anyone running an LT1?

[72highlander]

see lot's of builds and trucks with ls1's. anyone running an LT1? if so let's see some pics. i've looked and they can be had really reasonable and they had good power and economy as well.

[dmsteele92831]

Why would someome throw an LT1 in our trucks and not an LS1?

[brak]

Originally Posted by dmsteele92831

Why would someome throw an LT1 in our trucks and not an LS1?

because the cost and availability trumps that of the LS series.

Not to mention the ease of installation, due to the similarities in design to the engines that came stock in our trucks

[OLDCHEV4X4]

My LT1 is the 1971 Corvette style....
Complete with 4 bolt, steel crank, double hump heads, and original aluminum intake.

[Southedisto]

School me on older LT1's? What are some indicators?

[Boog]

Doesn't the late model LT1 have a funky front mounted ignition system or something like that?

[brak]

Originally Posted by Boog

Doesn't the late model LT1 have a funky front mounted ignition system or something like that?

You're talking about the "OptiSpark". It's mounted on the timing cover.'

Here's a crappy pic..

[shifty]

Originally Posted by dmsteele92831

Why would someome throw an LT1 in our trucks and not an LS1?

i dunno, a GenIII engine (LS1, LQ9, LQ4, LM7, etc...almost the same engines) costs just as much as, if not less than, the LT1 (GenII engine). the LT1 had some serious design flaws, too. i didn't bother with the LT1, went straight for GenIII. if i had my chance to do it all again, i would have went with an LS2 (GenIV).

installation of the GenII, III and IV engines is damn near the same. they are all SBC's , so don't let anyone fool you. the price difference is roughly the same if you consider mileage. i believe the main difference is, the LT1 is the most outdated EFI (non-TBI) performance engine that GM makes...and there are more aftermarket choices for bolt-on performance parts for the GenIII engines.

just my 2¢. i'm a little biased because i dropped an LS1 into my truck. i shouldn't have spent the extra cash on an LS1, should have gotten an LQ9 or LM7 or something. same general beast, different donor vehicle.

support for GenIII installation is greater, too.

oh yeah - i saw an LS1 and its T56 mate for $400 each in my local craigslist recently, and deals like this pop up all the time around here. THIS is why i say there really is no price difference.

[Billla]

LTs are basically GEN I's with reverse-flow cooling and very expensive distributor and water pumps Parts are starting to get a bit scarce...nothing scary yet but I just ordered a water pump drive and was told they were on back order.

It's a good - but not great - engine, but I'd probably stick with either a GEN I or a GEN III...I expect that the GEN II's will be a short footnote in the SBC history.

[duane67c-10]

you can use an older block with a distributor in the back, you can send the lt1 intake to a machine shop and get the distributor hole cut and the hold down bolt threads tapped, a buddy of mine is doing this for an s10.

[Slammed70]

Well Im gonna interject here and say that LT1s are the biggest pieces of **** to ever fall out of GMs heads.

As mentioned above they do have reverse flow cooling which does help a little, only in the fact that it allows you to run higher compression(10.5:1 factory). The downside is the expensive gear driven water pump, that is F-Body, B-body, and Y-body specific. Theres also a crossever tube on the back of the heads that leak no matter what you do to them.

And the ignition....GMs biggest **** up in my opinion, while its a good design and is accurate where as it uses light and an optical sensor to give you a total of 360 degrees of timing. But, it mounts over the timing cover and is driven off the front of the cam(Thats right, LT1s have a specific hollow camshaft) which means that if your timing cover has the slightest leak its gonna get in the Opti- and ****s things up. Also, it mounts under the water pump...also leaking onto the Opti- which is another problem. And the biggest problems people have with Optis- that only a handful of people know about is cam walk. When you get up in the R's and your cam starts "walking" it puts the bearing and bushing inside the Opti- into a bind and cause severe premature failure. It also uses a thin seal to keep the elements out the dont do **** to help, its supposed to allow it to breath out atomosphere(the green **** the builds up on the terminals) and not let anything else in, which obviously dont work. And you need a special LONG T-4 internal torx socket to change it ($60 bucks from the Snap-on guy)

And the 92(Y-body only)-93 models are air density models, where as 94-97 models are WAY better due to the MAF addition, and late model 95+ are all OBDII which can make some retrofits a pain.

While the engine itself is pretty stout, aluminum heads, forged internals, short runner/large plenum intake provides power EVERYwhere, its makes ~280HP and well over 330ftlbs.

If it was me I would stay as far away from the LT engines as I can. Only because of the ignition.

[centsless]

I have an LT1 in my 95 Impala SS and love it. As slammed said, they do have their issues, but on the police fleet we have here which gets run HARD, we replaced the distributors at around 75K. The tune up on one of these is also difficult, but not impossible. There again, they require a tune up about every 75k on a police unit. We had over 100 ov the Caprices and I never had to touch the coolant crossover pipe, and we are in a severe rust climate. My SS has 130k and it is also fine. I love the power it has to throw you in the back of the seat off the line, and it gets 26 mpg on the highway. I guess my point is that while the LT1 may have some issues, not all of them are bad, and they are a kick but ride!!

[Billla]

Originally Posted by duane67c-10

you can use an older block with a distributor in the back, you can send the lt1 intake to a machine shop and get the distributor hole cut and the hold down bolt threads tapped, a buddy of mine is doing this for an s10.

You can...but this is a pretty serious investment by the time you're done. Not for the timid, and in the end no real benefit vs. using the much-maligned Opti.

[Billla]

Originally Posted by Slammed70

Well Im gonna interject here and say that LT1s are the biggest pieces of **** to ever fall out of GMs heads.

Um, I guess I'll just note that I disagree and move on. I have an LT1 in my 1995 Impala SS with 191,000 hard-driven miles (including autocross and a drag strip or two) with the original opti...and it's a very smooth, powerful engine and had been essentially trouble-free the whole time I've had it.

Never had a leak from the crossover.
Never had a problem with the opti. The '94 optis were somewhat of a problem.

IMHO, lots of folks have been running these engines with great success for a long time. It's a relatively short-run engine, and the LS series is a better engine across the board...but I wouldn't just discard it. I'm building a 383 LT1 right now for my Impala, and I've considered putting the iron LT1 in my '72 with an aftermarket PCM...still thinking

[Slammed70]

Some people have had good luck with them, Ive owned too many LT1s(Including the infamous LT4 in my 95 Camaro) and Ive built too many to keep track of. I personally dont like them.

And the water cross over tube, if you never take them off then they should seal just fine.

[Billla]

Originally Posted by Slammed70

I personally dont like them.

I completely respect that.

The main issue with the tubes is that people try to reuse the bolts and washers - they're basically a single-use bolt (like everything else on a modern engine) and have to be replaced if you expect it to seal. I personally haven't had any problems with the couple that I've replaced.

[Angelse68cal]

I have a 92 LT1 in a chevy silverado ext cab that was bought from street performance .. Do the Illegal street Drags here once in a while and It will walk all over the LS1 LS2's All day Smokes Corvettes except the 427 vette and Grand nationals ..... It also has a build Art car trans So when I get on it feels like your going to space and I look back at some of the young kids and say LOL

[Musclerodz]

I am putting a LT1 in my Blazer because I am no longer putting it in my 68 Camaro. And since the money was already spent, less money to finish the Blazer. With the exception of the ignition issues they are as solid as any other SBC. You could always install the coil pack conversion to the tune of $600. If I was doing it again without the LT1 already in hand, I would not have used it. I like the engine, but it dates a build to me.

Mike

[Ackattack]

When I decided to go with EFI in my 72 GMC I debated between the TPI and LT1. I knocked the LT1 off the list because of the optispark.

Plus the TPI engine is a long runner design that makes more down low torque but give up upper RPM power. The LT1 has relatively short runners and has more top end. I figured the TPI was better for a truck.

[Fastfun]

I have a LT1 that I am going to put in my 72. I purchased the motor 5 years ago when the LS1 were hot and even motors from salvage vehicles were expensive. I think any motor that you put in your vehicles is going to date it, the tuned port was hot,then the LT1, then the LS1--2. There is always going to be the next best thing out there. Just put what you like and can afford and enjoy.

[67shortie]

That engine is really sweet

I will eventually be swapping in an LS based engine when I can afford it and drive the truck daily as a commuter. It will take some time and cash but in the long run better choice than paying on a new truck note for years.

My truck is solid and drives very well, why not I say.

[Slammed70]

Originally Posted by Musclerodz

You could always install the coil pack conversion to the tune of $600

Delteq still uses the optical sensor though to tell their **** when it needs to fire, all it does is cost money in my opinion. Because it basically just replaces the cap with more stuff to go wrong....it still uses all the **** in the Opti-

Best thing anyone could do for the GEN IIs is to drill/mill the intake for an HEI dist.

[Slammed70]

Originally Posted by Slammed70

Best thing anyone could do for the GEN IIs is to drill/mill the intake for an HEI dist.

Wait no....because then the injectors wouldnt fire if your not using the optical sensor then.

Ok, ok, best thing to do is chock this up as one of GMs mistakes and just stuff a blown 572 into everything.

[Billla]

Slammed70, I think it's just time to accept you're a dyed in the wool GEN I fan All the stuff you've "slammed" is why the LS is such a great engine '-)