ok i had a machine shop bore my block .20 and then i put wiesco 8:1 pistons in it...they assembled the block tho...i put the head back on it with a cometic head gasket...broke the block in by letting it idle and holding it at 1000 2000 then 3000 well i was just riding around easy as could be taking test rides...i got up to 50 mph hit 5th and hit 11 miles and the idler pulley bolt BROKEEEEee it jumped time and had oversize valves in it so it bent every single vavle....well i pulled the head off and got a reman head and put it on made sure it was in time.,..and now it wont start..it only has 20 pounds of compression...i double checked the time..its definetly in time...i was wondering if maybe the rings could have been messed up by the valves hitting the pistons or what..how do i do a leak down test and then what do i look or listen for and how do i look or listen and what would leaks tell me THANKS PLEASE REPLY

Originally posted by boosted_talon88
ok i had a machine shop bore my block .20 and then i put wiesco 8:1 pistons in it...they assembled the block tho...i put the head back on it with a cometic head gasket...broke the block in by letting it idle and holding it at 1000 2000 then 3000 well i was just riding around easy as could be taking test rides...i got up to 50 mph hit 5th and hit 11 miles and the idler pulley bolt BROKEEEEee it jumped time and had oversize valves in it so it bent every single vavle....well i pulled the head off and got a reman head and put it on made sure it was in time.,..and now it wont start..it only has 20 pounds of compression...i double checked the time..its definetly in time...i was wondering if maybe the rings could have been messed up by the valves hitting the pistons or what..how do i do a leak down test and then what do i look or listen for and how do i look or listen and what would leaks tell me THANKS PLEASE REPLY

Were there any marks on the top of the pistons when you pulled the head off to swap? Possibly could have cracked the rings. You can make your own leak down tester for about 50 bucks. Just do a search on google on how to make one.

Did you check the "reman" head before you put it on?

If you are 20psi across the board it sounds more install than anything. If it is varying and you got say 20 in one and 150 in another then obviously check that cylinder.

If it is 20 in one cylinder, I wouldn't bother with a leak down. Just put some air in there and you will be able to hear if it is going intake, exhaust or into the block, lol.

its 20 give or take all the way across...the oil dripping will tell me if its the block right? but other than that the leak down test ill be able to hear a leak in the turbo manifold or the intake mani.....