LT1 help

[nickr5208]

hey guys
im planning on swapping my slug 2.2 out for an LT1. im just looking for some info on the motor itself, and different options that i have to chose from. im pretty sure the common trans is a 460le.

also besides the common juckyard/ebay or finding a wrecked camaro which are all options im aware of, what are my other possibilities for getting one with low mileage, with a trans, and computer?

[Dimemaster]

Goodwrench, if you have the money.

[screamn91]

fbodyjunk.com

[Rob]

If you get a hold of a used engine and plan on working if over, I would suggest getting the LT4 conversion kit that form GMPP. It runs for about $2400 or something. Includes cam, rockers, heads, intake manifold, and gaskets. I've heard this is good for at least 400 hp. Here is a link.

[colin]

Rob,
You are incorrect. The LT4 was rated 330hp, nowhere near 400hp. I think you are confusing that motor with the ZR1 which was rated 400hp.

nick,
If you are wanting to swap in an LT1 that's a great idea. It is an awesome motor, makes gobs of power, and will perform very well in your truck.

I am currently putting an LT1/T56 into a '72 Chevrolet Vega. The swap is very straightforward in my car, but not so easy in your truck. I believe that the swap parts are available. You can get headers for a good price nowadays.

I would definitely recommend getting the V8 swap book from http://www.JagsThatRun.com I have the book and it's invaluable.

Also, you will need to check up on the fuel pump output between the 4.3L and the LT1. I'm not sure about that.

The wiring is easy. Since the PCM is under the hood you really only need a key-referenced 12v input to the PCM, and a 12v lead from the battery to power the PCM. It's pretty much standalone, although you will need to check up on how to get your gauges working correctly (I'm not sure how to do that, as I am going to be running Autometers through my whole car and only need the reference lead from the PCM for that).

The only year of LT1 without a 4L60E was 1993, with that engine being a Speed-Density-based motor. It is also batch-fired, like Tuned Port Injection. The harness on this engine is much simpler to work with! I am putting one of these into my car.

There are three variants of the LT1 after 1993. The first two are aluminum-headed and the only difference is the optispark drive and the front cover. Earlier engines have the optispark driven off of a small driveshaft that's keyed into the cam gear. Later versions (95+) had a vented optispark that's driven off of a pin on the end of the cam. The later version is more desirable as camshaft choices are more widely available, although there are workarounds to allow the use of any cam in an earlier LT1. I considered this very closely when choosing my motor, and decided that I would go with an earlier engine for simplicity (no routing of an intake, just a K&N cone filter on the throttle body). The workaround on the older LT1 is to use an electric water pump (like a Meziere) and not use the water pump drive that's located above the camshaft gear.

The third type of LT1 came in the ImpalaSS or 9C1 (police version). These engines all were cast-iron head engines and were rated at 260hp. I have talked to owners on NAISSO.net and they say they can match an LT1-based F-Body off the line because the camshaft profile is setup for torque not horsepower. I also have one of these engines (a '95 version) and it is SFI and MAF-based.

So, to sum it up, you can definitely do the swap but do your homework.

If I were you I would choose any LT1 that I could get my hands on. Expect to pay around $1000 for a motor/trans combination. I paid $1000 for my ImpalaSS motor alone (shipped from New York or something) and $700 for my '93 LT1 motor. Mind you, that was a few years ago.

If you have any questions at all, feel free to message me on AIM. My handle is BOpseth.

Later,
Colin

[Rob]

Originally Posted by colin

Rob,
You are incorrect. The LT4 was rated 330hp, nowhere near 400hp. I think you are confusing that motor with the ZR1 which was rated 400hp.

I apologize if I was incorrect, I was going by what the info in Summit said explaining the kit.

[colin]

I forgot a few things:

There are actually 4 LT1 styles. The 4th is a 4.3L version that came in some Caprices. These look exactly the same as the 5.7L variant. Make sure you look at the bellhousing on the driverside to see what the displacement is.

Secondly,
A set of AFR heads with a good cam will lay down a lot more power to the wheels than an LT4 car. An LT4 engine is mostly bling: taller ports in the intake and heads (negated with a quality aftermarket cylinder head and some port-matching to the intake), roller rockers, different cam, and a red-colored intake manifold.

Interestly, the LT4 engine has an almost identical power/torque curve to the LS1.

Later,
Colin

[colin]

Originally Posted by Rob

I apologize if I was incorrect, I was going by what the info in Summit said explaining the kit.

My guess is they are rating crank horsepower. Gross, not net.

[Rob]

Not sure.

[colin]

Well, I checked. And Summit says a "potential" for up to 430hp.

That's quite a bit of "potential" increase for an engine that originally made 330hp. I think they are referring to a horsepower that the cylinder heads will sustain given perfect conditions (i.e. PCM work, more aggressive camshaft, higher ratio rockers). Put it this way, the Z06 broke new ground because it made over 70hp more than the LT4. Enough said.

For more info on the LT4 check out: http://www.grandsportregistry.com/lt1vslt4.htm

Also, notice that the LT4 has higher compression than an LT1 (10.8:1 compared to 10.4:1), larger fuel injectors, and a few other minor things that have already been mentioned.

As I stated, AFR cylinder heads, roller rockers, and a good aftermarket cam (like the CC305) will make at least as much or more power than a stock LT4 and still leave a few bones in the bank.

My $0.02,
Colin