How often can I use the same Head Bolts? On my 351c? Closed chambered heads.
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...I would think, if the threads are in good shape and the Bolts are Straight, No pitted rust; and they can be brought up to 'Boss 351C' Torque Specs of 125 Ft/Lbs, they could be used over, Indefinitely!
One Might chose to upgrade to 'Grade 8' Bolts, or even, '12 Point Head' Aircraft Bolts. I upgraded to ARP Head Studs, with 'Hex' Nuts and Hardened Washers. And I would Recommend these for Installing All Aluminum Heads!...
One Might chose to upgrade to 'Grade 8' Bolts, or even, '12 Point Head' Aircraft Bolts. I upgraded to ARP Head Studs, with 'Hex' Nuts and Hardened Washers. And I would Recommend these for Installing All Aluminum Heads!...
Studs are good advice Marlin
Anytime a "long" bolt must be critically torqued, its best to replace it with a stud. With a V8 motor that will usually include the head bolts and the main bearing cap bolts. The reason for this ... the stud insures the torque is fully applied to stretch the stud as intended, whereas torque applied to a long bolt will tend to twist the bolt to some degree, like a torsion bar. The tendency for the bolt to twist makes it difficult to insure the bolt is stretched as intended, if it is not stretched properly the part shall not be clamped with the intended force.
-G
Anytime a "long" bolt must be critically torqued, its best to replace it with a stud. With a V8 motor that will usually include the head bolts and the main bearing cap bolts. The reason for this ... the stud insures the torque is fully applied to stretch the stud as intended, whereas torque applied to a long bolt will tend to twist the bolt to some degree, like a torsion bar. The tendency for the bolt to twist makes it difficult to insure the bolt is stretched as intended, if it is not stretched properly the part shall not be clamped with the intended force.
-G
Speaking of this, what is this group's thoughts on align honing the main bearing bores if one switches from bolts to studs? I've heard everything from not necessary to absolutely necessary. On my engine I had the bores align honed and then decided to switch to studs. Everything still measured the same and the crankshaft turned fine so after a conversation with my machinist we both felt it was fine to proceed with the build.
Thanks,
Chance
Thanks,
Chance
quote:Originally posted by 3FIFTY1C:
... what is this group's thoughts on align honing the main bearing bores if one switches from bolts to studs? ...
Not necessary because the location of the main caps is not dependent upon the main bolts, the caps are held securely in place by a very tight fit within the registers machined into the bulkheads.
-G
Chance, the problem you mention is a SBC thing that happens due to bore distortion resulting from the change from bolts to studs. In a SBC, Smokey Yunick found that even torquing the oil pump stud measurably distorts the bores.
On a 351C, such problems do not often surface- and the possibility goes to zero if you use a torque plate to hone the cylinders. Remember- steel torque plates for iron heads and aluminum torque plates for alloy heads.
On a 351C, such problems do not often surface- and the possibility goes to zero if you use a torque plate to hone the cylinders. Remember- steel torque plates for iron heads and aluminum torque plates for alloy heads.