C4 Tech/Performance L98 Corvette and LT1 Corvette Technical Info, Internal Engine, External Engine

Difference between an LT1 & L98?

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Old 06-22-2011, 03:25 PM
  #21  
l98tpi
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Originally Posted by cmjuhl
1990 L98 ENGINE SPECS.


ZSA L98 350-cid 245-t/250-hp V-8 9.5:1
ZSB L98 350-cid 245-t/250-hp V-8 9.5:1
ZSC L98 350-cid 245-t/250-hp V-8 9.5:1
You're 100lb/ft off on your torque rating.
Old 06-22-2011, 03:48 PM
  #22  
Repzard
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Originally Posted by MeanMachine350
Then why does it seem like the LT1 is the 'holy grail' on this forum? I see a lot of people bashing L98s and saying they would much prefer a LT1 in their cars when a L98 can be more reliable?

Honestly, I've heard way too many people groan upon hearing that I have an L98 in my car. I just brush it off because I know I'm happy with my reliable engine and I know that I can mod it to beat a LT1 someday
Because when youre compairing the L98 to the LT1 \ LT4 HP the L98 is the redheaded step child in a way.

Plus the LTx "was" a new gen motor when it came out.
Now the LTx is the LSx step child...LOL
Old 06-22-2011, 05:48 PM
  #23  
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Originally Posted by MeanMachine350
Then why does it seem like the LT1 is the 'holy grail' on this forum? I see a lot of people bashing L98s and saying they would much prefer a LT1 in their cars when a L98 can be more reliable?
Because people oversimplify things, and are generally stupid.
Old 06-22-2011, 05:58 PM
  #24  
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I myself be a owner of both motors ( had a 86) and now have a 93.

I liked the L98 better , It can be modded more than the LT1.
Also love the "seat in paints torque" it has over the LT1.

Plus the best thing about the L98 over the LT1 is it doesnt have that PITA Opticrapper
Old 06-22-2011, 07:31 PM
  #25  
MeanMachine350
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Originally Posted by Repzard

Plus the LTx "was" a new gen motor when it came out.
Now the LTx is the LSx step child...LOL
So what does that make the L98 now, the redheaded step sister?
Old 06-22-2011, 10:16 PM
  #26  
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Originally Posted by cuisinartvette
You sure about that?
Yup, read the article...http://www.chevyhiperformance.com/te...nfo/index.html
Old 06-22-2011, 10:27 PM
  #27  
93Rubie
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Originally Posted by ddahlgren
the L98 first generation sbc is probably the most supported engine by aftermarket ever built. Lots of parts choices and much cheaper than anything else. If the LT1 was such a great idea why did it get discontinued after 4 years? Why in the world would you put an ignition system in an engine that can't get wet and ofer zero increase in performance???
92-97 so actually 6 model years.

Here is the scope on GM engine development. The L98 was around doing its thing and being awesome. The they wanted to take on the big dogs and got the LT5 in 90. Over at GM Powertrain they where PO'ed that they did not get a chance to make this Euro-killing engine. So they in the late 80's early 90's redid the Small Block Chevy Gen1. The LT1 is a Gen 2, it was an engine for a new era of fuel economy and ever increasing emissions. They thought the most they could get was 250HP out of a SBC. Well, they hit 300, then with more development they realized 350 and even 400HP was within reach. They started work on a Gen 3 engine but realized soon they needed a clean sheet design. This still born Gen 3 became the LT4 in 96. The LS is a totally clean sheet design that started development in 93.

The SBC Gen 1 is the grandfather and in its L98 form, the still cool and relevant grandfather. The LT1 is the not far from the tree son, the Dad (LT1) realized if his kind was to survive he needed to mate with something totally new and better. Hence, the grandson (LS) is in spirit (basic layout, 4.40 bore spacing, legendary status) the same as his father and grandfather, he is ready for the new 21'st century and its unique automotive threats to the 2 valve pushrod existence.

The LS is a great engine like all SBC's. Everyone raves about it, for the same reasons that made the 55 SBC the HOT ONE. Easy to mod and make HP, reliable and durable, cheap to make, modify, and build, etc....

Nothing is created in a vacuum, the SBC is a great design and a mature one in the L98, it made the LT1/LT4 great, the great LT1/LT4, made the LSX series great, it is a evolutionary thing. They build on one another and make their breed better.

Last edited by 93Rubie; 06-22-2011 at 10:30 PM.
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Old 01-23-2013, 10:22 AM
  #28  
long88vette
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Default Lt1 with l98 intake and heads

I have a l98 with spun bearings and I also have a good lt1 can I put my l98 heads intake and distributor on the lt1 block?
Old 01-23-2013, 11:11 AM
  #29  
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So you can get rid of the 50 hp advantage that the LT1 provides?

No, you cannot put the L98 top end on the LT1 bottom, practically.


Since this has nothing to do with this thread, perhaps you might have started a new thread? IB4TL
Old 01-23-2013, 12:49 PM
  #30  
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I noticed that the best L98 year for the HP Torque was added during the thread while leaving the 330 lbft for the LT1 which was the 1992 rating, torque went up in 1993. As for the OPTI the first gen 92-94 in the vete may have issues, however, the gen II opti is a reliable unit going hundreds of thousands of miles in police and taxi service.

There were minor LT1 changes almost every year once the corvette recieved the vented opti things were pretty well sorted.
The problem with the L98 is the only thing that makes it an L98 the intake. Now the folks that say remove the intake and install the LT1 intake and your even on horsepower are probably wrong since there is a compression difference too. So the difference is a standard SBC with an intake that kills high rpm permformance or a second generation SBC that will rev that comes with 50 more horsepower and the same or 10 less lbft of torque depending on the year. IMO most of the OEM OPTI issues are other issues that the opti gets blame for.

I have a 6.0 GEN IV car in the stable and according to the internet its full of problems too.

Mike

Last edited by aboatguy; 01-23-2013 at 12:55 PM.
Old 01-23-2013, 01:02 PM
  #31  
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Originally Posted by aboatguy
Now the folks that say remove the intake and install the LT1 intake and your even on horsepower are probably wrong since there is a compression difference too.
There are lot of differences, and they ALL add up to the 50+hp advantage that the LT1 has;
Heads
Intake
Compression
Cam
Exhaust (from the manifolds to the tail pipes)
Cooling
ECM Speed/refinement
Ignition system accuracy


It ALL ADDS UP. You can slap a modified LT1 intake or a Miniram on an L98 and probably get ~270 hp. That's not 300 though. You can probably slap better heads on an L98 and get ~270/280hp (all else stock). That's not 300 hp either. Same goes for exhaust.

You aren't going to put any ONE LT1 part on an L98 and get 300hp. That won't happen. You may get 80% of the gains, but not all.
Old 01-23-2013, 01:29 PM
  #32  
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Originally Posted by tnz5106
And the L98 was the 2nd most awesome engine to the eye, the only one more awesome was the LT5!!!!! The lt1 is very plain.......sorry c4 brothers!!
I had not seen this thread before, although I agree... I think this one be perrrty..



Oh and IBTL
Old 01-23-2013, 02:01 PM
  #33  
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The bottom line is the LT1 has many small changes to the sum of its parts that add up to the extra HP over an L98. It is not possible to add all of the LT1 parts to an L98 because of the reverse flow cooling. The real question you are after is can a L98 be modified to make 300 HP and that answer is yes. The L98 engine design is a typical SBC and it would be very easy to acheive 300 HP.

To tell you the truth both engine designs can be modified to make impressive power but if your your goal is to make race level power (600 HP plus) the L98 (SBC) design get the nod since it has much more aftermarket support and many more parts available to acheive those goals.
Old 01-23-2013, 02:04 PM
  #34  
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Originally Posted by Repzard
I myself be a owner of both motors ( had a 86) and now have a 93. I agree 92-94 OPTI is not the most reliable piece of kit. 92-93 are batch fire..... So you may have a point IRT a 93 LTX.
I liked the L98 better , It can be modded more than the LT1. Concur it needs to be modded more. '
Also love the "seat in paints torque" it has over the LT1. The engine falls over so early that your continually shifting so it seems fast. In reality torque is a wash and LTX has more power under the curve..

Plus the best thing about the L98 over the LT1 is it doesnt have that PITA Opticrapper
Yes they are fragile ..... NOT

Last edited by aboatguy; 01-23-2013 at 02:09 PM.
Old 01-23-2013, 02:10 PM
  #35  
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Originally Posted by ch@0s
i had not seen this thread before, although i agree... I think this one be perrrty..



oh and ibtl
nice !
Old 01-23-2013, 02:16 PM
  #36  
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Originally Posted by Tom400CFI
There are lot of differences, and they ALL add up to the 50+hp advantage that the LT1 has;
Heads
Intake
Compression
Cam
Exhaust (from the manifolds to the tail pipes)
Cooling
ECM Speed/refinement
Ignition system accuracy


It ALL ADDS UP. You can slap a modified LT1 intake or a Miniram on an L98 and probably get ~270 hp. That's not 300 though. You can probably slap better heads on an L98 and get ~270/280hp (all else stock). That's not 300 hp either. Same goes for exhaust.

You aren't going to put any ONE LT1 part on an L98 and get 300hp. That won't happen. You may get 80% of the gains, but not all.
Thanks for making my point brother! As one of my heroes told me IRT HARLEY ... they didn't replace the Pan with the shovel because the Pan is better...and they sure as Hell didn't replace the Shovel with the Evo because the Shovel is better. (I'm a Panhead guy) So L98<LTX<GEN III< GEN IV <etc and it will continue to follow that trend until Uncle Sugar gets involved "...for the children..." )

Last edited by aboatguy; 01-23-2013 at 02:20 PM.
Old 01-23-2013, 08:57 PM
  #37  
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Originally Posted by cuisinartvette
&

Trust those things far as I can throw em.

Prices on those is SO tempting and lots to like about the cars its just that system they have on there, no way. Its as bad as the L98 intake lol.
I wouldn't mind having an opti Vette. I drove one: you know they give up a little down low torque to an L98 but the trade off is well worth it for the extra 1k+ rpm pull up top on the LT1 intake which can support even more flow if you need it.

Before the opti, I would take issue with the tach needle. Looks almost cartoonish with that needle whipping all over. Guys with boosted opti Vettes probably forgot they even have a tach needle.

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Old 01-23-2013, 09:04 PM
  #38  
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85-86 L98 230 hp (171 kW) and 330 lb•ft (447 N•m )
87 L98 240 hp (179 kW) and 345 lb•ft (467 N•m )
88-89 L98 245 hp (182 kW) and 345 lb•ft (467 N•m )
90 L98 250 hp (186 kW) and 345 lb•ft (467 N•m )
91 L98 250 hp (186 kW) and 340 lb•ft (460 N•m )

92 LT1 300 hp (220 kW) and 330 lb•ft (447 N•m )
93-96 LT1 300 hp (220 kW) and 340 lb•ft (461 N•m)
Old 01-23-2013, 09:42 PM
  #39  
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Guys with boosted opti Vettes probably forgot they even have a tach needle.
When you get yours going you wont have time to even look at the tach. Youll love it.
Old 01-24-2013, 01:20 AM
  #40  
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By far, the TPI motor is the best looking motor out there. Every time I open the hood, I just love the way it looks.

If I wanted high RPM HP, I'd get one of those platic looking motors.


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