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Re: Change head bolts to grade 8?

Thu Dec 13, 2012 7:22 am

There you go, Bob came through with the lengths for you. 3 1/4" is readily available but 2 3/8" is not. Just get 2 1/2" and shorten them 1/8" and you'll be good to go. I get the bolts from McMaster Carr because having ordered a lot of stuff from them over the past 25 or so years, I've always received good quality merchandise. Also, if you order today, you'll have it tomorrow. Their service is quite amazing!

Re: Change head bolts to grade 8?

Thu Dec 13, 2012 7:42 am

It is much better to take your time and get the bolts out with the head still on the bolt :D I will rap it with a big hammer and use an air wrench with the air cut back and let it beat on it some that will in most cases break the rust a loose. I use the factory head bolts. I believe they are grade 5s. As Carl said drop back on the torque when using anything on the threads from sealer to anti-seize. I like the old tried and true Indian head gasket shellac
http://www.ebay.com/itm/Permatex-Indian ... 1b&vxp=mtr

You want have to worry about leaking threads :wink:

Re: Change head bolts to grade 8?

Thu Dec 13, 2012 3:01 pm

The block should be back from the shop soon. I'll take in all of the data posted from you guys and we will talk about it while the ribs cook on the pellet grill. If we can't decide on the proper grade to use, we will use that as an excuse to put a turkey on. Maybe some Elk burgers wraped in maple bacon will help us decide if the blade should be mounted on the front or under the belly.


Thanks everyone.
Last edited by Dennis on Thu Dec 13, 2012 4:15 pm, edited 1 time in total.
Reason: Removed non-related advertising link

Re: Change head bolts to grade 8?

Fri Dec 14, 2012 8:32 am

Well, at least you have a good handle on proper decision making!

Re: Change head bolts to grade 8?

Fri Dec 14, 2012 10:01 am

Gary Dotson wrote:... I get the bolts from McMaster Carr because having ordered a lot of stuff from them over the past 25 or so years, I've always received good quality merchandise. Also, if you order today, you'll have it tomorrow. Their service is quite amazing!


I talked to a fellow that used to work at a McMaster Carr warehouse/distribution center. One million square feet of floor space. Their goal was to have your order on the UPS or FEDEX truck within 16 minutes of receiving it. And, yes that is amazing.

Re: Change head bolts to grade 8?

Fri Dec 14, 2012 11:34 am

Wonder how many pick-ups they have at that facility every day? I really love the selection of things on the McMaster website!

Re: Change head bolts to grade 8?

Fri Dec 14, 2012 1:22 pm

16 minutes tells you that you're getting what you click on and no turning back. Warehouse fulfillment in this day and age is amazing!!!

If you put grade 8 washers under the head of the bolts, you can use regular 2-1/2's and don't have to bother cutting them off...

Re: Change head bolts to grade 8?

Sun Jan 13, 2013 9:44 am

Gary Dotson wrote:There you go, Bob came through with the lengths for you. 3 1/4" is readily available but 2 3/8" is not. Just get 2 1/2" and shorten them 1/8" and you'll be good to go.


Are these the correct head bolts for the Cub?

http://www.fastenal.com/web/products/de ... ku=0153946

http://www.fastenal.com/web/products/de ... ?sku=15116

Re: Change head bolts to grade 8?

Sun Jan 13, 2013 11:02 am

i dont ever use bolts greater the grade 5 especially for head bolts. Lock tight is a no no in my book for head bolts as well. If you have a problem in the future with a valve or something It is a good chance if you brake a grade 5 bolt you will be able to drill it. with a grade 8 or higher it might cause a lot of trouble should one brake off especilly using lock tight. I have rebuilt a few engines that someone used a real hard bolts for head bolts. have had atleast one brake and sometimes up to 5 brake. No drill bit i could find anywhere would work. I ended up burning the bolts out then redrilling everything to the next size up.

Re: Change head bolts to grade 8?

Sun Jan 13, 2013 6:45 pm

If I entered the information into the fastenal website correctly, a grade 5 3/8"-16 x 2 3/8" zinc plated bolt is $0.91 each. Are the Case IH bolts zinc plated or are they something else? That seems to be a huge price difference.

Re: Change head bolts to grade 8?

Sun Jan 13, 2013 8:14 pm

cubbrian wrote:If I entered the information into the fastenal website correctly, a grade 5 3/8"-16 x 2 3/8" zinc plated bolt is $0.91 each. Are the Case IH bolts zinc plated or are they something else? That seems to be a huge price difference.


They are something else. One thing they can't be is grade 5 and meet the 45 lb torque spec. Suggest you read the complete thread. Personally, I would only use grade 9 and trim them to the correct length so they don't rust in the coolant chamber by being too long, goop them with Rectorseal #5 and retorque them after the first thermal cycle. http://www.fastenal.com/content/feds/pdf/Torque-Tension%20Chart%20for%20A307%20Gr5%20Gr8%20Gr9.pdf

Re: Change head bolts to grade 8?

Sun Jan 13, 2013 10:26 pm

I used the zinc plated ones because they will provide a little more resistance to corrosion than the plain bolts. Thread sealant and go.

Re: Change head bolts to grade 8?

Mon Jan 14, 2013 1:12 pm

Seems if you have to cut the bolts it would destroy the zinc plating.
Lots of different opinions on what should be used. :?:

Re: Change head bolts to grade 8?

Mon Jan 14, 2013 1:25 pm

If you don't cut the bolts the threads stick out into the water jacket. When they do that eventually they will rust. When they rust you will never get them out without snapping them. Original bolts were not plated. All plating does is slow down the inevitable. Put a plated bolt in that is too long, the threads will rust. Rust on the very end of the bolt will not gum up the threads if it is trimmed properly. The original bolts had to be better than grade 5 otherwise they would not make the 45 ft-lb torque spec before failure. If you are worried about opinions, spend the money on factory bolts and sleep well knowing you have done your best- but still use a thread sealer, like the PTFE paste I suggested to keep coolant from weeping up the bolts and leaking at the head as this is known to happen.

Re: Change head bolts to grade 8?

Mon Jan 14, 2013 4:10 pm

Fastenal carries the correct size in zinc plated grade 8 but I guess that won't work?
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