Case Stud Time Serts

[xrotaryguy]

I'm concerned that I need to chase the threads on my new case studs. I've installed 2 Time Serts from clarks, PN C8767L and I have case studs from Clarks, PN C8660. The studs are starting into the Time Certs about 1/4 turn before starting to bind. I don't want to force it and figured maybe I should ask the question. Do I need to chase the threads on these studs or no?

Thanks!

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[gnrand]

I would call Clarks and ask for the technical person on staff to get an answer to your question.

[notched]

The studs came in standard and several oversizes. Verify which size you have. Also keep in mind that even though they are a 3/8 thread, they are not conventional thread depth. They are shallow and that is to make a tight fit so that once they thread in they will not come back out.
I seem to remember using a standard 3/8 die and running it partially up the threads to remove some of the material. They were still a tight fit but it eased installation and they have been subjected to boost and have not pulled.

[xrotaryguy]

I have the standard studs according to the Clarks site. In fact, the site says to use the studs I have with the Time Serts they sell so I should be good to go. I'll contact them all the same just to be sure though.

Notched, that 3/8" die, was that 3/8-16 then? I think I have one of those somewhere in the garage.

Thanks, everyone!

[66vairguy]

The studs came in standard and several oversizes. Verify which size you have. Also keep in mind that even though they are a 3/8 thread, they are not conventional thread depth. They are shallow and that is to make a tight fit so that once they thread in they will not come back out.
I seem to remember using a standard 3/8 die and running it partially up the threads to remove some of the material. They were still a tight fit but it eased installation and they have been subjected to boost and have not pulled.

Notched is correct. Standard pitch, BUT the valley of the thread becomes progressively shallower as you turn in the thread. Works going into aluminum, but it will NOT work into a timesert (too hard). So yes you have to cut the threads to a standard depth using a die - thread pitch will not be affected. NOTE: The factory studs are very TOUGH (not sure about Clark's) and the die (must be a top quality die) will jam or bind resulting in a poor cut if you don't use a good lubricant. I found good ol' STP works the best. I get a clean thread, but be patient - it's very slow going with a lot of backing off then cutting about an 1/8 of a turn at a time.

After cutting the stud make sure it is clean and turns all the way into the Timesert. Then apply Loc-Tite permanent (AFTER starting the stud) and turn it to the desired depth (very quickly!!!). The stud will set in seconds and be tight and leak free. If you are slow you will have to heat the stud to move it. Some use Loc-Tite sealer you apply AFTER the stud is completely in.

BTW - AFAIK Ray Sedman at American Pi Corvair is the ONLY one who sells the correct depth 1-piece Timesert. Very reasonable and it pays to get every thread you can into the block.

[martyscarr]

BTW - AFAIK Ray Sedman at American Pi Corvair is the ONLY one who sells the correct depth 1-piece Timesert. Very reasonable and it pays to get every thread you can into the block.

Clark's also sells the special 7/8" long Timesert, part number C8767L http://www.corvair.com/user-cgi/search.cgi?part=C8767L Ray supplied the special, extra long inserts to Clark's.

Marty Scarr

[xrotaryguy]

Case studs went in well. It's tough to tell in the pics but they're pretty straight. I had no trouble fitting the cylinders and head. Thanks for the input, everyone.

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