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Subject: Head bolt replacement

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Bw    Posted 11-09-2020 at 01:40:36 [URL] [DELETE]        [Reply] [Email]  
  • Head bolt replacement
  • Am about to reassemble the motor on my 50 8N and forgot to source new head bolts. I know this has been discussed a few times looking thru the archive section but thought I would ask again for clarification.
    Would it be acceptable to use standard grade 8 bolts for the head? I have only found 2 1/2 rather then 2 3/8 but could cut them down if that is advisable? Also, The head size is 5/8 rather then 11/16, is that a problem? Would flat washers Or lock washers help (or hinder), that would take up most of the 1/8 difference in length if I didnt cut them down?
    I did see some suggestions in the archives on where to source originals but I would it would put me back a couple of weeks waiting on delivery.
    Thanks again

    Tim Daley(MI)    Posted 11-10-2020 at 06:28:48 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • The SEP '51 MPC has the length size wrong as pointed out. This is the one that is copied and reprinted as the '39-52 MPC. It lists the head bolt, p/n 8N-6065-A as 7/16-14 x 1-3/8" and it should be 2-3/8" long. The '49 MPC in our Manuals forum is missing page 29-A that has this info but the previous sketch of the parts exploded view has it shown, but not sizes. tat MPC shows PG 29 ending with p/n 9N-6018 and then PG 30 beginning with p/n 9N-6149. The correct hex head bolts are also shown and listed in the May, 1950 MPC, page 63, (NOT in the forum list) and they both have the correct length at 2-3/8". It stands to reason as the previously used 18-6066 studs were 2.78" long. FWIW: The head was changed in '50 too as p/n 8N-6050-A at s/n 263843. You might try calling McM-Carr and ask about shipping to Canada. I suspect it isn't their shipping end but most likely customs holding up things. I'd rather have to wait to get parts from them instead of having to buy from a local hardware store, fastenal, or worse, tsc, where they'll charge you $2-$3 per bolt! When I worked on the late Farmer Dan's 1940 9N two years ago to remove the Sherman Head he had on it, he initially had installed stainless steel hex bolts with the OEM 11/16" AF size on them. I remember that because I had to remove the throttle linkage and bracket bolted to the head too and modify a 01A-17017-B grinding clearance around the wrench head to clear the boogered up bracket. A standard 11/16" socket wouldn't clear.

    Tim Daley(MI)

    Steve Dabrowski    Posted 11-09-2020 at 18:32:48 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • You might try McMaster as Tim says, but look for large head bolts, I bought some of these in 5/8 for my loop rims, so I would have the original head size. They are extra strength and come in course threads and are available in standard partial threads.

    carl nny    Posted 11-09-2020 at 15:44:04 [URL] [DELETE]        [Reply] [Email]  
  • Re: Head bolt replacement
  • Some confusion here.. TD and TOH are saying 1-1/2 inch and you said 2-1/2 inch.. Just wanted you to be clear on the size..

    Carl nny

    TheOldHokie    Posted 11-09-2020 at 15:57:26 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • I regurgitated what is in the MPC but I realized almost immediately 1-3/8" sounds way too short. That has to be a missprint. FWIW YT sells 3" head bolts which sounds too long. Best to measure the head before purchasing but 2-1/2 sounds more likely.

    TOH

    BW    Posted 11-09-2020 at 17:15:56 [URL] [DELETE]        [Reply] [Email]  
  • Re: Head bolt replacement
  • The originals are 2 3/8...going to purchase 2 1/2

    BW    Posted 11-09-2020 at 12:14:07 [URL] [DELETE]        [Reply] [Email]  
  • Re: Head bolt replacement
  • Thanks for the replies, I will be picking up some bolts today.
    Tim...the problem with ordering from your guys is that I am in Canada and everything I have been ordering so far takes a minumum of a couple weeks to come in. With sipping/duty ect it is best to source some of these locally.

    Thanks again...this site has been a huge help with my project

    TheOldHokie    Posted 11-09-2020 at 08:45:06 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • Standard grade 8 bolts without a washer will work fine. If you want a little more spread on the clamping force I would recommend these - $8.83 for a bag of 10 and you will need two bags.

    TOH

    JMOR    Posted 11-09-2020 at 17:46:58 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • One thing for sure, if still available,given inflation, the cost from CNH will probably knock you down! Last I bought made me sit down in 2003 , at $50 for the set! 8N6065A

    TheOldHokie    Posted 11-09-2020 at 19:38:06 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • But they are "OEM" ....

    TOH

    JMOR    Posted 11-09-2020 at 23:45:53 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • If there is a 'next time', I won't make the same mistake twice. Hey, I was just a young whipper snapper at only 59 back then. :)

    JMOR    Posted 11-09-2020 at 17:48:55 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • correction, receipt says 2001.

    Tim Daley(MI)    Posted 11-09-2020 at 05:46:27 [URL] [DELETE]        [Reply] [No Email]  
  • Re: Head bolt replacement
  • The Ford N-Series head, p/n 6050, never used any washers -see MPC's. Grade 8, 7/16-14 x 1-1/2"L bolts will work fine. Industry standard is now 5/8" AF (Across Flats) but seems I found some at 11/16" somewhere -CRS taking its toll. I use McMaster-Carr for most of my hardware. NO 2-WEEK WAITING - Order it today, it's here usually a DAY or two later. Here's the LINK to a pack of 25 for about $13 shipping not included. Head takes 18 bolts. Take a drill smaller than 7/16 and use it as a guide to check the depth of each hole. If there is a blind hole, I can't remember if there are or aren't, and if so, calculate width of head and add or subtract to o/a length of bolt to see if they clear. You want to be safe, place a nut on the end of each bolt and dust off length to 1-3/8". Hand roll a small chamfer on the end of threads. The nut can then be removed which will deburr any remaining burr/rough edge on the end so bolt screws in easy.


    Tim Daley(MI)

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