89 150 hp, cylinder head

[Daniel1947]

I need to machine one cylinder head on my 1989 V6, 2.0L, 150HP, serial # 0C220883, because of piston damage. Mercury manual says maximum of .010 can be removed. Since there isn't anything bolting up to the head, and there isn't any liquid flowing through the head, similar to an automobile engine, I can't see anything wrong with machining more. It would only raise compression slightly and I would believe that could be overcome my possibly richening the jets. Anyone have any suggestions? These used heads are going for $90 to $200 apiece.

Thanks to all for the help.

 

[Laddies]

Re: 89 150 hp, cylinder head

Probably Mercury Marine don't know what their talking about

 

[Faztbullet]

Re: 89 150 hp, cylinder head

Mercury manual says maximum of .010 can be removed.

This is for one side only, if you take more you must remove other head and match removal.You can safely remove .025 on those heads and you might bump running(dynamic)compression 5 psi. A few dings wont hurt as they will fill in with carbon but make sure there is no ring/bearing debris/material in head to create a hot spot.

 

[Daniel1947]

Re: 89 150 hp, cylinder head

Thanks for the info. For the sake of discussion lets say I take .025 off both sides, do you think I should increase jet size's 1 or 2 sizes? I know in my days of building auto engines, it was necessary to richen mixture because of lower octane fuel. I could also decrease timing slightly.

 

[Faztbullet]

Re: 89 150 hp, cylinder head

Stock jets will be fine....

 

[Daniel1947]

Re: 89 150 hp, cylinder head

To Laddies & Faztbullet: Thanks for the information, I do appreciate the help.

 

[wired247]

Re: 89 150 hp, cylinder head

I think Ive got .140" off my heads.