Anyone seen a 1985 corvette piston? Stock?
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Anyone seen a 1985 corvette piston? Stock?
I am trying to find out what kind of piston design is in the '85 stock engine.
Are they flat top, or not? I knwo they are forged and stock compression is supposed to be 9.5, but that's about it.
Thanks.
Are they flat top, or not? I knwo they are forged and stock compression is supposed to be 9.5, but that's about it.
Thanks.
Drifting
Joined: Nov 2001
Posts: 1,783
Likes: 2
From: Latham NY
Re: Anyone seen a 1985 corvette piston? Stock? (jburnett)
Yes...It's an OEM 4013 design sourced from TRW by GM. Flat-top with 4 valve reliefs and heavy as lead! -Jeb
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Re: Anyone seen a 1985 corvette piston? Stock? (Bluevette85)
Thanks guys, Trying to figure out what sort of compression I would have switching to new heads.
Anyone know how to figure it out?
If I went to 58cc, 64cc, 67cc, 72cc, 76cc?
I know the stock heads are 82cc.
Anyone know how to figure it out?
If I went to 58cc, 64cc, 67cc, 72cc, 76cc?
I know the stock heads are 82cc.
Pro
Joined: Jan 2003
Posts: 669
Likes: 0
From: memphis tn
Re: Anyone seen a 1985 corvette piston? Stock? (Bluevette85)
Yes...It's an OEM 4013 design sourced from TRW by GM. Flat-top with 4 valve reliefs and heavy as lead! -Jeb
The 85 pistons are forged flat top with one long relief across the top not four. I'll post a picture tonight.
The 85 pistons are forged flat top with one long relief across the top not four. I'll post a picture tonight.
b.t.w. are the x rods worth anything?
[Modified by neverendingproject, 5:11 PM 9/18/2003]
Drifting
Joined: Nov 2001
Posts: 1,783
Likes: 2
From: Latham NY
Re: Anyone seen a 1985 corvette piston? Stock? (MrNuke)
Thanks guys, Trying to figure out what sort of compression I would have switching to new heads.
Anyone know how to figure it out?
If I went to 58cc, 64cc, 67cc, 72cc, 76cc?
I know the stock heads are 82cc.
Anyone know how to figure it out?
If I went to 58cc, 64cc, 67cc, 72cc, 76cc?
I know the stock heads are 82cc.
When I put on the 113 aluminum heads (58cc) and a 0.05" head gasket, my compression went to 10.6:1.
Instructor
Joined: Apr 2000
Posts: 171
Likes: 0
From: waukesha, wi usa
Re: Anyone seen a 1985 corvette piston? Stock? (MrNuke)
Pi x Radius squared = area of circle
area of circle x stroke = cc of cylinder
Convert the bore and stroke to centimeters 1" = 2.54 centimerter
Pi is 3.14
Figure the maximum volume of the block at bottom stroke and add the cc of the head
Divide max volume by minimum volume
you will also need to calculate the head gasket volume the same way and add it to the equation
area of circle x stroke = cc of cylinder
Convert the bore and stroke to centimeters 1" = 2.54 centimerter
Pi is 3.14
Figure the maximum volume of the block at bottom stroke and add the cc of the head
Divide max volume by minimum volume
you will also need to calculate the head gasket volume the same way and add it to the equation
Drifting
Joined: Jan 2002
Posts: 1,606
Likes: 1
From: Las Cruces NM
Re: Anyone seen a 1985 corvette piston? Stock? (MrNuke)
When I took the heads off my old '85 parts car, they were flat with one long relief.
There's some really good compression calculators on the internet that take into consideration everything from heads, pistons, all the way down to the head gasket thickness. I should have a couple bookmarked at home, so when I get home tonight, I'll see if I still have them and I'll post their links.
Chris
There's some really good compression calculators on the internet that take into consideration everything from heads, pistons, all the way down to the head gasket thickness. I should have a couple bookmarked at home, so when I get home tonight, I'll see if I still have them and I'll post their links.
Chris
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