Lt1 to Lt4 Conversion Kit
Thread Starter
Racer
Joined: Mar 2003
Posts: 307
Likes: 0
From: Dover Oh
Lt1 to Lt4 Conversion Kit
Sorry if this has been posted before, but has anyone installed the Summit Racing LT1 to LT4 GM conversion kit? Summit's web site claims over 400HP with just the addition of the kit that seem a bit high.
Anyone have any experience with this?
Anyone have any experience with this?
Melting Slicks
Joined: May 2003
Posts: 3,490
Likes: 68
From: Hewitt NJ
There's been many threads about this before...try the search and see if anything relevant comes up.
Just remember that the 425 HP output they claim is at the flywheel not the rear wheels. Assuming a 15% drivetrain loss it would put RWH at around 360. An LT4 with a "hot cam" and headers should have no trouble putting down similar numbers so I don't think their claim is far off.
Just remember that the 425 HP output they claim is at the flywheel not the rear wheels. Assuming a 15% drivetrain loss it would put RWH at around 360. An LT4 with a "hot cam" and headers should have no trouble putting down similar numbers so I don't think their claim is far off.
Race Director
Joined: Sep 2004
Posts: 13,793
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From: St. Peters MO Sometimes you have to prove yourself by doing alot of killing or alot of dying...
with admiral 94. I would also suggest looking into what it would cost to modify your current set up. I think you'd save some $$$ by getting the hotcam kit and your current heads ported.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Ahh, but if you port them same LT4 heads the tide turns 
The Summit kit is a decent deal, but you can find it on other websites for a little cheaper as well. Check out some of the GM dealers that offer the same kits most of them sell it cheaper. Then send the heads to Lloyd Elliot and have him port the heads. He can be reached at:
www.eportworks.com
He is a noted LTx head porter and well known on the CZ28 forum.
The Summit kit is a decent deal, but you can find it on other websites for a little cheaper as well. Check out some of the GM dealers that offer the same kits most of them sell it cheaper. Then send the heads to Lloyd Elliot and have him port the heads. He can be reached at:www.eportworks.com
He is a noted LTx head porter and well known on the CZ28 forum.
Instructor
Joined: Jun 2001
Posts: 132
Likes: 0
From: Monroe Washington..the State
We need to hook up TJ
Actually no there does not seem to be a gain. Some thing about the LT4 conture is killing it. either that or they need the new intake I designed
the one I posted over at LS1tech
Does not seem to matter who ports them or how much they flow they just do not produces like they should. I am working on the problem as we speak. Some are hinting it might even be related to the Opti....we will see I am putting in a Dyna spark and a MSD crank trigger distributor 
I have been using Lloyd for three years now
Actually no there does not seem to be a gain. Some thing about the LT4 conture is killing it. either that or they need the new intake I designed
the one I posted over at LS1techDoes not seem to matter who ports them or how much they flow they just do not produces like they should. I am working on the problem as we speak. Some are hinting it might even be related to the Opti....we will see
I am putting in a Dyna spark and a MSD crank trigger distributor I have been using Lloyd for three years now
Last edited by TwoFast4Lv; Jan 22, 2005 at 12:22 PM.
Le Mans Master
Joined: Jan 2003
Posts: 8,596
Likes: 19
From: Portland Oregon
Originally Posted by TwoFast4Lv
We need to hook up TJ
Actually no there does not seem to be a gain. Some thing about the LT4 conture is killing it. either that or they need the new intake I designed the one I posted over at LS1tech
Does not seem to matter who ports them or how much they flow they just do not produces like they should. I am working on the problem as we speak. Some are hinting it might even be related to the Opti....we will see I am putting in a Dyna spark and a MSD crank trigger distributor
I have been using Lloyd for three years now
Actually no there does not seem to be a gain. Some thing about the LT4 conture is killing it. either that or they need the new intake I designed
the one I posted over at LS1techDoes not seem to matter who ports them or how much they flow they just do not produces like they should. I am working on the problem as we speak. Some are hinting it might even be related to the Opti....we will see
I am putting in a Dyna spark and a MSD crank trigger distributor I have been using Lloyd for three years now
Melting Slicks
Joined: Jul 2003
Posts: 2,140
Likes: 0
From: Cincinnati Ohio
Originally Posted by bheston
Sorry if this has been posted before, but has anyone installed the Summit Racing LT1 to LT4 GM conversion kit? Summit's web site claims over 400HP with just the addition of the kit that seem a bit high.
Anyone have any experience with this?
Anyone have any experience with this?
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Le Mans Master
Joined: Jul 2000
Posts: 7,635
Likes: 326
From: Greenville SC
Lt1 to Lt4 Conversion Kit
Someone needs to make this a "sticky" in the tech tips or something, it comes up all the time. There have been several threads in just the past few weeks, and we all know how the "search" function sucks.
I think you would only get around 330 RWHP with long tube headers. Port the LT1 heads and add the rest, and you should get 360-370 RWHP with a good tune. More Performance did the LT4 conversion, and the got 429 GHP, but remember they also added long tube headers, larger TB, and it was GROSS HP (no accessories attached) on an engine dyno.
http://www.moreperformanceinc.com/press_1.php
Someone needs to make this a "sticky" in the tech tips or something, it comes up all the time. There have been several threads in just the past few weeks, and we all know how the "search" function sucks.
I think you would only get around 330 RWHP with long tube headers. Port the LT1 heads and add the rest, and you should get 360-370 RWHP with a good tune. More Performance did the LT4 conversion, and the got 429 GHP, but remember they also added long tube headers, larger TB, and it was GROSS HP (no accessories attached) on an engine dyno.
http://www.moreperformanceinc.com/press_1.php
