
You should come out cheaper, and be faster. (with exhaust)
Melting Slicks
Joined: Dec 2001
Posts: 2,437
Likes: 1
From: Gainesville Fl
Re: LT1 to LT4 conversion Kit ??? (94TR)
94TR: what all is included in that kit? i would think maybe about 390 fly wheel hp but not 425 you got me curious now what is different in that kit except the cam from my factory LT4!
Le Mans Master
Joined: May 2003
Posts: 5,362
Likes: 3
From: Delray Beach FL
Re: LT1 to LT4 conversion Kit ??? (1996man)
I was dreaming of this kit too. This is what the kit includes:
LT4 cylinder heads with valves and springs
LT4 intake manifold (red powdercoated)
LT4 Hot Cam
1.6:1 Bow Tie roller rockers
All necessary gaskets.
Quote in catalog: "The kit will give you a proven 425+ HP." On the other page in the catalog, they have the LT4 intake manifold and state "This intake manifold not only supports 425+ HP, its..."
Note: Modifications to your vehicles's computer engine management system are required. 1992-93 applications require a 1994-95 fuel rail.
Part #'s:
NAL-GMP3287-1 1992-95 $2,289.95
NAL-GMP3287-2 1996-97 $2,329.95
I guess the 1997 reference is for the Camaro.
It is a really nice upper end kit. I would also get new pushrods with it. Doesn't seem to include those.
LT4 cylinder heads with valves and springs
LT4 intake manifold (red powdercoated)
LT4 Hot Cam
1.6:1 Bow Tie roller rockers
All necessary gaskets.
Quote in catalog: "The kit will give you a proven 425+ HP." On the other page in the catalog, they have the LT4 intake manifold and state "This intake manifold not only supports 425+ HP, its..."
Note: Modifications to your vehicles's computer engine management system are required. 1992-93 applications require a 1994-95 fuel rail.
Part #'s:
NAL-GMP3287-1 1992-95 $2,289.95
NAL-GMP3287-2 1996-97 $2,329.95
I guess the 1997 reference is for the Camaro.
It is a really nice upper end kit. I would also get new pushrods with it. Doesn't seem to include those.
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: LT1 to LT4 conversion Kit ??? (94TR)
why dose the LT4 only make 330HP. :confused:
Melting Slicks
Joined: Dec 2001
Posts: 2,437
Likes: 1
From: Gainesville Fl
Re: LT1 to LT4 conversion Kit ??? (Whitvette)
i guess im still not sure how it makes 425 hp the only thing different from my motor i see is the cam and that only adds 30rwhp tops from what i have seen. Am i missing something?
Also do you have to pull the engine to do the cam swap or can you just take the radiator out and have enough room?
Also do you have to pull the engine to do the cam swap or can you just take the radiator out and have enough room?
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: LT1 to LT4 conversion Kit ??? (1996man)
The 425 was flywheel HP not at the wheels. Depends on dyno, depends on temps, gas quality, timing, etc....it could happen.....gotta have a chip programmed to get the full benefits of a cam swap now.
Engine needs to be lifted about 1" to clear the front crossmember. Use a floor jack with a block of wood under the oil pan to spread the load.
Engine needs to be lifted about 1" to clear the front crossmember. Use a floor jack with a block of wood under the oil pan to spread the load.
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Bench Racer
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From: Palm Beach Gardens FL
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Re: LT1 to LT4 conversion Kit ??? (95Purple)
What kind of torque increase did you get? Also, any idea what the HP/Torque rear wheel numbers were before your mods? Thanks!
Burning Brakes
Joined: Sep 2003
Posts: 1,214
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From: Miami FL
Re: LT1 to LT4 conversion Kit ??? (1996man)
Corvette Fever also did a story on this set up. LT1 to LT4. They used More Performance to do the insall and test at the flywheel on a dyno. 429hp and 400lb ft torque. They used LT4 heads and intake, Hotcam kit, GMPP 1.6 full roller rockers, 52mm throttlebody, custom chip, headers with performance cats. The Main difference in the stock LT4 set up would be the HOTCAM, 52mm throttlebody, custom chip and exhaust. I'm guessing that would be enough to get you 100hp over the stock LT4
Burning Brakes
Joined: Sep 2003
Posts: 1,214
Likes: 0
From: Miami FL
Re: LT1 to LT4 conversion Kit ??? (95Purple)
I just did the LT4 Hot cam on my LT1. I have ported heads and Tpis Long tube headers. Just had it tuned on the dyno at 277 rwhp. :(
Racer
Joined: Jul 2002
Posts: 250
Likes: 0
From: Victoria BC
Re: LT1 to LT4 conversion Kit ??? (TOO_HOTTVETTE)
Give this a read. Scanned article from Chevy High Performance
http://www.moreperformanceinc.com/lt4artic.htm
[Modified by shane99, 4:31 AM 10/2/2003]
http://www.moreperformanceinc.com/lt4artic.htm
[Modified by shane99, 4:31 AM 10/2/2003]
Burning Brakes
Joined: Sep 2003
Posts: 1,214
Likes: 0
From: Miami FL
Re: LT1 to LT4 conversion Kit ??? (shane99)
Give this a read. Scanned article from Chevy High Performance
http://www.moreperformanceinc.com/lt4artic.htm
This is basically the same article that appeared in Corvette Fever. It has the same author. I did this install in my '93 Vette
[Modified by shane99, 4:31 AM 10/2/2003]
http://www.moreperformanceinc.com/lt4artic.htm
This is basically the same article that appeared in Corvette Fever. It has the same author. I did this install in my '93 Vette
[Modified by shane99, 4:31 AM 10/2/2003]
Pro
Joined: Feb 2003
Posts: 540
Likes: 1
From: Taunton MA
Re: LT1 to LT4 conversion Kit ??? (vader86)
I would just do the LT4 hotcam,
more performance also offers a kit that claims 425 hp it is a little more expensive but it is also more complete heres the link http://www.moreperformanceinc.com/383lt1.htm
[Modified by comp94, 5:04 AM 10/2/2003]
Le Mans Master
Joined: Oct 2000
Posts: 6,362
Likes: 30
From: Oak Harbor WA
Re: LT1 to LT4 conversion Kit ??? (TOO_HOTTVETTE)
I just did the LT4 Hot cam on my LT1. I have ported heads and Tpis Long tube headers. Just had it tuned on the dyno at 277 rwhp. :(
Did you have a custom chip installed? Dont forget that the LT4 heads and intake will also flow better than the LT1
Did you have a custom chip installed? Dont forget that the LT4 heads and intake will also flow better than the LT1
Also, the LT4 uses 28# injectors, whereas the LT1 has only 24#'ers. I'm curious what your injector duty cycle is at. Are your heads really "ported" or just gasket matched?
Melting Slicks
Joined: Dec 2001
Posts: 2,437
Likes: 1
From: Gainesville Fl
Re: LT1 to LT4 conversion Kit ??? (shane99)
http://www.moreperformanceinc.com/lt4artic.htm
can someone post a link where this is easier to read or something? i dont know if my eyesight is failing or what but that print is awful faint
can someone post a link where this is easier to read or something? i dont know if my eyesight is failing or what but that print is awful faint
Race Director
Joined: May 2001
Posts: 14,165
Likes: 9
Re: LT1 to LT4 conversion Kit ??? (Goody)
I just did the LT4 Hot cam on my LT1. I have ported heads and Tpis Long tube headers. Just had it tuned on the dyno at 277 rwhp. :(
Did you have a custom chip installed? Dont forget that the LT4 heads and intake will also flow better than the LT1
There is something seriously wrong with your setup if all you have is 277. Most stock LT1's make 260RWHP. Was it dyno tuned with a WBO2 installed? Are you using the 1.6 RR's as well? They are required to get the full lift benefits of this cam. The LT4 and LT1 cams are really close to each other in actual measurements, but the RR's make a bit of difference due to rocker geometry changing total lift.
Also, the LT4 uses 28# injectors, whereas the LT1 has only 24#'ers. I'm curious what your injector duty cycle is at. Are your heads really "ported" or just gasket matched?
Did you have a custom chip installed? Dont forget that the LT4 heads and intake will also flow better than the LT1
There is something seriously wrong with your setup if all you have is 277. Most stock LT1's make 260RWHP. Was it dyno tuned with a WBO2 installed? Are you using the 1.6 RR's as well? They are required to get the full lift benefits of this cam. The LT4 and LT1 cams are really close to each other in actual measurements, but the RR's make a bit of difference due to rocker geometry changing total lift.
Also, the LT4 uses 28# injectors, whereas the LT1 has only 24#'ers. I'm curious what your injector duty cycle is at. Are your heads really "ported" or just gasket matched?
If it was a dynojet then yes you have something seriously wrong with your setup. If you are using 1.6 rockers, or have the hot cam kit, you should be WELL above that in horsepower. Even on stock heads my Hot Cam with headers made 336 horsepower. With ported cylinder heads I was up to 365.
The 24# injectors will most likely have a less than optimal duty cycle but they will work. If you don't believe me, look at my setup, I'm currently running stock injectors.
BTW, even with 1.5 rockers the hot cam should make well over 300 with headers and heads. Even if the heads are stock it should make 300 with headers.
If it's a Mustang dyno it could be normal but it still seems low. If it's a dynojet you've got issues, possibly the cam is out of time. Any strange driveability issues?
Le Mans Master
Joined: Jun 2002
Posts: 6,097
Likes: 2
From: Cincinnati Oh
Re: LT1 to LT4 conversion Kit ??? (vader86)
I would just do the LT4 hotcam, 1.6rr, and have the stock heads ported.
You should come out cheaper, and be faster. (with exhaust)
You should come out cheaper, and be faster. (with exhaust)
