SCAT 9000 Limits

[Lizardracing]

Imma put this right here.
9000 crank. Broken rods and lots of other parts too lol.
I had to cut the cap off the rod with a 5" cut off disk and the crank survived and it still in service.

[MELWAY]

Imma put this right here.
9000 crank. Broken rods and lots of other parts too lol.
I had to cut the cap off the rod with a 5" cut off disk and the crank survived and it still in service.

How on earth did that rod break like that???

[skinny z]

Imma put this right here.
9000 crank. Broken rods and lots of other parts too lol.
I had to cut the cap off the rod with a 5" cut off disk and the crank survived and it still in service.

Couple of questions. HP and RPM? And whose rods? I ask that last question because I'm shopping for those as well.

[Lizardracing]

Imma put this right here.
9000 crank. Broken rods and lots of other parts too lol.
I had to cut the cap off the rod with a 5" cut off disk and the crank survived and it still in service.

Couple of questions. HP and RPM? And whose rods? I ask that last question because I'm shopping for those as well.

600hp ish
7200 max. 3500rpm when it broke.
Scat Pro series I beams 7/16 arp 2000 bolts.
I think it first pull the valve head off. Then the piston shattered.

[skinny z]

Imma put this right here.
9000 crank. Broken rods and lots of other parts too lol.
I had to cut the cap off the rod with a 5" cut off disk and the crank survived and it still in service.

Couple of questions. HP and RPM? And whose rods? I ask that last question because I'm shopping for those as well.

600hp ish
7200 max. 3500rpm when it broke.
Scat Pro series I beams 7/16 arp 2000 bolts.
I think it first pull the valve head off. Then the piston shattered.

Certainly less power and RPM than my build direction (< 500 HP, +/- 6000 RPM) but I'm still wary of using the 9000 in an open road event application (which is unofficially where this is heading) plus drag racing and driving in general.
Thinking about using the same rod spec though.
As for the path of destruction, I've been through similar. Thinking that a bent valve eventually broke off and left me with one cylinder head and an intake manifold/carb to salvage.

[Lizardracing]

I found some valve springs that were down in pressure so I suspect the valves floated or bounced or something bad happened and it pulled the valve head off. I was using hyper pistons and when one shattered the small end of the rod took out everything else.
I saved the crank, 6 rods and the timing chain. Small bits of piston and rings were even in the cylinders on the opposite bank through the intake ports and took those pistons and heads out too. NASA called and told me the small end of the rod was orbiting Saturn. I know that’s true cause I never did find it or the pin for that matter.
Also, it split the block in half. Front to back.
Im in the process of building another just like this engine cause, well, what the hell. It’s only money.

[CamaroMan]

Sorry to resurrect - curious what size boat this was?

The boat motor I was talking about has a eq vortec head on it and hydraulic roller with a eps manifold as it has to sit under the sun deck of the boat and idle at 600 rpm to go into gear clean. It made 466ft/lbs at 3600rpm and 380hp at 5,200 rpm. Not huge horsepower but makes really good torque it made 422ft/lbs at 2500rpm and spends most of its time in the 3,500-4,000 rpm range. Sometimes for hours at a time, only taking a couple minute break here and there to switch kids on the tube or pick up the ones that flew off haha!

[BLstangin]

Sorry to resurrect - curious what size boat this was?

The boat motor I was talking about has a eq vortec head on it and hydraulic roller with a eps manifold as it has to sit under the sun deck of the boat and idle at 600 rpm to go into gear clean. It made 466ft/lbs at 3600rpm and 380hp at 5,200 rpm. Not huge horsepower but makes really good torque it made 422ft/lbs at 2500rpm and spends most of its time in the 3,500-4,000 rpm range. Sometimes for hours at a time, only taking a couple minute break here and there to switch kids on the tube or pick up the ones that flew off haha!

It's a 1993 196 crownline boat. 20' fiberglass.

[RAS]

The limits of a 9000 series SCAT crank? You probably could not afford to build that monster. Good cranks don't break. Fuel cars replace them before they develop cracks. A well balanced assembly, that stays out of detonation will run like hell forever. There are cast LS cranks making over 1000HP for years on end and they don't break. What kills cranks are bad tune ups, including fuel cars. Hydraulic a cylinder, detonation, piston or rod breakage. Note they have a hole in the middle of the crank. Why? Wouldn't solid steel be stronger. That hole prevents cracks! Cracks start in the middle of a solid bar. Metallurgy today is light years ahead of what it was 15-20 years ago.

[GARY C]

Imma put this right here.
9000 crank. Broken rods and lots of other parts too lol.
I had to cut the cap off the rod with a 5" cut off disk and the crank survived and it still in service.

Maybe I am missing something? The rod or rod bolt let go but your asking about the limits of the crank?

I have a set of 6.125 H beam rods... actually "7"- 6.125 H beam rods where the 2000 bolt let go on one of them... maybe we should be asking about the rod bolts.

[Lizardracing]

Not really asking anything specific as a just a testament to the SCAT 9000 crank because SO many people talk trash about them. I believe they have their place and time and budgets and do well. No, they aren't a Bryant, Callies, etc.....They are aren't trying to be either.
I replaced the two rods and it's now on around 50 more dirt track shows since this happened and all is well. The The older Darts weren't savable that were on it. Now topped with Brodix T1X heads.

[Metalhead]

I broke one... But I got it in an engine with unknown history that had been in a drag car, then put it through about 70,000km of street and circuit use at around 520hp and revving it to 7000 regularly, 7500 when needed, then another ~60,000km of street and circuit use with around 620hp and taking it to 8,000rpm when needed to avoid a gear change. It sure did make a mess when it finally let go though. I used it because I already owned it, I probably should have just paid up for a forged crank. But I definitely got my money's worth out of it!

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[blykins]

I did a 347 bracket race engine for a customer, 540 hp, launched at 5500, shifted at 7000. Used a 9000 series Scat crank. He lost a power valve and didn't realize it, washed the cylinders down, so we had to freshen up. Found a cracked rod journal when we magged it.

[skinny z]

70,000km of street and circuit use ...~60,000km of street and circuit use !

Now, that's my kind of mileage. Very similar to what I used to put on.
What's even more impressive is that the connecting rod held on. Say that's an Eagle SIR rod and you'll have made my day.

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[6.50camaro]

70,000km of street and circuit use ...~60,000km of street and circuit use !

Now, that's my kind of mileage. Very similar to what I used to put on.
What's even more impressive is that the connecting rod held on. Say that's an Eagle SIR rod and you'll have made my day.


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I'd put my money on a Scat ProStock series rod. Look at the rod cap, I believe Eagle SIR rods don't have that pronounced rib on the cap.