How much hp/torque can stock 2 bolt main caps take before it gets risky? Besides machining for a 4 bolt with splayed outs what else could I do? I'm working on a 383 with hyd roller at 236/242 @.050, afr 195cc eliminator heads, 9.6:1 comp, dual plane rpm airgap, demon 750.....

 

You can do a short fill, and fill part of the jackets with that stuff, hard-blok.

Head studs.
Main studs.
These depend on what kind of forces you're dealing with, high cylinder pressures you'd want the head studs, but if it's just high RPM the bottom end is where you want to focus your attention.

High end H beams
Forged crank.

Not much to do to the block itself aside from hard-blok or the 4 bolt splayed caps. But for the power output you're looking at, I doubt any of these are necessary.

 

i don't think a forged crank would be worth it with a 2bolt. there is a guy on turbomustangs pushing about 800hp(crank) through a stock shortblock but it is on borrowed time.

 

I'm pushing around 430 crank HP with a cast crank and 2 bolt block. I also had them do a line hone with arp main studs

 

It would help to use studs for the main caps.

 

I'm not saying any of those are necessary, just options.

I think the later 5.0L mustangs had stock forged cranks. Either way, a ford application isn't really relevant here.

 

block filler sucks for a car that sees a lot of street use. with all forged components and a two bolt block with billet main caps and all studed, 600 to 700 horsepower is about the limit for an sbc. depeding on usage, if the engine sees blasts to 8000 rpm on a frequent basis then you can expect the block to not live as long as a block that only sees street use and an occasiaonal blast down the quarter. blocks and cranks are first killed by rpm, then by how much power you put through them.

 

is any machining required for putting studs in for the main caps?
If I got aftermarket studded 2 bolt caps wouldn't I have to redo the bearings, which would mean taking apart the whole rotating assembly again right?
How much HP can the stock main caps with stock bolts take?

 

Putting in studs sometimes requires a rehone down the main saddles. I'd really recommend using 4 studs in a splayed configuration. I'd do that rather than using a 2 bolt set of studs.

Nonetheless, you're probably going to be under 450HP, so 2 (ARP) bolts, with stock caps should be fine. I'm thinking if you keep it under 6500RPM you'll be ok.

That's really hard to answer. I think ARP bolts or studs, in your 2 bolt setup should be fine. I'd torque it down and check your tolerances if possible, hopefully you can get by without rehoning it.

 

IIRC, the SBC originally came with a forged crank. Sometime around the early 1960s, cast cranks appeared. Several iterations of the SBC came from the factory with forged cranks across the years, however, although they became a bit more rare in later years.

Studded 2-bolt caps can take quite a lot of power output and RPM with the proper balance and a moderately lightweight rotating assembly. Splayed four-bolts are probably the strongest, and that can only be had by starting with a 2-bolt block. The case can be strengthened in the main web area by removing the stress risers, mechanical stress relieving procedures (such as shot-peining), and thermal seasoning. A main stud girdle can also help.