Cavi

I have some newbie questions, I have a lt1 and am starting to think of future plans. Mine is a 94 lt1 with six speed. I have seen a couple of guys swap the heads for the LT4 and the GM hotcam. What is the difference from the lt1 heads to the lt4? Is this a direct swap? What else needs to be done for this swap and what kind of gains can be expected and where in the RPM range? I am more interested in the low to mid rpm gains.

Strick

You will also need the LT4 intake. If your mileage is above say 100K, you might consider freshing up the bottom end to reduce the possibility of spinning a bearing.

LannyL81

What you will do is make your LT1 into a close LT4.

The best way I think to gauge the gain is to go for a drive in a 96 LT4 Corvette. Gotta be someone near you that will help out.

Strick

But with the hot cam, it will be just a bit more fun than a stock LT4.

93Rubie

http://www.grandsportregistry.com/lt1vslt4.htm

popo8

Dont forget an LT4 knock module as well....

Strick

I'll ask....why is that?

Toy90

I believe the lt4 sensor is less sensitive and the lt1 might give you false knock readings which would retard the timing even without an actual problem.

STL94LT1

Just incase you don't already know. The LT4 knock module will not work with your 92 ECM.

Cavi

Okay I followed the link to the comparison of the lt1 and lt4. It looks like the torque output is almost identical while the LT4 has 30 more horsepower, however it looks like the HP is mainly in the higher prm range. Truthfully this is not quite what I am looking for, I would rather have a bit more in the mid range and down low. Also, a quick look on ebay and it seems that I am going to spend close to 2000 for the heads and intake, does this sound correct?
With my goals stated, would I not be better off doing a freshining up of my stock engine, porting the heads and intake, and installing a better cam? Keep in mind I really do not plan on bieng up on the rev limiter on this car, it really is mid and low end I am looking for.
also who would be good to contact about tuning the ECM from a 1994?

Strick

From what I understand, stroking is what produces low end torque.

Cavi

Yes stroking would produce more low end torque, but it is not the only thing that can increase low end and mid range power.

Strick

What else produces low end torque? Other than better gear ratios.

Cavi

Gears do not add torque or hp they just change how fast or slow you are off the line, in simple terms. Lower gears will get you off the line but your top speed will. Be lower

blue94

Talk to a someone that ports heads and knows cams, (AI or LE) tell them what you want to accomplish and listen to them. If you are replacing the cam you may want to update to the later opti but that does add some parts to the list.

Porting the LT1 heads, cam, and LT headers can really add some power. But as stated in a eariler post if high miles you may want a refresh of the bottom end.

A 94 can use the LT4 knock module and is a good idea if you go with roller rockers and a bigger cam.

Strick

I know that gears don't increase torque. But gears will feel like you have more torque. Ever notice that the L98 has more torque than the LT1? But the LT1 has more horse power. That's why at most auto cross events, L98's do better than LT1s. Go to a road course and the L98 is much slower than the LT1. (we're talking OEM). So, my question is still how do you increase torque in a LT1 other than stroking?

tombrammer

The LT4 hot cam with 1.6 roller rockers, will boost your HP and TQ both and it will do it all across the rpm range. The LT4 hot cam has .525 lift with 1.6 rockers, while the stock LT4 cam has only .476 lift. I put the hot cam in my 93 6spd. and it increased power and SOP feel of that power all across the rpm band, it is IMO the perfect street cam. The thing you do not want to do is use the LT4 hot cam with the LT4 springs, step up to a better spring and you will do fine. At WOT when you shift a 6 speed at redline (5500rpm) you drop back to around 4000rpm which is perfect for the LT4 hot cam. There are better heads for the money than the LT4 heads.

Cavi

can I run the lt4 hot cam with the stock lt1 heads?

blue94

yes, but you need to change the springs and should go with roller rockers

tombrammer

You will need a retune for the computer too.