valve help needed

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4evr fixin
Posts: 15
Joined: Sun Apr 06, 2014 9:26 pm
Zip Code: 16053

valve help needed

Postby 4evr fixin » Mon Apr 04, 2016 9:26 pm

So I was hoping to restore compression by doing a quick valve job on my 49 cub. Unfortunately someone beat me to it. Instead of a narrow even seat 6out of the 8 valves have been lapped until the entire face of the valve is in contact. Which has the valve sitting pretty low in the port. I understand from several other posts that several people have bought the neway cutters for the valve seat but i think i need to relieve the area below the seat so it no longer contacts the valve. any ideas? if the 45 degree cutter was used to make the seat (or the factory spec 45 1/2) would you use a 46 degree cutter to relieve this area? Not even sure if the one i found that they had will fit down in to it.

tst
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Re: valve help needed

Postby tst » Mon Apr 04, 2016 10:08 pm

what shape are the valves in, I have found many times they have been ground down between wear and the grinding they fall to deep in the seats, so check the diameter of yours to new ones, intakes seats do not wear like exhaust and most of the time survive, the exhaust seats there is not much meat to grind a lot of metal out of them, I top them with a 30 degree seat to lower the valve contact but there is not much room to do so, so new seats have to be installed if worn badly

4evr fixin
Posts: 15
Joined: Sun Apr 06, 2014 9:26 pm
Zip Code: 16053

Re: valve help needed

Postby 4evr fixin » Tue Apr 05, 2016 6:03 am

Since I was using new valves I didn't bother checking the old ones or keeping track of where they came out of. The new valves are still above the top so I think it will be ok. At least according to the service manual pics. But I'm thinking the seat is too wide and will trap carbon and it will be back to square one.

Gary Dotson
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Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
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49 Leader "D" (Princess)
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Re: valve help needed

Postby Gary Dotson » Tue Apr 05, 2016 7:38 am

I cut my seats with a 45 deg. cutter, then bring the bottom of the seat up with a 60 deg. cutter. If needed, I lower the top of the seat with a 30 deg. cutter. I coat the seat with dy-chem, or sometimes a felt tip marker, so I can see how the seat is coming in. Yes, I prefer to use Nuway cutters.

4evr fixin
Posts: 15
Joined: Sun Apr 06, 2014 9:26 pm
Zip Code: 16053

Re: valve help needed

Postby 4evr fixin » Tue Apr 05, 2016 9:19 am

Thanks Gary I was wondering about the 60degree cutter and if it would cause any problems being too sharp an angle. But if it works that's probably what I will get. Sucks to buy it for a one time use but sometimes that's the way the cookie crumbles. What diameter did you get? Is one inch about right?

Eugene
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Re: valve help needed

Postby Eugene » Tue Apr 05, 2016 9:27 am

Small engine shop will probably have a valve seat grinder. Probably cheaper to have the shop touch up the seats than to purchase the cutter/stone.
I have an excuse. CRS.

4evr fixin
Posts: 15
Joined: Sun Apr 06, 2014 9:26 pm
Zip Code: 16053

Re: valve help needed

Postby 4evr fixin » Tue Apr 05, 2016 10:17 am

Yeah they should have. Unfortunately none around here seem to they all want me to remove the engine completely tear it down and bring them the block so they can take it to a machine shop to get it done. I would love to completely rebuild it but I use it pretty regular and don't have time or money for that right now. Plus none of them can give me a time frame. Could be a day to a month. And they don't seem to want to tell me where they take it so I can deal with them directly. One guy did call and gave me the machine shops prices but it's a guy who has a full time job so it would be whenever he gets around to it. Will probably cost about double but I won't have to buy a lot of extra parts..... Might blow up in my face but I think I'm going to just save the hassle and do it myself.

Eugene
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Re: valve help needed

Postby Eugene » Tue Apr 05, 2016 11:35 am

Neway has a Briggs valve seat grinding kit also lots of stones for purchase. The stones are fairly reasonable if you have the rest of the valve seat kit. They also have kits for rent. It will take some measurements to see if the stones will fit in the Cub engine.

I would go with the 45 and 45 1/2 degree cut.
I have an excuse. CRS.

Gary Dotson
Team Cub Mentor
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Posts: 3075
Joined: Thu Aug 03, 2006 6:20 am
Zip Code: 43358
Tractors Owned: 48 Cub Diesel (Cubota)
53 Cockshutt 20 restored (Shooter)
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47 Leader "B" (Herckie)
49 Leader "D" (Princess)
49 Leader "D" very rough
48 Leader "D" unrestored
Kubota B6200E
Kubota B6200HST
Kubota B8200HST-D
Circle of Safety: Y
Location: OH West Mansfield

Re: valve help needed

Postby Gary Dotson » Wed Apr 06, 2016 8:28 am

I don't recall which cutters I used but 1" should be about right. The cutting blades can be adjusted in or out to suit your needs. I have the automotive cutters (about 10 cutters in my set) but for the Cub, the lawn & garden cutters will work fine. For the 5/16 pilot, you'll need a fairly short one and the lawn & garden pilot will work well. I had to shorten one of my automotive pilots for the Cub.


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