Who can identify heads?
Thread Starter
Intermediate
Joined: Jun 2011
Posts: 25
Likes: 0
Who can identify heads?
I pulled my engine out due to severe oil leak and high miles. I was
expecting aluminum heads and found these on the car instead. I'm
used to an 8-10 digit casting number, but there isn't one. They have
screw in studs and a small hump on the intake port.
expecting aluminum heads and found these on the car instead. I'm
used to an 8-10 digit casting number, but there isn't one. They have
screw in studs and a small hump on the intake port.
Race Director
Joined: Apr 2000
Posts: 15,344
Likes: 4,008
From: Texas
I'll guess you have an early '86 coupe with iron heads.
The casting number ends in 624. They have 76 cc combustion chambers with 1.94" intake valves and 1.50" exhaust valves.
From Mike Antonick's book ...
Corvette Specs:
The Corvettes driven by journalists at the July 1985 press event for 1986 models had new alumnum cylinder heads which were highly touted in the press materials. But two weeks after the preview, Chevrolet sent a letter to the media announcing the new heads would not be on 1986 production models initially because of quality problems. The heads were redesigned and did make it in time for installation on all 1986 convertibles. Of 27,794 1986 coupes built, the last 8,594 had aluminum heads.
Wording of the aluminum head delay letter from Chevrolet Public Relations.
Introduction of aluminum heads #9428 sent 08/01/85:
WARREN, MI - Introduction of aluminum cylinder heads on Chevrolet's 1986 Corvette will be delayed while the heads are redesigned to eliminate a cracking condition around the head attachment bosses.
As a result, early-production '86 Corvettes will be equipped with cast iron heads.
Castings in the water jacket area of the aluminum heads had been thinned intentionally to reduce mass and improve cooling. Durability tests revealed the thinning weakened the structure enough to allow the bosses to crack under high stress.
Design of the heads has been revised to alleviate the problem, and they will be placed in production as soon as testing confirms their integrity.
Thread Starter
Intermediate
Joined: Jun 2011
Posts: 25
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I have a 1990 coupe. There's a 350, R and 193 marking on the head. They are definitely
iron, but never seen screw in studs on a stock iron head. The casting is very clean, unlike
most of the centerbolt heads I"ve seen.
iron, but never seen screw in studs on a stock iron head. The casting is very clean, unlike
most of the centerbolt heads I"ve seen.
Le Mans Master
Joined: Sep 2006
Posts: 6,050
Likes: 147
From: Phoenix AZ
2021 C4 of the Year - Modified Finalist
Those are not 86 heads. The 86ers have perimeter valve cover bolts, not centerbolts. Look at the front of the head, the part that faces the radiator.
If there are a couple dashes up next to the rocker cover seal ing surfaces, they are swirl ports.
If there is a saw tooth pattern, they are vortecs.
If there is a rectangular block, they might be camaro/firebird heads.
We need a pic.
The front of the heads used to be a GM identifier as to what the built-up engine was in the warehouse. In case a tag was misplaced, the person looking knew where to start.
If there are a couple dashes up next to the rocker cover seal ing surfaces, they are swirl ports.
If there is a saw tooth pattern, they are vortecs.
If there is a rectangular block, they might be camaro/firebird heads.
We need a pic.
The front of the heads used to be a GM identifier as to what the built-up engine was in the warehouse. In case a tag was misplaced, the person looking knew where to start.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Thread Starter
Intermediate
Joined: Jun 2011
Posts: 25
Likes: 0
took more pics.
yes, there is a 193.
mine is on right, stock LO5 head on left.
In the pic of the right side head - the cast # to the left of the 3rd valve up from the floor,
is it 193? If so its a Caprice head probably 1990 or so.
is it 193? If so its a Caprice head probably 1990 or so.
mine is on right, stock LO5 head on left.
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