Low compression / rebuild options
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Freshman User
Joined: Dec 2013
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Low compression / rebuild options
I have a 91 F150. 300 I6 with low compression in cylinder 2. Wet/dry test indicates ring problem. I've read some posts on here indicating that a wet/dry test might not hold much merit and that a leak down is the preferred method. Thoughts on this? I put 25ccs of ATF in the cylinder for the wet test. If it is the rings, I'll rebuild it. If it's a valve I'll just pull the head. What are some "tasteful" modifications that could buy me some more power without having to change a whole lot of other things on the truck to keep up. I'm thinking of a cam and maybe some head work so it'll breathe better. This is a SD motor, how does that go with tuning? (A shop, not me) Worth noting : I recently replaced the fuel injectors and front fuel pump /tank. I was suspecting that it had been running lean with a bad injector and burnt a valve.
FTE Legend
Joined: Nov 2015
Posts: 30,880
Likes: 4,117
From: Angier, NC
A leak down will tell you right where the issue is and I dont see the need for the gauge to know the % leak down.
Put the hole you are going to check at TDC, valves closed and put a little air in the spark plug hole.
Air out the tail pipe bad exh valve.
Air out the air intake bad intake valve.
Air out the oil fill cap bad rings.
Dave ----
Put the hole you are going to check at TDC, valves closed and put a little air in the spark plug hole.
Air out the tail pipe bad exh valve.
Air out the air intake bad intake valve.
Air out the oil fill cap bad rings.
Dave ----
Thread Starter
|
Freshman User
Joined: Dec 2013
Posts: 25
Likes: 1
A leak down will tell you right where the issue is and I dont see the need for the gauge to know the % leak down.
Put the hole you are going to check at TDC, valves closed and put a little air in the spark plug hole.
Air out the tail pipe bad exh valve.
Air out the air intake bad intake valve.
Air out the oil fill cap bad rings.
Dave ----
Put the hole you are going to check at TDC, valves closed and put a little air in the spark plug hole.
Air out the tail pipe bad exh valve.
Air out the air intake bad intake valve.
Air out the oil fill cap bad rings.
Dave ----
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