[helmerrock]

I am in the process of preparing a set of 061 heads. I’ve had the guides cut for PC seals and have new valves stock length single groove. I’m finding that the stock retainers are about.050 too long on the bottom end and with run into the seals. Valve lift is under .470. I’m not sure what is the best solution. 1. Could I machine .050 from the bottom end of the stock retainers since the extra length is not needed for “O” ring seals. 2. Are there aftermarket retainers that are shorter than the original stock ones? 3. Could I use .050 offset locks and shim valves to gain clearance? 4. Go back to machine shop and mill tops of guides? Any guidance or advice is appreciated

[67Fbird]

I ...(hence opinion coming) would cut down the guides. Adding the +.050 locks MAY run your keeper into the bottom of your rocker arm (i am mocking mine up for that exact issue as I needed to add +.050 locks to soften my springs a little bit) I just had my #62 heads worked with new guides xxxxx...with specific instructions of keeper to teflon seel clearance must allow for .0600 valve lift.

BTW cutting down the guides is a pretty easy task therefore should NOT break the bank.

[steve25]

What springs are you using?

You could go the offset keeper or lock route, but down the road if you go to roller rockers you might then have rocker to retainer clearance issues.

If your open spring pressure is not over 300 psi and those stock retainers work well with the valve springs,( IE drop in easy on top ) then yes make a simple retainer support jig and just grind them .050” shorter.

I believe the comp cams 740 retainer will work with the stock springs.

I will check on that later, and they are shorter then stock retainers.

[Bill Eveland]

I've "machined" the bottom of the retainers by hand (roloc disc on an angle die grinder) before without issue, just measure thickness before and after and as you're going along.

[helmerrock]

I’m using stock springs from Paul Spotts. Cam will be 2801 summit. Pretty much a stock build. This is my first time getting into head work, in past projects I trusted someone else to do my head work. Sometimes good , sometimes not so good

[Formulas]

I always cut guides down to minimum to accept Viton pc seal with about .060 extra height for possible spring shims

Usually that allows in the neighborhood of .530 lift with stock height valves and retainers
But as usual measure measure plan plan measure cut

[Tom Vaught]

As was posted if you measure the internal distance allowed in the PC seal and machine the valve guide to just allow the seal to just be above the head THEN the retainer to seal distance with the valves you have is the best you can do unless you rework the spring retainers.

So the info provided by Formulas does allow barely allow running a .530 lift camshaft.

I have trimmed down the spring pockets/guides on heads many times ONCE I measured up the springs available, the valves, and the retainers. It required more effort but at the end of the day is a better solution vs the other methods. The guides will still support the valve stems very well.

Tom V.

[Vengeance Race Engines]

Originally Posted by helmerrock

I am in the process of preparing a set of 061 heads. I’ve had the guides cut for PC seals and have new valves stock length single groove. I’m finding that the stock retainers are about.050 too long on the bottom end and with run into the seals. Valve lift is under .470. I’m not sure what is the best solution. 1. Could I machine .050 from the bottom end of the stock retainers since the extra length is not needed for “O” ring seals. 2. Are there aftermarket retainers that are shorter than the original stock ones? 3. Could I use .050 offset locks and shim valves to gain clearance? 4. Go back to machine shop and mill tops of guides? Any guidance or advice is appreciated

Anytime the guide is being cut for a newer style seal, the height should be cut as well. Not just the O.D. at the top, for this reason. On a side note, I would strongly recommend jacketed Viton seals over plastic PC seals. Hope this helps.

[AG]

+0.50" locks will raise the retainer 0.050". As advised before, if you have your guides cut down for positive seals, always lower them as much as you can go to give you flexibility to change cam lift later on.

[steve25]

If you can avoid it never cut down all the wayl

unless your running triple springs with there small center ID it’s good to have some center pad left to both locate and stabilize the springs!