Another Thing On Valve Jobs

[John Saeli]

Years ago when we did a valve job, we'd use Prussian Blue, and if the pattern looked right, we moved to the next valve. Years ago most components were "Made In The USA" and you could trust the parts. Not today. For that reason, a modern professional shop will vacuum test every port when they are done. Strangely, even though you can get a perfect pattern, every once in a while a valve will leak and not hold vacuum. Usually turns turns out the valve face is not perfectly true, or the Guide isn't true. I wouldn't let a shop do my valves if they don't vacuum test. I sometimes hear from my customers, "My guy says you are full of $hit, been doing valves for 40 years and doesn't need a vacuum tester. Never heard of 1". OK.
I should have put this picture in my earlier post. This is what a finished CASE Power Cell "Lanova" Head should look like. All models. Intakes Flush, Exhaust Valves no deeper than 1-1/8" down.

Today, I still use Prussian Blue, but if I have a problem, I then use a paint pen, which will usually tell me what's going on.

 

[Brown David]

Anyone who won't do a vacuum test has no business doing head/valve jobs.

 

[rustred]

well there is a one degree interference angle for seating the valve quickly once running. are u using it? or just 45 degree on the seat and valve? i also did valve grinding before and did not even hear of the vacuum thing , nor was it mentioned in my schooling. and of course you checked the seat with bluing or just pencil marks. plus the new valve face gets checked in the resurfacer. must be a new thing now to vacuum them ?

 

[John Saeli]

well there is a one degree interference angle for seating the valve quickly once running. are u using it? or just 45 degree on the seat and valve? i also did valve grinding before and did not even hear of the vacuum thing , nor was it mentioned in my schooling. and of course you checked the seat with bluing or just pencil marks. plus the new valve face gets checked in the resurfacer. must be a new thing now to vacuum them ?

I like the white paint pen better than a pencil. Vacuum testing valve seats have been a must for many years. Maybe alright to get away it w/ a gas head, but definitely a must for diesel heads.

 

[Brown David]

I like the white paint pen better than a pencil. Vacuum testing valve seats have been a must for many years. Maybe alright to get away it w/ a gas head, but definitely a must for diesel heads.

Yes, you could likely get away with it on gas heads, but why would anyone want to?

The whole point of doing a valve/seat/head job is to seal the combustion chamber as tightly as possible.

 

[rustred]

and also when you shave the head , .010 is kinda the minimum , .020 is pretty normal that would be replacing what you lost in the valve recesssion. whats your thoughts on that?

 

[John Saeli]

and also when you shave the head , .010 is kinda the minimum , .020 is pretty normal that would be replacing what you lost in the valve recesssion. whats your thoughts on that?

You shave a CASE Lanova head .020" and you've destroyed it's integrity. Never more than .005", and more like .003" simply to true it up if needed. Actually any CASE head. No vacuum tester??!! Shave a head .020""??!! What kind of a shop are you running anyways?

 

[CasebyCase58]

Pulled these heads off an 800-B. I was told it ran when parked but cannot confirm. Are these heads going to need some rework? Definitely not flush.

 

[jon f mn]

Pulled these heads off an 800-B. I was told it ran when parked but cannot confirm. Are these heads going to need some rework? Definitely not flush.

They don't look as bad as some, not likely cracked at least since there is no pitting. But I'll bet it didn't start well. New valves and seats will fix those up nicely.

 

[John Saeli]

They don't look as bad as some, not likely cracked at least since there is no pitting. But I'll bet it didn't start well. New valves and seats will fix those up nicely.

Jon: Look closer. Massive pitting.

 

[John Saeli]

Pulled these heads off an 800-B. I was told it ran when parked but cannot confirm. Are these heads going to need some rework? Definitely not flush.

Unacceptable valve recession and check for a crack. The pitting in the combustion area is a sign of coolant. If it turns out to be a head gasket, it's your lucky day, go buy a lottery ticket. Could also be a cracked head, or cracked sleeve.

 

[John Saeli]

Pulled these heads off an 800-B. I was told it ran when parked but cannot confirm. Are these heads going to need some rework? Definitely not flush.

Oopps!! Should have posted here. Unacceptable valve recession and check for a crack. The pitting in the combustion area is a sign of coolant. If it turns out to be a head gasket, it's your lucky day, go buy a lottery ticket. Could also be a cracked head, or cracked sleeve.

 

[John Saeli]

Oopps!! Should have posted here. Unacceptable valve recession and check for a crack. The pitting in the combustion area is a sign of coolant. If it turns out to be a head gasket, it's your lucky day, go buy a lottery ticket. Could also be a cracked head, or cracked sleeve.

I hate this new site.

 

[CasebyCase58]

Cracked block unfortunately. Coolant rail near the freeze plug. In the process of swapping blocks. The crankshaft was lightly scored, had to get that polished. I assume that that it was from antifreeze in the oil.

 

[Brown David]

I hate this new site.

I took you to be quite a sensible man until you made that statement.

Just joking.... mostly.

The new format is great IMO.

 

[jon f mn]

Jon: Look closer. Massive pitting.

Ive done 9 heads in the last 6 years or so and none looked that good when we started. One had 6 cracks that were repaired. So far none are leaking.

 

[DRussell]

The new format is great IMO.

Clearly not everyone agrees with you.

 

[Brown David]

Clearly not everyone agrees with you.

Clearly that's not unusual. Everyone is different in many ways.

Whenever someone speaks up about not liking the new version I will voice my opinion that it is far superior to the previous mess.

Everytime.

 

[DRussell]

Clearly that's not unusual. Everyone is different in many ways.

Whenever someone speaks up about not liking the new version I will voice my opinion that it is far superior to the previous mess.

Everytime.

I've noticed.

 

[mEl]

Clearly that's not unusual. Everyone is different in many ways.

Whenever someone speaks up about not liking the new version I will voice my opinion that it is far superior to the previous mess.

Everytime.

DB, X2