Packard Forum Index » Pre-War (1899-1942)

I was given some good advice regarding valve project and I’m lost as to whether or not to purchase new valves for my 41 110…my exhaust valve guides are really loose so I ordered a set of new old stock guides..purchased the recommended valve guide drivers and feel comfortable that I can remove them….my valves appear to be original with the Packard name on them…I really don’t know if my valves are good to re-lap or not…seats all look nice on block…I’ve attached a photo of one of my valves and they appear the same to me as far as wear and condition….I don’t mind paying for new valves if that’s the correct thing to do …but don’t want to learn later I could have used them…I have a brand new set of valves from a 1940 I believe but they seem slightly larger in diameter..thanks always for the advice….

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It rather goes without saying that when replacing the guides, you should also grind the seats and valves. No point in all the work otherwise, at least in my experienced opinion. You probably don't absolutely have to but it would be best to do it and get it done right at the same time.

As far as replacing the guides yourself, my fear is in cracking the block which is why I always without fail have it done professionally. I can do nearly anything needed on a car and have done so all my life but I draw the line there.

De-carbon valves and valve pockets. Wire wheel is good for valves and 1 inch knotted wire brush in a die grinder or drill works great for pockets. Mic your valve stems in the wear area. Make sure they are in spec. After installing the new guides check the valve fit in the guide. If in spec, grind valves to angle. Grind valve seats (3 angle job) and lap valves to seats. If you don't have the grinding equipment, find somebody who does. You can bring them the valves but they'll have to come to you to grind the seats unless you take the car somewhere to have the job done. You want your valve seats concentric, so you're going to pilot the grinder off the new guides. Do the complete job once, and do it right. Saves money and aggravation down the road. PB

Ok thanks for the help..I will do exactly that…I can get my hands on a valve grinder….want to do it correctly..tks

The three angle seat job is still confusing to me…in what order with angles…45 to 30 to 60?

Quote:

Exhaust valves should have a 45 degree seat. Intakes should have a 30 degree seat.

The 3 angle valve seat goes lowest to highest. 30-45-60 for the exhaust. I did 20-30-45 for the intakes (mostly 20-30 because I didn't have room to add a 45).

Have the valves refaced at 45 for exhaust and 30 for intake. Then grind 45 seats in the block for exhaust and 30 for the intakes. I then marked where the seat was located on the valve face by coloring the face with permanent marker, placing the valve in the block, then gently twisting the valve a little to mark where valve and block contacted. I then used the 30 and 60 stones to adjust the location of the seat on the valve face, as well as the width of the seat. My understanding is that the seat should be located in the middle to upper third of the valve face, and should be about 2mm wide.

I just did this on my brother in law's '52. Haven't finished doing other things so the valves are not reinstalled and the engine hasn't been tested. But from talking to guys who rebuild engines, it sounds like I did a halfway decent job. See the blog here:

Grinding initial seats and valve refacing

3 angle seats and lapping valves