I'm building a blower motor in a budget and I was woundering how big of a roll the crank plays in a street blown aplication (P600b +/- 12#).

I have been saving and buying little by little (for a long time)... and as for now, I have some Lloyd Elliot heads, ported intake, and a 4 bolt main Vette block.

I could either go with a 355 with a stock crank or I a 383 if I need to buy a crank.

I want to enjoy my setup asap, so buying extra parts that I'll not need it's out of the question.... however I don't want to blowup my engine and waste so much money just becuase I wanted to save $500 in a crank

I was looking at some of my options on Combination Motorsports, and I was woundering if a "Scat 9000 Series Cast Crankshaft " would be any better than a stock crank

ALSO
I want the most out of my setup and I was woundering what Cam would you guys recomend


thanks
leo

 

I wouldn't replace the stock crank with a new cast one. You can get a forged eagle from Summit for $600 and change. While the stock one would probably be fine, you're right that it's good insurance to go for the upgrade...

 

I would say a forged 4340 crank, 4 bolt mains, 4340 rods, and strong pistons are a must right off the bat. But realize that just because you have a 4340 crank doesnt mean you're invincible. Heat can still kill the engine, bad tolerances, bad machine work etc. I say build the 2nd motor to handle some power, and perhaps drive the car without boost till it's done, then sell the running motor. Or you can put low boost on the stock one and hope it doesnt nuke before the new motor is ready.

The fine details make the difference, a good machine shop and assembler is more then worth the cost compared to a cheap one.

 

My buddy ran 542 Hp on 18 psi with his old turbo setup on stock crank and rods (ARP bolts) with speedpro forged pistons. It can be done

 

Scat Crank is considerably stronger than stock, but still weaker than a forged crank by a bit. However, at 12# on that setup, I don't think the Scat would suffer any catastrophic failures . I used to have one, but the guy I bought it from used it with large doses of nitrous. I used it solely for N/A setup. He took it out only to upgrade his bottomend, it was still in great condition after many miles. Bottomline.. if you have the money.. spring for it. Its likely you'll want to be harder on the motor later, and it'd be cheaper just to take care of it now. But if you can't, it will work.. and probably work well.. How often do you take a 600rwhp car to w.o.t. for any substantial period of time anyways on the street? once a week?


I like Comps 214/224 cam on a 114lsa for a blower, its been used with some success. Its like .560/.600 IIRC.. or at least damned close to that.

Good Luck,
Josh

 

thanks for the replays guys...
In a build up like this... with component will have the most stress? (the pistons?)


leo

 

Pistons first, then the rod bolts and pins. The stock rods and pistons arent bad - but the stock pistons are weak as anything.

Thing is though, if you're pulling it apart to have new pistons put in, why not spend the extra effort and get the rest done too?

Thermal coating may also come in handy...

 

thanks Geoff,

BTW that's exatly what I'm doing (building a 2nd engine while still driving my hotcammed slow Z , When it's all doneI just swapt engines in a weekned)


leo

 

That's the exact setup that I'm using for my turbo motor.

-Chris

 

Chris - what are you looking for power wise from your setup?

 

I'll probably crank the boost down to make 500-550. I just want to go 10.50s and still be able to drive the thing.

On a side note, the build is almost done. The turbo is mounted, piping is built, engine is in. I just have to TIG all the piping and clean up some wiring and it's done!

-Chris