What kinda revs can one of those SCAT forged 4.25" BBC stroker cranks handle?

Assuming the 496 was built using SCAT 6.385" H-Beams (about 785 Gram Weight) and a good forged piston like JE/SRP?

I ask because a buddy is currently building a tubbed '55 Chevy shortbed and wants to build a 496 that he can spin to 7000+ on shifts and NOT worry everytime he does it.

Thanks guys.

Originally posted by bluerebl:
What kinda revs can one of those SCAT forged 4.25" BBC stroker cranks handle?

Assuming the 496 was built using SCAT 6.385" H-Beams (about 785 Gram Weight) and a good forged piston like JE/SRP?

I ask because a buddy is currently building a tubbed '55 Chevy and wants to build a 496 that he can spin to 7000+ on shifts and NOT worry everytime he does it.

Thanks guys. A lot :D

Seriously, it is a very well done crank & 7500 should be no problem with the lighter parts.
Now,,, why does he need to spin it to 7000+ ??
You can easily make around 700 Hp with a 496 at less than 6500 with a reasonably mild 10.0-11.0 engine that will run on pump gas.
Add some compression & a bit more head & about 800 is not out of the question again without spinning the snot out of it.
Big engines make torque, lots of it & HP is nothing but a function of torque times RPM.
Just my thoughts, I guess it depends on what he is doing.

bluerebl - I don't mean to jump your thread, but your friend might benefit from the answer to my question:
Mike, without giving away too many secrets, what kind of components (heads, cam, intake) would yield 700 hp on pump gas? Would these components yield adequate vacuum for PB boosters? I'm building the same type of motor, and have seen these #'s on D2K, but I thought that they were optimistic. Thanks, Kirk

Many engine builders use Scat cranks in crate engines for up to 1000hp! I would personally use a different crank for a 1000hp motor but should be fine for an 800hp motor up to 7000rpm. Is the 55'Chevy stock wt. or fiberglass,lexan etc. You didn't sat what hp. engine your friend wants to build, but easily could build 496 a 700hp engine like Mike said and keep rpms below 7000 for longevity. Only would go over 7000 for max effort engine for all out build. Depends on what you want to build! :D

He's looking at the AFR 305 heads, UltraDyne Solid Flat Tappet, .612/.630" lift, 288/296 adv, 255/263 @.050", 110 LSA, 11.0:1 CR, etc.

All steel '55 short bed, back-halfed (ladder bars/coil over), 31x18.5x15 M/T tires, Mustang II front clip, 9" rear, Detroit locker, 4.56 gears, TH400, 10" Coan 3500-4000 stall converter, etc.

I don't think he really plans on 7000+ shifts, he just wants to know it would hold if he did. He's aiming for high 10's with good traction, I guess we'll see if he does it.

Cable & Kirk,
AFR 315, Vic Jr, 850 Demon, Comp roller 254/260- .698/.666-111 sep, 10.0 compression, 2" dyno headers
670HP@ 6300 @ 610tt lbs @ about 45-4600.
Over 500 ft lbs from 2900.
Idled about 850, don't remember the vacuum
This was on a dyno considered pretty conservative,,, Mine :D
Also this engine was pulling over 2" of vacuum from around 5000 on up which means the carb was too small.
Add about 1 point of compression and a little more carb & I have no doubt it would have gone over 700 honest HP.

Using Harold's cam you listed & 11.0 with the 305 head with the CNC chamber option, a decent carb & intake & you will have 700HP
I am very confident that cam will make more power than the one I used.

Cable, email me for pricing on the AFR heads ;)

Talk about dragging out an old post, I'm kinda curious as to what happened with this motor he was building Cable,,did he get the results he was looking for? e.t. wise? thanks

The last time I talked with him he was still collecting parts, but mostly for the truck itself.

I think he got sold into building a 540+ using a Dart block, but going with SCAT crank/rods.

If I hear anything more, I'll post it.

Hey Fellas, do a search for a class action
Lawsuit against Scat cranks. Seems that there
have been quite a few cranks that have failed
as of late.

The Scat cranks are made in China and the claim
is that the forgings are of questionable quality.

I do not use Scat so I cannot speak from
personal experience, but you may want to
check anyway. I have read that they are failing
in SB's so it definately would be risky to
use one in a big block.

Our resident engine builder "wolfplace" says Scat cranks are of pretty good quality,say compared to "Eagle", his word is good enough for me. I've also read that Scat cranks are 25% stronger than GM cranks. The smallblocks that are failing are the ones making big power trying to keep up with us big block guys :D I doubt many smallblocks would have held together for 5.5 years as my current 454 has,and it still runs good. Are you sure you're not posting just because they are made in china? as Schurkey does? Anyone else heard of this class action lawsuit? :confused: Do you even know the difference between a smallblock and a bigblock crank? bigblock cranks are bigger and much stronger,forged or cast!!

My son used a cast steel Scat crank in a small block and it lasted through a very hard hit when the truck hit a culvert while doing stupid stuff. The motor was almost in the front seat and didn't break or bend the crank. Same can't be said for my son's nose which he said hurt for a long time.

Rapid Robert,

Don't shoot the messenger. Just do your
homework and maybe you'll find out for
yourself.

As for knowing the difference between a sm
blk crank and a BB crank .... Uh well yes !
I know that a BB will put out a lot more
power per/hole if built correctly. ;)

I am running the standard stroke SCAT crank Forged steel, and have had mine up to 7500 no problem (was on accident though..missed a shift) smile.gif anyway...I typically run mine to 6500-6800rpm all the time

Originally posted by Johnny B.:
Rapid Robert,

Don't shoot the messenger. Just do your
homework and maybe you'll find out for
yourself.

As for knowing the difference between a sm
blk crank and a BB crank .... Uh well yes !
I know that a BB will put out a lot more
power per/hole if built correctly. ;) So,,, what exactly is this supposed "class action suit" all about??
Or more to the point, who brought it & under what circumstances??

Instead of posting questionable & incomplete information why not pick up the phone & call Scat??

I have been using them for over 12 years & have had three failures.
All were cast & two were in applications they did not belong.
The other was a problem with how the crank was lightened & has since been addressed by Scat.

I also know of another for sure that did break in a road race deal & was probably flawed but I can tell you of a number of "USA" cranks that have broken too.
If you are going to build performance engines,,, stuff happens & parts break.

Scat cranks are forged in china, the difference being is they are completely finished in house by Scat in LA except for the cast ones & they are all checked before shipment & the reject rate has been at 20% at times so the quality control is very good.

Are they all perfect?? I highly doubt it but in 12+ years I have not had to send one back or had a problem that could not easily be corrected.
Are they sometimes a pain to balance, yes, just as almost any non custom crank can be at times.
Does this mean they are no good,, in my opinion at least no.

If it is in your budget would I recommend an Oliver, Bryant, Winberg, Callies XL etc.,,, you bet but there are folks on here who both do not need or cannot afford a $2000 crank for what they are doing & to these I recommend Scat as an economical quality alternative,,

Another very nice crank is the Callies Dragon Slayer but in all honesty I have had both these & Scats side by side, checked hardness, sizing, finish etc, & without a name cast into them you would not be able to tell them apart.

A good portion of the all American apple pie autos we are driving these days came from offshore too & you might be very surprised to find out who's crank is in GM's crate 383's along with a number of the cranks that are bought from GM, Chry & Ford performance parts ;)

Just a little factual information, not anything "searched out" on the internet :rolleyes:

i have used scat 4340 in 2 differnt small blocks one was a blown 383 with a 3.750 and a 6 inch rod with a 6-71 2 afb,s atop 4.10 gears t 400 3500 sthal and spun it to 7,500 quite reguarly and it did fine . the other is in a 427 motown copy with a 4.00 stroke and it has seen a few trips into 7,000 rpm range . never pluged one into a bbc so i can only speak from past exp. id say be realistic with yourself and your build all parts have limitations of some kind.. my luyck has been great with my past 2 scat crank,s

p/s hey wolfplace my appoligies for the cheap shot the other day..

Originally posted by zl-1madness:
p/s hey wolfplace my appoligies for the cheap shot the other day.. =
Thanks & not a problem, we are all here to hopefully learn a little & sometimes there are going to be ruffled feathers.

I try very hard not to get personal & to stay civil even when I get a bit "annoyed" but sometimes,,,, well you know :D

Anyway,,, roll on & good luck with your project.
If you have questions just ask away & I am sure you will find a wealth of information on here from a lot of pretty good people with varying backgrounds & differing opinions but what the hell,,, if everyone thought the same way it would get pretty boring around here graemlins/beers.gif

One of my customers runs a blown 540 in his bracket 86 Camaro and runs 20psi boost on his scat crank for two seasons with no problems. That much can't be said for the rest of his bottom end, but the crank held up! It allowed him time to save up for a Hank the Crank billet unit. I plan to run a forged Scat in my next project a mild 900hp blown 540 in either a Chevelle, Camaro, or Nova (haven't made up my mind yet which body).

stc37-
Wow! Goodluck with your mild 900hp blown 540!
:D

Digging up an old post of mine, but I am now in the early stages of building another BBC for my Datsun 280z, this time a 496.

Nothing really wrong with my 454, except it has a stock cast crank, stock rods, and TRW 2465 pistons with almost no valve to piston clearence.

My plan is to use my current 454 block which is a 4 bolt and studded.

I plan on using a SCAT forged 4.25" crankshaft, SCAT 6.385" H-Beam rods, SRP forged 11:1 to 12:1 pistons, Vic Jr. intake, Holley 850+cfm carb, and AFR 305 or 325 cc heads (which ones?).

Can I still get 700 HP with a UltraDyne/Lunati A6, A7, or A8 solid flat tappet?

Thanks guys!!