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best RB 4.15 crank for the money?

Posted By: chrisf

best RB 4.15 crank for the money? - 12/12/19 07:48 PM

whats the best way to go for a RB 4.15 crank that is under $1500? shooting for the 750-ish hp range.
Posted By: DusterKid

Re: best RB 4.15 crank for the money? - 12/12/19 08:17 PM

I have yet to hear anything bad about Monlar stuff....I have no personal experience with any of their stuff though.
Posted By: AndyF

Re: best RB 4.15 crank for the money? - 12/12/19 08:30 PM

Molnar has them in four flavors. 8/6 bolt and 2.2/2.375 pin. I'd highly recommend the 2.200 pin if you're buying rods at the same time. No good reason to use the extra heavy Mopar rods. I also don't think there is any reason to use an 8 bolt flange at 750 hp but sometimes you have to do what you have to do.
Posted By: galen

Re: best RB 4.15 crank for the money? - 12/12/19 08:53 PM

On my second Molnar crank and rods. 1st was a 3.91 with chevy journals and 6.7 rods B block.. Second is RB 4.5 with 7.1 rods. Machine work was spot on on both. Also the Molnar rods came standard with ARP 2000 bolts.
Posted By: dvw

Re: best RB 4.15 crank for the money? - 12/12/19 08:55 PM

Molnar crank and rods in mine. Toms great to deal with. Reasonable price. Spot on machining. Never dynoed mine but Wallace says 908 hp.
Doug
Posted By: an8sec70cuda

Re: best RB 4.15 crank for the money? - 12/12/19 09:09 PM

iagree I wouldn't hesitate for a second to use Molnar's products.
Posted By: furious70

Re: best RB 4.15 crank for the money? - 12/12/19 09:18 PM

I have an RB 4.15 2.375 Eagle crank from around 2006-07 still in a box on the shelf, how would it compare?
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/12/19 11:39 PM

Originally Posted by furious70
I have an RB 4.15 2.375 Eagle crank from around 2006-07 still in a box on the shelf, how would it compare?

As the owner of 2 Eagle cranks, I'd say yours should be checked for taper in the crank & rod journals and whether the snout where the damper fits is undersized.
Posted By: Cab_Burge

Re: best RB 4.15 crank for the money? - 12/13/19 12:50 AM

Call 440 Source and see how much their cranks are now scope
Why are you choosing that stroke instead of 4.250 stroke with the 2.200 rod journal sizes? work
Posted By: GY3

Re: best RB 4.15 crank for the money? - 12/13/19 05:10 AM

I'm a huge fan of Molnar. Tom AND his parts. punkrocka

I've beat the crap out of his rods and crank and no issues.
Posted By: 451Mopar

Re: best RB 4.15 crank for the money? - 12/13/19 05:36 AM

Originally Posted by AndyF
Molnar has them in four flavors. 8/6 bolt and 2.2/2.375 pin. I'd highly recommend the 2.200 pin if you're buying rods at the same time. No good reason to use the extra heavy Mopar rods. I also don't think there is any reason to use an 8 bolt flange at 750 hp but sometimes you have to do what you have to do.


iagree
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/13/19 02:47 PM

Originally Posted by Cab_Burge
Call 440 Source and see how much their cranks are now scope

How's the Quality Control on 440 Source cranks these days? It wasn't very good to start with, IIRC.
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/13/19 02:55 PM

Originally Posted by Cab_Burge
Why are you choosing that stroke instead of 4.250 stroke with the 2.200 rod journal sizes? work

Not answering for the OP, but just an observation that a 4.15" x 2.20" combination could be a no-grind & drop-in deal.
Posted By: Azzkikrcuda

Re: best RB 4.15 crank for the money? - 12/13/19 04:10 PM

The 4.250 stroke 2.20 rod combo required no grinding in my RB block. I wouldn't bother with a 4.15 crank when you can get the 4.25 cranks for the same money and most likely not have any grinding to do. For the brand I have used 440 source, Molnar and Eagle and I have had no issues with any of them. Make sure you check them or have them checked by a machinist. I would buy who ever has the best price.
Posted By: birdtracker

Re: best RB 4.15 crank for the money? - 12/13/19 04:38 PM

Ohio Crankshaft. Birdtracker
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/13/19 05:04 PM

Originally Posted by birdtracker
Ohio Crankshaft...

Another company with a history of crankshaft QC issues. scope
Posted By: birdtracker

Re: best RB 4.15 crank for the money? - 12/13/19 05:09 PM

I bought a 4.25 crank from them. It was extremely spot on. Birdtracker
Posted By: Roughbird72

Re: best RB 4.15 crank for the money? - 12/13/19 05:51 PM

My twocents
I would have the indexing checked on any crank that came over on the slow boat.
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/13/19 05:52 PM

Originally Posted by birdtracker
I bought a 4.25 crank from them. It was extremely spot on. Birdtracker

Good to hear. There's been a lot of bad-mouthing of OC's products on SpeedTalk over the years that left me w/ the concern that their cranks can be seriously hit-or-miss on machining accuracy.
Posted By: Cab_Burge

Re: best RB 4.15 crank for the money? - 12/13/19 06:01 PM

I've use 8 or more Ohio BB Mopar stroker cranks with no issues other than one got damaged in shipping work
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/13/19 06:20 PM

It always comes down to "trust, but verify." But some brands I'd put more trust in to start with.
Posted By: birdtracker

Re: best RB 4.15 crank for the money? - 12/13/19 07:49 PM

I thought I would have to at least polish a journal or 2, but mine was nice. It spins free in the block as it should.Birdtracker
Posted By: roadrunner34

Re: best RB 4.15 crank for the money? - 12/14/19 03:20 PM

Run an OC rotating assembly in my 493 and a molnar crank in my 540 that is currently na but will be procharged. No issue with either.
Posted By: Sammy

Re: best RB 4.15 crank for the money? - 12/14/19 04:01 PM

Originally Posted by BradH
Originally Posted by birdtracker
Ohio Crankshaft...

Another company with a history of crankshaft QC issues. scope



Ohio crankshaft was spot on. Perfect.
Just gave them specifications I wanted and they met my expectations.
Posted By: BradH

Re: best RB 4.15 crank for the money? - 12/14/19 06:46 PM

Sounds like OC got on top of the QC issue. All I know is how many unhappy customers of theirs were posting about poorly machined parts on SpeedTalk a few(?) years ago. Basically scared me away from wanting to get anything from them when I was looking for cranks.
Posted By: pittsburghracer

Re: best RB 4.15 crank for the money? - 12/14/19 07:40 PM

A Chevy buddy of mine had them (Ohio crankshaft) build a Dart short block for him and the engine Siezed on its fourth pass. I read the four page write up on reasons why and dirt and filth were blamed.
Posted By: mopar dave

Re: best RB 4.15 crank for the money? - 12/14/19 09:52 PM

If you can get a Molnar crank for that, get Molnar. I never had the issue with the dirty parts that someone spoke of from Molnar either. His cranks a pretty much a discount considering the quality you get from him for the money.
Posted By: 73DAD

Re: best RB 4.15 crank for the money? - 12/18/19 12:17 PM

What's the best U.S. made crank for the money? Or am I stuck with using factory cranks.
Posted By: AndyF

Re: best RB 4.15 crank for the money? - 12/18/19 04:24 PM

Originally Posted by 73DAD
What's the best U.S. made crank for the money? Or am I stuck with using factory cranks.


Does it have to be mined, smelted, rolled, forged and machined in the USA before it is allowed in your shop or just final machined?
Posted By: 73DAD

Re: best RB 4.15 crank for the money? - 12/20/19 04:32 PM

Originally Posted by AndyF
Originally Posted by 73DAD
What's the best U.S. made crank for the money? Or am I stuck with using factory cranks.


Does it have to be mined, smelted, rolled, forged and machined in the USA before it is allowed in your shop or just final machined?


Where can I get that first one?
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