To Lt Or To Ls? Grumpyvette Please Chime In On This One!!

[OMONLA]

I'm in the market for another Z and this time i just have to go the V8 route. Question is which would cost me less in the long run? there is very little id be doing myself but the main swap would have to be done profesionally("paid for) so i'd need to gather all the right parts to get her done then i'd slowly build on her from there.

I'd be looking for around 400rwhp, of course with mods ...and to be honest with my leadfoot, that may very well get me into gobs of trouble.

 

So all this being said which would be cheaper/more "readily available"

and still net me that type power?...and LT1 or an LS1?

 

with the LT1 which year has the better motor and in what Gm vehicle do i source it from?

Same question as above for the LS-1

 

I would appreciate any and all tips

[Mycarispurty]

I prefer LT1s, but then I'm biased since I had one in a Trans Am. The F-body is the place to get an LT1. Other cars like Buick Roadmasters, Caprices, things like that had them, but had iron heads. The f-body ones had the aluminum heads. 93-94 had a flaw kinda in the Opti Spark dizzy's design, go with a 95+ with the vented style if you can. The Vette LT1 blocks should have 4 bolt main caps while the rest were 2 bolt. It's easy to find a place near or in any major city that parts out 4th gen F-bodys. You can usually get a good running, semi low mile LT1 from a wrecked Camaro or whatever with the PCM and wiring for around $700-800. Plus the benefit is all the old trannys bolt up to them. If you have a TH350 laying around from a 70s truck, it'll bolt right up.

[OMONLA]

And in terms of power will i see the numbers im hoping for?

[Filmjay]

I'd look for an LS1. The intake runner design of the LS flows far more efficiently than the LT1. A stock Gen3 LS1 (97-01 Corvette) was rated between 345-382hp...depending on application.

The Gen4 LT1's (93-02 Camaro) were only rated for 275-285hp

 

The sweet spot for LS1's were the 01 Vette. The '01 LS1 got the intake from the new LS6, got a slight bump in HP (+5hp), and had a new cam that allowed GM to remove the EGR system from the motor.

 

Another option could be a 4.4L Northstar (LC3) and supercharger unit from an 06+ Caddy STS-V and XLR-V. IF you can find one of these Caddy's junked, you'd be looking at a rated 469hp. About 320hp from the non-supecharged versions.

I don't see many(any) in Z-cars, and (depending on your metal working/fabrication ability) it's only a matter of moving the lower-right bolt hole up about an inch on a 700R4 or stick shift bellhousing from an S10 truck and a custom flywheel available from www.chrfab.com.

[mark]

I've got one of each. A 383 lt-1 in a 73 Z and a stock ls 1 in a 72 Z. The 383 has 420 hp at the wheels, the ls1 is about 325 at the wheels in stock form. Several guys on here have gotten over 400 hp at the wheels with only a cam and valve spring change (I think).

 

For bang for your buck, especially with some one else doing the work, I think the ls1 is the way to go. There is a bigger market for the ls1 stuff and as already mentioned with the lt-1 you will probabaly have some issues with the optispark.

 

Either motor has the potential to get the power you are looking for. Both have proven installation kits.

 

The ls1 motor does have an alunminum block that will save you some weight. I think the weight difference between the blocks is about 80 lbs.

 

Good luck with your project.

[grumpyvette]

If your starting with nothing, Id suggest finding and using an LS1 corvette wreck as the base car you salvage from.

BOTH ENGINES CAN REACH YOUR GOAL,but what youll have once its complete is differant.

While its true the ls1 engines cost more and are more difficult to locate and match up to a conventional trans lay out in the early (Z) and motor mounts oil pans etc cost more, the 400 rear wheel hp part and lighter weight make it a better but probably more expensive choice here.

getting 400 rear wheel hp from an lt1 is more difficult than from a ls1 in decent condition.

Yes I think the cost differance favors the LT1 but if your serious about the 400 rwhp (thats close to 500 flwhp) and a lighter weight engine, I think the LS1 has the slight advantage

 

theres pictures in this thread, of an LT1

 

http://forums.hybridz.org/showthread.php?t=140805

[OMONLA]

so i think i have all the info i need then...off to the junkyard!

[DavyZ]

Let us know what you find at the junk yard. I think an automotive engine recycler would be better, no?

 

Davy

[rejracer]

I have a 94 impala SS which came from the factory with an LT1. They are potent motors and mods are available. However GM only produced these motors for 7 years. They have some weak spots, such as water pumps are prone to failure, the Optispark does not like to rev much past 6k or the rotor tends to fail. The factory PCM cannot rev past 7200. The factory iron manifolds crack (I assume you would be going with headers).

 

If you get a LT1 make sure the optispark is vented, and that the car comes out of a Vette Y-body or camaro or F-Body to get the aluminium heads. Try to avoid the 97 aluminum castings. Although they do flow better than the original castings they are thin and lack enough material in them to be ported.

 

My suggestion based on the aftermarket support of the LT1 versus LS1, LS1 is the clear winner. Aluminum blocks, heads, your choice of stroke from factory cranks, better rods, better heads, coil on plug ignition, composite intakes. It's just a better upgrade path in my opinion.

 

The initial investment may be slightly higher, but the long term cost I believe would be lower as there is much larger supply of used parts on the market.

 

Hope that helps