how different are LT1 and L99?
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From: Monroe, SD
how different are LT1 and L99? i have a '95 caprice with a L99 engine. just wondering how diffrent from the Lt1's they are? i know they have 200 hp and 265 tq and that they are 265ci but not much else.
anyone know what heads they have, size valves. if it is even worth messing with to get a little more outta it?
anyone know what heads they have, size valves. if it is even worth messing with to get a little more outta it?
Your L99 is basically the same as an LT1 but with a smaller bore (3.75" vs 4.0") and stroke (3.0" vs 3.48"). The heads and cam on the L99 are the same as that of the larger displacement LT1s found in other B-bodies (Impalla SS, Caprice).
Same cam and valvetrain but the heads are a different casting using smaller valves. To get more out of an L99 try the LT1 boltons. If you want more then do like I did and throw in a junkyard LT1, cost me $550 look me up on www.Impalassforum.com I have a link in my sig about all the little details but basically it is a direct boltin.
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Verdad Gallardo Thread Starter
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From: Monroe, SD
Originally Posted by zcarguy
96capricemgr,
Do you still have the original L99 sitting around?
If so I might be interested in the crank and rods assuming you're willing to sell them.
ZcarGuy
Do you still have the original L99 sitting around?
If so I might be interested in the crank and rods assuming you're willing to sell them.
ZcarGuy
The crank and rods went to another guy planning to destroke an LT1, that was like 2 years ago and I don't think the project moved atall since. I still have the block and heads not that they are good for anything.
Staging Lane
Joined: Jul 2004
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Originally Posted by AAron
making a 302?
I also might have to replace the stock PCM but not sure yet. I'm considering trying to use MegaSquirt and Spark but haven't really done enough research into it yet to know if I can retain the Opti.
Any thoughts or ideas?
ZcarGuy
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From: Monroe, SD
don't get me wrong i love 302 chevys but there really is no displacement for displacement. you will just get more power out of a 350. now if money was no object and you want a high reving small block the 302 is the ****, but it is still cheaper and you get more power outta a 350,355 or so.
My L99 put down 203 rwhp on the dyno, on 87 octane, running 10:1 afr. If I'd had time to tune (it was a dyno day), I probably could have gotten 215 out of her. 
And then if I ran 93 octane, maybe a little more.
This is with headers, ported intake, 58mm throttle body, hi-flo cat, etc. All my 'stuff' from my heads/cam motor pulled off and stuck on the L99. (The h/c motor in my 94Z went boom, so I put a L99 in there because it was cheap and available. Don't need as much power in the 94Z when it has so much style.
)
And then if I ran 93 octane, maybe a little more.This is with headers, ported intake, 58mm throttle body, hi-flo cat, etc. All my 'stuff' from my heads/cam motor pulled off and stuck on the L99. (The h/c motor in my 94Z went boom, so I put a L99 in there because it was cheap and available. Don't need as much power in the 94Z when it has so much style.
) My Caprice came with an L99 that made way for an LT1 then later a cam and now I am looking at a LE stage one plus setup. The L99 was OK and I have even debated playing with one again I have enough gear and stall I could get stupid with a cam and whatnot. Maybe the ZZ3 cam that is in the LT1 now, bet that would lope something feirce in that baby motor and rev to 6500 easy.
Originally Posted by 96capricemgr
The crank and rods went to another guy planning to destroke an LT1, that was like 2 years ago and I don't think the project moved atall since. I still have the block and heads not that they are good for anything.
Thanks,
Daren
AAron,
Add some cash and I might trade a killer LT1 for your L99.
96capricemgr,
That is a long way off. I will be working in Wisconsin in two weeks, but will be flying up. Probably too heavy for carry on!
(I had an L99 in my racecar a couple of years ago. It made a little over 300 rwhp with only a cam, lifters and springs!)
Add some cash and I might trade a killer LT1 for your L99.
96capricemgr,
That is a long way off. I will be working in Wisconsin in two weeks, but will be flying up. Probably too heavy for carry on!
(I had an L99 in my racecar a couple of years ago. It made a little over 300 rwhp with only a cam, lifters and springs!)
and i didn't think youd want it 