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Posted By Discussion Topic: '37 21-stud Sharp Head stud alignment issue     gninow 07-03-2022 @ 4:55 PM reply profile send p.m. Member Posts: 3 Joined: Apr 2022 I'm now at the point where I can begin the reassembly of my '37 21 stud early ford flathead. I was about to check the valve and piston clearances the new Sharp heads I bought from H&H Flathead. Although the '37s came with dome pistons, mine has flat tops, so the heads were custom milled to accommodate flat top pistons and still provide 8.5:1 compression ratio but, it's a good practice to check clearances. The problem I'm having at the moment is, after installing the new head studs (yes, I checked that they were straight using my machinist's stone), I cannot install the heads over the studs without persuasion - and I simply do not want to come to blows with these nice new heads. I lit the underside of the heads after I positioned them over the studs to see which studs were hanging up and discovered one stud is about 1MM off the centre of the hole in the head. The holes machines into the head are 12MM and a hone will be fine to get those holes to allow clearance for the head to slip on without coming to blows. But, the one stud that's off 1MM is going to need to be bore/drilled/machined out 1MM - my question is this; is it okay to drill/mill/bore that one hole out to 13mm? Your experienced advice would be appreciated. The engine is to be installed in my '35 3Window Coupe. Cheers. UPDATE: Here's the current state of affairs - when installing a new clean and dry stud into the block, the stud has normal clearance which means, it wiggles side to side - these studs and holes are not machines to tight tolerances and therefore, can be a bit off the perpendicular to the block surface and therefore, cause minor fitment issues. But, once the stud is installed into the block with sealing compound and the stud is installed into the block to the hilt, there is no guarantee the stud will seat perpendicular to the head surface and therefore, some minor adjustments with a reamer will be in order. This is the case for my new heads. The heads that came off my block originally came off without a fight. I have checked out the head stud holes and they are 14MM average diameter - the new head holes are 12MM. The 14MM holes allows the head to 'move' a tiny bit once seated over the block and therefore, the reason they came off easily. Since my heads were '37 OEM aluminium, there is no telling if they were used on my block exclusively or several others through the years. I've ordered a 1/4-1/2 reamer which will arrive tomorrow and will ream all but the one stud that is the worst, at which point I will check fitment before I plunge a 13MM end mill bit through that hole - wish me luck folks! I will report back - cheers. This message was edited by gninow on 7-6-22 @ 9:23 PM 50CaPU 07-03-2022 @ 5:06 PM reply profile send p.m. Member Posts: 28 Joined: Dec 2009 Although the stud areas should be beefy, for the cost of the heads I would not accept a machine job done incorrectly. IMO H&H should make it right and re machine another head for you. T. Tim Downtown, Ca ford38v8 07-03-2022 @ 5:30 PM reply profile send p.m. Senior Posts: 2739 Joined: Oct 2009 I agree with 50caPU, but find it very strange that one hole would be incorrect on the head. You might save yourself an argument with them if you switch heads to see if the other one is the same, and also, maybe your block has been reworked? You also say that the heads were milled deeply, perhaps at an incorrect angle? If push comes to shove and you use the off center head by redrilling, the opposite side of that hole may wind up too close to the head gasket to seal properly. Try verifying that your block is not the problem before hitting on H+H. I don’t envy your situation. Alan 40 Coupe 07-04-2022 @ 5:03 AM reply profile send p.m. Senior Posts: 1650 Joined: Oct 2009 After installing the stud in the block, is it perpendicular to the block deck, check in a couple of different planes. There could be a problem with the stud or the blocks threads. marko39 07-04-2022 @ 5:29 AM reply profile send p.m. Member Posts: 40 Joined: Sep 2016 Try a different stud first. 1934 Ford 07-07-2022 @ 1:32 PM reply profile send p.m. Senior Posts: 568 Joined: Oct 2009 I don't envy your problem, but want to share that 21 stud flathead engines are always a tight fit, both on and off. My head puller, made from a spark plug base and a slap hammer is always hard to get the heads off going straight . up the studs. Getting them back on is also a chore. i agree that a different stud is a good idea, it would be a shame to ruin the threads in re-assembly. 1934 Ford's since 1972 zeke3 07-07-2022 @ 6:50 PM reply profile send p.m. Member Posts: 77 Joined: Apr 2011 I am planning to make a couple of drill guides to drill out a cylinder head stud that broke on my 1937 21 stud engine. My cylinder heads are cast iron and the hole size is 0.466", 14 mm sounds like it will be way too large for the hole size. I agree with Tim above, you should go back to the supplier before modifying them. gninow 07-10-2022 @ 10:55 AM reply profile send p.m. Member Posts: 3 Joined: Apr 2022 After all the input here and speaking to H&H I decided to be conservative and bought a very expensive .5" bit (12.7MM) and plunge to through all the holes. It took some considerable time and it fit, that is with one exception - the most off centre of the lot so, I went ahead with the clearance check and afterwards using two nuts to lock I sinstalled the problematic stud into the hole through the head. I've marked the top of that stud with an "X" using my mini-dermal as a future reminder which stud was problematic. I'll also make a note in my log book about the issue for the next owner - sometime after I've gone to the Big Show! The head still sits quite tight over the studs so I do not expect there will be any issues once the car is on the road. This message was edited by gninow on 7-12-22 @ 4:43 PM gninow 07-10-2022 @ 10:57 AM reply profile send p.m. Member Posts: 3 Joined: Apr 2022 I think I'll build a head puller for myself - would love to see an image of your puller. Cheers.

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