Hi, Two years ago I bought this '50 Shoebox from a guy in Miami and shipped it to the Netherlands. At the moment I'm tearing apart my flathead to check out what state it is in. When my car arrived one of the things I noticed was the fact that it had two different heads, one was an 8BA and the other an 8RT. Of course, there's not really a physical difference there, only the model of car it went into. But now we took the intake off and found this (see attachment). One of the springs is completely different, and I believe the retainer as well. The other retainers look more like the 1951 type (part 6517), right? As we don't have any other material to compare with, I'm turning to you guys! Thanks in advance! Posted using the Full Custom H.A.M.B. App!
The 8-RT head is a truck head. The difference in the valve keeper is in 1951 they changed over to a system that makes the valve rotate during use. The 49 and 50 valves don't rotate. You can use either one as long as it has the right spring. My guess would be they had some minor problem with the engine and use parts from different engine which will work but are not entirely correct.
Posted it over on the Ford Barn a few moments ago. Thanks! Thanks for the info! The reason I opened up the flathead was (what I thought) was a valve tick, and I'm thinking about changing some valvetrain parts. I was just wondering if someone recognizes these valve assemblies to be '51, so I know what I'm working with. Cool tudor btw!
As you have found, two different styles of valve retainers and springs. Either style will work with a stock lift. The rotating style will have a shorter spring so keep the style of retainer matched up with the spring it came with. If you go with a different grind for the cam, you should go with the one without the rotator. That way the longer spring can be used allowing more lift. Again, as long as the styles stay paired up, either will work. The rotator was the new and improved version. I just did the valves on an engine build and tried to shim the stock springs with rotators to work with a 400 JR. cam. After shimming a bunch I got the seat pressure up but wasn't confident that I had enough lift left. I then switched to zephyr springs and no rotators. I hope it was o.k. to answer this over here rather than posting on the Ford Barn. Neal
If this helps you can try this fellow in germany he does a lot of flathead rebuilds and parts http://oldhotrodparts.de/ A little closer to you Hope this helps
Thanks! I'll check him out sometime. It's not that I can't get a hold of the parts though, just wanted to know what I'm working with. Thanks for the info! Of course, it's okay to answer it here! I think I've got it figured out, my '50 flathead was swapped for a '51 once. Thanks all! Posted using the Full Custom H.A.M.B. App!
i have an 8rt ,they are truck my dad just built up his 8ba for the 52 customline new valve seats were installed.when it was time to fire it up there was very little compression,turns out he had to buy adjustable valves as the stock ones have no adjustment the valve seat height is lower now after machining the old seats out j
Lose the rotaters, just buy new Isky springs and retainers and keepers they are not that expensive. New guides while you are at it.
Wouter, like Gaz34 say try Thedinga in Emmen, very friendly guy and friendly prices and he knows what he is talking about. Groeten Hennie
Watch what the pressure is on aftermarket springs. Isky used to have some that were way heavier than needed for a flathead. A stock spring will cover a lot of cams and the zephyrs will cover 99% of the rest. The seat pressure for the valve springs has been discussed before and what I took from it is many use too stiff of springs. Neal
Yes, I should have been more specific. The 185-G springs are light enough for most street application cams.
Don't the 8RT heads have greater cc volume than the 8BA, something closer to the 8CM? This would mean the 2 heads have different compression ratios.
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