Motor Build time 5.9 or 6.7

FWIW, drilling and tapping a block for 14mm mains can be done cheap, correctly, by hand, using the cap as a drill jig, in less than a hour.
 
^ I believe this may be true.. But with the heat tooling, I feel a line bore is needed to clean and "true" the bore back up...
Just to my 2 cents...
 
12VRoush said:
^ I believe this may be true.. But with the heat tooling, I feel a line bore is needed to clean and "true" the bore back up...
Just to my 2 cents...
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I agree, at least watching closely during assembly and linebore if necessary.
 
I have put many sets of 12mm ARP 2000 mains in and always have to clearance the girdle. They make to lengths in the mains one is shorter to keep from moding the girdle and should not be used in high HP builds and you have to gauge the set of the stud.
 
Runninlean said:
I have put many sets of 12mm ARP 2000 mains in and always have to clearance the girdle. They make to lengths in the mains one is shorter to keep from moding the girdle and should not be used in high HP builds and you have to gauge the set of the stud.
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I agree. Its actually a block stiffener. What I do if people dont want to girdle is clearance the stock stiffener and tig weld another stock stiffener to it. Ben prooven many times to 5000+rpm in sled applications many times. A good bottom end balance is key.
 
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9724VF350 said:
FWIW, drilling and tapping a block for 14mm mains can be done cheap, correctly, by hand, using the cap as a drill jig, in less than a hour.
Click to expand...

I still cant believe people use 14mm fasteners in the cummins block. The block is weaker than the 12mm fasteners that come stock. Then when you go to 14mm, you just take material away making the block even weaker. The cr blocks that i have seen fail(which isnt many) have all cracked in the head bolt holes. We run 5000+ rpms with a stock girdle and stock main bolts. We have used 425, 625 and h11 studs, all holding fine at 150+psi. Most of the guys in pro street run stock head bolts. If you have a 12mm fastener fail, it was either faulty to begin with or it was installed wrong.
 
Blacksdieselhp said:
I still cant believe people use 14mm fasteners in the cummins block. The block is weaker than the 12mm fasteners that come stock. Then when you go to 14mm, you just take material away making the block even weaker. The cr blocks that i have seen fail(which isnt many) have all cracked in the head bolt holes. We run 5000+ rpms with a stock girdle and stock main bolts. We have used 425, 625 and h11 studs, all holding fine at 150+psi. Most of the guys in pro street run stock head bolts. If you have a 12mm fastener fail, it was either faulty to begin with or it was installed wrong.
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Why do you suppose a stock 14mm bolt is shaped the way it is? I agree, the strength of the fastener is not the issue.
 
Blacksdieselhp said:
I still cant believe people use 14mm fasteners in the cummins block. The block is weaker than the 12mm fasteners that come stock. Then when you go to 14mm, you just take material away making the block even weaker. The cr blocks that i have seen fail(which isnt many) have all cracked in the head bolt holes. We run 5000+ rpms with a stock girdle and stock main bolts. We have used 425, 625 and h11 studs, all holding fine at 150+psi. Most of the guys in pro street run stock head bolts. If you have a 12mm fastener fail, it was either faulty to begin with or it was installed wrong.
Click to expand...

9724VF350 said:
Why do you suppose a stock 14mm bolt is shaped the way it is? I agree, the strength of the fastener is not the issue.
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100% agree. Way too many times I hear of people trying to reinvent the wheel and over thinking it. Simplicity works if set up properly.
 
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I've argued with myself for hours about this. Why do we need 26 studs to hold the head down and only 14 studs/bolts to hold the crank up in? I realize cylinder pressure trying to force it's way out accounts for some of it, but the quantity and quality of fastener seems a bit lopsided. I'd like to point one of those fancy valve spring camera's at a main cap parting line and see what's happening there.
 
We have never seen any evidence of mains walking or any flex at 5000+rpms. I have been surprised so far.
 
I have with stock main bolts. The block and cap mating surfaces polish up. You either have a choice $$12mm upgrades or low $ 14mm + machining. Personally I'd do the 14mm every time.
 
Pretty sure i decided to go with Monster Mike and his short block build. Doing his 14mm mains, special dowls, 14mm head studs, his girdle, cam bearings throughout, his billet rods, wrist pins and fully balanced rotating assy. Also doing a 5.9 with 6.7 head, inj and a custom bowl design. Here is a few pics of his girdle setup. U can see how it is machined into the block and ties everything together. Not saying he is the Almighty, but im pretty confident this will hold for my modest goals.

E02E840C-414E-4DB6-AD67-A8958C8273C2-245-000000155AF0344A_zps4aa995b5.jpg


89B95618-1490-4279-B82D-A074A90308E7-245-0000001561724A58_zpscaee8fd2.jpg
 
Yes, im hoping I will have less trouble next year.
Just not sure on the cam I want to run, I have a Hamilton 194/220 now. Thinking of stepping it up to the newest one they offer, Vincent. Will be using a T4 66/80 over a T6 88/110 with my already Hellmann side draft 6.7 head. Just need to have the head ported this winter. Im thinking I should have a good solid 1000-1200hp setup that will hopefully live!!
 
Yea, that sounds kinda backwards. I would expect to read 6.7 block with 5.9 head.
 
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