LT1 Engine - Which Years Will Fit A '93?

[LT1Silverhawk]

Once again, I turn to the masters...

A while back I was on here because the transmission on '93 Z28 I had picked up had a bad tranny and you guys were super helpful.

Now that the transmission has been replaced with a rebuilt one, it seems like the headgaskets maybe going bad. The car does have 184k miles so not surprising.

I can't do a headgasket job because it is too expensive so I'm thinking of doing what I did before with my '96: drop in a another motor with low miles.

Due to different emissions and whatnot throughout the LT1 years, I am wondering which years will drop into a '93 without any issues. There are a few for sale locally but the oldest one is a '95 and the best one is a '96 with 48k miles.

Any recommendations?

Thanks in advance... as always, you guys rock.

[Morley]

I may be mistaken but I believe the 93 was a unique year, meaning only a 93 works in a 93. The other years were sequential port injection while I believe the 93 was batch fire. Now you could make any year work in your car with some modifications.
Since when is a replacement engine cheaper than replacing a couple of head gaskets?

[LT1Silverhawk]

Well, 'back in the day', with my first Camaro, a '96, I didn't know how to properly maintain it and blew out the head gasket. Local shops were quoting about $2500 to do the head gaskets due to the difficulty and having to possibly machine the heads.

But I was quoted $1600 for a used low-mileage motor installed. Perhaps I've been going to the wrong guys?

Aside from that, Morley, do you know of a good source to verify the batch vs. sequential port injection?

Thanks,

[Morley]

1994 was the introduction of sequential port FI on the LT1 http://www.fuelinjection.com/lt1lt4.html
If you are just getting the bare engine (no FI manifold and such) you could use in with your 93 stuff. There will be 2 sensors on the engine that you won't be using..crank and cam position sensors. Other than that, it'll drop right in.
If you are gong to pull the engine anyway, do the head gaskets on your engine yourself. With the engine out it should take just a few hours to do it.

[LT1Silverhawk]

Well, if it’s just the head gaskets then yes, it won’t take very long. But if there is other work involved such as resurfacing the heads then I got some shopping around to do.

Normally all this wouldn’t bother me but this Camaro is about to become my daily driver. I lost my Camry a few weeks ago to an out of control car while I was away on vacation . And between work and other daily life things, it’s hard to find time to work on a car, especially in the winter.

So, taking in what you said Morley, I guess I can go for the ’96 motor with 48k miles and swap the necessary parts and drop it in. That is, of course, if the original motor is too far gone.

Thanks Morley… Your insights are always helpful.

[Morley]

I haven't had any machine work done in some time but resurfacing a pair of heads and having the valves done shouldn't be more than $100/head I would think. It usually takes about a week to get this work done, depending on how busy the shop is.
With the engine out it would give you time to look it over real good for oil leaks and the like and get them fixed too.

[LT1Silverhawk]

Again, what you say is true and far more cheaper and practical.

The only issue keeping me from doing that - aside from my fear of removing an LT1 - is the time needed to do all the work. Not to turn this into a sob story, but my schedule is so busy and complicated right now that to do anything beyond on oil change is practically out of the question. That is why I am considering having another dropped in.

Or I can suck it up and continue driving my raggedy but faithful '89 S10 until I can get the Camaro ready. And that may be a smart move in the long run because a motor with 184k miles with the head gasket going out may have alot more to replace than I can handle at one point.

Then again, if I do pull the motor, I guess I can go for the performance upgrades now, i.e. the internals. But my fear is that if I do that, the car will never be ready!

How much do you think it would cost to port the stock heads for better flow? I can do that and also port the intake.

Thanks for the help and letting me rant...

[Morley]

You can port the heads yourself. Do a google search on head porting, it isn't too difficult. As to the intake, about the best thing you could do is what is called "gasket matching". Put the gaskets on the ports and make either the ports match the gaskets or make the gaskets match the ports (whichever over hangs the other). After that, just look inside and around the ports for ant obstructions (ie flashing, irregular casting bumps, etc) and smooth them out.

[LT1Silverhawk]

Well if you have confidence in a rookie such as myself to do the porting on my own, then I'll give it a shot .

For the intake, I've seen LT1 intakes being ported to match the size of the LT4s and being sold for like $150 on eBay (but that was a few months ago). I was considering doing the same thing to mine.

Any thoughts on that?

[Morley]

Originally Posted by LT1Silverhawk

Well if you have confidence in a rookie such as myself to do the porting on my own, then I'll give it a shot .

For the intake, I've seen LT1 intakes being ported to match the size of the LT4s and being sold for like $150 on eBay (but that was a few months ago). I was considering doing the same thing to mine.

Any thoughts on that?

If the LT! head ports aren't the same as the LT$ (don't believe they are) making it look like an LT4 won't do any good. Just match the gaskets to the heads, then match the intake to the gaskets and you'll have nice smooth flow.

[LT1Silverhawk]

Dude, my bad! I messed up and wasn't clear. I actually meant to say intake manifold. Should've completed that thought!

I've seen the LT1 intake manifolds being ported out to match the opening of the LT4 intakes. LT4 intake manifolds are no longer sold by GM Performance but Edelbrock has a better version of it for a bit more.

Have you heared anything about the intake manifolds being ported to go from accepting a 52 mm throttlebody to accepting a 58 mm throttlebody?

[poormillionaire2]

You have to port the manifold in order for it to take full advantage of a 58mm TB. Well, in the front where the manifold meets the TB. The 52mm TB is the largest you can go on a stock manifold because the manifold openings are 52mm. Any larger, and you will have to enlarge the openings to take full advantage of it.

And for your earlier question, if you drop any other LT1 in your car other than a 93, you will need to take the entire engine management system out of the donor car as well. As stated earlier, the 93 LT1 is a unique in itself. It doesn't have a MAF or 24lb injectors to name a few. So any other computer system will not even match...just to let you know.

[LT1Silverhawk]

Originally Posted by poormillionaire2

You have to port the manifold in order for it to take full advantage of a 58mm TB. Well, in the front where the manifold meets the TB. The 52mm TB is the largest you can go on a stock manifold because the manifold openings are 52mm. Any larger, and you will have to enlarge the openings to take full advantage of it.

And for your earlier question, if you drop any other LT1 in your car other than a 93, you will need to take the entire engine management system out of the donor car as well. As stated earlier, the 93 LT1 is a unique in itself. It doesn't have a MAF or 24lb injectors to name a few. So any other computer system will not even match...just to let you know.

Right, I follow you on the the port sizes on the intake manifold to accept the larger throttle body but what I would like to know is if that is the best way to go, bang-for-the-buck speaking.

As for the motor, would it not be possible to drop in a motor from another year by changing the necessary sensors and electronic components? Or is it a '93 in a '93 only, no way around it?

By the way, I appreciate your help.

[Morley]

Originally Posted by LT1Silverhawk

Right, I follow you on the the port sizes on the intake manifold to accept the larger throttle body but what I would like to know is if that is the best way to go, bang-for-the-buck speaking.

As for the motor, would it not be possible to drop in a motor from another year by changing the necessary sensors and electronic components? Or is it a '93 in a '93 only, no way around it?

By the way, I appreciate your help.

52MM is really big enough for any air flow a street engine is ever going to need. The stock throttle body bores were 48 mm, so getting a 52 mm would be a good increase in potential air flow.
If you use an LT1 from 94 & up, just swap the FI system and sensors from your engine to the new one. The new engine will have a crank and cam position sensors, just don't hook them up.

[LT1Silverhawk]

Originally Posted by Morley

52MM is really big enough for any air flow a street engine is ever going to need. The stock throttle body bores were 48 mm, so getting a 52 mm would be a good increase in potential air flow.
If you use an LT1 from 94 & up, just swap the FI system and sensors from your engine to the new one. The new engine will have a crank and cam position sensors, just don't hook them up.

Are the stock throttlebodies 48mm? Then I have been under the wrong impression that they were 52mm. Then my next question is, if I decide to upgrade to a 52mm throttlebody, should I port the front of the intake manifold to accept the upgrade and allow for a better airflow?

Morley, or any one else who can help, which components of the fuel injection system and sensors would I swap over to a newer motor? I realize this might be a very detailed answer so if anyone can help, I will greatly appreciate it.

Thanks for all your help you guys.