RogersJetboat454
Commander
- Joined
- Jul 9, 2010
- Messages
- 2,964
Re: Mercruiser V6 issues
So it's pre-Vortec. If you answer my other questions, we may better narrow down the year. Or if you can find the correct serial number, that would be even better.
Personally I pre-lash the valves one cylinder at a time. I don't do the blanket "turn it to this position, and adjust these numbers". Are you getting oil pressure when you turn the engine over? It's important that the lifters have oil in them when you set lash.
When I set valves, I pick a cylinder to work on. I turn the crank, and watch the rocker arms for that cylinder move. When I see the intake rocker open, then close, I turn the crank a few more degrees (say 45-90?) after the close, then start adjusting the nuts. I spin the push rods with my fingers while tightening down it's respective nut. When I feel a little drag on the push rod, I know I'm relatively close to zero lash, and I give the nut about 1/4 turn after that. It has always gotten me in the ball park where the engine will run pretty well.
Not so much from the outside, although if you have a plastic timing cover, that's an indicator that you have a balance shaft engine. If it had a balance shaft, you should have noticed something a little different when the intake was off. The balance shaft is a cast iron rod with offset weights. It lives above the lifters in the lifter valley. As much as I loathe Autozone, they have pictures of what the inside of a balance shaft engine looks like here; | Repair Guides | Engine Mechanical Components | Balance Shaft | AutoZone.com
So it's pre-Vortec. If you answer my other questions, we may better narrow down the year. Or if you can find the correct serial number, that would be even better.
Personally I pre-lash the valves one cylinder at a time. I don't do the blanket "turn it to this position, and adjust these numbers". Are you getting oil pressure when you turn the engine over? It's important that the lifters have oil in them when you set lash.
When I set valves, I pick a cylinder to work on. I turn the crank, and watch the rocker arms for that cylinder move. When I see the intake rocker open, then close, I turn the crank a few more degrees (say 45-90?) after the close, then start adjusting the nuts. I spin the push rods with my fingers while tightening down it's respective nut. When I feel a little drag on the push rod, I know I'm relatively close to zero lash, and I give the nut about 1/4 turn after that. It has always gotten me in the ball park where the engine will run pretty well.
Not so much from the outside, although if you have a plastic timing cover, that's an indicator that you have a balance shaft engine. If it had a balance shaft, you should have noticed something a little different when the intake was off. The balance shaft is a cast iron rod with offset weights. It lives above the lifters in the lifter valley. As much as I loathe Autozone, they have pictures of what the inside of a balance shaft engine looks like here; | Repair Guides | Engine Mechanical Components | Balance Shaft | AutoZone.com
