pdx-vette

The L98 is Tuned-Port Fuel Injection & the LT1 is Sequential-Port Fuel Injection, so which is the better system for long term reliability & maintenance?

DrDyno

PDX, you need a bit more input before you're going to get any meaningful answers. For instance, what's your definition of "long term?" Are you asking because you want C4 buying advice or are you planning to upgrade an existing car? If it's the latter, are you going to rebuild an existing engine or use "as is?" If as is, what's the current mileage on each? ...see what I mean?

Relative to your second paragraph, "stimulating" is a subjective term. Are you looking for acceleration or top end stimulation? With either, your choice of transmission and rear end gearing are almost as important as your choice of engine. Let the Collective know exactly what your intentions are and you'll get some good answers.

ps- I just noticed you edited out your second paragraph. I'll leave it in my answer.

pdx-vette

I removed the question because I presented it incorrectly. I meant to ask if the L98 torque or the LT1 HP make for the more stimulating driving experience?
I'm referring to weekend trips to the coast or mountains.

I was reading the following old thread:

https://www.corvetteforum.com/forums...98-vs-lt1.html

I realize the general rule is to purchase the newest year that finances will allow, because of the lower age & better performance, but this doesn't answer the question of the better quality motor.

Hypothetically, if there were L98 & LT1 engines from about the same year, with the same amount of miles & maintained in the same manner, which would probably have better overall reliability & lower maintenance costs?
I'm aware of the manifold issue with the L98 & Opti-Spark issue with the LT1.

I'm simply curious about stock vehicles & engines.

rocco16

Both would be equally reliable.
Maintenance costs would be comparable, with the nod going to the L98, possibly.
Performance; nod goes to LT1. To me, that the "stimulating" part......

aDigitalPhantom

I say LT1, but remember not all LT1s are sequential.

MavsAK

Every LT1 car I've driven isn't quite as responsive as my L98. It's not so much the peak torque (at 350 cubes anyway... stroker, or 400 cubes+ on the other hand....THAT is where you start seeing the difference in runner design), but the throttle response.
The L98 is also more healthy below peak torque than the LT1.
L98 cars are also lighter typically.
And you can always put a mini ram on the SBC later if you want the all out flow of the LTX intake, and you'd still have the Gen 1 Distributor.

The LT1 ....has opti. Which can be a pain in finding a reliable replacement unit when it goes. (and it probably will if your water pump takes a dump.) Cost wise... I think the L98 is a little cheaper, but not by much.

Neither car is exactly shop friendly though. Ask any L98 guy who's ever been pressed for time or has too many other projects in the way to get the car in the garage that weekend when something goes wrong how many shops have taken one look at that intake and went glassy eyed and fearful.

LT1 guys, can have the same pretty easily with the opti, and waterpump. So it's just a matter of which part of the car is going to make them go glass eyed

I'd say the L98, is likely slightly more reliable in the end. Mostly due to the opti and waterpump situation on the LT1. I just can't have that kind of faith that the wp is never ever going to fail and dump on the dizzy.

pologreen1

Which do you own? You have been here 2 years and never seen or heard this stuff?

I'll bite. Neither, they both suck. Stop lurking and get a C4 and build it, or go get a C5 + if you don't have one already. OR get a mustang if deciding between LT1 and L98 is too confusing.

pdx-vette

Therein lies the conundrum.

I think that I read a reference to that somewhere. I'll continue to research it.

You've provided a great comparison. Thank you.

Tom400CFI

LT1 makes more tq from idle to ~2400 RPM. TPI makes more tq from ~2400- ~3500, although the peak difference is less then 20 lbs. Then the LT1 makes more tq from about 3500 on up. Both make about the same peak tq (albeit at different RPM's).

Both are reliable. Reliability has nothing to do w/sequential vs batch fire, and some LT1's ((up to '93) are batch fire -same as the L98.

So which is "better"? They're both fun in their own way, and they both have plenty of tq and throttle response (instant, in both cases). The LT1, however, has way more hp, 1000 more useful RPM and as a result, will handily out perform the L98 in most situations.

If you're trying to decide what to buy, what you really need to do is drive both and then decide what strikes your fancy.

JD Shredds

I'd say your question was answered pretty efficiently by the above responses. Both have known flaws, but both are pretty reliable engines. As for driving experience, the gearing/rear ratio is going to have a big impact on that, not to mention the suspension package as far as ride and handling variations, if that matters to you.

I will say I'm only a month into owning my '94 (which I still think was maintained very well) and I already may be looking at a failing water pump (which was replaced along with opti once before). However, outside of that pain in the neck design flaw, its generally going to be a solid and reliable engine when maintained.

Digidash

So as a L98 owner, I am interested in knowing what kind of hp I can get out of the motor with the TPI set up. I previously had an LT1 '94 and feel that was pretty quick. I would be keen I getting the '87 into the 13's if it is not too much work.

crowz

The key part to me comes into 2 areas. One autocross and two trust.

The first is universal and the 2nd is personal opinion.

I own both. Ive had 3 l98's (one was actually a 1980 4 bolt main motor out of a suburban (still have that motor now with about 600k miles on it btw ) and the other two being the 86 coupe I had and the 87 convertible I have now.

I have 1 lt1 which is a 97 formula firebird with a 6 speed manual.

The l98 is simple. I mean brick dumb old school simple to me. But that's because I spent 2 years of hell trying to diagnose a problem with it when I converted my 85 trans am to tpi. Turned out when I was doing the tpi a friend of mine helped me out by putting the double roller timing chain gear on. It had an adjustable timing gear and he set it wrong. But that horror story caused me to learn the tpi system like the back of my hand trying to run down an non existent problem with the tpi. So I trust it. I know it.

The lt1 is a pain to work on in that firebird I have. Partly because of the opticrap partly because that engine compartment is sized for a 6 cyl or smaller in my opinion. Its a picky motor that the least thing off causes major headaches and the cooling system is a royal pain to bleed right.

Anyways to me (which I explained what Ive been thru to better weight my opinion as it may not apply to others) the l98 is a much easier to maintain motor. Its just... simple.

As for autocrossing. If the track has been laid out with long straight aways the lt1 does great. But if the track is a low speed bruiser the l98 dominates. Not just from my experience with my cars but from the times others have turned it with identical cars and driver swapping between them. The lt1 just doesn't do as well. I don't know the exact numbers for x hp at x rpm and x torque at x rpm to compare them. Im going by real world experience.

But in a drag race of 1/8 and 1/4 my lt1 will rape my older l98s. Also top end on teh lt1 is a blast too.

I haven't timed my 87 convertible yet and since its a 383 stroker its not really a fair comparison.

To me the l98 feels more at home down low and the lt1 feels more at home up top rpm wise.

So that's a bit of fact and a bunch of opinion

crowz

My 86 coupe with 4+3 manual ran 13's all day long stock. Supercharged it hit low 12's right off the bat. High 11's in the end.

pdx-vette

It's valued fact & opinion. Thank you!

JD Shredds

What rear end ratio is your car equipped with? If its the 4+3, its 3.07, but if its an auto, standard rear axle was a lower ratio (I think either 2.59 or 2.73). Makes a difference in acceleration. And since you're comparing to a '94 LT1, was that manual or auto? Any idea on which gears that had?

Yeah, as crowz said... a stock L98 is capable of getting below 14. But gearing is a big part of the equation.

Bandit's C4

The subject is on over 20 to 30 year old technology.

The specimens you find today ultimately fall under one of two catagories... a well maintained and preserved powerplant versus a well-used and worn engine destined for a rebuild/junkyard. Which of those two do you have in mind that will ultimately hit your financial resources?

Besides... a 3.07 gear behind a LT1 is far from a slouch.

pdx-vette

You present a good point. About how many miles, if well maintained, should these engines go before needing a rebuild?

crowz

Miles = condition isn't something we can answer really.

A motor maintained badly will be toast at 100k miles possibly where as a well maintained motor could be within 5 hp of where it was new at 300k miles.

Hard to really say. A compression test and a few hard passes from launch are better than fixed mileage guestimates.

Digidash

Both cars are/were 6 speeds. I Don't know what the '94 had in the rear but my '89 has 3.31. I did a 13.9 at 103 with the '94 spinning the tires through first. Since I had no helmet that was the last pass they let me run. My current car really lays down at 4k rpm. It has a leak at the front driver cat. I think the main cat may be clogged ( original exhaust 92k miles). Healthy this car should be low 14's. Right now it feels like a 15 second car. I just got the car and I can tell it has old plugs and a dirty air filter. Needs a tune up. Tires are new Nexens. Clutch is good. I'm looking to wake this motor up and break into the 13's.

Tom400CFI

Either motor should go right on by 200k EASY and probably right on past 300k if well maintained. They're both SBC's. I've had qutie a few cruise past 200k running like new, and I currently have 265k on my '96 Silverado (which does heavy pulling in the rocky mountains) and it also, runs like new, or better.