steel or cast crank for Stock Eliminator? - Page 2

Bob Bender · 02-22-2009, 07:30 PM

Quote:

Originally Posted by Joe DeMarzo

Bub, that is way you are the man,

JOE YOU ARE RIGHT ......................BUB IS THE "MAN"

Rory McNeil · 02-22-2009, 08:57 PM

For what it`s worth, I have a 78 Ford Fairmont bracket car with a 428 Cobra Jet and a Jerico 4 speed that runs 10.0`s at 132MPH, has gone 1.29 60 foot. All the 428 Fords came with cast cranks, I don`t rev my engine to 7000 RPM, but it does hit 6700 thru the traps. The crank is a .010" under stock Ford 40 plus year old piece, and has been in the car for 14 seasons now, never had any problems with the crank. I have the crank MagnaFluxed every 4 or 5 years when I freshen the engine, and so far, it looks like it will outlast me! I have heard that sitting on a 2 step for a long time isn`t a great idea, but I don`t normally do that anyhow. Maybe the Ford cranks are just a bit better!

Dinsdale · 02-23-2009, 12:42 AM

What Rory said.. My bracket 67 Mustang is a 427 with a stock 428 crank. Jerico and 3150 lbs. Nothing fancy done to the crank and I go through the lights at 7500. So far, the crank is about the only thing I haven't broken. Car has run a best of 9.83 @ 136.78 MPH. Results with other brands may vary !!!

Chris Cogan · 02-26-2009, 11:11 PM

GM cast nodular iron cranks are stout enough for the majority of stock/super stock applications. On a 396, there is roughly 3lbs difference between cast and forged and for a 454, the wieght penalty is closer to 4lbs. I have seen numerous 468's with 2 bolt mains and cast cranks (bracket engines between 600 - 675HP) and never have I seen a broken crank.

BTW, 3 to 4 lbs off the crank is not insignificant in terms of performance. Maybe not measurable on a water brake dyno, but physics still governs our universe the last time I checked.

Take care guys.

SS Engine Guy · 02-27-2009, 02:20 AM

What Bub said! And to add I have used cast cranks in S/SS cars of all kinds over the years. The most important part is to mag properly and to have someone with the experience to read what the mag is telling them. Good balance job and you are good to go. I usually run cast cranks 4 years as long as the magnaflux viewings haven't changed in 3000+lbs cars. If the balance isn't correct it dosen't matter if you have an unobtainium crank and 8 bolt mains it is coming apart. Just imagine at 7000 rpm the explosion that is going off in the bottom end when something breaks. Personally I have also seen more broken forged cranks than cast. Also just because the local machine shop has the latest greatest balancer dosen't mean that the guy operating it knows what he is doing. If you haven't ever seen or had this done, find a shop with all the BHJ block-true fixtures. The variances in a SBC will make you wonder how it ever went 10 miles in a passenger car much less a racecar. Find a company or crank grinder that can talk to you about fillet radius, crank snout runout, etc and you won't have a problem.

treessavoy · 03-25-2009, 11:46 PM

Quote:

Originally Posted by Bub Whitaker

Enlighten me...since you opened this thread again, others would would like to hear your experience

Mopar 400ci with a cast crank and 4 speed , 65 b-body and 11 inch slicks....crank broke on the line after a 5500rpm launch, it was prepared by an excellent machine shop in Al that built a number of IHRA stockers...some with cast cranks.......just my experience.

You have been enlightened.

RJ · 03-26-2009, 05:15 AM

Built a 295/350 SS motor with a cast crank back in the early 90's, never had a problem with the crank.

Bub Whitaker · 03-26-2009, 07:51 PM

Quote:

Originally Posted by treessavoy

Mopar 400ci with a cast crank and 4 speed , 65 b-body and 11 inch slicks....crank broke on the line after a 5500rpm launch, it was prepared by an excellent machine shop in Al that built a number of IHRA stockers...some with cast cranks.......just my experience.

You have been enlightened.

Bummer

njk53 · 03-26-2009, 08:09 PM

An engineer in the Performance Group at the GM Tech Center once told me cast cranks possess the durability to withstand up to 7,000 engine RPM. He also stated that beyond 7,000 it is a crap shoot.

treessavoy · 03-30-2009, 11:26 AM

Quote:

Originally Posted by Bub Whitaker

Bummer

My experience may have been an aberration because I've known a bunch of people that have had great success with cast cranks.

Hell, I watched a Hemi 4-speed guy blow 3 separate pieces of crank out underneath the car when he dropped the clutch...ouch!

Jim

02-22-2009, 08:57 PM	#12
Rory McNeil VIP Member Join Date: Jun 2007 Location: from Vancouver BC Canada, now in Nova Scotia Posts: 1,311 Likes: 317 Liked 1,104 Times in 302 Posts	Re: steel or cast crank for Stock Eliminator? For what it`s worth, I have a 78 Ford Fairmont bracket car with a 428 Cobra Jet and a Jerico 4 speed that runs 10.0`s at 132MPH, has gone 1.29 60 foot. All the 428 Fords came with cast cranks, I don`t rev my engine to 7000 RPM, but it does hit 6700 thru the traps. The crank is a .010" under stock Ford 40 plus year old piece, and has been in the car for 14 seasons now, never had any problems with the crank. I have the crank MagnaFluxed every 4 or 5 years when I freshen the engine, and so far, it looks like it will outlast me! I have heard that sitting on a 2 step for a long time isn`t a great idea, but I don`t normally do that anyhow. Maybe the Ford cranks are just a bit better! __________________ NHRA 6390 STK M/S 85 Mustang

02-23-2009, 12:42 AM	#13
Dinsdale Member Join Date: Oct 2004 Location: Canada Posts: 313 Likes: 0 Liked 6 Times in 2 Posts	Re: steel or cast crank for Stock Eliminator? What Rory said.. My bracket 67 Mustang is a 427 with a stock 428 crank. Jerico and 3150 lbs. Nothing fancy done to the crank and I go through the lights at 7500. So far, the crank is about the only thing I haven't broken. Car has run a best of 9.83 @ 136.78 MPH. Results with other brands may vary !!!

02-26-2009, 11:11 PM	#14
Chris Cogan Junior Member Join Date: Apr 2007 Location: Defiance, OH Posts: 47 Likes: 0 Liked 0 Times in 0 Posts	Re: steel or cast crank for Stock Eliminator? GM cast nodular iron cranks are stout enough for the majority of stock/super stock applications. On a 396, there is roughly 3lbs difference between cast and forged and for a 454, the wieght penalty is closer to 4lbs. I have seen numerous 468's with 2 bolt mains and cast cranks (bracket engines between 600 - 675HP) and never have I seen a broken crank. BTW, 3 to 4 lbs off the crank is not insignificant in terms of performance. Maybe not measurable on a water brake dyno, but physics still governs our universe the last time I checked. Take care guys. __________________ Chris Cogan

02-27-2009, 02:20 AM	#15
SS Engine Guy Member Join Date: Sep 2003 Location: usa Posts: 256 Likes: 1 Liked 1 Time in 1 Post	Re: steel or cast crank for Stock Eliminator? What Bub said! And to add I have used cast cranks in S/SS cars of all kinds over the years. The most important part is to mag properly and to have someone with the experience to read what the mag is telling them. Good balance job and you are good to go. I usually run cast cranks 4 years as long as the magnaflux viewings haven't changed in 3000+lbs cars. If the balance isn't correct it dosen't matter if you have an unobtainium crank and 8 bolt mains it is coming apart. Just imagine at 7000 rpm the explosion that is going off in the bottom end when something breaks. Personally I have also seen more broken forged cranks than cast. Also just because the local machine shop has the latest greatest balancer dosen't mean that the guy operating it knows what he is doing. If you haven't ever seen or had this done, find a shop with all the BHJ block-true fixtures. The variances in a SBC will make you wonder how it ever went 10 miles in a passenger car much less a racecar. Find a company or crank grinder that can talk to you about fillet radius, crank snout runout, etc and you won't have a problem.

03-26-2009, 05:15 AM	#17
RJ Member Join Date: Oct 2002 Posts: 248 Likes: 0 Liked 0 Times in 0 Posts	Re: steel or cast crank for Stock Eliminator? Built a 295/350 SS motor with a cast crank back in the early 90's, never had a problem with the crank.

03-26-2009, 08:09 PM	#19
njk53 Senior Member Join Date: Jul 2007 Location: East China, MI Posts: 504 Likes: 0 Liked 0 Times in 0 Posts	Re: steel or cast crank for Stock Eliminator? An engineer in the Performance Group at the GM Tech Center once told me cast cranks possess the durability to withstand up to 7,000 engine RPM. He also stated that beyond 7,000 it is a crap shoot. __________________ Nelson Kowal Stock 345