93 engine into a 91 ZR-1 - ZR-1 Net Registry Forums

mrycar · 08-23-2005

My father had a little mishap with his ZR-1 caused by sudden reduction of speed and an dramatic increase in RPM when a gearshift went down instead of up. (he was not driving another relative was).

End result was a loud knocking sound from the engine. So he is purchasing the 93 LT5 crate engine that is for sale, here to put in his car.

What components does he need to purchase to make a successful swap into his 1991? Only an ECM and a prom or are there other missing components that need to be purchased?

Looks like after the succesful transplant, I'll have a spare LT5 to play with. I purchased a kit from Kurt White (his old 368 kit) and need sleeves to convert my Dad's old engine. Any leads on where I can find them?

Thanks,

Mike Shaffer
1991 ZR-1 "the Wet Vette"
Almont, Mi

Kevin · 08-23-2005

this is exactly why I don't let other people drive my car

ZR1 MK · 08-23-2005

Talk to Mike at www.acsvette.com for the sleeves and many of your machine shop needs.

Pete · 08-24-2005

Mike,i've put a 91 LT5 into a 94 ZR1 with no issues,you're basicly doing the opposite.
From what i can remember.
You can run the stock ECM you will have to block off the EGR on the 93 motor and extend the low oil level sensor wires since the 91's have it on the left side (driver side)of the pan and the 93-95 LT5's have them on the right side (passenger side).
Also use the 91 vacuum hoses since the newer motors have the differantial MAP under the plenum where as the 91's have them under the ECM
All the rest is the same.

Good Luck
Pete

mrycar · 08-24-2005

Pete, thanks for the info.

The Engine that my Dad is purchasing from ZRchris has a wiring harness and I have access to newer LT5 ECM's, looking at the wiring diagrams, it looks like most of the remaining stock wiring from 1991 will work with the 1993 ECM.

So will get a new ECM and prom for a 1993, and attach it to the 1993 engine on the 1991 ZR-1.

If that doesn't work, then will go with the option you proposed.

Mike
1991 "wet Vette" ZR-1
1991 ZR-1 (dad's)

LTLive · 08-25-2005

If you're going to do the swap there may be a few polution sensors that are not the same, plus the harness plugs may be different.

Sounds like there were other problems with the engine. A 5-2 or a 4-1 mis-shift shouldn't have damaged the engine. LT5's a pretty bullet proof. I know I have missed a few shifts in autocrosses and have been able to recover with no problems.

Aren't you the on who blew his plenum through his new paint job with wet NOS? I think we know who the driver was.

08-23-2005	#1
mrycar Join Date: Aug 2005 Location: Almont, mi Posts: 11	93 engine into a 91 ZR-1 My father had a little mishap with his ZR-1 caused by sudden reduction of speed and an dramatic increase in RPM when a gearshift went down instead of up. (he was not driving another relative was). End result was a loud knocking sound from the engine. So he is purchasing the 93 LT5 crate engine that is for sale, here to put in his car. What components does he need to purchase to make a successful swap into his 1991? Only an ECM and a prom or are there other missing components that need to be purchased? Looks like after the succesful transplant, I'll have a spare LT5 to play with. I purchased a kit from Kurt White (his old 368 kit) and need sleeves to convert my Dad's old engine. Any leads on where I can find them? Thanks, Mike Shaffer 1991 ZR-1 "the Wet Vette" Almont, Mi

08-23-2005	#2
Kevin Join Date: Jun 2005 Location: pittsburgh Posts: 4,632	this is exactly why I don't let other people drive my car __________________ It's not the car, it's the people - Doug Johnson 90 r/r "KEYS ON" nick named "T.L.B"

08-23-2005	#3
ZR1 MK Join Date: Aug 2005 Location: NY Posts: 143	Talk to Mike at www.acsvette.com for the sleeves and many of your machine shop needs. __________________ Mike 427 cu in LT5 [URL="http://zr1mk.weebly.com"]http://zr1mk.weebly.com[/URL]

08-24-2005	#4
Pete Join Date: Dec 2003 Location: Chicagoland,IL Posts: 2,679	Mike,i've put a 91 LT5 into a 94 ZR1 with no issues,you're basicly doing the opposite. From what i can remember. You can run the stock ECM you will have to block off the EGR on the 93 motor and extend the low oil level sensor wires since the 91's have it on the left side (driver side)of the pan and the 93-95 LT5's have them on the right side (passenger side). Also use the 91 vacuum hoses since the newer motors have the differantial MAP under the plenum where as the 91's have them under the ECM All the rest is the same. Good Luck Pete __________________ '91 #1635 PoloGreen 350 LT5 11.09 @ 129.27 11.04 @ 128.86 474RWHP 400RWTQ http://www.youtube.com/watch?v=SFNFOhGGlR4 http://www.youtube.com/watch?v=ZlRIOMwaDYY https://sites.google.com/site/peteszr1garage

08-25-2005	#6
LTLive Join Date: Aug 2005 Posts: 2	If you're going to do the swap there may be a few polution sensors that are not the same, plus the harness plugs may be different. Sounds like there were other problems with the engine. A 5-2 or a 4-1 mis-shift shouldn't have damaged the engine. LT5's a pretty bullet proof. I know I have missed a few shifts in autocrosses and have been able to recover with no problems. Aren't you the on who blew his plenum through his new paint job with wet NOS? I think we know who the driver was.