AGRSSV

Hey all! Just quickly have a few questions with regards to a 383 small block build I'm planning to start soon.
Main question is what length rods to go? 5.7" or 6"? What are the benefits of using each?
Other question is with regards to main caps. Looks as tho I have sourced a 010 casting 4 bolt block. Will splayed mains caps fit straight up, or does the block need to be machined to suit them.
Thanks in advance!

Redbeard

With the 4bolt block deal,I wouldn't be converting from conventional 4bolt to splayed as the integrity of the block will be compromised-too many holes. If you want splayed,get a 2bolt block and get it converted.

My 2 cents.

AGRSSV

That's the sort of info I was after. I was thinking that might be the case. What caps would be suited to handle around 600hp, stepped or splayed caps?

Redbeard

They both would if you use steel caps. Splayed would be the pick though,as there is two different axis that the stresses are working on. A two bolt block would hold together but the question would be 'for how long' though!

AGRSSV

Nah i'll be using a 4 bolt setup for sure, not worth taking the gamble. I think i'll just stick to the stepped ones and just use upgraded bolts, will do the job I think.

AGRSSV

Soooooo 5.7" or 6"¿? Pros and cons of each?

Coupethis

I would choose the 5.7" rod in a street engine. More piston to take the stress IMO.

ProStreet427TT

Your standard cast 4 bolt caps will be sufficient, just fit an ARP main stud kit. A 6" rod is a must in any sbc; it lowers the piston-to-rod angle which means your pistons will survive longer. Every time your pistons get pushed up the bore there is immense pressure on the skirts, by fitting a longer rod you are reducing the angle of the rod-to-piston which in turn reduces the pressure on your piston skirts.
Any motor should be fitted with the longest rod possible as it helps. 5.7's are ok but a 6" rod is better.

__________________
Anything unattempted remains impossible.

My toy warehouse:
'92 VP SS Commodore
'94 VR SS Commodore
'94 VR circuit car, EFI 355sbc, single T-70, unfinished
'02 CV8 Monaro Pro Streetcar, 615ci Dart bbc, staged EFI, twin 100mm t/b, twin GT60 Garretts, unfinished
'66 Impala 9 seater s/w, factory 396bbc
'72 Nova, tubbed, 671 blown 355sbc
'85 Mustang, 347ci SVO stroker motor, Vortech V7YSi. 9.55 @ 142, 1.30 60ft on 11.5" tyre, 2800 stall & no i/c. (For Sale)

ProStreet427TT

An 010 4 bolt block will take a severe beating before it gives up. My old 352 nitrous motor was 14.5:1cr with 6" Manley rods & only had a factory 010 block with cast caps & a factory GM steel crank. It made just under 640hp n/a & 938hp with a 350 shot. I was dumping the whole 350 shot into it off the start line when I released the transbrake... & with a 6200 stall it made for a great launch. 1.26 60ft times in a 1246kg car.
I had no problems at all running it n/a but dumping that amount of NOS into it was shock-loading the bottom end which in turn kept fracturing cranks & now & again would blow the centre 4 bolt cap in half... but only with the NOS.
So as you can see i've pushed a standard block & crank to it's limit without an ugly blow-up.

__________________
Anything unattempted remains impossible.

My toy warehouse:
'92 VP SS Commodore
'94 VR SS Commodore
'94 VR circuit car, EFI 355sbc, single T-70, unfinished
'02 CV8 Monaro Pro Streetcar, 615ci Dart bbc, staged EFI, twin 100mm t/b, twin GT60 Garretts, unfinished
'66 Impala 9 seater s/w, factory 396bbc
'72 Nova, tubbed, 671 blown 355sbc
'85 Mustang, 347ci SVO stroker motor, Vortech V7YSi. 9.55 @ 142, 1.30 60ft on 11.5" tyre, 2800 stall & no i/c. (For Sale)

78torana

Can you post a pic Prostreet, sounds like a beast.

AGRSSV

Soooooo a 5.7" or 6"? Both reasons make sence. To be honest I was leaning towards a 5.7" based purely on a great choice piston wise.

ProStreet427TT

There were some pics in my gallery on here but they've gone...

A 6" rod is far better if you can get pistons to suit without them being custom.

__________________
Anything unattempted remains impossible.

My toy warehouse:
'92 VP SS Commodore
'94 VR SS Commodore
'94 VR circuit car, EFI 355sbc, single T-70, unfinished
'02 CV8 Monaro Pro Streetcar, 615ci Dart bbc, staged EFI, twin 100mm t/b, twin GT60 Garretts, unfinished
'66 Impala 9 seater s/w, factory 396bbc
'72 Nova, tubbed, 671 blown 355sbc
'85 Mustang, 347ci SVO stroker motor, Vortech V7YSi. 9.55 @ 142, 1.30 60ft on 11.5" tyre, 2800 stall & no i/c. (For Sale)