Problem found with rebuild!

[frdmstnggt]

:bash: My engine has been stumbling and barely running since the rebuild. Today I tried a last resort to find the problem and I found it.:idea: I ran a compression check on the driver's side bank, which I thought was the problem. Cylinders 5 and 6 (front two on the drivers side) ran a 60psi compression. Cylinders 1, 7, and 8 ran between 150psi to 180psi. So this leads me to believe that my valves are bent or something of that nature. So this weekend, from Friday to Sunday, I will be pulling the drivers side head. The fun begins again...:whine: :cryying:

 

[lightninmike]

yep that would do it, did you put the heads and cams on??
if you did i can assure you that when you were putting the chains on is when it got funked up. same thing happen to me hell same side too. good luck with it bro
oh and when you have the shop put new valves in make sure they check the guides too

 

[frdmstnggt]

thanks mike, i just hope that it can be fixxed.

 

[Fade 2 Black]

Anything can be fixed so don't worry there. Have you done a leakdown test to make sure it's the valve(s) and not the rings? Good luck either way and I know how you feel since I just got done doing mine for the second time this year.

 

[frdmstnggt]

I have to pull the heads first Bob. All the pistons, rods, rings and bearings are all brand new. I hope that the rings wouldn't be the problem. Also, does anyone know the normal/max compression psi I should be looking for. I got 180psi max on one cylinder. I just need to know what to look for.

 

[wydopnthrtl]

I agree with mike. This is a common problem on these motors. The cam jumps a tooth or two when your putting it together.

Rich

 

[lightninmike]

Yeah it will make you sick.
Oh and when putting it back together make sure the dot on the crank gear is at the 6 o'clock position, this puts all the pistons below the deck and you shouldnt have valve contact if the cam jumps on you. If the keyway is at the 12 o'clock position thats when you run into this problem.
Like Bob said it could be rings but i dont think they would account for 120psi missing although when i had a bent valve i couldnt get any pressure in the cylinder at all

 

[Fade 2 Black]

Just saying so if it were something else you wouldn't spend time where it wasn't needed.

Actually Mike when the crank gear mark is down (crank key is at roughly 10:00 position) the #1 is at TDC, rotating the crank 45* CCW from there puts it in "safe mode" where all the pistons are below deck and you can turn the cams without making contact. If it did make contact from being out of time then it'd be more than a tooth, maybe 2, 3 or more and would have also gotten all the valves on the affected side IMO.

At any rate good luck with the teardown and I hope it isn't too costly to repair/remedy. At least you'll have decent weather, lol.

 

[frdmstnggt]

lol, thanks again Bob. Actually I am going to pull them off this weekend. My only concern is that my engine is already in the engine bay and I replaced the factory style heads bolts w/ ARP head studs which I loc-tite in there. Not much room to try and double-nut the stud for removing it. Can't put the head directly off either. Wish you were still out here Bob, definitaly could use some of your wisdom and experience here. :beer:

 

[frdmstnggt]

well... ttt for more comments

 

[JohnnyLightning]

make sure the crank key way is 12:00. this way the pistons are down enough so the valves cannot make contact when timing it!.Most likely this is what happend, when you turned your cam sprocket to align the chains up it slipped and the cam rotated too far and the valve/valves hit the top of the piston..with the keyway @ 12:00 if it slips again it will not hit the piston this time, Good Luck...JL

 

[lightninmike]

Just saying so if it were something else you wouldn't spend time where it wasn't needed.

Actually Mike when the crank gear mark is down (crank key is at roughly 10:00 position) the #1 is at TDC, rotating the crank 45* CCW from there puts it in "safe mode" where all the pistons are below deck and you can turn the cams without making contact. If it did make contact from being out of time then it'd be more than a tooth, maybe 2, 3 or more and would have also gotten all the valves on the affected side IMO.

At any rate good luck with the teardown and I hope it isn't too costly to repair/remedy. At least you'll have decent weather, lol.

Yeah thats it, i knew it was something like that but almost only counts in horse shoes and hand granades