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[Doctor Gollum]

Is it running yet?

[JamesV6CDX]

Is it running yet?

Under normal circumstances, it would have been by the end of tomorrow - but, I need to wait for someone to come over and help me lift the head on

[GastronomicKleptomaniac]

Pop the valve in a power drill. Vastly speeds up the lapping process ,)

[JamesV6CDX]

Pop the valve in a power drill. Vastly speeds up the lapping process ,)

I tried that on one of the others and had an absolute mare with it afterwards.

I find that doing that, you don't hear / feel it cutting, and can't get the pressure as correct

[Bigron]

Continual rotation in one direction doesn't work - so I was told in my earlier years, but I cannot remember the reason why. I was also told of an accessory for a power drill that mimicked the alternating-direction action of hand grinding but it's unlikely to be available still as so few people lap valves in nowadays.

Ron.

[X30XE]

If it makes you feel reassured, I didn't put nearly as much effort or scrutiny into grinding the valves on my V8 as you have already and it passed it's emissions test with flying colours last week.   

[Andy B]

. I was also told of an accessory for a power drill that mimicked the alternating-direction action of hand grinding but it's unlikely to be available still as so few people lap valves in nowadays.

Ron.

Like  this?   

http://www.ebay.co.uk/itm/BGS-Werkzeug-22-28-mm-Valve-Lapping-Grinding-Tool-Pro-Range-1738-/271211992150?hash=item3f257e9456:g:mbUAAOSwBLlU1nhh

[Bigron]

Exactly what I was thinking of, Andy - it has gone up a bit! 

Ron.

[zirk]

Continual rotation in one direction doesn't work - so I was told in my earlier years, but I cannot remember the reason why. I was also told of an accessory for a power drill that mimicked the alternating-direction action of hand grinding but it's unlikely to be available still as so few people lap valves in nowadays.

Ron.

Can cause twist marks or scoring of the seats / valves rather than a nice flat surface where they meet.

Seem to remember something like dont go past the 360 degree rotation, and 1 foward 1/2 back then 1 foward again, but that was a loooong time ago. 

[Bigron]

Yes Zirk; now you say it, I remember! I used to rub the rod between my palms (NO, dirty minded lot!) back and forth like chafing your hands on a cold day with the same sort of light pressure until I got p*ssed off with it and had coffee.....

Ron.

[JamesV6CDX]

It's still fluid tight - not lost a drop - so Job Jobbed. A Jetwash / final clean just in case there are any traces of valve paste, and it's good to drop on.

The timing chain procedure looks reasonably simple on paper, but watch this space

[JamesV6CDX]

Funny how something as simple as getting a valve to seat can make me so happy 

I've spent most of the day "rubbing the rod back and forth" in order to achieve this result, so I'm now sat back in the bath with a cold G+T (no beer in the fridge, fail  )

[Nick W]

Continual rotation in one direction doesn't work - so I was told in my earlier years, but I cannot remember the reason why. I was also told of an accessory for a power drill that mimicked the alternating-direction action of hand grinding but it's unlikely to be available still as so few people lap valves in nowadays.

As unavailable as Amazon?  LINK


What James has done here(put valves from one used head into another) shows just how well the seats are machined on modern engines/equipment: you wouldn't have even considered doing that on an old engine with just grinding paste - you would've had both the seat and the valve reground and then lapped(which even with coarse paste is a final finishing operation) them to match each other.

[Andy B]

.....

As unavailable as Amazon?  LINK

 .....

see my post above ..... 

[Bigron]

Yes, Nick, and there is a major difference in durability in modern engines nowadays, too. In my austin A30, it was considered time for a rebore and new piston rings, etc., after 40k miles!
My Omega has done more than three times that mileage already.
Slightly off topic, but when I eventually get around to rebuilding my Sunbeam S8 motorbike, I will need to have harder valve seats installed to cope with unleaded petrol - unless anyone has experience of the lead supplement that I hear you can get for the petrol?
Or maybe there is a petrochemical expert in the forum who can tell me how to treat the petrol to be like leaded?

Ron.