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Dec 3, 2011 | 12:49 AM

Bredd1

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From: Miramar Florida

Alternator

What is the difference beween alternators on '86 & '87 corvettes. They look to be the same & same amp rating. The one for '86 seems harder to find, and the one '87 is more available.

Dec 3, 2011 | 12:50 AM

Bredd1

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From: Miramar Florida

My car had an engine swap, how can I tell if its '86 or '87?

Dec 3, 2011 | 01:57 AM

gerardvg

Safety Car

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From: Melbourne, Victoria, Australia

They look the same, the connections and plug are the same.
Some list them for individual years others say 86-91 alternator?
I cannot tell them apart

Click the link below which shows 86-91...

http://www.parts123.com/parts123/yb....Z5Z5Z50000050F

I have converted my 85 vette to the cs type 86-91 alternator with a conversion harness.
(84-85 had different type)

Dec 3, 2011 | 07:14 AM

weaselbeak

Racer

Joined: Sep 2010

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From: se iowa

I was told by the junkyard that the 87 alternator was a one year only. Did they lie to me? Not to thread jack but it has some relevance.

Dec 4, 2011 | 12:58 AM

Cliff Harris

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From: Anaheim CA

There was a problem with the early alternators in the '86-'87 era. They had a PLASTIC internal fan. There was talk of a class action lawsuit about this, but I don't think it ever happened.

Mine apparently got brittle from the engine compartment heat and shattered during a high RPM autocross run. All the plastic pieces flying around in there wiped out the internal wiring and the alternator was dead after the run. I now have a lifetime guarantee alternator that I got at Kragen (now O'Reilly). It has a metal internal fan, so I guess they learned.

I heard they went to the metal internal fan in mid '87. That's the one you want. You need to make sure the connector matches too.

Dec 4, 2011 | 05:08 AM

Bredd1

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From: Miramar Florida

Thanks Cliff, is there any other differences between the '86 & '87 L98 engines that are not interchangable? The reason I ask is that my car is an '84 with a L98 engine swap from the Crossfire. The engine was likely changed several years ago but not by the guy I bought it bought it from and he didn't know what year the engine was. Any way that I can tell or does it matter because there were really no difference. My care does have aluminum heads, but when I had to replace the smog pump bracket I had to order one that fits a '86. It may be a Frankenstein, with a mix of parts. I'm not sure.

Dec 4, 2011 | 06:45 PM

Bredd1

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From: Miramar Florida

I purchased my new alternator and installed it today. I purchased the one that came up as '87 model. I did see that the internal fan was metal on the new one and was plastic on the old one. Thanks for your help.

Dec 5, 2011 | 02:11 AM

Cliff Harris

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From: Anaheim CA

The '85 and early '86 cars have cast iron heads (mine does, got it 12-24-85). I don't remember in what exact month (March of '86, I think) the convertible was introduced and all engines after that had aluminum heads.

Since I have an '86 I'm not sure exactly what year, but GM changed the connectors in the engine compartment to a new type that had better sealing. That happened around '88 or '89. The relays changed too, to match the new connectors. Somebody else needs to jump in here and clarify this.

I just took a peek at my engine because I remembered that I replaced my cold start injector connector with a new style (you can't get the older ones any more). The older ones have a rubber hood about 2" long. The newer ones just have an oval shaped rubber plug in the top. Check your injector connectors.

Last edited by Cliff Harris; Dec 6, 2011 at 02:33 AM. Reason: Added info on injector connectors.