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Model G Oversized valve guides

Posted: Mon Apr 16, 2018 11:32 am
by Hardhat_Barry
Does anyone know where I can get oversized valve guides for the Model G (1949)?

Or does anyone have fix for a valve guide that can just be pushed in i.e. slightly loose?


Model G Oversized valve guides

Posted: Mon Apr 16, 2018 11:38 am
by Wayne
Part number 22641/5 - - plus 5 thou oversize guide - in stock

Model G Oversized valve guides

Posted: Mon Apr 16, 2018 4:55 pm
by Hardhat_Barry
I rang up Hitchcocks this morning and they said they dont do them.

I give up!!

Model G Oversized valve guides

Posted: Mon Apr 16, 2018 5:09 pm
by Hardhat_Barry
Yay rang hitchcocks and they are sending one out free delivery!!!!

Also found out about crank shims while I was on the phone :)

Model G Oversized valve guides

Posted: Tue Apr 17, 2018 1:07 am
by Alan R
Hi Guys---------from a machinist's point of view valve guides are a straight forward piece of turning, drilling and reaming.........Either cast iron or Phos. Bronze in bar form is readily available commercially.......If you are able heat the head up such that the old guides drop out and the new ones drop in then this is preferable to drifting them out with a hammer and in a cold state.....it helps keep the machined hole in the cyl. head in good condition............Don't forget to lap the valve in afterwards....PS}--- Even if you can't heat the head up you can always put the new guides in the freezer overnight...This'll reduce their size enough that they can then just drop into place......WEAR GLOVES !!!

Model G Oversized valve guides

Posted: Tue Apr 17, 2018 3:03 pm
by Hardhat_Barry
Yes I could have used my lovely Boxford CUD lathe and it was an option but it would have been a bit fiddly never tried to make a valve guide before.

Model G Oversized valve guides

Posted: Tue Apr 17, 2018 8:51 pm
by Alan R
Hi Barry-------Good choice of lathe there, matey !! Taper roller headstock bearings, 1 Vee and 1 flat on the bedway which is induction hardened......Headstock Spindle takes a hollow drawbar collet attachment,other attachments include fixed and travelling steadies, BIG faceplate etc, etc.....Knocks spots off a puny Myford any day.......The valve guides are not that small really ( Try making 22BA bolts !!)......... Practice with some scrap Aluminium or Brass at first...............Go on !!....Be Bold !!......

Model G Oversized valve guides

Posted: Tue Apr 17, 2018 8:53 pm
by Alan R
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Model G Oversized valve guides

Posted: Tue Apr 17, 2018 8:56 pm
by Alan R
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