Hey guys,

My friend is giving me a 35,000 mile, LT1 engine, but it's the 4.3 version of the motor. It comes with the ENTIRE wiring harness, accessories, intake, air cleaner, everything... and even comes with an 4L80E transmission.

I'd love to get an ~82-92 Camaro or Firebird to drop this in. I'm not expecting insane amounts of power by any means, but I wanted to know if it would be worth it.

I believe the lower displacement LT1 puts out 200hp and 245lbs of torque, is that correct?

I realize also with the 4L80E automatic transmission, it should be a bit more efficient than the 700R4 (not that there is anything wrong with the 700R4). What I would like to see, is a 3rd gen that runs high 14s, and gets 18 in the city, and 25+ on the highway. Something I can beat the **** out of, and still have fun in.

I just want to know if it's going to be worth it. I had an 82 TransAm MANY years ago... and I miss the third gen body style, but I'm wondering if this motor will meet my expectations. Since it originally went in a Caprice, I figure it should do well in a 3rd gen.

I'd like to hear from anyone who has bothered with the 4.3...

I'm getting it for free, and that's why I'm thinking about platforms to put it in.


Thanks!!!

 

Its not a bad motor, it'd probably be about on-par with the best of the 305 engines the 3rdgens came with performace wise, and would probably get better mileage to boot. Would also be an easy upgrade to the larger 5.7 LT1 in the future if all the groundwork is already done with the 4.3.

The LT1 came with the 4L60E transmission though, not the 4L80E... the 4L60E is a computer controlled version of the 700R4. The 4L80E is a whole different animal which is loosely based on the TH400. Very strong transmission, but its not as efficient as the 4L60E because its a BIG heavy transmission and sucks up alot of power to turn it. It also requires its own separate computer control system. The 4L60E is more than adequate to use behind the 4.3 though, and they worked fine behind the 5.7 LT1 and LS1 for many years as well.

 

Thanks Air Adam,


Since I'm assuming the amount of work required was similar if not identical to what you've already gone through, can you tell me... how much work was it? Pulling a motor out, especially in a longitudinally mounted car is ridiculously easy, but... did you have to do any customizing? You say that the 4L60E is similar to the 700R4, does that mean that I would be able to utilize the existing driveshaft?

What all did you need to replace? I assume of course that everything in the engine compartment gets replaced. How about the gauges? Since this motor is still OBD-1, I assume the feed that comes out of the computer is still more or less analog. For your gauges, did you have to do a lot of crazy stuff, or was it mostly just plug and play? IE: wired up the speedometer with the correct wires, and then Temp, Fuel Gauge, Voltage, etc... are all independant, correct?


Thanks!!!

 

Don't do it, unless you are getting the entire package for under $500. The 5.3L LSx based engines are going for a steal right now and they make the same as an LT1 with more potential as a bolt-on engine because of the heads.

LT1's should be dirt cheap anyways, the L99 would be a worse choice than an L98.

As far as 4L60E vs 4L80E the 4l80 is just a stronger transmission, not nessesarily more efficient. Has a higher rated limit.

And if you don't even own a thirdgen right now just save the pennies and find a good running L98 car. About the only time the L99 is going to give you a performance boost is if you have a V6 car, or a TBI equipped thirdgen. Any TPI thirdgen should meet or beat a L99 powered thirdgen. Its a sideways move, no gain in power.

 

I would agree with most of this but would go on to say that an lt1 swap to begin with just isn't the greatest idea in a 3rd gen. Now, I am not saying that because you did it, however, I don't see the point in swapping in essentially the same engine that is already in some of these cars. After you swap the top end they really can make about the same power. Stock for stock my L98 ran dead even or beat every LT1 I raced as well.

Maybe its the price of the complete engine and tranny that makes it a better deal. I am not sure but the last time I looked a good condition LT1 and tranny was going for around a grand; maybe the prices have dropped way off since then.

 

Yeah... I know... i know...

The thing is, I'm getting this 4.3 motor for free, with transmission, wiring harness, everything. I realize it's not a power house, but it's only got $35k miles on it. I used to have a 1982 Pontiac TransAm, and I loved that car, it was a blast. I'd love to have that car back, but have modern reliability and performance (so to speak). Mine was the LG4 with the computer controlled QuadraJet. Normally not a bad carb, but I'm looking for a bit more response. 200hp / 245ft-lbs would be equivelant to say, a modded 84 HO, I believe. Since didn't they come with 180hp? The torque is the same, but the engine would be more responsive, I would probably get pretty decent fuel economy, and still really enjoy the car.

I do have pretty much everything, but I'm missing some of the accessories. (A/C compressor, bracket for the alternator, etc).


I'd really like to get an 82 TransAm again. I veered off and I had a 76 Camaro for some time, and then recently sold my 81 TransAm.

In terms of performance, I've got a 73 Oldsmobile Cutlass Supreme right now with a 69 Olds 455 big block ~400hp, and 500+ foot pounds of torque. So I'm not looking for earth shattering performance... just thinking about having something that would be fairly fun to drive, be relatively quick (looking for low 15s), get decent fuel economy (expecting 25 on the highway?) and be reliable.

Basically, I'm looking for something to drop my 35k mile 4.3 L99 into... unless you have some better ideas?



Thanks!
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Free is a good price... and that's what I'm getting it for. Of course, this is the L99, not the full blown LT1. But it's basically the same motor, just a smaller bore version of it.


I'm assuming that the hardest part of the job is the wiring, right? Because pulling and dropping a motor is easy when nothing needs to be customized and everything just "bolts up" like I assume it will?

 

although this motor does not have the raw power of its big brother atleast you can get it all in your car run it for a while then build from there...
if it's free it's for me!!!!!!!!!

 

When I bought my LT1 swap, LSx based swaps were still in the 4 to 5k range for the drivetrain alone, very uncommon and expensive.

Now, certainly, I'd never go LT1 now unless I got a stunning deal on it. LSx based swaps are the way to go for a street car that has to do it all, and get economy. I am unwilling to sacrifice fuel economy for performance with todays market on gas. Sure, its cheaper now than it was, alot cheaper.

 

Since your getting the motor for free... I say go for it. I had a blast swapping mine out. Learned a whole lot of stuff in the process too. As far as the wiring goes all you have to do is label the wires for your gauges and then match them to the ones in the l99 harness. Try www.lt1swap.com for more info on the wiring. You will have to buy or make your own fuel lines. If you can get the power steering lines with the motor you can reuse them. Just have to bend them a little. Your going to want at least a tpi fuel pump for the tank.

 

Makes sense. Please don't think I brought that up because of your swap though.

 

I have doubts if it could match a 305 TPI---its missing 30-55lbs-ft of torque. (HP of 305 TPI varies alot depending on trans and year--so your ahead 10 or tying it or down as much as 30hp)

I wonder if you could stroke it to a 305? That would make up and beat the torque difference.

 

You know, I always assumed the TPI motors were pigs, just like all the other MPFI and SFI motors from the 80s. But 215hp and 275lbs of torque really isn't THAT bad considering the time... 9.5:1 compression is pretty impressive actually.

Almost every third gen I have ever raced in any of the cars I've owned has always been a total dog, but I'm guessing that 95% of the people that bought these cars with V8s got the LG4s. You can make them powerful, but from the factory, man... low 16s is lucky.

I would figure that the LT1 motor (the 200hp version) and the 305 TPI motor are probably pretty similar in performance. There is a noticeable lack of torque, but I've always felt that these motors were designed to produce big power down low and in the mid-rpms... but lack somewhat in the upper rpms... at least in stock form due to the way the intakes are designed.

I'd bet a TPI would walk away from an LT1 (200hp version) up till about 30, and then the LT1 might keep up with the TPI after that.

Doesn't seem like such a worthwhile swap for the lower L99 version now... heh...

 

Actually it is very funny you should mention this, I did just that in a Caprice. It is very easy and my block did not even require any clearancing. The L99 has the same 3.736 bore as the 305, in fact it even uses the same 305 pistons. The difference is the crankshaft and connecting rods. The 3" crank in the L99 can be tossed for a 3.48" 305 crankshaft. The 5.94" rods that came in the L99 can be tossed for 5.7" rods from a 305/350. I did it really cheap to replace the 4.3 crank with a wipped rod bearing surface (spun bearing). I put in a production LT4 cam and the car, 5,000 lbs B-car with shorty headers and 9C1 dual exhaust ran 15.3s @ 94 mph in the 1/4.

 

or if you want you could use the l99 crank an rods in a 350 block an make a chev 302

 

I heard you have to notch the frame in front of the right motor mount or the a/c compressor won't clear. If it's free I'd jump on it though. You may have trouble if the caprice had pass key theft system getting it to bypass.