I would like to know what the differences are between the LT1 and the L98. My friend is arguing that they are the same engine. I don't think so. Also what year did the LT1 come out. He says that he has an LT1 in his '89 GTA, but I say no way. Please inform me.

 

Your friend happens to be one of those sad pathetic souls who despite the best intentions of others to correct his misinformation or ignorance is bound to forever be an idiot.
First if your friend has an 89 GTA and is has the curved runners that are found on a TPI, then he has a TPI. It is possible that someone swapped an LT1 into the car before he owned it.
Second, the LT1 and TPI are as different as a dog and a cat. The TPI has the long curved runner set up that generates lots of low end torque but dies above 4500 rpm. The LT1 has the short runner design and looks nothing like the TPI intake. The LT1 breaths much better above 4500 rpm than does the TPI.
Finally, the Z28 and the TransAm got the LT1 in 93 (the Vette got it in 92).

Hope this helps.

 

Also, let me add that the LT-1's have about a point higher compression. And aluminum heads to handle the compression. And a reverse cooling system to handle the heat. And a crank-triggered ignition system called "opti-spark". It was basically the next logical step. But all in all, they arent that different, as the LT-1 design was more or less designed from what they learned with the L98.

------------------
-80 Camaro 350, Carter AFB, headers, dual exh, ram air, all sorts of crap
-88 Iroc-Z 350tpi, 3.27 gears, 4 wheel disc, MSD 6a, tpi airfoil, k+n's, white gauges, accel coil, flowmaster, pretty quick

 

In one way they L98 and LT1 engines are the same, they are both the good old 4.00" x 3.48" 350!!!

------------------
1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission with 2.77:1 Rear End

Current Mods: LT4 Hot Cam, Edelbrock TES 1 5/8" Headers, Hooker 3" Aerochamber Cat-Back System, Performance Resource Chip with 160* Thermostat, Accel Ignition Coil, Cap, Rotor, 8.8mm Wires, K&N Filters, JET TPI Air Foil, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET (w/o LT4 cam): 14.32 @ 97.7mph
(corrected for elevation)

 

Please do not quote me on this, but if I happen to be correct the LT1 added the roller valve train. P.S. Howdy fellow Minnesotan. This weather in MN sucks, my car has been in hibernation (spelling?) to long!

------------------
1987 T.A.
4 bolt 40 over MSD 6al BBK/EDL throttle body Accel coil, wires Compu Cam Roller roc K&N filter Jet custom chip Removed screens and cooling fins on M.A.F. Ported Corvette heads 700r4 shift kit 40+ 4th gear 2300 stall Stock GTA rims with 255/50/16 rear 245/50/16 front Z rated comp ta's

 

The roller valve train was introduced in 1987.

The L98 is dimensionally the same engine, but a few different feature. The reverse flow cooling, cam driven water pump, front mounted optispark, gear driven oil pump. Cams, rods, valvetrain components, and pistons are the same as the 1987 and up L98s and are interchangable. Heads, cranks, and manifolds are not interchangeable. The 95-97 LT1s had a longer dowel pin on the cam for the front components.

The performance potential for the L98 is much greater because of the greater diversity and availability of aftermarket components.

------------------
'92 Z28 Black 5.7L 5 Speed
'95 Competition Yellow Corvette Coupe 6 Speed

 

the l98 is a better motor as a guy with an lt1 found out yesterday. He had the same mods i have with the exeption of the throttle body. we were both spinning off the line and i hokked just a little before him and yanked 3 cars by the middle of 2nd gear. and i kept pulling on him untill about 90 when i shut off. the l98 has a big torque advantage and can make similar power levels. if you have a choice stay with the l98.

------------------
90 iroc l98
last season best corected 13.62 @102
mods
full exhaust, AFPR, pulley, jet stage 1 chip, billet servo, 52mm throttle body and a few other little things.

 

I definitely have to agree with Greg. I have lots of experience with this. Seems most every kid with an LT1 wants to race the old (92) green camaro.

 

I'm gonna add my understanding to this, but I am not sure if I am right or not.

I was lead to believe that the LT1 was the replacement for the L98 because the LT1 is more or less a revision of the L98. Further, I was lead to believe that the LS1 is the replacment F-Body engine, but that it is not a revision of the LT1 or the L98, but that the LS1 is COMPLETLEY different (i.e. different firing order and all).

Don't know how much sense that makes (don't have time to proofread) but that is the way I was lead to understand it.

------------------
1989 IROC-Z
350c.i. TPI
rebuilt 700R4 with shift kit
3'' Monza Pacesetter cat back exhaust (minus the muffler)[SOUNDS OF THIS ON MY WEBPAGE]
new dual cats
3.23 Posi rear
hypertech chip
under drive pulleys
adjustable fuel pressure regulator
K&N Air Filters
Excalibur alarm, keyless entry and remote start
new:
struts, shocks, bearings, distributor, cap, rotor, alternator, battery, regulator
245 ZR16 50 Tires, Rotors and brake pads all the way around

Go to my webpage to find out more about it.
You can also see pictures, and hear sounds as well.
http://go.to/iroc-z

AOL IMer: JRShotliff

 

Even though I have a third gen and love it, the lt1 was a superior advancment. A stock 4th gen with a lt1 V8 will walk all over a third gen tpi v8 car (giving equally talented drivers). I remember when vipers first came out at the track turning 14's and 13's. It wasnt the cars fault, it was the drivers. I could be totally wrong about this but everyone says on this board their 350 tpi camaro is a l98. Isnt this Wrong? Did or did not the l98 only came in the Vette? Isnt your car a B2L?

------------------
87z 383,afr 190's, crane hyd roller(224/230-.509/.528,112 sep),Ported and polished mini ram, 30lb inj, 3.42 gears, strange 12 bolt, tremec 5spd, , 1,3/4" slp headers.

 

First of all, Yes the LS1 is a completely new engine. Its all aluminum, and none of the parts, i think, will interchange with prior small blocks. Also, the L98 is just the engine code for the 350 TPI. It is the same engine as the Vette, but with differences that give it 30-40 more horsepower. I was also wondering, I see all of the engine desription with like 2 bolt mains or 4 bolt main, etc. What is the difference??

 

I was wondering what everyone thinks. I plan to replace my 305 TBI to a either a 350 TPI or an LT1. What engine do you think is superior, or which should I get. I also plan to install a T56 6speed Transmission soon, which might make the LT1 a little more compatible. I'm not sure. Please inform me.

 

AJohnson, if you are interested in a L98, LT1, or LS1 I know a guy here in MN who usually has several of each at reasonable prices. Also combos with a trans. For more info contact me a jzeddies@isd.net For some reason, again don't quote me on this, but I believe the LT1 added roller tip rocker arms that the L98 did not.

------------------
1987 T.A.
4 bolt 40 over MSD 6al BBK/EDL throttle body Accel coil, wires Compu Cam Roller roc K&N filter Jet custom chip Removed screens and cooling fins on M.A.F. Ported Corvette heads 700r4 shift kit 40+ 4th gear 2300 stall Stock GTA rims with 255/50/16 rear 245/50/16 front Z rated comp ta's

 

87Z...a TPI 350 is BOTH. The B2L denotes the iron heads versus the aluminum heads of the Vette. On my RPO codes, I have both L98 and B2L.

 

the LT1 has stamped rockers- NO ROLLER TIPS, only the LT4 had FULL roller rockers. LS1 has a standard tip with a ROLLER TRUNION.

------------------
'92 Z28 Black 5.7L 5 Speed
'95 Competition Yellow Corvette Coupe 6 Speed

 

The '92 & '93 LT1 was batch fire & carried over a computer ~similar~ to the LB9 / L98.

the front of the blocks are different to accomodate a gear driven H2O pump so you can't "make an L98 an LT1"

The intakes aren't interchangable, due to water passages (reverse flow on the LT1) *but* Mike Kurtz of PMAC trannies in TX has LT1 heads on a 406 because you can weld the water passages and rework them - not something I'm interested in doing! -

Glenn hit it head on with the heads on TPI motors. All 305's iron, only Vettes with alum. but I think 85 or 86 might have had iron in vettes.

There is a LOT of wiring involved in a swap. My friend is doing an LT1 into an 87 GM vehicle. He has removed wiring (18lbs worth) for ABS, windshield wipers, and other fun things. The LT1 harnesses are "all in one" and less fun to swap than TPI ones

I am probably going to sell my TPI (complete off an 86 Iroc) that was going on my Monte SS in favour of an LT1 because I will be doing a 350 or bigger and an LT1 is a lot more cost effective than new heads + Mini-Ram + rebuild of my 350 core.

</ramble>