Hand lapping valves

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cannucky

cannucky

The Guy With No Birthday
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Just finished my first head and have a couple of questions . Is it normal for the smaller exhaust valves & seats to have a much smaller grey line ? All four exhaust valves came out the same but are about half the thickness of the line on the intake valves & seats which also came out the same as each other . They all also came out the same consistant colour and line thickness with no pitting or scratches etc so is that allI really want from this process or should I keep going until the exhaust valves& seats match the intake ?
 
In years past I use to do a lot of hand lapping, still have my double ended wooden dowel with the two different size suction cups and a few cans of fine or coarse grit paste compound. What you what is a continuous line on the valve and the seat and the more even in width around the valve and the seat the better. This means you have a good seal, stop right there.
 
I am assuming (and maybe assuming too much) that the exhaust valve and seat are cut at a 1 degree difference in angle so that the contact when new is just at the outer edge of the contact between them. If that is the case, then a thin line at the outer edge is all you should get.

I have always assumed this is done on the exhaust side to keep the hot gases in the combustion stroke away from the main contact face of the exhaust valve, as it runs a lot hotter anyway, and this would help avoid burning through the exhaust face/seat. (But corrections to that thinking may be in order!)
 
I have done a crapload of them by hand over the years and I'd be real happy to see what you are seeing right where they are now.
 
Heres a couple of pics of what I have done
magnify_2016-09-18_11-33-08.jpg
magnify_2016-09-18_11-28-01.jpg
 
inertia said:
imho the intake seat is too high and try another valve or a touch of 30* stone.. 3/32 is what I prefer as a seat width, with an interference angle of 1*.
The exhaust seat is difficult to see, but likely needs a touch of 60*..
and perhaps 30.

Lapping may not be your best choice, even tho they held fluid for hours/days.

You sure know how to put a guilt trip on a guy for yrs..

I'm sorry you made me have to choose between familly/grandkids/trophy/championship vs. your heads-waiting weeks for parts that are a day away..

Sorry you couldn't wait a few days , after waiting weeks for parts..

I may never try to help another person again, the guilt trip when I fail has too high an emotional ... whatever..

I can't believe last weekend was my proudest, and this weekend the saddest

FB_IMG_1472074897159.jpg
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wish you well..

I resign..
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As I read this post I must reply......Dear Brother, How deeply in my bowels I feel what you are saying. My stomach is in knots with empathy. Sometimes I read these threads and go, "No way, no way, will I become involved this grand nonsense."

SGBARRACUDA said:
In years past I use to do a lot of hand lapping, still have my double ended wooden dowel with the two different size suction cups and a few cans of fine or coarse grit paste compound. What you what is a continuous line on the valve and the seat and the more even in width around the valve and the seat the better. This means you have a good seal, stop right there.
Click to expand...
In years past I use to .....hint, hint.

Marcohotrod said:
the exhaust valves should have a wider seat , to transfer the more heat.
Click to expand...
Very true!
 
Well I opened this thread to get advice from those that have done this , not to start a shyte show .For the record I have never asked Grant (Inertia)to choose between his family and my heads or any other work he has done for me .I considered him my friend and have never said an unkind word about him . In June when I was asking around about which machine shop I should send them to Grants answer was none , he insists I give them to him so in July thats what I did .I know he has a full plate and after calling him every couple of weeks to see where we are at it has become pretty obvious he has neither the time nor the inclanation to do them so I picked them up saturday and here we are .
Grant at no time did I say anything to make you feel guilty until this very moment , All I can say is it's a shame you couldn't just pick up the phone and talk to me like an man instead of posting here and making it seem like I was pressuring you to make a choice that you know damn well I would never do , any guilt you feel over your failing to live up to your word is just that your failure not mine .I've told you several times in the past that you owe me no apologies well you sure as f@$k owe me one now .-Chris
 
SGBARRACUDA said:
In years past I use to do a lot of hand lapping, still have my double ended wooden dowel with the two different size suction cups and a few cans of fine or coarse grit paste compound. What you what is a continuous line on the valve and the seat and the more even in width around the valve and the seat the better. This means you have a good seal, stop right there.
Click to expand...

x2.
 
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