400 450 new LP head

Ed Mock · Nov 22, 2015

Any idea how much machining and cost is required on the new LP cylinder heads that are currently being offered without valves (part # 364586R11)? These heads are being offered by Yesterday Tractors. There is a good photo on their website.

fastfarmall · Nov 22, 2015

I got a 450 LP. Mine is still good,but have wandered the same thing,i was going to ask at the machine shop, next time i am there !!

D Slater · Nov 22, 2015

One report on page 2 of the pulling forum, both classic and modern. getting close to going on page 3 in classic though.
If the valve guides have the proper valve stem clearance and relationship to valve seats it would be a simple job with new valves, provided all surfaces and bolt holes are correct.
Machine work varies from place to place but should be a modest fee to check them unless guides need work or valve seats need anything but a touchup. Then shouldn't be more than a regular valve grinding job for just a valve seat job. In a perfect head and valves they could just be installed and run, but always check because probably not. If any surface needs cut that will add to cost. Machine shops don't have much competition in my area. Last one I had surfaced was $80. That maybe reasonable but getting older so everything seems high in relation to what I was used to in past.

rustred · Nov 22, 2015

i am sure it would still be the regular valve grinding price, what ever they charge. buy the time you buy valves and seats it will not be cheap. you didn't specify if the head has the seats or not. but any time new valves and seats are used both must still must be resurfaced to get proper valve seat width and position on the valve. you cannot just install them just because they are new and call it good. don't work that way. the only thing you would save money on would be the soaking and cleaning costs.

D Slater · Nov 22, 2015

After reading the head description on YT it looks like you have to do machining just like you would if new guides were installed in a head and not sized. Since they sell new valve kits with them looks like they would at least size the guides when built unless the new valve quality is not the best on stem sizes being equal. Never looked at one so maybe they didn't make them with replaceable guides like originals, don't know. Also says customer is responsible for surfacing if needed. Think all those heads are from the same source no mater the seller.

mattwillson · Nov 23, 2015

I bought one of those LP heads from YT and of course the valve kit as well. I lapped the valves into each seat and assembled it. The only issue I found was that the casting needed to be clearanced around the push rods.....that kind've sucked as I already had it bolted on the engine. It's been a year since I installed it and works fine. The spark plug threads are a bit sloppy, so one of these days I may have to heli-coil them. Compression went from 75psi to 155psi, in case anyone is interested, and I had to adjust the waste gate on the turbo to lower the boost to around 10 psi.

400 450 new LP head

Ed Mock

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fastfarmall

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D Slater

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rustred

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D Slater

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mattwillson

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