Volvo 496 valve issues
10-25-2011, 06:07 PM
#5
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sac,
The first time a keeper broke on a cylinder head of any type, they would all go in the trash and get replaced with new ones. At the same time, I would be looking very closely at the valves to see if there is a problem with the keeper grooves.
Is it the actual keepers breaking, the two little locks on each valve ? Usually they can break and not really cause a dropped valve. I have taken them out of race engines in several pieces but still holding the valve in place.
Or . . . is the valve itself breaking right at the keeper groove ?
Haven't heard of any major problems myself.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
The first time a keeper broke on a cylinder head of any type, they would all go in the trash and get replaced with new ones. At the same time, I would be looking very closely at the valves to see if there is a problem with the keeper grooves.
Is it the actual keepers breaking, the two little locks on each valve ? Usually they can break and not really cause a dropped valve. I have taken them out of race engines in several pieces but still holding the valve in place.
Or . . . is the valve itself breaking right at the keeper groove ?
Haven't heard of any major problems myself.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
10-26-2011, 01:10 AM
#6
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Join Date: Jan 2004
Location: San Diego, California
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I have heard of this a few limited times and in those cases it was caused by either raw water sitting in the steel and iron guides and valves in the iron stock heads and rusting to a point where some valves were seizing in the guides and hitting the pistons which inturn broke the keepers off the valve stems. If you see rust and damage like this in the ports, especially the exhasut ports I would suspect this may be an issue. The stock Volvo exahust manifolds and risers are a wet joint type and water can leak past the deteriorated riser gaskets on some and let water enter the engine in this way.
Just a thought on something we have seen on the 8.1L marine engines from raw water intrusion. We have also seen some rocker arm pivot ball galling issues on some of these GM assembled base engines that did not receive enough oiling at initial startup. Broken, bent pushrods and rockers resulted some of which caused broken valve springs, locks and keepers. You can determine this by looking at the individual rockers around the outside of the ball pivot area for bluing of the steel showing this superheating caused by the galling.
We have never really seen keepers on stock 8.1L -496 engines
break or fail for no other apparent issues on any of the marinizers engines.
Hope this information helps in your investigation.
Best Regards,
Ray @ Raylar
Best Regards,
Ray @ Raylar
Just a thought on something we have seen on the 8.1L marine engines from raw water intrusion. We have also seen some rocker arm pivot ball galling issues on some of these GM assembled base engines that did not receive enough oiling at initial startup. Broken, bent pushrods and rockers resulted some of which caused broken valve springs, locks and keepers. You can determine this by looking at the individual rockers around the outside of the ball pivot area for bluing of the steel showing this superheating caused by the galling.
We have never really seen keepers on stock 8.1L -496 engines
break or fail for no other apparent issues on any of the marinizers engines.
Hope this information helps in your investigation.
Best Regards,
Ray @ Raylar
Best Regards,
Ray @ Raylar
Last edited by Raylar; 10-26-2011 at 01:12 AM.
