Hi guys, Rebuilding an 8BA and need to replace the entire valve train. This was a stuck engine and needs new guides, valves, springs etc. It came back from my machine shop clear of cracks in the valve seats. Most of the new valve train kits I see all have stainless valves. My question is can I lap these stainless valves into the existing valve seats. I am talking old school here and want to do this withe the suction cup and compound method. Thank you for any help.
I wouldn't recommend it, it would probably work kinda ok but would not be ideal....if he bores don't need machine shop attention I would still have a shop hot tank it to clean out the water passages and touch up he valve saeats
The shop did hot tank it and cleaned it out. Then they magnafluxed and pressure tested. I have a good block. My question was can I hand lap the new stainless steel valves into the existing seats. This is a 53 Merc motor and I believe the Ford valve seats were hardened from the factory.
Hopefully, one of the real knowledgeable guys will chime in here, because it gets a little complicated. If the Mercs are like Fords, by '53, the the insert valve seats had been eliminated and they had gone to rotating valves and (I believe) shorter valves. If the stainless valves you are considering are specifically for the later engines, you may be all right as to length, but if you are thinking Chevrolet valves which are longer than the Ford valves, there may be a problem. Be careful about mixing and matching valve parts on these engines.
Thank you for the response. I understand the difference between Chevy valves and Ford valves. These are Ford stainless valves.
I don't doubt that, but I was referring more to the early vs. late 8BA stuff. If you are going a new valve train, you should have no problem. If you try to use some early parts with some of the later rotator parts, there may be a mismatch. Just a heads up.
I am not an expert, but unless you are building a very high performance engine, stick with original style valves. That way you know it will all fit together and work properly. Post your question on www.fordbarn.com for expert opinions.
Lapping in valves is not a new deal, many engine rebuilds back in the day would sit and hand lap valves to seats. Today there are hand held cutters to clean up the valve seats and then lap in a new valve. small engine shops have done this for years. Is it the best way? ..no, but will it work, yes.. Todays technology and tooling is the best ever and the best way to do the job, just not the only way.. Just one suggestion ...use Marvel Mistry Oil or some other valve lube product during the break in period as new tight valve guides tend to stick the valve just of off the seats where the spring tension is at its lowest pressure.( flatheads don't have a lot of valve spring tension ( 50 to 60 lbs. on the seat ). Sticking is usually caused by carbon build up on the valve stem right at the guide, especially on the exhaust valves. M.M.O. or other valve lube will help keep those stems clean ... I use 2 oz.'s M.M.O. with every fill up even after the 600 mile break in period. I also recommend oils that have some amount of ZDP/ZINK additive package or add it yourself at every oil change.. Most modern oils do not have this additive added anymore ...
Proper lapping is only done to verify a "good" seal between the valve & seat & shouldn't take more than a few minutes per valve ; if the 'fine-line' doesn't show-up right away, either the valve or seat was miss-cut, & needs to be corrected! If it takes 20,000 miles off your rebuild, it was done WRONG!!!
That's pretty much what I thought...so I probably need to drop off the new valves to my machine shop and have them match them to the seats. Then I can do some minor lapping as I assemble.
Check out NEWAY valve seat cutters on google they don't cost much and you can cut your seats by hand .. All that is needed is a pilot and the cutter. I see the pilots on eBay all the time for ford flatheads
RosevilleCarl will have valuable input for you. If he doesn't see the thread, start a conversation with him on your question. He is very knowledgeable on the flatty and helpful.
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