RUMCars Forum

General Category => Unusual Microcar Discussion => Topic started by: Bob Purton on August 15, 2012, 05:52:47 PM

Title: Villiers piston rings
Post by: Bob Purton on August 15, 2012, 05:52:47 PM

Does anyone know where I can get some villiers 197 piston rings? I need a pair of .002" over size.  Villiers 9E. TRied the usual suspects but it appears to be an unusual oversize, I can get +.003 and +.005 but not .002!

Title: Re: Villiers piston rings
Post by: richard on August 15, 2012, 06:46:18 PM

guess you dont mean +020 then . i know you know what you mean but +010 , +020 and +030 is more usual isnt it ?

Title: Re: Villiers piston rings
Post by: Barry on August 15, 2012, 07:02:12 PM

I would go for the +.03 and check them with a feeler in the bore.
Just take a bit off each end of the ring with a diamond file until the ring gap is right.  It is boarder-line acceptable though.

If the piston were 70mm as standard you have one that is 70.508 (+0.02")

70.508 diameter is 221.507mm circumference.

       +0.02" (.508mm)
       +0.03" (.762mm)

70.762 diameter is 222.305mm circumference.

That's about .8mm to machine off (0.031")  Might be just a bit too much for the ring retaining pin?

Title: Re: Villiers piston rings
Post by: g-o-g-g-o on August 15, 2012, 09:06:35 PM

Hi Bob
          I have a welworthy piston ring meassurer in my collection of car tools - I have used it to graet extent in my rebilding of heinkel engines - it is very accurate when I cant get the correct size of piston ring I get the next size up and just file it down with a set of jewellers files until it is right - You are welcome to borrow it or you can bring the next size over ond file it down yourself at my house.
                                                                                                                                             Mike

Title: Re: Villiers piston rings
Post by: Bob Purton on August 15, 2012, 10:33:53 PM

Thanks for the usefull advise on this one. I may take you up on that MIke. I will just try for a little longer to find the correct size first.

Title: Re: Villiers piston rings
Post by: Big Al on August 16, 2012, 07:07:50 AM

Interesting stuff. Need to find out what this Welworthy piston ring measurer is. I have done mine by trial and error in the barrel without calculations. An engineering solution would be so much better.