Tappet has play?

Post by **wesk** » Sun Jul 03, 2016 7:49 pm

As I recall the non-rotator exhaust valves are the same length as the intakes. The rotator exhaust valves will be the thickness of the rotator cap shorter.

southpw · Post by **southpw** » Mon Jul 04, 2016 3:05 am

Thanks Wes

45auto · Post by **45auto** » Wed Jul 06, 2016 7:55 am

Southpaw, what you are running into with the exhaust valves can be confusing. It wasn't until I bought a set of NORS M38 Valves that I could see what was going on. They came with an instruction sheet on how to install and adjust. They use the thin set of valve locks like you have. I will most likely never use them. If you end up not using the locks, I'm sure someone will like to have them as they would be hard to find!!

The original exhaust valves in our M38s is an early attempt to rotate the exhaust valve to keep them from burning. As Wes has pointed out, they use a cap on the end of the valve which allowed the valve to rotate within it. The problems was, if the valve ever stuck or was slow to close, the cap could fall off. This was common after an engine has sat for a while. The next generation of rotating valves had the rotating assembly within the spring retainer, which is now obsolete. Quarter Ton Military on ebay has some and has sold quite a few, but they are the only ones I have seen new.

The fix now is to use the MB style valve and retainer which does not rotate. Below is a link for the rotating valve spring retainer sold by QTM.

http://www.ebay.com/itm/290798894259?_t ... EBIDX%3AIT

southpw · Post by **southpw** » Wed Jul 06, 2016 10:21 am

Thanks Harold. I have that link saved now. I buy a bunch of stuff from QTM but Canada Post is threatening to strike so need to hold off until that mess is cleared up before i can order anything.

4x4M38 · Post by **4x4M38** » Wed Jul 06, 2016 11:52 am

Have you tried Brian Asbury?

southpw · Post by **southpw** » Wed Jul 06, 2016 2:43 pm

No Brian i have not. I should check though. I have to machine some parts for him as well so maybe i should get onto doing that job before calling him lol

southpw · Post by **southpw** » Sat Aug 06, 2016 11:41 am

Im just about to put my engine back together and remembered about these washers that were installed on top of my valve springs, some upside down

These are not listed in the manual. They are all 0.055" thick. Were they used as spacers to help compression when the springs were wearing? Speaking of, I ordered new springs and some of them are below the min uncompressed length of 2.500". (ranging between 2.460-2.530. This was the case with the springs that came out which is why I ordered new.
I do not know engines so better to ask then to "assume". Should I be concerned with the variation in lengths?
Brad

Post by **wesk** » Sat Aug 06, 2016 12:51 pm

They look like aftermarket spring shims used to boost spring pressures for Hi -Po applications like rougher cams. You probably should not reverse them. Those are oiling channels to reduce wear between the spacer and the top of the spring.
Those spring compression upping washers would only be used as a band aid for soft springs or as a way to shorten spring life when used with HiPo cams.

Free length is 2 1/2" which of course must have a plus or minus tolerance. I don't feel a minus .040 is a big deal.

The big deal with your springs are weather they pass the compression checks as shown in TM 9-1804A pages 73, 74 & 75 for the L-134 and TM 9-8015-1 Pages 60-64 for the F-134.

southpw · Post by **southpw** » Sat Aug 06, 2016 4:19 pm

Thank you Wes. I will go to the shop and see if they can check that for me. I will omit the washers during my rebuild.

southpw · Post by **southpw** » Tue Sep 20, 2016 5:29 pm

So now that I have everyrhing back together, I adjusted the valves in the following way...
1. Turned crank until #1 cylinder is at TDC. Head is off so easy to confirm and distributor points to #1 wire.
2. Adjust first and second valve(from the front of engine) to .016" clearance
3. Turned crank 180°, adjusted 7th and 8th valve as I should be at TDC of #4 cylinder
4. Turned 90° and adjusted 3rd and 4th valve as #2 cylinder was at TDC.
5. Turned 180° and adjust 5th and 6th valves.

Does this sound correct?

Brad