1986 automatic compression test
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
1986 automatic compression test
I have an 86 automatic that's been rebuilt into a 383 stroker. I just recently had my heads ported (Dart pro1 aluminum 200cc). The heads were in good shape with little miles on them. after reinstall I did a compression test and I have a range of from 205-209 in each cylinder. I was told that was high. I also noticed im getting a head gasket leak near the front. Is my compression too high? Is the compression causing the head gasket leak? I have reused my Head bolts a few times and was told to try and new set and retorque to see if that solves the leak. Is compression is too high whats the remedy? thicker head gasket?
Heres the list of parts on the car
383 stroker
accel manifold
Superam intake
30 pd injectors
58mm throttle body
Dart pro1 aluminum heads ported 200cc
Mild cam (valve lift .480 and 264 duration intake, .480 lift and 274 duration on exhaust) (.20 camlift, 210 duration at .050 intake and .32 camlift and 216 duration exhaust)
tpis headers
Heres the list of parts on the car
383 stroker
accel manifold
Superam intake
30 pd injectors
58mm throttle body
Dart pro1 aluminum heads ported 200cc
Mild cam (valve lift .480 and 264 duration intake, .480 lift and 274 duration on exhaust) (.20 camlift, 210 duration at .050 intake and .32 camlift and 216 duration exhaust)
tpis headers
Burning Brakes
Joined: Jun 2003
Posts: 849
Likes: 1
From: dubuque iowa
true a bigger durration can would help to bleed off high compression but without knowing the compression he is running there is really no way of telling exactly what may be going on.
Thread Starter
Racer
Joined: Sep 2002
Posts: 420
Likes: 1
From: SAN DIEGO CA
Im running 200cc dart pro1 heads. I used that cam because I thought it would help me pass California emission better. Ive passed every year. I dont mind going with another cam if you think i would still pass emissions. The engines fairly new and i never checked compression so maybe its always been that high. I was also chasing down a small coolant leak from the headgasket extremely small leak). I switched out the head gaskets three weeks ago. Its leaking in the same spot as before even though the heads were installed opposite sides this time ( dart heads can be installed on the left or right side of the engine.) im hoping i dont have to take the engine out and have the block decked! The car has never over heated. Im hoping 210 compression wouldnt cause the headgasket to leak. im using an old craftmans torque wrench and wondering how accurate i got the torque. I put it at 65 pounds per bolt.
Melting Slicks
Joined: Jun 2013
Posts: 3,065
Likes: 39
Hi, like I said before, never reuse head bolts. You need to get new ones, you need to shave your heads, you need a new gasket, and you need a better torque wrench. Torque wrenches loose their accuracy over time. You can even just borrow one, probably good to borrow a snap on torque wrench. And also, get your hands on a straight edge and a set of feeler gauges and see if you have any warping on the deck.
Safety Car
Joined: Sep 2001
Posts: 4,134
Likes: 531
From: Glenbeulah Wi
Im running 200cc dart pro1 heads. I used that cam because I thought it would help me pass California emission better. Ive passed every year. I dont mind going with another cam if you think i would still pass emissions. The engines fairly new and i never checked compression so maybe its always been that high. I was also chasing down a small coolant leak from the headgasket extremely small leak). I switched out the head gaskets three weeks ago. Its leaking in the same spot as before even though the heads were installed opposite sides this time ( dart heads can be installed on the left or right side of the engine.) im hoping i dont have to take the engine out and have the block decked! The car has never over heated. Im hoping 210 compression wouldnt cause the headgasket to leak. im using an old craftmans torque wrench and wondering how accurate i got the torque. I put it at 65 pounds per bolt.
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