Guru_4_hire

how long will they live on a 6500 rpm motor?

l88rocket

that's just a cast stock replacement.if you buy anything from scat have a good engine builder go over it well.I have had problems with them before.it's been year or so since I have used there stuff and there quality control was having problems,I would go forged crank.

I would recommend a eagle forged crank,with h-beam rods.

Guru_4_hire

does he have 5.7" or 6" rods? Does a block need clearenced for 6" rods?

Little Mouse

PM motorhead for details on his engine, you will have to clearence
the block regardless of rod length, the better machine shops have
a fixture that they use to grind the blocks for 3.75 stroke cranks.

l88rocket

A 6 inch rod takes less grinding than a 5.7.

Little Mouse

If you are buying new rods get the rods that have the top shoulder
at an angle that will help you with cam clearence.

MotorHead

THe vid in my sig shows a Scat 9000 crank spinning at 6500 RPM. It's got almost 20,000 miles on it now. Another forum member Vetdrms drags his 406ci and shifts at 7000RPM and he has a Scat 9000. I don't know how many passes he has made but I would imagine quite a few over the years.

THey are good, strong cranks made of nodular iron that are much better than stock and will withstand short high RPM bursts. I would not put one in a racing engine at high sustained RPM but the short 6500 RPM blips are OK, like you would do at a drag strip. Like mentioned above, go over it with a fine tooth comb as they can be out of tolerance a little from the factory

Guru_4_hire

I think I better go with forged then even though I dont really want to shell out the green.

MotorHead

Yea 20,000 miles in a 6500 RPM 550HP small block, could break any second now

bluegtp

I have a 383 9000 scat crank sitting in my living room right now.....it'll be going in in the next prob 2 weeks or so.....depending on money....if not then within the next month......I've heard good things about them......my ideal rpm range will be 6500.....again with short bursts playing around on the street or at track!......

I ordered it from northernautoparts and the guy there told me I may want to get a machine shop to double check the specs on it!....he said the exact same thing of past issues with quality control......


ryan

jackson

I ran a 3.8" scat 9000 in a 388 street car ... car's still running ... no problem.

I ran a 3.48" scat 9000 in a 355 asphalt circle track car for 3 seasons ... hi rpm ... lotsa hard on-off throttle ... motor eventually failed ... one of the $600/set Ross pistons came apart .. not the $150 crank. Wasn't really the piston's fault either ... wore out motor had lotsa bore clearance and lotsa piston skirt slap ... but SOB was darned quick! From what you seem to expect, scat 9000 will be aok ... but have it checked closely for index, journal sizing & taper. If possible get the internal balance 383 piece that requires 6" rods/short-skirt pistons.

Guru_4_hire

I wont be drag racing, I want to road race, so I will probably be in sustained middle to high RPMs.

comp

if i was you i'd go forged than

Guru_4_hire

Yeah it is looking that way.

MotorHead

Road racing at high RPM, go with forged crank, forged everything

7t2vette