Rocket Racing crank
September 28th, 2018, 11:52 AM
#1
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Rocket Racing crank
I'm thinking of using a Rocket Racing 4340 steel 455 crank in my early 400. This crank is set up to use a big block Chevy rods and is internally balanced. Has any one used one of these? Any feedback on Rocket Racing? Thanks
September 28th, 2018, 01:20 PM
#2
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RR generally has a stellar reputation. You'll get more feedback on realoldspower.com though. Dig around on there for plenty of info on cranks.
Note that it has Chevy *journals*. You probably can't use off-the-shelf BBC rods, but depends on your piston choice. This is normally done to get more stroke out of the crank because the Olds journals were larger than they needed to be.
It's just easier to get custom rods with Chevy journals than to get custom rods with Olds journals.
Frankly the blocks let go long before the cranks, so if you're worried about strength then go for the RR block first.
New cranks are wicked cool but it's hard to justify below 600hp.
Note that it has Chevy *journals*. You probably can't use off-the-shelf BBC rods, but depends on your piston choice. This is normally done to get more stroke out of the crank because the Olds journals were larger than they needed to be.
It's just easier to get custom rods with Chevy journals than to get custom rods with Olds journals.
Frankly the blocks let go long before the cranks, so if you're worried about strength then go for the RR block first.
New cranks are wicked cool but it's hard to justify below 600hp.
September 28th, 2018, 02:15 PM
#3
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Especially since an early 400 already has a forged crank. Of course, a 455 crank with 4.250" stroke in an early 400 block is already going to require custom pistons and rods. That combo gives you a 427 cu in Olds motor with stock bore, however the 4.000" bore and 4.250" stroke combo probably isn't the best choice.
September 29th, 2018, 02:44 PM
#4
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The stock stroke RR/Scat crank uses Olds rod journals. Only the 4.500” stroke uses BBC rod journals. The Eagle Stroker is the same. And they both widened the journal to accept out of the box 7.100 BBC rods.
I did a 400E with a 455 crank. It was a factory 3x2 intake with Procomp heads and a 4.090 bore. Made 480hp and over 530tq. Ran pretty good.
I did a 400E with a 455 crank. It was a factory 3x2 intake with Procomp heads and a 4.090 bore. Made 480hp and over 530tq. Ran pretty good.
September 29th, 2018, 04:47 PM
#5
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I see Scat has a steel 4.25 stroke crank with BBC journals. I could use the 7.100 rod and would only need the custom piston. RaceTec said they would make anything I want no problem. I would like to use the Mahle pistons you have but it looks like I will need a compression height of about 1.400 give or take. How do you think it will work with pocket ported B heads with a little larger intake valve and the tri-power?
September 30th, 2018, 06:36 AM
#6
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The tri-power is your bottle neck. I wouldn't spend too much time and money on the heads at this point.
And if you use a 7.00" rod you can use an off the shelf Pontiac stroker piston. However not sure why you would do all this while using the tri-power setup. Again in stock form that's your bottle neck. You could easily just put 455 crank and rods in it and move on. That Scat crank is way overkill for this build. Jmo.
And if you use a 7.00" rod you can use an off the shelf Pontiac stroker piston. However not sure why you would do all this while using the tri-power setup. Again in stock form that's your bottle neck. You could easily just put 455 crank and rods in it and move on. That Scat crank is way overkill for this build. Jmo.
September 30th, 2018, 07:10 AM
#8
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No, but you seem hell bent on wasting $1900.00 on a crank, that in this build, will amount to nothing so go right ahead.
However if you’re keeping the tripower then spend that $1900 on head and intake work instead. If you want a new 455 crank then buy the Eagle one at a qtr of the price. That makes way more sense to me.
Then grab a custom piston from there. Again not sure why you’re wanting to throw a longer rod etc in it for no apparent reason.
However if you’re keeping the tripower then spend that $1900 on head and intake work instead. If you want a new 455 crank then buy the Eagle one at a qtr of the price. That makes way more sense to me.
Then grab a custom piston from there. Again not sure why you’re wanting to throw a longer rod etc in it for no apparent reason.
Last edited by cutlassefi; September 30th, 2018 at 07:12 AM.
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