86 Vert Cam

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Oct 30, 2015 | 12:42 PM

Number90

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From: Tri-Cities WA

86 Vert Cam

I have some roughness at idle that does not sounds like a miss. It actually sounds real nice if you know what I mean.

Does anyone know if the stock cam for a 86 vert track car had any overlap to it? Or what the stock cam specs are?

She has 80K on her and I do not believe the cam has been changed and she runs real smooth above idle. I do not believe the engine has ever been opened up.

Thanks,
John

Oct 30, 2015 | 12:49 PM

antfarmer2

Race Director

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look at your spark wires and look for arks and sparks in the dark. how old are the plugs?

Oct 30, 2015 | 01:07 PM

WW7

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From: WV

The stock cam in the 88-89 was the most radical cam they used in the L98 motors and it didn't have any lope at all, sounded smooth just like the other L98 Corvettes...I would say there's something not right with your motor at idle..WW

Here are the C4 Corvette stock cam specs...

1985-1986:
Duration @ 0.050 202/206 Lift with 1.5 R 403/415 Lobe Seperation 114.5

CAM 87 L98 14093643 In/Exh Dur@.050" 202'/206' Lift (w/1.5) .403"/.415" LobSep 114.5'
CAM 88-89 L98 10066049 In/Exh Dur@.050" 207'/213' Lift (w/1.5) .415"/.430" LobSep 117'
CAM 90-91 L98 10111773 In/Exh Dur@.050" 202'/207' Lift (w/1.5) .413"/.428" LobSep 114.5'

92 LT1 205/207 @ 0.050" .451"/.450" Lift, LSA 117
93-95 LT1 202/207 @ 0.050" .450"/.460" Lift, LSA 116
96 LT1 200/207 @ 0.050" .447"/.459" LSA 117
96 LT4 203/210 @ 0.050" .475"/.479" LSA 115

Last edited by WW7; Oct 30, 2015 at 01:34 PM.

Oct 30, 2015 | 01:29 PM

Number90

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From: Tri-Cities WA

Nice, I'm starting to see a Dart 427 with a Big ***** Thumpr in my future. But you are correct that first I probably better check the tune up stuff. It'd just be sad if they just forgot to put silicone on the boots however way cheaper.

I'll let you know what I find. I'm still interested in the stock cam specs tho if any one has them.

Thanks

Oct 30, 2015 | 01:36 PM

WW7

Le Mans Master

Joined: Aug 2007

Posts: 8,735

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From: WV

Specs are posted above....

..... Also , be careful putting silicone on your plug wire boots, I did it to mine and the heat kept pushing the boots off the plugs and causing a miss..I'm not the first to have that problem...

...WW

Last edited by WW7; Oct 30, 2015 at 01:43 PM.

Oct 30, 2015 | 02:16 PM

Number90

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From: Tri-Cities WA

If my calc's are right that's 25 degrees of overlap or am I off a decimal point. There's a little scavenging going on there for a stock cam or maybe I'm wishing for a little loping and not a tune up issue.

Anyway, has anyone just changed the rockers to 1.6 rollers leaving everything else the same on an '86 L98 with stock aluminum heads?