1986-L98
Le Mans Master
Joined: Jul 1999
Posts: 7,072
Likes: 4
From: Maryland
Re: 1986-L98 (Storz)
All 1987 vettes had the aluminum heads so I believe they also had the forged pistons. 1986 was the transition year. The early coupes had cast pistons and iron heads. 1986 convertible production was held up until the Al heads were ready for production so all 86 convertibles had the forged pistons with it. late 1986 coupes had Al / forged. I don't know what the VIN transition number is, but the NCRS C4 manuals (soon to be out) will probably have an estimate of the transition point based on C4 survey data. ~Juliet
Drifting
Joined: Dec 2001
Posts: 1,313
Likes: 1
From: providence ut
Re: 1986-L98 (vader86)
Mr. Nuke we've been going back and forth on this subject for years I have a supercharged 85 and am real interested .where did you get the spec on the 85 engine. thanks :chevy
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Racer
Joined: Nov 2002
Posts: 471
Likes: 0
From: Queens NY
Re: 1986-L98 (lead foot 85 vet)
I also have an early '86... build date 10/85.. I didn't think ANY of those 80s motors have forged internals.. so do I have cast or forged?
I remember my old '88 Iroc had cast
I remember my old '88 Iroc had cast
Melting Slicks
Joined: Aug 2001
Posts: 2,516
Likes: 0
From: Lockport NY
Re: 1986-L98 (Juliet)
...1986 convertible production was held up until the Al heads were ready for production so all 86 convertibles had the forged pistons with it...NCRS C4 manuals (soon to be out) will probably have an estimate of the transition point based on C4 survey data. ~Juliet
AFAIK, I've never submitted any data based on VIN to any survey. Who has been surveying C4 owners???
Le Mans Master
Joined: Jul 1999
Posts: 7,072
Likes: 4
From: Maryland
Re: 1986-L98 (Rich B.)
Now you guys got me all confused. The head transition was definately during 1986. Did a change in pistons happen at the same time? I was under the impression based on stuff I've read in this thread an other similar ones in the past that they changed at the same time. But I honestly have no info to substantiate that. :eek:
Vito Cimilluca is the C4 Team leader for the NCRS. He's got an ongoing C4 survey. There's one for 84-86 and a second for 87-89. I put the survey forms into PDF format and loaded them on my NCRS chapter website here: http://www.ncrs.org/masondixon/c4/C4TechPhotos.htm If you would like to contribute, you can fill them out and snail them to Vito at the address on the forms. :yesnod: Sorry to hijack the thread with this. :crazy:
Back to the original question - did the pistons change at the same time as the heads or was that a different and completely unrelated transition? NCRS won't probably have info in the TIN&JG about pistons since they aren't visible and a judged item. They'll definately have info about the iron vs. Alum. heads though. :flag Sorry if I got things boogered up here guys. :p:
[Modified by Juliet, 2:04 PM 12/22/2002]
AFAIK, I've never submitted any data based on VIN to any survey. Who has been surveying C4 owners???
Back to the original question - did the pistons change at the same time as the heads or was that a different and completely unrelated transition? NCRS won't probably have info in the TIN&JG about pistons since they aren't visible and a judged item. They'll definately have info about the iron vs. Alum. heads though. :flag Sorry if I got things boogered up here guys. :p:
[Modified by Juliet, 2:04 PM 12/22/2002]
Safety Car
Joined: Dec 1999
Posts: 4,691
Likes: 1
From: Framingham MA
Re: 1986-L98 (Juliet)
The Forged piston were a model year change between and 85 and 86. The pistons were changed with the Aluminum heads, but both are cast and it was just for compression ratio.
Safety Car
Joined: Dec 1999
Posts: 4,691
Likes: 1
From: Framingham MA
Re: 1986-L98 (CarAteMyMoney)
I also have an early '86... build date 10/85.. I didn't think ANY of those 80s motors have forged internals.. so do I have cast or forged?
[Modified by dgoodhue, 6:06 PM 12/22/2002]
Racer
Joined: Nov 2002
Posts: 471
Likes: 0
From: Queens NY
Re: 1986-L98 (dgoodhue)
I took a magnet to it before, and I have iron heads, so i'm guessing I have the cast pistons?
Is there a book or website that has all this information? I also need to figure out which top I have
[Modified by CarAteMyMoney, 11:06 PM 12/22/2002]
Is there a book or website that has all this information? I also need to figure out which top I have
[Modified by CarAteMyMoney, 11:06 PM 12/22/2002]
Safety Car
Joined: Dec 1999
Posts: 4,691
Likes: 1
From: Framingham MA
Re: 1986-L98 (CarAteMyMoney)
I took a magnet to it before, and I have iron heads, so i'm guessing I have the cast pistons?
Is there a book or website that has all this information? I also need to figure out which top I have
Is there a book or website that has all this information? I also need to figure out which top I have
[Modified by dgoodhue, 10:58 AM 12/23/2002]
Team Owner
Joined: Sep 2001
Posts: 62,160
Likes: 1,733
From: Athens AL
C7 of the Year - Unmodified Finalist 2021
C4 of Year Finalist (performance mods) 2019
Re: 1986-L98 (dgoodhue)
the change in tops was at the same time as the head changes as far as i can tell, my VIN is 16,000-something and the head change was around 18,000 and i know i have the earlier top.
