Cracked Valve Cover Merc 170

[SDSeville]

I cracked the valve cover on my 1986 Merc 170 3.7 while changing the gasket this morning. I had the torque wrench set for 7.5 foot pounds and was tightening alternate sides diagonally. This corner cracked before I hit the proper torque.



The local marina says they can't get the part. Can this be welded?

 

[Bt Doctur]

Re: Cracked Valve Cover Merc 170

if its cleaned well enough it can be TIG`d otherwise locate a valve cover from a Ford 460 V-8

 

[SDSeville]

Re: Cracked Valve Cover Merc 170

Great idea. Thanks. There are tons of aftermarket valve covers for the 460. Is there anything I should watch out for in using an auto cover rather than a marine one?

 

[Bt Doctur]

Re: Cracked Valve Cover Merc 170

nope, as long as nothing is mounted on your old one

 

[Don S]

Re: Cracked Valve Cover Merc 170

The only thing you might need is a fitting for the vent hose. NOT a PCV valve, just a vent fitting.

 

[SDSeville]

Re: Cracked Valve Cover Merc 170

The only thing you might need is a fitting for the vent hose. NOT a PCV valve, just a vent fitting.

Oh yeah, the flame arrestor has a vent hose that connects to the valve cover. ...or maybe the crank case has a ventilation hose that connects to the flame arrestor? Either way, can I add a fitting for the vent hose to an aftermarket valve cover?

 

[SDSeville]

Re: Cracked Valve Cover Merc 170

...So do I need to add this vent? If so, how would I do it?
Thanks for you help

 

[stonyloam]

Re: Cracked Valve Cover Merc 170

I think I would try a JB Weld fix first. Grind a groove in the crack, and drill a small hole at the end so it does not travel more. Fill with JB, and reenforce on inside with thin aluminum (beer can will do), and give it a try. For the ford cover you should be able to find a through fitting of the correct size at the auto parts store.

 

[nola mike]

Re: Cracked Valve Cover Merc 170

I think I would try a JB Weld fix first. Grind a groove in the crack, and drill a small hole at the end so it does not travel more. Fill with JB, and reenforce on inside with thin aluminum (beer can will do), and give it a try. For the ford cover you should be able to find a through fitting of the correct size at the auto parts store.

Thanks Terry, I didn't want to be the first to respond suggesting a half-assed fix Valve cover isn't really critical, just needs to keep oil in and dirt out...

 

[stonyloam]

Re: Cracked Valve Cover Merc 170

Thanks Terry, I didn't want to be the first to respond suggesting a half-assed fix Valve cover isn't really critical, just needs to keep oil in and dirt out...

LOL! Yeah, that is the only cast Al part on that engine that I would try that on.

 

[SDSeville]

Re: Cracked Valve Cover Merc 170

I will give it a try, but I am not sure JB weld will work on this one. It actually moved about 1/8" when I tightened it, so I suspect it would do so again. If JB Weld does not work, I can get a set of ford 460 covers (only sold in sets) for about $50. The only concern I have is the installing the vent, which should not be too bad.

 

[Bt Doctur]

Re: Cracked Valve Cover Merc 170

$22.00 /pair steel .simply drill the size hole where you want the vent line
http://www.ebay.com/itm/CHROME-STEE...pt=Motors_Car_Truck_Parts_Accessories&vxp=mtr

 

[fishrdan]

Re: Cracked Valve Cover Merc 170

Does that crack travel 3" or so across the valve cover? JB weld might be possible. I think the aluminum brazing rods would patch up the crack, but I wouldn't do it if I had to go out and buy the brazing rods and MAPP torch. There is a Mercruiser 470 aluminum valve cover on Ebay for $50 or so...

 

[SDSeville]

Re: Cracked Valve Cover Merc 170

Just to close the loop on this one -- thanks for the help everyone. I wound up ordering the covers from Bt Doctur's link and got a valve cover breather from O'Reilly.