Don't think anyone has asked this question, but I read somewhere's to increase the strength of the 2 bolt mains you can use studs. Does anyone have any idea how much horsepower this can hold to the crank and I'm sure it is cheaper than doing the splayed 4 bolt mains, right? I plan on trying to get 600 horses to the crank with about 400 na and 150-200 shot of nitrous. Thanks for any help.

 

I think you would want to look at getting it splayed. You might get away with it but I think you will be past the limit. I am not 100% sure. It will be cheap insurance anyways. Its cheaper to splay a block than it is to replace the short block and possibly the entire motor. Imagine what it would look like if it let go at about 6000rpm on the bottle. How much of a mess....

If you do it, get some really good arp studs.

 

For $400 I got the splayed caps, ARP hardware for it and all the machine work required. For $300 they do 4 bolt cap conversions the same as above but straight bolts instead of splayed.

 

I am doing a VERY SIMILAR setup... LE3 383 and a 200 shot. Everyone said no no no to the nitrous on a studded 2 bolt.

 

Something to consider with those main cap conversions is the coefficient of linear expansion. This number is different for each material and determines how much something will expand or contract with respect to a change in temperature. A lot of the splayed cap conversions are a different material than the block so the clearance on the block side is different than the cap side of the main once the engine is warm. This can cause premature bearing wear if the car is used for daily driving. For your power I'd definitely recommend four-bolt mains. Is it possible to get the main caps (4-bolt) from a Corvette LT-1 from a parts store since they'de be the same material? Just a few things to consider.....

 

I think you will be fine at that power level with studded 2 bolt mains. I also believe that the parts you are using in the bottom end should affect this choice as well. Nitrous is not used all the time, and thats not really that large of a shot. There are plenty of stock bottom ends holding almost that much as we speak. 400 hp @ the crank is what 340 or so @ the wheels...regular bolts would be fine at that power level. I am currently building an engine thats using studded 2 bolt mains and I am not the least bit worried about. I am also spraying a 150 shot as well....I say build it strong but put more money were it matters..in the power department. There are plenty of guys with similar setups and have been running them for years.


Kyle

 

Guys are running that much power on whole stock bottomends, not a lot of them but there are guys sucessfully doing it so if you make any upgrade I think you will be fine. There are actually a couple of b-bodies with dual power and stock bottoms the slower of the two has dyno numbers over 600 at the wheels the other one is in the 10s so his must make that much too.

 

It'll probably handle it for a while, but it will be ugly and expensive when it fails. I would play it safe and go with splayed 4 bolt caps.

 

I generally go 450 on studded 2-bolt, 550 on studded 4 bolt and above that is splayed cap land. You need to spread the load out to the pan rails. Don't get those caps that just register in the original 2-bolt space, you need to cut the block for flat caps so that the register point is out towards the pan rails. I use Pro-Gram and Silver Seal. Linear expansion is crap as far as these applications go, we did all the thermal testing and there is not a difference, What kind of main caps do you think LS1 motors use along with Donovan aluminum blocks etc.....

 

studs and splaying nowhere near comparable. however, if you are going to be making decent power, you shouldn't have to worry about splayed mains. even stock bottom ended lt1's ill rev 6500. a stud kit on a 2 bolt will do the same thing, but for longer than with regular bolts....

 

I make the power in my sig with a studded 2 bolt.