Scat sbc premium pro series I beam HP limit

[reginald]

I was considering using scat 7/16 premium pro series I beams in my 550hp 400sbc , what are peoples thoughts on this idea? good bad or?

[Keith Morganstein]

Good!

[mag2555]

Your all good with that pick, just note that sometimes a light home ball hone job thru the pin hole is needed to get them floating right , so check every one !

[houser45]

I have used them in multiple 540 hp winged sprint cars at 7900 to 8300 rpm. Fairly light piston though. No failures. Wrist pin bores are usually at .0005”. They will need opened up

[reginald]

That sounds promising. Not sure how light your pistons are but im using a pro series srp flat top. With rings and pin mine weight 540grams, hopefully thats acceptable for a 6500 rpm limit with those rods.

[houser45]

380 gr piston. 25 gr rings, 105 gram pins

[MELWAY]

I have used them in multiple 540 hp winged sprint cars at 7900 to 8300 rpm. Fairly light piston though. No failures. Wrist pin bores are usually at .0005”. They will need opened up

Is that with Std scat 8740 bolt or with 2000 upgrade

[reginald]

As these 6 inch I beams are considerably lighter than H beams, did you use a crank made for 5.7 rods or 6 inch? Thanks

[Keith Morganstein]

As these 6 inch I beams are considerably lighter than H beams, did you use a crank made for 5.7 rods or 6 inch? Thanks

They are not that light. Plent of h-beams are lighter.

What stroke are you planning? 6 inch rod is good with a 3.48 stroke. 6" Needed for many 3.75" stroke internal balanced cranks

There are countless engines running in circles with these rods. They work and most everyone knows that. If you're worried though, step up to Molnar h-beams or Crower rods

[swampbuggy]

To the O.P.....if you have not purchased your rods yet, here is a good choice. Manley H-Beam with ARP 2000 bolts and rest at ease. Mark H. BTW they are mid. priced rods.

[77cruiser]

I have them in my 550 hp 421, get spun to 6500 quite often.

[steve cowan]

I just run my 383 sbc 510 hp for a year, 50 passes 5.7 " I - beam 3/8 8740 arp bolt
Run it to 7500-7600 rpm on the shifts
I was worried a bit but on disassembley the bearings are in excellent condition,failed rods are mostly from incorrect rod bolt tension and dirt behind bearings causing a a spun bearing and then rod bolt failure, excess rpm is probably a contender but I think tune up, correct clearance for applications and precise measuring on assembly is paramount

[MELWAY]

Hey Steve Cowan. What material crank u got in 383

[steve cowan]

Scat 4340 standard weight forged
What you thoughts James??

[MELWAY]

Yeah they Are tuff as nails. I use heaps of them

I’m wondering what the HP and RPM limits are of the cast 9000 cranks

I broke a scat cast Holden at 550hp trashed whole engine