1993 Z28 Engine Replacement
11-05-2016, 10:43 PM
#1
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Join Date: Jan 2016
Location: Northeast Louisiana
Posts: 25
1993 Z28 Engine Replacement
After getting the trans sorted, 3" exhaust fixed, etc. The light tap we first heard from the engine has increased in noise. At first we thought it was just a lifter from it sitting up for awhile but pulling the valve covers and checking everything it sounds like it has problems deeper in. It's louder when the passenger side valve cover is off.
When I get time I will be pulling the engine to see what all is wrong with it. If it needs a rebuild I want it done right, but don't want the car to sit for any length of time.
I am thinking of swapping in another Lt1 350 (non of the 265 versions) just to get it going so he can enjoy it while the other engine is getting redone. Would a iron headed version work from a fullsized car? Would the camaro camshaft need to be put into it for the computer to work properly?
The car currently has BBK headers, 3" single exhaust, electric fan over ride mod, Hypertek stage 2 chip, 160 deg therostat.
When I get time I will be pulling the engine to see what all is wrong with it. If it needs a rebuild I want it done right, but don't want the car to sit for any length of time.
I am thinking of swapping in another Lt1 350 (non of the 265 versions) just to get it going so he can enjoy it while the other engine is getting redone. Would a iron headed version work from a fullsized car? Would the camaro camshaft need to be put into it for the computer to work properly?
The car currently has BBK headers, 3" single exhaust, electric fan over ride mod, Hypertek stage 2 chip, 160 deg therostat.
11-06-2016, 11:29 AM
#2
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Re: 1993 Z28 Engine Replacement
You will have a mismatch on the IAC valve connector and your fuel lines. Easiest thing to do would be to use the 93 intake/fuel rails/injectors/throttle body on the iron head engine. If it's an auto trans, you need the connection for the TV cable on the throttle body as well.
Check the knock sensor on the iron head engine. I think there are two. You only need to connect one, and it needs to be a ~4,000 ohm sensor (measured from the single pin to ground). If it's a late model iron head engine, it may have 100,000 ohm sensor, in which case you would have to swap the 93 sensor into the iron head block.
The knock sensor is necessary, because your biggest risk with using the 93 aluminum head program with the iron head engine may be that the timing is too aggressive. Not sure, I've never compared the aluminum head and iron head timing tables. But the big advantage of the aluminum head version is the ability to use aggressive timing, with a higher compression ratio. The iron head engine already has a lower compression ratio, so maybe it's a wash. But the Hypertech chip may have added even more aggressive timing.
The 93 ECM, running speed density, is all about the volumetric efficiency (VE) tables, to get the ECM's calculation of mass air flow right. With different head flow (iron heads flow more), different cam profile intended to produce higher low end torque for the heavy B-Body, and improved VE from the exhaust upgrades, may be a bit of risk sticking with the Hypertech chip.
Just a guess, though.
Check the knock sensor on the iron head engine. I think there are two. You only need to connect one, and it needs to be a ~4,000 ohm sensor (measured from the single pin to ground). If it's a late model iron head engine, it may have 100,000 ohm sensor, in which case you would have to swap the 93 sensor into the iron head block.
The knock sensor is necessary, because your biggest risk with using the 93 aluminum head program with the iron head engine may be that the timing is too aggressive. Not sure, I've never compared the aluminum head and iron head timing tables. But the big advantage of the aluminum head version is the ability to use aggressive timing, with a higher compression ratio. The iron head engine already has a lower compression ratio, so maybe it's a wash. But the Hypertech chip may have added even more aggressive timing.
The 93 ECM, running speed density, is all about the volumetric efficiency (VE) tables, to get the ECM's calculation of mass air flow right. With different head flow (iron heads flow more), different cam profile intended to produce higher low end torque for the heavy B-Body, and improved VE from the exhaust upgrades, may be a bit of risk sticking with the Hypertech chip.
Just a guess, though.
Last edited by Injuneer; 11-06-2016 at 08:49 PM.
11-06-2016, 08:41 PM
#3
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Join Date: Jan 2016
Location: Northeast Louisiana
Posts: 25
Re: 1993 Z28 Engine Replacement
It sounds like a very good educated guess. This car will be fixed, just trying to decide the best course of action before we even pull the engine. I figured it would be best to swap in all the sensors and intake from the 93.
Yes this car is a auto.
Yes this car is a auto.
06-28-2017, 10:58 AM
#4
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Join Date: Jan 2016
Location: Northeast Louisiana
Posts: 25
Re: 1993 Z28 Engine Replacement
Finally found out some of the problems on this car, and working on sorting out the last details before handing over the keys to my oldest boy. The speedometer not working turned out the drive gear on the speedometer in the trans came off and was just spinning freely, easy fix, done.
The engine, well that turned out into a full rebuild. When we had the engine finally pulled a rod bearing was so spun it was double stacked. We wound up trashing the crank, rods, roller lifters and a few other parts.
The original plan was just to do a near stock rebuild with up graded parts. I went off to work and my dad decided to have a guy he worked with do the work. While I was gone they decided to make changes and I didn't know they were doing it till the engine was going back together. It turns out once I got back home and was sent pictures of the assembly I seen the block was cut to clear the crank. It turns out it's is now a 383 LT1.
It has a eagle crank, Eagle rods 4340 5.7" I-beam and Mahle Forged Pistons 930200130. Now on the next part I know a lot of people would boo or go why we used the stock cam again and the stock intake and heads. Our main purpose is to give him a good solid base to work on. He can do the mods later on. (save his money up and learn to respect the cost)
So right now that give him a good 383 bottom end, stock cam, 1993 ecm with hypertech stage 2 chip, BBK long tubes, 3" single exhaust, K&N cold air intake, fan over ride control, new 4l60 (stock) 160 deg therostat.
Later on I will be talking to him and explaining to him what mods can be done and in what order he should go. Then plug the info into desktop dyno to give him a idea and show him the hp/tq relation ship curve as to what changes should be made first and why. (Mainly looking at later on Ported Lt1 intake/heads or Lt4 versions, Roller rockers and cam, plus a tune)
I am still going to help him with getting a custom tune but the stock cam should help him get use to going to a good performance car from the stockers he is use to driving.
The engine, well that turned out into a full rebuild. When we had the engine finally pulled a rod bearing was so spun it was double stacked. We wound up trashing the crank, rods, roller lifters and a few other parts.
The original plan was just to do a near stock rebuild with up graded parts. I went off to work and my dad decided to have a guy he worked with do the work. While I was gone they decided to make changes and I didn't know they were doing it till the engine was going back together. It turns out once I got back home and was sent pictures of the assembly I seen the block was cut to clear the crank. It turns out it's is now a 383 LT1.
It has a eagle crank, Eagle rods 4340 5.7" I-beam and Mahle Forged Pistons 930200130. Now on the next part I know a lot of people would boo or go why we used the stock cam again and the stock intake and heads. Our main purpose is to give him a good solid base to work on. He can do the mods later on. (save his money up and learn to respect the cost)
So right now that give him a good 383 bottom end, stock cam, 1993 ecm with hypertech stage 2 chip, BBK long tubes, 3" single exhaust, K&N cold air intake, fan over ride control, new 4l60 (stock) 160 deg therostat.
Later on I will be talking to him and explaining to him what mods can be done and in what order he should go. Then plug the info into desktop dyno to give him a idea and show him the hp/tq relation ship curve as to what changes should be made first and why. (Mainly looking at later on Ported Lt1 intake/heads or Lt4 versions, Roller rockers and cam, plus a tune)
I am still going to help him with getting a custom tune but the stock cam should help him get use to going to a good performance car from the stockers he is use to driving.