Erndog Posted July 9, 2022 Share Posted July 9, 2022 Does anyone out there have a good source for head bolts? I have a 1930 Master engine that needs new headbolts. They appear to be 7/16 x 5 1/4 14 tpi. Link to comment Share on other sites More sharing options...
Jim Nelson Posted July 9, 2022 Share Posted July 9, 2022 First, 7/16 - 14 is a standard size ( nat. course thread). A good industrial nut / bolt supply house should have them in stock. Bring a separate head bolt you want to duplicate - length etc. Buy an extra, JIC, Does your head use washers? If so, a few extras also. If you need any suppliers of these, let me know as I have several suppliers including a great local nut/bolt shop. 1 Link to comment Share on other sites More sharing options...
Buick35 Posted July 17, 2022 Share Posted July 17, 2022 I don't know about the 30 model but my 35 shop manual says they shouldn't be tightened more than you can pull with a 9" wrench with one hand. I thought that was pretty technical. Link to comment Share on other sites More sharing options...
raydurr Posted July 17, 2022 Share Posted July 17, 2022 I am pretty sure that the 1929 Buick engine uses the same head bolts. Contact Tony Bult in Whitewater WI. He has them if anybody does. Link to comment Share on other sites More sharing options...
EmTee Posted July 18, 2022 Share Posted July 18, 2022 4 hours ago, Buick35 said: my 35 shop manual says they shouldn't be tightened more than you can pull with a 9" wrench with one hand. That's also exactly what my '38 shop manual says... Link to comment Share on other sites More sharing options...
Mark Shaw Posted July 18, 2022 Share Posted July 18, 2022 1 1 Link to comment Share on other sites More sharing options...
Erndog Posted August 23, 2022 Author Share Posted August 23, 2022 0I acquired 15 bolts from McMaster-Carr. They weren't very expensive and appear to be an exact match. 5 1/4" long vs the original 5 5/32", but should work fine. Link to comment Share on other sites More sharing options...
Jim Nelson Posted August 23, 2022 Share Posted August 23, 2022 These need to be a minimum of 'grade 5' for strength. ( 3 pointed star on the top. Grade 8 have a 6 pointed star on top ). I always use 'grade 8' bolts which are the strongest. (With split lock washers. ). BTW, if the bolt heads do not have any marks then they will be grade 2 which is a no-no. Not strong enough ! ! I use stainless grade 5 min. for the three bolts that hold the water pump. Same on the lock washers. Link to comment Share on other sites More sharing options...
Erndog Posted August 24, 2022 Author Share Posted August 24, 2022 2 hours ago, Jim Nelson said: These need to be a minimum of 'grade 5' for strength. ( 3 pointed star on the top. Grade 8 have a 6 pointed star on top ). I always use 'grade 8' bolts which are the strongest. (With split lock washers. ). BTW, if the bolt heads do not have any marks then they will be grade 2 which is a no-no. Not strong enough ! ! I use stainless grade 5 min. for the three bolts that hold the water pump. Same on the lock washers. They're grade 8's. 1 Link to comment Share on other sites More sharing options...
Robert Engle Posted August 24, 2022 Share Posted August 24, 2022 I will respectfully disagree with using high grade bolts in place of original lower grade bolts. The original bolts worked quite satisfactorily at a 9" wrench torque. Higher grade bolts require higher torque to perform properly. Higher torque will put undo stress on the castings. Think of the bolt as a spring. It must be stretched a bit to work properly. Bob Engle 7 1 Link to comment Share on other sites More sharing options...
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