Has anyone ever had an issue with using a 2 bolt main

Chris Hardy · 10-14-2012, 05:24 PM

Has anyone ever had an issue with using a 2 bolt main, small block chevy for stock eliminator? I have built 2 bolts for bracket 350's and never had an issue. Thanks
Chris

rod · 10-14-2012, 06:37 PM

way back in the old days, there were NO 4 bolt blocks, and not even cap conversions. everyone used two bolt blocks. granted there were no 4" pistons pushing on the mains. but there were more alterdes, gas dragsters and JR. fueleres running with 2 bolts blocks than you could count with a calculator.
in this day of good line hone systems, good main studs, good oil and oil systems and much better bearing tech, there is no reason a 2 bolt block can't live.
one thing happens to racers, when someone moves up a step, everyone else thinks they have to, until that step becomes the norm. you can move up until your money runs out. but until you get to top fuel or F-1, there is ALWAYS something better.
ego makes things difficult. use a 2 bolt and then lie to your friends.
rod in AZ

Chris Hardy · 10-14-2012, 07:10 PM

I feel the same way. Very nicely put. Thank you.

Chris

Mike Taylor 3601 · 10-15-2012, 09:28 AM

I like everyone wants to sell a their 350 it's always a 4blt.,or tell you their car has a 350 4blt. like it adds HP.
Another way to look @ it is 4blt has 2 more hole drill in main webbing.

Rod's post pretty much covered it
Mike Taylor 3601

Chris Hardy · 10-15-2012, 10:48 AM

Thanks.

I'm staying with 2 bolts

FED 387 · 10-15-2012, 10:54 AM

I think part of the reason 4 bolts were used in some applications was for durability/engine life like in trucks or marine engines. RPM ranges also come into play here too. Stock/Sprint car/endurance racing where you are off and on the throttle constantly tends to want to stretch the cranks. Using a 2 bolt crank in a low RPM NHRA Stock class car equipped with a Small Block Chevy engine where the engines are not running extremely high RPM (like over 9500-10,500 or maybe more) in most cases would probably be sufficient.
Yes for the added insurance that a 4 bolt offers it's probably worth the extra $$$, but to just go out and build a 4 bolt from the get go for a 6800-7000+ RPM short burst engine might not justify the extra cost but you can always convert the block from 2 to 4 (if the rules allow it) if you feel you need a to. my 2 cents worth FED387

10-14-2012, 05:24 PM	#1
Chris Hardy Junior Member Join Date: Jul 2012 Location: Muskegon, Michigan Posts: 57 Likes: 0 Liked 4 Times in 1 Post	Has anyone ever had an issue with using a 2 bolt main Has anyone ever had an issue with using a 2 bolt main, small block chevy for stock eliminator? I have built 2 bolts for bracket 350's and never had an issue. Thanks Chris

10-14-2012, 06:37 PM	#2
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 313 Likes: 0 Liked 20 Times in 15 Posts	Re: Has anyone ever had an issue with using a 2 bolt main way back in the old days, there were NO 4 bolt blocks, and not even cap conversions. everyone used two bolt blocks. granted there were no 4" pistons pushing on the mains. but there were more alterdes, gas dragsters and JR. fueleres running with 2 bolts blocks than you could count with a calculator. in this day of good line hone systems, good main studs, good oil and oil systems and much better bearing tech, there is no reason a 2 bolt block can't live. one thing happens to racers, when someone moves up a step, everyone else thinks they have to, until that step becomes the norm. you can move up until your money runs out. but until you get to top fuel or F-1, there is ALWAYS something better. ego makes things difficult. use a 2 bolt and then lie to your friends. rod in AZ

10-14-2012, 07:10 PM	#3
Chris Hardy Junior Member Join Date: Jul 2012 Location: Muskegon, Michigan Posts: 57 Likes: 0 Liked 4 Times in 1 Post	Re: Has anyone ever had an issue with using a 2 bolt main I feel the same way. Very nicely put. Thank you. Chris

10-15-2012, 09:28 AM	#4
Mike Taylor 3601 VIP Member Join Date: Oct 2008 Location: Somerset,Ky Posts: 1,361 Likes: 333 Liked 279 Times in 96 Posts	Re: Has anyone ever had an issue with using a 2 bolt main I like everyone wants to sell a their 350 it's always a 4blt.,or tell you their car has a 350 4blt. like it adds HP. Another way to look @ it is 4blt has 2 more hole drill in main webbing. Rod's post pretty much covered it Mike Taylor 3601

10-15-2012, 10:48 AM	#5
Chris Hardy Junior Member Join Date: Jul 2012 Location: Muskegon, Michigan Posts: 57 Likes: 0 Liked 4 Times in 1 Post	Re: Has anyone ever had an issue with using a 2 bolt main Thanks. I'm staying with 2 bolts

10-15-2012, 10:54 AM	#6
FED 387 VIP Member Join Date: Jun 2006 Posts: 3,409 Likes: 505 Liked 329 Times in 177 Posts	Re: Has anyone ever had an issue with using a 2 bolt main I think part of the reason 4 bolts were used in some applications was for durability/engine life like in trucks or marine engines. RPM ranges also come into play here too. Stock/Sprint car/endurance racing where you are off and on the throttle constantly tends to want to stretch the cranks. Using a 2 bolt crank in a low RPM NHRA Stock class car equipped with a Small Block Chevy engine where the engines are not running extremely high RPM (like over 9500-10,500 or maybe more) in most cases would probably be sufficient. Yes for the added insurance that a 4 bolt offers it's probably worth the extra $$$, but to just go out and build a 4 bolt from the get go for a 6800-7000+ RPM short burst engine might not justify the extra cost but you can always convert the block from 2 to 4 (if the rules allow it) if you feel you need a to. my 2 cents worth FED387