Re: best RB 4.15 crank for the money? - 12/12/1908:30 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.
Re: best RB 4.15 crank for the money? - 12/12/1908:53 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.
Re: best RB 4.15 crank for the money? - 12/12/1911:39 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.
Re: best RB 4.15 crank for the money? - 12/13/1905:36 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.
Re: best RB 4.15 crank for the money? - 12/13/1904:10 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.
Re: best RB 4.15 crank for the money? - 12/13/1905:52 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.
Re: best RB 4.15 crank for the money? - 12/14/1906:46 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.
Re: best RB 4.15 crank for the money? - 12/14/1907:40 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.
Re: best RB 4.15 crank for the money? - 12/14/1909:52 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.