Holy Holey Valve Batman...

deville

Seaman Apprentice
Joined
Jul 6, 2011
Messages
36
I'm working on a '70 Glastron Bayflite 164 W/ a Volvo/Penta AQ130/250. Had a 'slight' miss and wouldnt rev over 2100 RPM. Well, I did a comp. test and was SLAPPED in the face: #1-0 psi, #2-160, #3-165, #4-155. So I pulled the head expecting a blown gasket or cracked head (I have read that the slighest overheating will pop these heads). Boy was I suprised to find a perfect gasket amd a pretty head, but a hole in the#1 intake valve- about the size of a pencil eraser-on the edge of the valve. The piston, cylinder, and the comp. chamber isnt chewed up like one would expect, but the exh. valve scares me- the valve piece had to go somewhere, right? So I'm going to replace both int. and exh. valves, but my problem is FINDING these valves. I've called all local parts stores with no luck. I've called the nearest volvo dealer with no luck. I've called my volvo/penta boat man but he will only sell me a complete head for $800.00. Come on, really? I just need 2 valves. Can some one please HELP ME???
 

PiratePast40

Lieutenant Commander
Joined
Mar 21, 2009
Messages
1,734
Re: Holy Holey Valve Batman...

Clean the head thoroughly and look for cracks, especially in the valve seat areas. If you don't feel comfortable doing the cleaning and lapping in the new valves yourself, take it to a machine shop and have them clean and magnaflux the head for you. They can also do the seat work. Ask them to NOT shave the head unless absoutely necessary since you're running relatively high compression allready.

Don't mean to heap extra work on you, but it's a good idea to pull the cam to inspect for wear. You should replace the front seal anyway so it's not that much more work to pull the cam for inspection.
 

deville

Seaman Apprentice
Joined
Jul 6, 2011
Messages
36
Re: Holy Holey Valve Batman...

Thanks guys. I was getting a little worried. 75.00 bucks is a whole lot better than 800.00 for a complete used head (which is better than1,600.00 for a new bare casting). Since I'm in there, it would be wize to re-gasket the head and intake/exhaust, but my new ? is do I need new head bolts? Do I worry about H.bolt stretch or compensate w/ more torque? Let the ordering madness begin
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Holy Holey Valve Batman...

You do not need new head bolts. They are not torque to yield bolts.
 
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