What do you think causes this?

[PeteB]

Not arb related I know but - what do you think causes this?

 

I am rebuilding a Rover V8 that was in my Hot Rod. I removed it to change a load of gaskets and adjust the gearbox and then discovering that it could do with a de-coke, ripped off the heads. It has to be said that there was a lot of oil sludge about and it reeked of cooked oil!

 

On stripping down the heads I noticed that a couple of valves had started to have the colletted end mushroom over and there is significant wear to the valve top and rockers. The valves were difficult to pull through the valve quide and very likely to have scored them out. As Rover V8 engines have hydraulically adjusted valves someone has not badly adjusted them in the past and the pushrods are all straight.

 

Is this caused by age or has someone got a tad excited and revved it 'til the valves have bounced? (the noise of a V8 "on cam" can be addictive!) What do you reckon? Anyone got any big valve heads or indeed a 4.2 - 4.6 going cheap?

[Treegeek]

?? how worn are the valve guides ??

[TimberCutterDartmoor]

Rover V8 - likes quantity more than quality of oil I seem to remember; not that the latter is unimportant... Sorry that doesn't help!

[mikecotterill]

Bit of a guess but rover v8's have a reputation for low oil pressure and needing regular oil changes, maybe various galleries have got blocked and reduced flow to up top.

[spudulike]

Think you may be better off on Piston heads.com or petrol heads.co.uk:thumbup:

 

If the hydraulic tappets have not been filling properly then they can tap noisily so if regular oil changes havent been done then it probably is a mixture of old age and abuse.

 

In my experience it is best to throw all you can at it to fix it if you want it doine right.

 

Measure up the diameter of the valve stems and replace as necessary, if the valves are worn then replace the valve guides - not sure if you can drive them out or not - only done them on an old mini years ago - do the springs whilst you are at it and clean up those ports - the cylinder heads do lots of work - and can let through lots of oil:thumbdown: