Mercruiser net lash?

[boatwaters]

I'm doing the valves on a mercruiser mpi with the roller style rockers. I went to look in the book #32 and it just says to adjust valve clearance. I look in the specification section and it says "Net lash, no adjustment." I'm not really sure what that means, do I just torque them to something? If so I don't see the spec. I'm used to doing it the other way where you turn the engine over, adjust a few and keep going. Not used to this way.

 

[John_S]

Re: Mercruiser net lash?

I don't have access to the particular merc sm right now, to see what kind of mpi you are refering to. I believe the V6 vortecs use a torque value. The V8s generally use the method that you are familiar with. I assume you meant roller hyd lifters, not roller rockers. Roller rockers, as far as I know, only came on some of the Merc performance engines. And wouldn't think that would change the procedure to adj the lifters.

 

[Don S]

Re: Mercruiser net lash?

Book #32 is for a 4.3L, so assuming you have a 4.3, the valves are not adjustable. You just torque the rocker nut to spec, no adjusting like a SB V8.

 

[boatwaters]

Re: Mercruiser net lash?

Not sure what the rocker arms are called but they do have bearings in them on the sides for them to pivot. They probably aren't rollers then, a roller would have a roller on the end that goes against the valve. So these are most likely not the rollers but they do have the bearings on the side.

 

[boatwaters]

Re: Mercruiser net lash?

Book #32 is for a 4.3L, so assuming you have a 4.3, the valves are not adjustable. You just torque the rocker nut to spec, no adjusting like a SB V8.

I can't seem to find the spec, I've looked in the spec section but I must be missing it. Or do you just bottom out the bolt?

 

[Don S]

Re: Mercruiser net lash?

Pag 3A-8 of the specs states no adjustment.
Page 3A-14 has the torque specs for the rocker arm bolts. (not nuts as I mistakenly said before)

 

[boatwaters]

Re: Mercruiser net lash?

Thanks Don I see it there, don't know how I missed it. Thanks for the quick replies.

 

[Don S]

Re: Mercruiser net lash?

Just seemed like something was missing from the Merc manual. Here are a couple of steps from the Volvo manual (same engine) with info not in the Merc manual.

 

[boatwaters]

Re: Mercruiser net lash?

Hey Don, thanks for the info. I had already done the valves though. I did them in that order (that was in the merc book) but I also rotated the engine so the one that I was going to do the valve would be closed. It is all back together and test run went good.