Valve clearance

Peter J

Peter J

Well-known member
Hey Guys,
When I purchased my 29, I got the opinion that it had been "cosmetically" restored for a little old lady to putt around the neighborhood. Sure nuff, all sorts of mechanical (and dangerous) shortcuts were made. One shortcut seems to be the valve train. Low compression should have been my tipoff but it seems that none were ever adjusted as they have solid lifters. Clearances average about .04 for intake and about .13 for exhaust. Should I try to grind them or just get adjustable lifters. I'm suprised the old girl ran at all. Another problem is that I'm real short on fancy tools.
Thanks for your thoughts, Pete
 
Nothing wrong with uing two-piece valve guides or solid lifters. We have just become used to using conveniences to make our lives easier during mintenance. For the time being, just grind the stem(s) to adjust. When (if) you need to open the engine up where thecamshaft comes out, THEN you can install adjustable lifters. BTW, no fancy tools are needed. I would target .012" on intakes and .014 on exhaust valves. If you miss it by .001 or .002, it won't be a big deal considering what the purpoe of this engine is for.
.
 
I agree with Brent. It is a fairly straight forward task to pull the head, valve cover, and then grind the stems to get the clearance you need. I suggest that once you get close to the correct clearance that you clean the valve seats and faces up by seating them with a hand tool and some grinding compound. Then do the finish grind on the valve stems. Gar Williams
 
How much work do you want to get into ?? I'm sure you probably mean .013" for the exhaust which will be fine as is.. I'm thinking you mean .004" for the intakes,, thats a bit thin but it'll run.. You will have to pull the cylinder head to adjust the intakes, because the valves do have to come out like the others stated.. To grind the stems you need to find someone with a valve grinding machine to trim a bit off the ends.. Make sure you mark each one so they can go back in the same hole and take the clearance measurement to the shop that has the grinder.. As long as you do have clearance on every valve it won't affect the compression test..
 
Thanks guys, that sounds like the way to go for now. I just can't understand how the valves got that way in the first place unless the "builder" just installed them and hoped for the best. I assume the clearances as they are contributed to a lot of strange noises and clicks. It seems that with almost zero clearance, the valves didn't have time to seat during the cycles? I still need to pull the pan to see what's up down there. The trans. sounds like a coffee grinder but that's another story.
 
I'm wondering about this.. What if he really does have .040" and .130" clearances?? After all, aren't all decimals and zeros and such stuff on the feeler strips?? He may really have something wrong with that monster..
 
Patrick,
The intakes were at or about .004 or less. I just missed a decimal point. I'm just wondering about the noise one (or more) were producing. I didn't mention earlier that #1 wasn't firing at all before I pulled the side plate.
 
Why are you pulling the pan?? Have you run a compression test?? Why isn't #1 firing?? If there is no or hardly any valve clearance then if a valve isn't seating then that or those cylinders won't being doing any work.. Whatever noise this monster is making I think trying to locate it before tearing anything apart is prudent..
 
#1 not firing is the big mystery. Compression up with the rest, spark good, plug good. I didn't do any leakdown test when I checked the compression if that would show me anything. I'm going to pull the pan to see what the lower end looks like and I'll need to anyway if I decide to go with adjustable lifers. You are correct, of course, I'm going to do some further investigation before taking aything else apart. Thanks !
 
Just an added note. If you go with the adjustables, you must realise that finding the clearence is one thing, adjusting is a nother. To adjust you must turn the engine over till the valve is up or open, guess at the adjustment, turn it back so the valve is closed and check the adjustment, and if more is needed turn it back over till its open -------- Well you get the idea. Iceman
 
I have heard that adjustables can be a pain. I may just grind the solid lifters for now and see how it turns out. Hopefully I can solve some mysteries. I still can't figure how the clearances got so weird.
Thanks All, Pete
 
My 1933 Chev had adjustable lifters. It was an overhead valve motor, so I would run it at idle and turn the adjusters and check the clearance while it ran.

Seemed O.K. at the time .

Marc
 
Flamingo,

Yes, you are correct. That's why I stated that it was an overhead valve motor.

Also, I'm not sure that my method was correct, i.e. with the motor running. I just figured out the method on my own, as I didn't have much help when I was working on the car.

Posting it here, I'm sure that others would comment or maybe think that there is a way to run the Model A engine while you made the measurements ?

Marc
 
marc hildebrant said:
Flamingo,

Yes, you are correct. That's why I stated that it was an overhead valve motor.

Also, I'm not sure that my method was correct, i.e. with the motor running. I just figured out the method on my own, as I didn't have much help when I was working on the car.

Posting it here, I'm sure that others would comment or maybe think that there is a way to run the Model A engine while you made the measurements ?

Marc
Click to expand...
Let some eles do it.
 
Peter J said:
I have heard that adjustables can be a pain. I may just grind the solid lifters for now and see how it turns out. Hopefully I can solve some mysteries. I still can't figure how the clearances got so weird.
Thanks All, Pete
Click to expand...

Peter, I think you meant to type "grind the valve stem" rather than "grind the solid lifter". Following Brent's suggested clearances will give you good results.
Dave in MN
 
Of course your right Dave, I meant the stems rather than the lifters. Brent's clearances look good also.......Thanks All !
 
If you have a grinder or disk sander, make a jig to hold the valve stem straight and vertical. Grind off a little at a time and cool it before checking the new clearance because grinding makes the stem hot and it expands giving you a false clearance reading.
 
Patrick L. said:
How much work do you want to get into ?? I'm sure you probably mean .013" for the exhaust which will be fine as is.. I'm thinking you mean .004" for the intakes,, thats a bit thin but it'll run.. You will have to pull the cylinder head to adjust the intakes, because the valves do have to come out like the others stated.. To grind the stems you need to find someone with a valve grinding machine to trim a bit off the ends.. Make sure you mark each one so they can go back in the same hole and take the clearance measurement to the shop that has the grinder.. As long as you do have clearance on every valve it won't affect the compression test..
Click to expand...
Patrick, if it's an old engine I see no problem grinding the valve stems off at your home shop on the bench grinder. I have done this to two different engines with good results.

Personally I like them a little looser than the numbers mentioned here. about .015 & .017 or even .017 all across.
 
You must log in or register to reply here.
Back
Top