LT1, LT4, Forgotten???

[2Loose]

I never see very much posted by anyone building up an LTx motor. Are they the "forgotten" souls of the sbc world now that the LS motors are all the rage? I've seen some that make pretty impressive hp and still get pretty good mileage, that's what I am hoping to achieve. Still, it seems that there are a lot of them around in the parts yards getting passed over. I pulled mine with a T56 out of a wrecked '93 Z28, with the wiring harness and computer, and nobody else was much interested in it.
Willy

[Goatman]

No even close to what a LS-x can do power, durability, or mileage wise.


I know where there's an complete LT1 Camaro hit in the rear, but running, for $1400 and no one wants it....

[WS6]

The LTs are great motors. However, the Gen3/4 is a better motor. Most people want the best they can get because they want a lot of power and all this new fangled stuff. If you've got an LT and you're not looking for huge power or anything exotic. Run it and be proud. They are great motors and can perform very well.

[Samckitt]

I haven't forgotten about them. And "hopefully" will be running mine soon. Too much to do around the house & not enough time to do it.

[bigvegan]

The LTs are fine engines, it's just that they're too "electronicky" for the old school hot rodders wanting easy big power (e.g. carbs), but not sufficiently modern for the guy who wants the latest and greatest tech under the hood. The fact that the LSXs have an aluminum block and don't have the Optispark is another factor.

Plus, at this point the last LT engine is about 10 years old, which means a lot of them are at the end of their initial lifecycle, and a lot of people would rather start with an aluminum block before spending lots of time and money doing a rebuild, which is why I think the LTs are somewhat out of favor.

There are a fair number of threads on the LT engines at the 4th gen Camaro websites, so they do still have their fans.

That's a KILLER '55 by the way. Nice work!

[GeoffP]

LT1's are great IMHO. I currently have two of them, one in my 87 Z28 (from a 95 Z28) and one in my 68 (from a 93 Z28) that I just installed this past year. I'm really happy with both other than the problems I've had with the OptiSpark on the engine in my 68. I wish GM would've done something different for the ignition system - the early opti's suck and the later ones aren't all that much better (even though they are a lot cheaper to replace when it goes out).

GeoffP
68 Camaro LT1/T-56
87 Camaro LT1/4L60E

Edit - forgot signature

[Lowend]

I've been in on several serious LT1/LT4 builds and owned a '95 Firebird with an LT1 - great engine.
But here is the thing. The LT1 is basically a traditional small block; with fuel injection, a reverse flow cooling system (that doesn't seem to make and difference) and a crappy ignition system.
... ok so I'm oversimplifiing a little, but still there is really no reason to build up an LT1 vs say a Gen 1 small block with an Accel DFI.

The LSxx is a whole 'nother ballgame

[2Loose]

There's a long story behind how I ended up with the '93 LT1 + T56 and wire harness, but basically I only had to put in labor to pull it, didn't cost me a dime. I figured it's a block, rotating assembly aluminum heads, and an EFI fuel injection system. Couldn't for the life of me figur out why the LS motors were getting such good "press".....
My costs are for the stroker setup, the ported heads, (it was cheaper for me to go buy the ported Lloyd Elliot heads than to send over my stock ones from Hawaii), and port the intake to match the heads and the new throttle body. Now that I almost have it together, and need to burn a custom ship, I want to see if the problems of trying to adapt a LS setup for the same amount of money to make 520 broad based hp could even be done. I doubt it, as I had the building blocks already here, and to switch over to the LS based system involved a whole buncha bucks more every time I looked at it. So will report back once it is running and I get a rw dyno report on what I actually have. And how it drives. The motor don't really care if the block is aluminum. The Optispark can be used to signal individual coils. A lot can be done if you already have an LT motor and tranny vs looking from scratch at "which way should I go". The cost of trying to adapt my LT based T56 to an LS motor looked overwhelming to me, so I chose to pass on that. Almost spent the buck to go that route though, came awfuldamnclose. But in the end stuck with the LT, so lets see if the ported heads, modified intake, upgraded injectors, and TB, and custom chip, can actually pull it off.

Good test of the "what ifs"....
Willy

[Lawrence]

There's a cammed one in my '68 Camaro daily, and a forged and procharged one in my '55 Bel Air. It's harder to find parts and info for them, but it's all out there if you look hard enough.

[MonzaRacer]

The big trick is if someone has a lot of cash to blow the more bling factor the better so the LSx engines get the nod.
I 'll stick with my L98/first and second gen SBC engines.
I have called everyone for LSx engines, been told they are so cheap and in such supply yada yada.
so I am going to dare to be different and build a forged rotating assembly 283.
I have all the bearings still std, got 6 forged pistons for free so I gotta buy 2 and some moly rings.
got the engine for free, less one rod ,steel crank and all.
My choice is either use a set of 185 casting 307 heads (same bore as 283 just mill to raise the compression a few steps) that have 184/160 valves swirl polished.
OR the double humps I have swapped for, 202/160 ,may have to clearance the cyl a little but since its gonna be 040 over it should be good to go and its a 61 block so its super thick, hard to break. I have even been offered a set of splayed caps for a small journal block for cheap.
My fun part is that retrofit roller lifters as I want to use a LT 4 HOT roller cam are $500. so I may not run that one.
I figure an all forged rotating assemby 283 040 ought to be able to rip 8500 no problemand make decent power for small engine.
As for LSx engines if I could source good cores it wouldnt be bad but the cheapest running engine I found was $1400 nad still need expensive intake and MSD LSx ign so add another $1000 and then parts to bolt them into and specail headers in the $500 range ,more for my Monza.
Heck for $1000 I can build a sweet 355 even and have it ready to run pretty much.
I will not denigrate the LSx but for some its out of our range right now.
I got a LT4 hot cammed 355 in my truck with SR Torquer heads w/202/160 valves and its a stump puller. Pulls my car trailer and still has 2.73 gears!.
But the air ride on my old rusty truck gets a lot of people too hehe. And I drive it 35 to 45 miles a day 5 to 6 days a week since I built the truck in 02 and sat the fresh 355 in in July of 05 and still driving.
LSx ,keep them till I can buy one in good shape for $500 bucks and have it run for $500 or less,,,,, never happen I dont think.
But good luck to all.
Lee

[TT402LS1]

Whats a LT1, LT4? Oh! LOL!!!

Ron

[lt1chevelle]

i didnt for get about them i have one for my 65 chevelle it makes good power when you get the heads all tricked out and put a nice size cam in it mines suppose to make 420 to the wheels. some ppl just can afford the ls1 and put twin t on them like some ppl ^

[TT402LS1]

Ron

[lt1chevelle]

Ron

[MuscleRodz]

Not forgotten, but considered dated next to a LSx. I built a LT-1 for my '68 Camaro several year back. Camaro is still not done and LSx's are now affordable and still mainstream. I will still be installing the LT-1, too much money in it to sell, but it has been handed down to my '69 K5 Blazer.

Mike

[camaro608]

hell no i just bought one over an LS1

[v7guy]

i've got a couple of them, the distributor is a pain but you can get around that.

I might have an LSx motor if they were cheaper (that whole dropping sleeves thing the first couple of years scared me too). Now I just have too much extra stuff for the LT1/4 motors to justify tossing it all. Plus modding an LT motor is alot cheaper than an LS one.

[got_hp?]

The LT1 is basically a traditional small block; with fuel injection, a reverse flow cooling system (that doesn't seem to make and difference) and a crappy ignition system.
... ok so I'm oversimplifiing a little, but still there is really no reason to build up an LT1 vs say a Gen 1 small block with an Accel DFI.

you didnt really oversimplify, you pretty much nailed it.

crappy ignition thats not used on any other engine = expensive and pita to work with, and also inferior to other styles

mediocre reverse flow heads = head upgrades are expensive and still get out performed by similar costing SBC or LSX, heads, (sbc heads can be converted to be used, but the cost outweighs its worth, might as well just build sbc)

poor flowing intake without a decent cost replacement to upgrade to.



with whats available these days between SBC-EFI and LSX stuff, i dont see any reason to build one.
(coming from a guy who built one 2 yrs ago and didnt know any better at the time)

[Samckitt]

If you were building a small block Chevy with port fuel injection, what intake would you use? My guess is a single plane intake with port injection, & a 1000 cfm throttle body? Maybe with aluminum fast burn vortec heads. I know there are better, like AFR, but aren't they expensive? Is there anything that works good other than a carb style intake. to me the carb style injected intakes still look like it has a carb when you raise the hood.

[WS6]

you didnt really oversimplify, you pretty much nailed it.

crappy ignition thats not used on any other engine = expensive and pita to work with, and also inferior to other styles

mediocre reverse flow heads = head upgrades are expensive and still get out performed by similar costing SBC or LSX, heads, (sbc heads can be converted to be used, but the cost outweighs its worth, might as well just build sbc)

poor flowing intake without a decent cost replacement to upgrade to.



with whats available these days between SBC-EFI and LSX stuff, i dont see any reason to build one.
(coming from a guy who built one 2 yrs ago and didnt know any better at the time)

What you have to consider is that even with all these limiting factors, and you're absolutely right about them, these engine correctly built still make 500hp with nothing more than heads, cam, and a hydraulic roller. It won't break the bank to make that type of power either.

That's pretty awsome considering aftermarket support is virtually nonexistent. It's also a heck of a lot of power for a street car. It's potentially to ones own detriment that they blow off an LT as just being some old forgotten motor.