Valve rotators

Upon checking my old parts books I found that the only engine that used the VS 647 valve springs after 1960 was the GMC 637 V8 gasoline truck engine for the outer valve springs. It was listed in the Sealed Power parts book for the 1966-1972 engines. There must be modern easier to find components that will work. I will research it further.
Thomas

Thank you for the information. It is a good start. I will post the information on the valve springs when I find it.
regards
Thomas

Hi Tom,

I found an old Thompson part catalog online, see the below link. The RC-17A rotator looks to be Chrysler (page 24). I did not find the valve spring VS 647 in the catalog, maybe you will have better luck.

archive.org/details/ThompsonTradeCatalog...es/page/n23/mode/2up

Best regards,
Bill

Hi Tom, the Actonite Cord has a set of those rotators on the exhaust valves.
The caps do have RC - 17 stamped on them and the valve springs are shorter that the standard springs to suit the deeper cap. The rotator is constructed with tiny bearing balls between the two pieces.
Attached are some pictures of the rotator cap and a standard Cord valve spring cap.
Sorry I have no idea where they originally came from.

In a 1954 ACD newsletter it was suggested to use valve rotators for the exhaust valves. It said that Thompson roto cap No. RC-17 used with valve spring # VS 647 work well. What vehicle were these originally used in and are there new part numbers because the old numbers do not turn up in searches?
Thomas