Piston rings Specialloid

[pete4000]

Hello,

I had a valve seat problem on my shadow 2 weeks ago and I had to pull off the heads.
I figure out that one of my inlet seat was in very bad condition.

When taking off the heads, I control my pistons and find out that my engine was fitted with original Specialloid pistons in +0.020. I have control them and they are in good condition. I would like to keep them and just put a new set of rings. I 've contacted several suppliers but they don't have rings for those pistons. Could anyone help ??
Many thanks,
Pete

 

[passenger0_0]

Hi Pete,

I've also got specialloid pistons in my race engine albeit E7/11 but from the look of your pistons you are using 9:1 CR pistons which share the same size rings.
I searched internationally but could not get any rings and ended up using a manufacturer here in New Zealand who made me 6 piston sets for NZ$120. They were parallel compression rings and one piece oil control rings, all in cast iron, but after lapping them in into the bore with Brasso the engine goes great and has good compression (well it would with my CR) and doesn't smoke (only when throttling down from over 6,000 rpm and then wacking open the throttle). I know they are not fashionable anymore but cast iron rings will be a cost effective way to keep using these pistons.
Cheers David

 

[pete4000]

Hi David,

Many thanks for your answer, I appreciate. I understand that you had the same problem as me. It seems to be very complicate to find those kind of rings nowdays.
It will be very kind from you if I could get in touch with this person in NZ and order him a set for my pistons.
Kind regards,
Pete

 

[van drenth]

Pete, in mine spares i have 2x oil control ring 84+010x18x126 and 4x compression ring 84+010-1/16x.118 made by wellworthy and still in original wrapping. Are those the ones you looking for?
Regards, van Drenth JC

 

[Bill Thomas]

Hello Pete, I had this trouble a long time ago and found a 2000cc leyland van has same size pistons, But the rings are a little thicker and deeper, I got someone to turn out the grooves on the pistons, Just a thought if you get stuck, good luck bill.

 

[mercurycrest]

Hi,
Bill has the right idea.. Use high quality modern design rings. I put Perfect Circle brand 84mm Chevy Luv rings (chrome top ring and 3 peice oil ring) in my D over 80,000 miles ago and compression is nearly unchanged.
Cheers, John

 

[passenger0_0]

Hi Pete,
I note that there are some very helpful suggestions, including a very generous offer byvan Drenth JC. If you do wish to pursue the the cast iron rings, they are made by Franklin Engineering Services, ph(**64) 9 238 4437, email kelven@fesltd.co.nz.
One thing to note is that you will need to use a dummy piston and rod to lap the rings into the bore before gapping them as they are made by the more traditional process of turning centrifugal cast iron bar.
Good luck with the work.
Cheers David

 

[timetraveller]

Interesting! I never did that. Assuming that the rings will go into the bore at all then all I do is push each ring down into the bore with the base of the piston to ensure that it is exactly 90 degree to the bore and then use a feeler guage to measure the gap.

 

[passenger0_0]

Normally that's all you should need to do but with some types of cast iron tings if you install just the new ring into the bore and peer inside you can often see light between the bore and ring with about 0.001"-0.002" gap due to distortion diring the manufacturing process - mine touched in just 3 places. Using a fine liquid lapping compound (I used Brasso) such as metal polish and an old piston fixes the problem after about 10-15 minutes of careful work. If you gap the ring prior to lapping then the gap gets too large. Modern rings dont have the bore contact issue but getting rings for the original specialloid pistons, especially HC onces can be a problem, especially if you don't want to machine out the groves.

 

[pete4000]

Thank you all for your answers ! And thank you for your very nice proposition Van Drenth JC. I will have been very interested by buying your rings but unfortunuatly, the rings I need are the following dimension :
- 84 mm +.020
- 1/16' - 0.135' Compression rings
- 1/8' - 0.125' Scrapers rings

I'm going to follow up David, Bill and John proposition, find or made rings and adapt them to my pistons, or adapt my pistons to the rings.

Pete