Valve Guides - Beetle Head

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No More Landy
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Valve Guides - Beetle Head

Post by No More Landy »

Hi Guys

I had to take out my daughters engine due to almost no compression on one cycliner and I found that the valve guides are all very worn.

I tapped out each guide and extracted them all with a home made puller pipe and threaded rod and they all measure 12.1mm outside.

The only place in Cape Town I found them in stock have the 12.2 outside diameter guide.

Johannesburg list a 12mm as standard diameter and 13mm is oversize.

Any advise as to how to fit/drill/ream out the holes to suite and then whether I need to also ream the inside diameter to match the valves once pressed in the head again.

Thanks all.


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Re: Valve Guides - Beetle Head

Post by retrovan »

Have a look at the lift of your cam, as normally if the lifters are gone, the cam is as well.

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Re: Valve Guides - Beetle Head

Post by No More Landy »

Do I understand you that if the guides are worn the actual cam followers etc. could be worn ?

Could you elaborate as I don't quite know how much I need to srtrip her further to check.
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Re: Valve Guides - Beetle Head

Post by retrovan »

No, it could point to that you have compression loose, not sure if valve guide by it self can give such a loose.

Test the amount of lift you have on your lifter rods when you turn your engine to see if your cam lobes are still OK.

Could be that your valve lifters or cam lobes are worn. There could also give low compression.

Also see if your tappets are hitting the valve stem off center to allow them to turn.

Herman
1952 Split Beetle 1835cc
1968 Fastback 2Lt.type4
1972 Low Light Bay Panel Van 2Lt type 4
1975 Fleetline Panel Van 1914cc
2020 MeFusco Beetle Truck 2Lt type 4
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Re: Valve Guides - Beetle Head

Post by No More Landy »

The cylinder that had no compression I filled the compression chamber in the head with fuel and it just ran past the valve seats. The other cylinders held the petrol without immediate loss but all the guides were also worn/rattle fit so am hoping this is the issue but will also check the cam lift.
Thank you


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Re: Valve Guides - Beetle Head

Post by Edmond »

Maybe that head has a burnt exhaust valve. Rather send them to an engineering shop, have them supply, fit and ream the guides plus recut the valve seats. Replace the exhaust valves as a matter of course, reuse the intake valves if they still spec out ok. I had my baja's heads done by mr cylinder head about 4 yrs ago they supplied, fitted and teamed the guides and I supplied them a full set of new exhaust and intake valves.
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