low compression cause?
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Junior User
Joined: Aug 2003
Posts: 86
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From: Utah
low compression cause?
i just did a compression check on my 302 and all cyl. are showing between 105 psi and 110 psi except one and im showing 80 psi how common is it for these 302s to burn valves? would i have to change the cam if i put 351 heads on it and converted it to 4 barel
thanks
sean
302 stock bronco
thanks
sean
302 stock bronco
Elder User
Joined: Dec 2002
Posts: 649
Likes: 1
From: Monterey bay area
low compression cause?
i just did a compression check on my 302 and all cyl. are showing between 105 psi and 110 psi except one and im showing 80 psi how common is it for these 302s to burn valves? would i have to change the cam if i put 351 heads on it and converted it to 4 barel
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The answer to your Q is NO, you would not have to change the cam. The 351W heads on a 302 will need special Edebrock or ARP bolts to bolt onto the 302 block.
The pushrod length will be the same provided the heads weren't overmilled....(best way to check this is a pushrod length checker)
Depending on the smog laws, I'd look at some ported 351w heads, with screw in studs, hardened guideplates and pushrods...
the combustion chambers for the earlier heads are 60.4cc's and will also help with compression...as well as airflow.
----------------------------------------------
The answer to your Q is NO, you would not have to change the cam. The 351W heads on a 302 will need special Edebrock or ARP bolts to bolt onto the 302 block.
The pushrod length will be the same provided the heads weren't overmilled....(best way to check this is a pushrod length checker)
Depending on the smog laws, I'd look at some ported 351w heads, with screw in studs, hardened guideplates and pushrods...
the combustion chambers for the earlier heads are 60.4cc's and will also help with compression...as well as airflow.
Posting Guru
Joined: Jul 2003
Posts: 1,486
Likes: 0
From: Independence, MO
low compression cause?
for that one cylinder, put two teaspoons of oil in the cylinder, then check the compression again, if it makes a significant difference then theres most likely a ring/piston issue, if not much different then possibly a burnt/bent valve, or crbon build up on the valve seat? just some possibilities. DW
