I'm in the process of rebuilding an 53 8BA engine and it is basically a stock rebuild with an Isky 77-B cam. I cannot find a stock set of head bolts so I ordered the Speedway head stud kit Part # 91015310 and in reading the instruction listed on line for that kit it specifically states "NOTE: Do not let any machine shop deck, mill, grind or remove any material from the block’s deck surface!!" this is the first time I have ever heard of this. It goes on to state "Ford made the deck (top of the block) material too thin at the factory! Remember, any material removed will ruin the block. If you over-torque, all you do is pull the deck of the block up at the bolt hole and cause a very uneven surface, which no gasket will ever seal!!" How true is this? My block is currently at the machine shop and he has not started the work yet as we are waiting for the parts to come in so he can set the required clearance for the pistons. If this is true, then I'll tell him not to deck my block. But I'm curious how true this is because I have seen many builds online where the deck is clearly resurfaced. I just want the deck surface the minimum required to have a new sealing surface, not doing anything extra. Any advice will help, thanks.
Over the years I've heard it stated that milling the block deck on a flathead should be avoided. Ask this over on the Ford Barn. They'll give you the straight scoop. How many flatheads has your machinist done in the past? This may be a learning experience for him too. -Dave
I don't know how many exactly, but he has done many throughout the years. This is a well experienced man (older) and the machine shop has been around for 30 or 40 years Its an old-time type of machine shop. He got pictures of hot rod flatties he's done, know where to check for cracks and which are critical asked if he was going to have to do valves or not or if I was going to use adjustable lifters.
Lay a straight edge diagonally across the deck to see if it's flat. If it is flat, don't mill it. However, here's what the pro's say: https://fordbarn.com/forum/showthread.php?t=25340 Read more here: https://www.google.com/search?q=dec...i57j69i60l2.4015j0j4&sourceid=chrome&ie=UTF-8 I just went out and measured the deck thickness of a stock 49-53 Ford/Merc 8BA that has never been decked. The deck measures 5/32 of an inch thick at the water jacket holes. The threaded bolt holes have extra cast metal surrounding them (to allow for threading) and extend further into the block, about 7/8 in. Some of the bolt holes go into the water jacket passages. Personally, I would not mill the deck unless it was in very bad condition. I would follow the directions town sedan gave above. Pay a visit to your shop machinist and take a close look at your current deck thickness.
They said 38 to 48 do the straight edge thing at a shop I worked at we would surface grind heads and leave them a little high in the middle heads would pull down and seal a head that is low in the middle not.
Perhaps I am missing something but, the above post confuses me. Why would you ever grind a head? Does that mean they are put on a belt sander? To my dismay, I have seen this done as a shortcut to an unknowing customer. Heads are supposed to be machine milled flat with no allowance for "pull down". The goal is to have 2 parallel mating surfaces prior to assembly that can be torqued to specs. for a tight seal.
I always have the decks checked and milled to be flat. I don't think we've ever had to remove more than .004 to .006.
They are thick enough to relieve. My 8BA after a little work. No cracks, no pins, no helicoils. Some good ones still out there. Don't get crazy on the milling, but flat surfaces mate better. I also had to mill the new Navarro heads as they were not flat out of the box. A slightly thicker head gasket controlled my compression ratio.
The shop had one of these. With a little practice you could get a head straight with no setup time I did hundreds the shop did mostly head work https://www.bing.com/images/search?view=detailV2&id=5FD8CC45FB01CFB55D934B88B827270D8AD58017&thid=OIP.pbXVitO9UYBBYNvEbVIU1gAAAA&mediaurl=http://cavcosales.homestead.com/publishImages/SurfaceEquipment01CA1889-Peterson_72DE_DryGrinder~~element23.JPG&exph=263&expw=350&q=cylinder+head+surface+grinder&selectedindex=24&qpvt=cylinder+head+surface+grinder&ajaxhist=0&vt=0
I don't know how you leave a block high in the center but there is a lot I don't know. I do know that a flathead camshaft is not in the center and if a BHJ fixture is used things will be all screwed up.
Sorry for the confusion what I was try to get across if the blocks checked a few thousands high in the center the head should seal fine if low less of a chance it will seal.
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