Classic Inlines Viton Valve Stem Seals

Hello All!

I am in the process of a full rebuild on my early '65 7-main 200. I have been working on the head while the block is still in the works.

All of the old valve stem seals were toast....and I want to replace them with something better then the originals...that didn't seem to seal well from the get go. Classic Inlines offers a set of .530" Viton seals that are listed as "No machine work required to install". I ordered a set and they are WAY to small.

The Guide O.D. is .630"

The Seal I.D. (metal jacket) is only .610"

I can't get them on without damaging them, or machining my head....which I shouldn't have to do according to them.

Am I doing something wrong?

Something sounds wrong on the size (.100 to big) of the stock guide? If they do measure that much then you would need to machine them down to .500 or .530 depending on seal number you have, or go back to a stock umbrella type seal. Which seal number did you order ? See the link below, good luck

These are the .530 seals they may need to be pressed on or use a deep socket to drive them on should be a tight fit but not much more then about .010 difference.
http://www.classicinlines.com/proddetai ... VVS%2D530T

Bubba22349, Thanks for the Reply!

The .530" you linked here from Classic Inlines are indeed what I ordered and they are way too small. I mic'd them out as follows:

I.D. of the steel jacket = .610"
I.D. of Viton seal = .530"

I measured all 12 valve guides which are all as they left FoMoCo and they all measure between .625" and .635" O.D. which means they require machining regardless of what Viton seal you buy......no question.

There are only 4 different sizes of those Viton seals available that I can find: 0.420", 0.431", 0.500" and 0.530".

According to the casting date codes on the head, it was cast April 8th, 1965 and is original to this motor....not sure if that tells you anything.

MrFalconman, then you will need to machine the O.D. Of the guides to the right size for those seals. It's a fairly easy job I have some of the old Perfect Circle guide cutters (see below link for an idea of what they look like) Comp Cams also makes them too. Besides the right size cutter (.530) and mandril that fits the inside (I.D.) Of the valve guide you will need a slow turning or variable speed 1/2 inch drill or a drill press to machine them. One last thing, while you are machining the guide for the seals make sure you have enough clearance between the bottom of the valve spring retainer to the top of the valve seal when cam is at full lift especially if you plan on using a performance cam in the future. You would be looking for distance of the valve lift plus about a min. of .060 to .125 of an inch and this might require shortening the valve guide tops a little too. Most auto machine shops can also do the job at the time you are doing a valve job. Good luck

http://www.ebay.com/itm/PERFECT-CIRCLE- ... 1486524166