Posted By: onyxba
Big block 4.150 stroke 2.375 rod 4340 crank? - 12/18/14 11:37 PM
What crank would you run, eagle, scat, molnar. ohio crank. Drag race 750 to 800 horsepower? Thanks for any reply's.
Big block 4.150 stroke 2.375 rod 4340 crank?
Posted By: dogdays
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/18/14 11:43 PM
Whatever would fit in an aftermarket block.
Unless you have a set of really nice aftermarket rods that use that pin there is NO REASON to use the big crankpin. As you are trying for big power why not go directly to a 4.25 or 4.375 or even 4.5" crank and the 2.2 pin? Selection improves greatly. Plus you don't have to turn the motor so tight.
R. my
Unless you have a set of really nice aftermarket rods that use that pin there is NO REASON to use the big crankpin. As you are trying for big power why not go directly to a 4.25 or 4.375 or even 4.5" crank and the 2.2 pin? Selection improves greatly. Plus you don't have to turn the motor so tight.
R. my
Posted By: Anonymous
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/18/14 11:44 PM
any will work but some have certain cranks in 8 bolt flange only so don't get caught on that
I love Scat cranks but freight from west coast to east coast means we use lots of Eagle--Never a failure and we beat the snot out of them Honest the Eagle has been refined over the years and is a very good unit--need more? Go Callies and sleep better--get a polished unit that looks like Jewelry but... $$$$$$ Eagle can take a beating--800HP on one is no big deal at all---and.....is available NOW Todd at Marsh Performance will ship you one today for a very good price--!!!!!!!!!!!!!!!!!!!!!!!! Service you can't beat
Don't get all hung up in this one better than that one--the builders attention to bearings and such will have way more to do with good service life--No Detonation--timing correct--bearing clearences right for the application and away you go
Try King HP bearings for some happy measuring.
Good luck!
I love Scat cranks but freight from west coast to east coast means we use lots of Eagle--Never a failure and we beat the snot out of them Honest the Eagle has been refined over the years and is a very good unit--need more? Go Callies and sleep better--get a polished unit that looks like Jewelry but... $$$$$$ Eagle can take a beating--800HP on one is no big deal at all---and.....is available NOW Todd at Marsh Performance will ship you one today for a very good price--!!!!!!!!!!!!!!!!!!!!!!!! Service you can't beat
Don't get all hung up in this one better than that one--the builders attention to bearings and such will have way more to do with good service life--No Detonation--timing correct--bearing clearences right for the application and away you go
Try King HP bearings for some happy measuring.
Good luck!
Posted By: rickseeman
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/18/14 11:48 PM
Quote:
What crank would you run, eagle, scat, molnar. ohio crank. Drag race 750 to 800 horsepower? Thanks for any reply's.
I assume they are all made by the same 12 year old girl in China. And I assume any of them would be fine for your application.
Posted By: dogdays
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 12:17 AM
Go to www.wiseco.com Click on the K1 clearance section. Find the 4.25" stroke forged crank for $400.
That's a screaming deal.
R.
That's a screaming deal.
R.
Posted By: JohnRR
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 12:17 AM
Quote:Quote:
What crank would you run, eagle, scat, molnar. ohio crank. Drag race 750 to 800 horsepower? Thanks for any reply's.
I assume they are all made by the same 12 year old girl in China. And I assume any of them would be fine for your application.
to a degree I agree but I would go with the Molnar .
As dogdays mentioned , your bigger concern is the BLOCK ...
Posted By: onyxba
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 12:27 AM
block is a mopar mega block cross bolted mains. using a milodon dual line oiling system. We have lost # 6 rod bearing 2 times. clearance rods .0028 main.0032 feel we are jinxed on this one. The crank has no name on it so don't know what brand it is. Looking for options on new crank. Thanks for the replys. Current rod are carillo sshemi rods.
Posted By: GTS340
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 01:43 AM
Quote:
Go to www.wiseco.com Click on the K1 clearance section. Find the 4.25" stroke forged crank for $400.
That's a screaming deal.
R.
That particular crank is 6 bolt flange and has 2.375 rod journals. It was actually $363 when I ordered one about a month ago. At that time I got one of the 2 that were still available.
Posted By: Cab_Burge
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 02:22 AM
I quit using the 2.375 Mopar rod journal size stroker cranks about ten years ago, maybe you should to 
The smaller I.D. diameter rod bearings don't travel as far per revolution as the larger ones do 
Another plus in my mind is the lighter recripocating weight and less stress at the same RPM from the lighter rods
As far as tight rod bearing clearances like your using I would open them up to at least .0030 or bigger, same thing on the mains, try .0035 or larger When the same components fail time after time there is usually a reason for it, the hard part is figuring out what is causing it 
What brand and part number rod bearings are you using?What type of rods. aluminum or steel? How about oil pressure hot at the upper RPM and weight of oil BTW, what RPM are you using as the shift RPM in each gear and at the finish line? #6 rod journal gets its oil from #4 main bearing, if your using the stock type internal oiling to the rocker shafts the oil for those comes out of the #4 main also
The smaller I.D. diameter rod bearings don't travel as far per revolution as the larger ones do Another plus in my mind is the lighter recripocating weight and less stress at the same RPM from the lighter rods As far as tight rod bearing clearances like your using I would open them up to at least .0030 or bigger, same thing on the mains, try .0035 or larger When the same components fail time after time there is usually a reason for it, the hard part is figuring out what is causing it What brand and part number rod bearings are you using?What type of rods. aluminum or steel? How about oil pressure hot at the upper RPM and weight of oil BTW, what RPM are you using as the shift RPM in each gear and at the finish line? #6 rod journal gets its oil from #4 main bearing, if your using the stock type internal oiling to the rocker shafts the oil for those comes out of the #4 main also
Posted By: AndyF
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 04:39 AM
Have you run a reamer thru all of the oil passages? It is very easy for one oil passage to be restricted. I've lost rod bearings for that reason before.
Posted By: gregsdart
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 03:11 PM
Quote:
Have you run a reamer thru all of the oil passages? It is very easy for one oil passage to be restricted. I've lost rod bearings for that reason before.
My first thought was oiling problems. Molner has the best rep of the three IMHO. Great guy to deal with as well.
Posted By: BradH
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 03:16 PM
Quote:
... the Eagle has been refined over the years and is a very good unit...
All I can add to this comment is that Dwayne Porter (Porter Racing Heads) had mentioned a couple of years ago that the last Eagle cranks he'd had were good w/o having to have "correction re-grinds", and that all the journals on the Eagle 3.75"-stroke 6-bolt I crank bought after that measured OK, too.
Scat's stuff has a good reputation, but seem priced a lot higher than what I think the comparable cranks on the market are.
If I was collecting parts from scratch today, I'd look into the 2.200" rod journal option, too. I'd also give the Molnar stuff some serious consideration, if Tom M. has one that fits my combination.
Posted By: onyxba
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 05:09 PM
Thanks to all who responded. 1st engine referred with my brother bearing clearances were .003 rods and .003 mains, I thought what I wrote correct so I asked him, he checked notes on build and these were the clearances. rod bearings were calico CB663hndbx4. Rods are carillo steel CR426ss. Shift at 7000 and go through the 1/8 at 6400. 440 source oil pan with drag link through pan 10 quarts 15w40 rotella, wix racing filter.Oil pressure at idle hot 60 to 65. Don't know what oil pressure is at end of pass, my friend who's car it is hasn't got comfortable driving the car enough to look at gauges for that information. 2nd go around clevite cb527p bearing. That bearing in clevite was all we could find at .030 rod bearing. Clearances on this were .0035 rod .0030 mains. The engine has 440-1 heads so oil to the top end is oiled externally with 1 60 holly jet feeding both heads. All other bearings in great shape, even #7 which you know is fed off of #4 main. This block is supposed to be priority main oiling so if there are any oil mods to this block, I would greatly appreciate any advice. Thanks again to all help.
Posted By: JohnRR
Re: Big block 4.150 stroke 2.375 rod 4340 crank? - 12/19/14 06:43 PM
Quote:
Thanks to all who responded. 1st engine referred with my brother bearing clearances were .003 rods and .003 mains, I thought what I wrote correct so I asked him, he checked notes on build and these were the clearances. rod bearings were calico CB663hndbx4. Rods are carillo steel CR426ss. Shift at 7000 and go through the 1/8 at 6400. 440 source oil pan with drag link through pan 10 quarts 15w40 rotella, wix racing filter.Oil pressure at idle hot 60 to 65. Don't know what oil pressure is at end of pass, my friend who's car it is hasn't got comfortable driving the car enough to look at gauges for that information. 2nd go around clevite cb527p bearing. That bearing in clevite was all we could find at .030 rod bearing. Clearances on this were .0035 rod .0030 mains. The engine has 440-1 heads so oil to the top end is oiled externally with 1 60 holly jet feeding both heads. All other bearings in great shape, even #7 which you know is fed off of #4 main. This block is supposed to be priority main oiling so if there are any oil mods to this block, I would greatly appreciate any advice. Thanks again to all help.
.0035 rod clearance to start, isn't that a little much ?
Also you said you have a MEGA BLOCK, is it a MEGABLOCK or a WORLD block ? World has priority main oiling, Megablock does not.