Are there supposed to be three or two lengths of bolts used to hold down ford heads? I have stripped down two 8 ba engines in the last few years and only found two lengths of head bolts. Two don't seem to grab much thread Thanks Rich
3, look at a head, it gets thinner at the bottom. long bolts on top, medium in the middle, short on the bottom
memory says only 2 medium each side... the short ones don't have enough thread... the long ones won't go all the way in... regular hardware store bolts have larger wrench size to thread size than the flattie head bolts...
Two different lengths is all I've found on 3 or 4 8BAs..........unless I'm real confused. A 53 Merc I pulled apart had 2 longer bolts for something.
The three 8BA engines I have taken apart lately all had only two lengths of head bolts, and yes, the the short ones seem to be a little short in those two holes (luckily, I use aluminum heads that take only 45 ft lbs of torque). That being said, a friend sent me a whole bunch of 8BA bolts that he had extra. In the batch he sent, there were a a couple of "mediums". I think Ford decided to save a few pennies at some time in the 8BA production. It would be interesting to know what really went down. I don't think it's a Ford vs. Mercury thing, as one of the engines I took apart was a '51 Merc.
I've pulled apart several 8ba's and only had two lengths of head bolts. The replacement set of head bolts I bough from Mac Van Pelt for my 8ba when I rebuilt it only lad 2 lengths not 3.
One reason why there would be 3 sizes is that if someone installed the exhaust separators into the shared exhaust ports. With the exhaust separators installed you need a shorter bolt or washers installed under the bolt heads. There would only be 2 shorter bolts in this case.
Decided to take matters into my own hands. Went to my buddy's machine shop this am, borrowed a heavy duty die and handle gonna make my own medium size Ford head bolts Rich
Find a nice deep barrel and toss all your bolts in it. Studs are best for Flatheads because they clamp better and let you torque them absolutely to specifications. If you don't like the way they look, add chrome acorn nut covers. This advice from someone who once dealt with blown head gaskets in his wasted youth.
You may want to consider the fact that Fords have a different spec thread than regular bolts. As I understand it, this is to prevent coolant leakage. This is why you should never clean the threads with a "regular" tap; I always use an old head bolt with grooves filed in it.
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