Thanks Thanks:  0
Likes Likes:  0
Dislikes Dislikes:  0
Results 1 to 12 of 12
  1. #1
    Member
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    393
    Post Thanks / Like
    Rides
    0

    Question LT4 Conversion kit

    Can anyone tell me how close a LT1 engine with the GM LT1 to LT4 conversion kit installed is to a LT4 engine from the plant? Is the only difference the top of the pistons maybe? I have an LT1 coupe and if I don't upgrade to a C5 or C6, I am considering the LT4 conversion kit after I pay my LT1 off.

  2. #2
    Technical Writer for Internet & Print Media
    Join Date
    Jan 2001
    Location
    CenCoast CA
    Posts
    11,688
    Post Thanks / Like
    Rides
    0

    Default

    In order to answer that question, you need to post what's in the "LT1 to LT4 Conversion Kit".

  3. #3
    Moderator KANE's Avatar
    Join Date
    Mar 2002
    Location
    KY
    Posts
    3,230
    Post Thanks / Like
    Rides
    1

    Default

    Quote Originally Posted by air1jpg View Post
    Can anyone tell me how close a LT1 engine with the GM LT1 to LT4 conversion kit installed is to a LT4 engine from the plant? Is the only difference the top of the pistons maybe? I have an LT1 coupe and if I don't upgrade to a C5 or C6, I am considering the LT4 conversion kit after I pay my LT1 off.
    Jon-

    NOT an LT4 package... but a set of 1.6 roller rockers, exhaust, and a new tune will go a long way to stepping the performance on your LT1.

    On an LT1 Formula that I had back in the 90s, the engine responded very well to a JET stage II chip, 3 in exhaust, a Honker intake, and 1.6 rockers. You could get similar improvements out of a black wing air filter, better flowing exhaust, and a recalibrated ECM. Made a big difference on my car and not nearly as pricey as the full LT4 conversion.
    1982 Dark Blue Corvette
    Crossfire Injection | L83 | .465"/.488" Cam | EBL | 3.73
    0-60mph in 5 seconds



    1995 Trans Am
    1 of 1 Trans Am | 100% documented | RPOs 48U, MN6, and GU6
    1982 Chevrolet Corvette , 350 2k RPM Stall Converter + Updgraded Transmission + Governor Set For 5,450rpm Shifts 3.73 Code 42 Dark Mettalic Blue with a twist

  4. #4
    Member
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    393
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by Hib Halverson View Post
    In order to answer that question, you need to post what's in the "LT1 to LT4 Conversion Kit".
    It is a kit from GMpartsdirect.com that is a upper intake kit including the cam.

  5. #5
    Technical Writer for Internet & Print Media
    Join Date
    Jan 2001
    Location
    CenCoast CA
    Posts
    11,688
    Post Thanks / Like
    Rides
    0

    Default

    Besides the intake manifold and the camshaft, the LT4 has different cylinder heads, different intake valves, different rocker arms, different timing chain assy, different injectors, different throttle body and some other items.

    If the GM Parts Direct "kit" includes the camshaft and the intake then the resulting modified LT1 won't be anything close to what the production LT4 was.

  6. #6
    LT4 Conversion kit Tuna's Avatar
    Join Date
    Mar 2003
    Location
    Mustang, OK
    Posts
    3,573
    Post Thanks / Like
    Rides
    1

    Default

    I used the GMPartDirect kit back in 2003 to convert my LT1. The kit included LT4 heads with the 1.6 rockers, the LT4 intake, the LT4 Hot Cam, and all the rest of the stuff to put the engine back together. It will not be an LT4 once converted. I included the LT4 OptiSpark in my conversion since I was converting a 92 LT1.

    The LT4 has different pistons and other components that you don't touch with the basic conversion. Depending on the LT1 year, the injectors are different flow rates.

    A converted LT1 will run very similar to an LT4 with the Hot Cam afterward but it will still not be an LT4.
    Tuna
    New avatar - my latest novel
    Antiques To Die For



  7. #7
    Member
    Join Date
    Jun 2007
    Location
    Louisville, KY
    Posts
    393
    Post Thanks / Like
    Rides
    0

    Default

    Quote Originally Posted by Tuna View Post
    I used the GMPartDirect kit back in 2003 to convert my LT1. The kit included LT4 heads with the 1.6 rockers, the LT4 intake, the LT4 Hot Cam, and all the rest of the stuff to put the engine back together. It will not be an LT4 once converted. I included the LT4 OptiSpark in my conversion since I was converting a 92 LT1.

    The LT4 has different pistons and other components that you don't touch with the basic conversion. Depending on the LT1 year, the injectors are different flow rates.

    A converted LT1 will run very similar to an LT4 with the Hot Cam afterward but it will still not be an LT4.
    My LT1 is a 96, will it be close enough in power difference to be worth the money to have the kit installed?

  8. #8
    Moderator KANE's Avatar
    Join Date
    Mar 2002
    Location
    KY
    Posts
    3,230
    Post Thanks / Like
    Rides
    1

    Default

    Quote Originally Posted by air1jpg View Post
    My LT1 is a 96, will it be close enough in power difference to be worth the money to have the kit installed?
    My $.02-

    No. It is not worth the money.


    You could go with headers, port work to the LT1 heads (or new Lloyds), ECM tune, 1.6 RR, and an LT4 hot cam. You'd most likely do better. Once you've decided to modify the car- you may as well go big. You'll never be able to sell it as a true LT4.

    Let me know if you want a recommendation on who to do porting in Louisville. Drew at Street & Strip could help you out with this kinda work.
    1982 Dark Blue Corvette
    Crossfire Injection | L83 | .465"/.488" Cam | EBL | 3.73
    0-60mph in 5 seconds



    1995 Trans Am
    1 of 1 Trans Am | 100% documented | RPOs 48U, MN6, and GU6
    1982 Chevrolet Corvette , 350 2k RPM Stall Converter + Updgraded Transmission + Governor Set For 5,450rpm Shifts 3.73 Code 42 Dark Mettalic Blue with a twist

  9. #9
    LT4 Conversion kit 6 Shooter's Avatar
    Join Date
    May 2002
    Location
    Missoura Ozarks
    Posts
    8,600
    Post Thanks / Like
    Rides
    0

    Flag Ya know you could buy an LT4 engine or sell your Vette and buy a 96 LT4 Vette, ...


    ...here's a shot of one I use to own, they are sweet rides!
    Later . . . . . .
    6 Shooter

  10. #10
    LT4 Conversion kit Tuna's Avatar
    Join Date
    Mar 2003
    Location
    Mustang, OK
    Posts
    3,573
    Post Thanks / Like
    Rides
    1

    Default

    Quote Originally Posted by air1jpg View Post
    My LT1 is a 96, will it be close enough in power difference to be worth the money to have the kit installed?
    A stock LT1 should rear wheel dyno around 250-260 HP. After the LT4 conversion and Hot Cam, 330-350 at the rear wheels would be reasonable with a good exhaust included.

    My '92 dyno'ed at 328 with the '92 24# injectors and 48mm TB through Corsa cat back exhaust. It would have done better with 28-30# injectors and a 52mm TB.

    So, a gain of 80-100 HP is possible and the 'cool factor' of showing off the 'red' LT4 intake when you raise the hood can make it worth it.

  11. #11
    Registered User
    Join Date
    Jun 2005
    Location
    Mandeville, La
    Posts
    615
    Post Thanks / Like
    Rides
    0

    Default

    LT1 vs LT4

    Specific Diffrences Here.

  12. #12
    New Member
    Join Date
    Oct 2009
    Location
    Somewhere in Illinois
    Posts
    13
    Post Thanks / Like
    Rides
    0

    Default

    Converted LT1s run like, well, LT4s once the ecu is tuned for the new combo. The minor difference in compression between the LT1 and LT4 won't matter all that much. Just stabbing in a hot cam and putting rockers on a LT1 is a nice budget approach, but won't get you what you want unless you port the heads or go with LT4 heads and required LT4 intake. The LT1 heads aren't as good as LT4 heads. If you've got the coin, AFR's "LT4" 195 and 210 heads are awesome and blow away the LT4 heads, but that's getting off topic.

    As for the hot cam, it really works well with the factory LT4 heads and will easily give you 400+ hp at the crank while keeping the idle and driving characteristics near factory.

    http://www.gmpartsdirect.com/results...ber=pk12550630

    http://www.jegs.com/i/Edelbrock/350/...oductId=878543

    http://www.airflowresearch.com/index.php?cPath=27_28

Similar Threads

  1. GM performance parts LT1 to LT4 conversion kit
    By dhiltgen in forum LT4 Forum
    Replies: 8
    Last Post: 04-17-07, 08:23 PM
  2. LT1 to LT4 Conversion
    By 92ghost in forum LT4 Forum
    Replies: 37
    Last Post: 03-06-05, 03:12 AM
  3. LT4 conversion just as good?
    By WantaVette in forum LT4 Forum
    Replies: 2
    Last Post: 07-02-04, 08:31 AM
  4. 5 or 6 speed conversion kit for c 3
    By billyvette in forum C3 Technical and Performance
    Replies: 7
    Last Post: 01-01-04, 10:04 AM
  5. "Cool" A/C R12 to 134a Conversion Kit
    By 21again in forum C3 Technical and Performance
    Replies: 15
    Last Post: 07-22-03, 12:35 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •