New valve seats?

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morris-out
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New valve seats?

Post by morris-out »

Hi All
Had to remove the head due to head gasket failure, one thing led to another and I’m now looking at the exhaust valve seat.
In the photo it can be seen that after some polishing the valve seat is pitted, in your opinion does this look bad enough to require new valve seats?[frame]Image[/frame]

The head does require a skim so will have to take it to a machinist but don’t want to spend more dosh than necessary.

Thanks
Dennis
katy
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Re: New valve seats?

Post by katy »

Should just need the seat refaced (ground).
Talk slow, think fast!
bmcecosse
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Re: New valve seats?

Post by bmcecosse »

Why does the head need skimmed? The seat looks ok - it could be 'ground in' with paste etc - but a recut would speed matters up considerably.
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morris-out
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Re: New valve seats?

Post by morris-out »

I have a small amout of pitting in the spot were the gasket failed at narrowest point between cylinders and I'm worried about it compromising the new gasket.[frame]Image[/frame]

Maybe it would be ok?
bmcecosse
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Re: New valve seats?

Post by bmcecosse »

I wouldn't say it was essential, but if it gives you peace of mind!
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morris-out
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Re: New valve seats?

Post by morris-out »

Thanks for your advice katy and bmc,I will see what the cost is but as you say its about peace of mind, the bores look fantastic so it must of been rebores at some stage.
The piston head in the cylinder that had lost compression was really clean I suppose unburnt fuel was decoking it, may have had very low compression for some time untill it failed totally but wasnt obvious on the low compression engine.

Cheers

Dennis
bmcecosse
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Re: New valve seats?

Post by bmcecosse »

'Clean' usually suggests water has been entering that cylinder - so check carefully for cracks etc........
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morris-out
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Re: New valve seats?

Post by morris-out »

Ok will do that.
Thanks and will report back, unfortunately work tomorrow.
phurn
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Re: New valve seats?

Post by phurn »

yeah! when mine went the two cylinders that werent firing were thick with soot! cleaned up a treat though... if yours didnt fail near a waterway id be extra carefull when looking for cracks in the cylinderhead or worse, block.
morris-out
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Re: New valve seats?

Post by morris-out »

Here is a pic of the area including the very clean piston, I still have to clean the block up and then will get my magnifying glass out.
When I checked the oil there was no signs of water or even mayo on tne filler cap, also no oil in the water so I'm hopeful that the block is ok, hope so, just told the wife that head gasket would cost around a fiver, opps forgot to mention the engine that is also required :wink:[frame]Image[/frame]
bmcecosse
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Re: New valve seats?

Post by bmcecosse »

I think it will be fine - don 't panic.
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morris-out
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Re: New valve seats?

Post by morris-out »

Hi All

Got my car going again a couple of weeks ago and is now running great again appart from a very noisy broken exhaust.
The machinist that skimmed the head recommended that I also had the valve guides replaced so the head should be good for a few miles.
Only problem I that I managed to dislodge a tappet when pulling the push rod out and didnt notice until I rotated the engine with the starter handle to make sure all was well.- all was not well, I noticed that push doing strange things so had to sort that out.
Thanks for your advice in solving my problems.

Cheers
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