HP rating for stock GM main bolts
04-04-2018 | 10:52 AM
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HP rating for stock GM main bolts
I searched but couldn't find anything so...
What's the max suggested HP range for stock GM main cap bolts in a gen 5 454?
-Running stock forged GM 4" crank, 4 bolt main, 8.5:1 with 5-6 lbs boost, 6,000 RPM.
What's the max suggested HP range for stock GM main cap bolts in a gen 5 454?
-Running stock forged GM 4" crank, 4 bolt main, 8.5:1 with 5-6 lbs boost, 6,000 RPM.
Last edited by Mohavvalley; 04-04-2018 at 11:44 AM.
04-04-2018 | 11:43 AM
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Thanks MT.. But I'm looking to know what I can run these to as I'm building the bottom end for future expansion, I picked up a 6-71 for cheap that will most likely be going on a few years down the road when I get it running and upgrade the drive.
So what is a comfortable HP & RPM range for stock GM bolts given the above set up...700..800..900..1,000hp?
6,500RPM max at XXX HP ?
Or to put it another way at what horse power & RPM should I replace the stock main cap bolts with ARP 8740's
Thanks
So what is a comfortable HP & RPM range for stock GM bolts given the above set up...700..800..900..1,000hp?
6,500RPM max at XXX HP ?
Or to put it another way at what horse power & RPM should I replace the stock main cap bolts with ARP 8740's
Thanks
Last edited by Mohavvalley; 04-04-2018 at 01:27 PM.
04-04-2018 | 01:29 PM
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From: NW Michigan
Don't under estimate GM cap bolts. If it makes you feel better then replace with arp (cheap) however I'd be more concerned with a professional balance on your rotating assembly. GM forged 4 bolt forged assemblies are pretty tough. Good aftermarket rods with arp bolts is also extra insurance however. I've only broke one 7/16 GM rod cap and it broke near the bolt. (Weak point) If your planning for future 1,000 hp then you might as well spend the money now. Spend the $2,000 or so now on rods and balance. With that said though I've ran 800 plus with stock GM rotating assemblies however not with extending runs. Achieving a reliable 800-1,000 hp is what's gonna get costly. I think everyone would agree with that. For your current 6-71 I wouldn't stress much over it. We've run 420 mb on stock GM forged 454's with 6 pds of boost with zero problems. Just my personal experience and opinion of course.
04-04-2018 | 01:55 PM
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P.S. I'm talking about the main bolts not the rod bolts, I'm well aware of the need for better rods at higher HP
04-04-2018 | 02:00 PM
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Id put stud girdles on anything over 550hp, but that me, you cant tell me there's no deflection in the stud at 5500 on a non girdled engine, Brad Smith told me a story of a SBC he did a dyno test on non girdle vs adding them, he told me if he hadn't seen it for him self he wouldn't believe it.
04-04-2018 | 02:22 PM
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Id put stud girdles on anything over 550hp, but that me, you cant tell me there's no deflection in the stud at 5500 on a non girdled engine, Brad Smith told me a story of a SBC he did a dyno test on non girdle vs adding them, he told me if he hadn't seen it for him self he wouldn't believe it.
