Corvette Action Center - The ultimate online hub of Corvette news and information! Click here to go to the Corvette Forums!

Supporting Vendors / Dealers - Supporting Membership - Advertising Information - Corvette Amazon Shop
Page 1 of 2 12 LastLast
Results 1 to 15 of 29
  1. #1
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default Lt1 Heads On A L98!

    I am doing the research now for the switch of a tpi intake to a lt1 intake.i went on the site where the guy sells lt1 intakes that are adapted to fit l98's.i see how he has to change the bolt holes to match the l98 heads and was wondering if i can skip this step by just changing over to lt1 heads.i wanted to do a head change anyway as a part of my cam,head,intake,exhaust setup.is this changeover possible?what would it take to do?
    My original plans called for the zz9 cam,ported 113 or afr heads,miniram intake,hooker headers.BUT,since i have to limit my budget,i am now looking into the lt1 intake conversion to save $.i have a friend with a lt1 that is converting to the lt4 setup and would give me his heads and intake.so i figured that if i can somehow bolt the lt1 heads ,after a little porting,i can knock out the heads,intake part in 1 step saving lots$.he already has his intake and heads off so they are ready to send out for the poting,intake adapting if i want them.

  2. #2
    Gone but not forgotten Mad-Mic's Avatar
    Join Date
    Feb 2002
    Location
    Annapolis Maryland
    Posts
    2,552
    Corvette(s)
    1987 Redskin Red Coupe

    Default

    Quote Originally Posted by 87L98Z52
    I am doing the research now for the switch of a tpi intake to a lt1 intake.i went on the site where the guy sells lt1 intakes that are adapted to fit l98's.i see how he has to change the bolt holes to match the l98 heads and was wondering if i can skip this step by just changing over to lt1 heads.i wanted to do a head change anyway as a part of my cam,head,intake,exhaust setup.is this changeover possible?what would it take to do?
    My original plans called for the zz9 cam,ported 113 or afr heads,miniram intake,hooker headers.BUT,since i have to limit my budget,i am now looking into the lt1 intake conversion to save $.i have a friend with a lt1 that is converting to the lt4 setup and would give me his heads and intake.so i figured that if i can somehow bolt the lt1 heads ,after a little porting,i can knock out the heads,intake part in 1 step saving lots$.he already has his intake and heads off so they are ready to send out for the poting,intake adapting if i want them.
    save yourself the money and time. if he's going to give it to you then see if the owner of www.lt1intake.com will do the labor on the conversion. LT1 intakes and heads don't match up with the SBC1 waterjackets. it has been done but i don't think the time and money would be worth it. sell the LT1 heads cheap and get some money back for the intake work.

    best of luck!

    87 Coupe
    Old Times! New ones coming Soon!
    Best 60' 1.815 on Good Year F1 Street Tires!
    Best ET 13.187
    Best MPH 105.84
    Check out my Car Domain Site!
    www.CorvetteKillStories.com

  3. #3
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default

    Thanks for the fast reply mad mic,if i can just you 1 more ?
    How much would my stock heads hold me back if i just opt for the lt1 conversion and zz9 cam for now?i dont have headers either but i do have the front and rear y pipe and flowmasters now.i figured i can just do the heads and headers at a later time when i can spend that much on making my joyrides more joyfull!LOL
    THANKS!

  4. #4
    Gone but not forgotten bossvette's Avatar
    Join Date
    May 2003
    Location
    West Unity Ohio
    Posts
    4,895
    Corvette(s)
    1968 1997

    Default

    the LT-1 is a reverse cool motor (the water cools the heads first then the block) and the water passages are different then the L-98, even though they may bolt on I don't think they will work very well.

    68 4 speed 97 6 Speed

  5. #5
    Member vader86's Avatar
    Join Date
    Sep 2001
    Location
    Baton Rouge/LSU
    Posts
    827
    Corvette(s)
    1986 White Coupe w all options.

    Default

    LT1 heads are setup for the reverse cooling, so those wont work.

    The 128 heads that come stock in 87 are said to be good for about 300-325hp untouched.

    Ported, you should be able to get 350 to 375 out of them before air flow becomes a problem at high rpm.

    They would not hold you back with a ZZ9 cam if they were ported, unported they shouldnt actually kill off major HP but you wont be at the full potential of the cam, which i think is in between 300 and 350.

  6. #6
    Gone but not forgotten Mad-Mic's Avatar
    Join Date
    Feb 2002
    Location
    Annapolis Maryland
    Posts
    2,552
    Corvette(s)
    1987 Redskin Red Coupe

    Default

    Quote Originally Posted by 87L98Z52
    Thanks for the fast reply mad mic,if i can just you 1 more ?
    How much would my stock heads hold me back if i just opt for the lt1 conversion and zz9 cam for now?i dont have headers either but i do have the front and rear y pipe and flowmasters now.i figured i can just do the heads and headers at a later time when i can spend that much on making my joyrides more joyfull!LOL
    THANKS!
    87 heads won't flow the rate needed for the lift of the cam. i think the cut off is .480" lift. the guide plates have to be cut down so you'd have to machine the heads anyway. find a good machine shop to do it and they should work with you about how much you want to spend on the machining for extra power ect. thats the boat i'm in now. i got the LT1 intake, ZZ409 cam, and a few other goodies ready to be put on. just need a set of heads. i also am building a shortblock so i'm in no hurry for the heads at this moment. just trying to see how quick i can get her with out touching internal's right now. i think i'm just gonna buy a set of Dport 113 heads and have them reworked so the cam can clear the lift on 1.6 RR's which will be .555" lift.

    87 Coupe
    Old Times! New ones coming Soon!
    Best 60' 1.815 on Good Year F1 Street Tires!
    Best ET 13.187
    Best MPH 105.84
    Check out my Car Domain Site!
    www.CorvetteKillStories.com

  7. #7
    Gone but not forgotten Mad-Mic's Avatar
    Join Date
    Feb 2002
    Location
    Annapolis Maryland
    Posts
    2,552
    Corvette(s)
    1987 Redskin Red Coupe

    Default

    Quote Originally Posted by vader86
    LT1 heads are setup for the reverse cooling, so those wont work.

    The 128 heads that come stock in 87 are said to be good for about 300-325hp untouched.

    Ported, you should be able to get 350 to 375 out of them before air flow becomes a problem at high rpm.

    They would not hold you back with a ZZ9 cam if they were ported, unported they shouldnt actually kill off major HP but you wont be at the full potential of the cam, which i think is in between 300 and 350.
    i think i'm in that 300-325 hp at the crank now. so far so good when i redyno the car next month after a few more bolt on's (AIR elim kit, crank pulley, MAT relocation kit) i'll let you guys know what she pulled.

    last time i dynoed i was hot when we hooked her up as i just got there and on my first pull blew a home made rubber EGR tube from the header install i did (rushed it to the dyno before shaking down everything ) and i thought it was a header gasket cause it was around 7:30 at night but she pulled 240 rwhp and 345 rwtq. i'm sure cooled down and now she'll pull in the 270 rwhp range and about 370 rwtq. with the other mods i will install (AIR elim kit, crank pulley, MAT relocation kit) maybe in the 290 rwhp 380+ rwtq range. atleast this is what i hope. we shall see then i am going to swap to the LT1 intake and see what the difference is on the dyno since i get dyno time so cheap from www.HeffnersPerformance.com at 80 bucks an hour

    i'll let you guys know the how it turns out

    87 Coupe
    Old Times! New ones coming Soon!
    Best 60' 1.815 on Good Year F1 Street Tires!
    Best ET 13.187
    Best MPH 105.84
    Check out my Car Domain Site!
    www.CorvetteKillStories.com

  8. #8
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default

    From talking to tpis,my understanding was that i would just have to change springs,lifters,rocker arms to install the zz9 in my 128's.with the stock springs,etc it only takes up to .480 lift.i didnt think there was any work needed to the heads to install the new springs.am i wrong?

  9. #9
    Gone but not forgotten Mad-Mic's Avatar
    Join Date
    Feb 2002
    Location
    Annapolis Maryland
    Posts
    2,552
    Corvette(s)
    1987 Redskin Red Coupe

    Default

    i was told (not by TPiS) that the cam would not work cause of the guide plates needing cut down. yes you are corret about the .480" lift but the exhaust side is .520" lift.

    ZZ-9 HydraulicRoller:

    Intake Exhaust Advertised duration 282 287
    Duration at .050 212 226
    Gross lift .483 .520
    Lobe separation 112


    mine is

    ZZ-409 Hyd Roller:

    Adv. duration 287/287, duration @.050 226/226, Lift .520/.520. 112 LSA.


    granted these specs are on 1.5" RR's i'm going to use 1.6" to get the .555" lift might want to ask TPiS about the guideplates needing cut down for the lift to clear.

    better to be safe than sorry

    87 Coupe
    Old Times! New ones coming Soon!
    Best 60' 1.815 on Good Year F1 Street Tires!
    Best ET 13.187
    Best MPH 105.84
    Check out my Car Domain Site!
    www.CorvetteKillStories.com

  10. #10
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default

    Sorry about that mic,what i meant to say is that the stock heads with stock springs only take up to .480 lift.i did know about the .520 on the exh side.i am going to contact tpis though because i have there insider hints book here and ill tell you what it says.

    "one prob to beware of with chevy aluminum heads with cams over .480 lift-if the valve springs are shimmed this can be a prob.our zz9 cam does not need to have more than 95 psi on the seat,which should give you enough retainer to guide clearance."

    I am going to ask them though because i also have there01' catalog and they have yourzz-409 cam listed as dur 225,240 lift.525,.558 with 116 lobe sep.
    they have the super profile l98 listed with the spec you gave for the cam you have.must be some kind of mix up!

  11. #11
    Gone but not forgotten Mad-Mic's Avatar
    Join Date
    Feb 2002
    Location
    Annapolis Maryland
    Posts
    2,552
    Corvette(s)
    1987 Redskin Red Coupe

    Default

    Quote Originally Posted by 87L98Z52
    Sorry about that mic,what i meant to say is that the stock heads with stock springs only take up to .480 lift.i did know about the .520 on the exh side.i am going to contact tpis though because i have there insider hints book here and ill tell you what it says.

    "one prob to beware of with chevy aluminum heads with cams over .480 lift-if the valve springs are shimmed this can be a prob.our zz9 cam does not need to have more than 95 psi on the seat,which should give you enough retainer to guide clearance."

    I am going to ask them though because i also have there01' catalog and they have yourzz-409 cam listed as dur 225,240 lift.525,.558 with 116 lobe sep.
    they have the super profile l98 listed with the spec you gave for the cam you have.must be some kind of mix up!
    -=Jeff=- sent me the cam w/ cam card i'll have to look at it later when i get some time and let ya know the exact specs from cam doctor

    87 Coupe
    Old Times! New ones coming Soon!
    Best 60' 1.815 on Good Year F1 Street Tires!
    Best ET 13.187
    Best MPH 105.84
    Check out my Car Domain Site!
    www.CorvetteKillStories.com

  12. #12
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default

    THANKS,it does sound like a nice cam!i will let you know what tpis says about all this when i talk to them.do you have any idea what kind of idle the zz9 or your zz409 have.i am looking for something with a little bit of a lopy idle.

  13. #13
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default

    i have been looking into the lt1 heads on a l98 somemore and have found out there are people already doing this.lt1intake.com has 2 links on his website that tells you how.by doing this conversion,the lt1 intake would now be a bolt on plus you would still have to drill the hole for the dist.but you would have good flowing heads and a nice intake for alot less than afr heads and miniram.the only other issue im now looking into is how the acc would bolt on to the lt1 heads.look into these articles off of johns site,does not seem to be to hard of a conversion.they plug the large coolant ports and just drill a small hole for the stock coolant hole by using a head gasket from a l98 head.the exhaust ports are the same as the l98 ones also.

  14. #14
    Member
    Join Date
    Mar 2004
    Location
    long island,ny
    Posts
    41
    Corvette(s)
    1987 red,z52,4+3 coupe

    Default

    Found a thread on this also

    http://www.thirdgen.org/techbb2/show...hreadid=178262

    seems very possible!again,my only concern is the alt,etc bolting up.does anybody know if they have the same mounting holes as l98 heads?

  15. #15
    Member -=Jeff=-'s Avatar
    Join Date
    Feb 2001
    Location
    Bartlett, IL. (Chicago Suburb)
    Posts
    1,115
    Corvette(s)
    1990 ZR-1

    Default

    Mad- mic right with cam specs

    here they are off TPiS's website

    ZZ-9 HydraulicRoller:
    Intake Exhaust Advertised duration 282 287
    Duration at .050 212 226
    Gross lift .483 .520
    Lobe separation 112

    ZZ-409 Hyd Roller:
    Adv. duration 287/287, duration @.050 226/226, Lift .520/.520. 112 LSA.

    ZZ-9X Hyd Roller:
    duration @.050 225/240, Lift .525/.558 on a 112 LSA.

    ZZ-X Hyd Roller:
    Adv duration 290/290, duration @.050 239/239, Lift .558/.558, on a 112LSA.


    The Super Profile is a lower lift cam then the ZZ9 and a tighter LSA (I should know I use to have that cam)
    -=Jeff=-
    1990 ZR-1 #1051
    ----------------------------------------
    NCM Lifetime Member #978
    ----------------------------------------

Page 1 of 2 12 LastLast

Similar Threads

  1. LT1,LT4,LS1,LS6.... Whats the difference?
    By sscam69 in forum LT4 Forum
    Replies: 28
    Last Post: 04-29-06, 03:06 PM
  2. LT1 Shorty Headers On 87 L98 Heads
    By ARODFX in forum C4 Technical and Performance
    Replies: 7
    Last Post: 02-17-04, 02:25 PM
  3. Vortech heads or machine work?
    By akfox1 in forum C3 Technical and Performance
    Replies: 10
    Last Post: 10-24-01, 10:55 PM
  4. LT1 heads- valves increased to LT4 size
    By C4TOMCAT in forum LT4 Forum
    Replies: 1
    Last Post: 06-10-01, 12:58 PM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
© CORVETTE is a registered trademark of the General Motors Corporation & Chevrolet Motor Division.  Neither Chevrolet Motor Division nor any subsidiaries of GM© shall bear any responsibility for CorvetteActionCenter.com content, comments, or advertising. CorvetteActionCenter.com is independent from GM© and is not affiliated with, sponsored or supported by GM©.  Copyright/trademark/sales mark infringements are not intended, or implied.  All Rights Reserved