My new rebuild should have around 400hp/470tq but I don't think that going to be enough to keep me happy. thats where the juice comes in I just don't want to use too much and grenade another engine. heres what I've got for a short block.
-517 block with 2 bolt mains (not high nickel)
-stock main bolts
-stock crank ground 10/10
-eagle 5.7" H-beam rods
-Speed Pro lightweight forged pistons

Is 225-250HP nitrous out of the question? Engine shouldn't see past 6000rpm on engine alone and probably a few hundred rpm less when being sprayed.

With a more or less stock bottom end,I'd stick to 100-150 shot max.

Would using studs on the mains help a good deal more?

ARP bolts or studs will help...but its likely that you would need to align hone/bore the mains aftr adding the new bolts/studs. If you have to do that..look into splayed caps..its about 300 bucks more than just good studs. What did you gapp your piston rings at? I wouldn't spray over 150HP on a SBC with a stock 400 crank(JMO) On my 400 build, I splayed the caps and im using a 4340 crank along with 6" h beams and forged pistons..Im only going to spray 200HP

The rings arn't gapped yet cause the engine is still sitting in pieces. I'll gap them accordingly to the max amount of nitrous I'll be able to use.

Whats my weekest link?

What is Your CR? with the vortecs(thin castings) and small chambers, unless you have big dish pistons, your CR is probably over 11-1. Use good head bolts and race gas for the Nitrous enrichment..retard the timing 4-6º..gap the top ring @.006 per inch(.025 @ 4.155) and I would try a 200 shot

I've got 16.5cc D shaped dished that are advertised as 9.8:1 but with zero deck compression should be around 10.3-10.5 depending on the size of my chambers.

When people upgrade to ARP bolts or studs, what is the biggest motivation? Are they afraid their stock ones will snap or stretch or what?

I come up with 10.11-1CR with a .040 quench. Good main saddle bolts/studs increase the clamping force..they also help in saddle"walk" . The crankshaft is going to flex...they just help it to return to where it belongs

Not that I recommend it, but I know a guy that's making around 500rwhp (close to 600hp /flywheel) with a Procharged 406. It's got a stock 2-bolt block with ARP main bolts, stock rods with ARP bolts, and TRW(heavy) forged pistons. Spins the motor 6500rpm and has probably 15K miles on it. I personally wouldn't hit your motor with more then 150hp or so worth of N2O, but there are guys doin it, and with cheaper parts then you have.

-Joe

Originally posted by bigjimzlll:
ARP bolts or studs will help...but its likely that you would need to align hone/bore the mains aftr adding the new bolts/studs. Why would I need to do that? Its not like the main cap bolts have any press fit like rod bolts do... Not trying to second guess you but I just wanna know why smile.gif

heres a thought sell the vortecs and take the money you get from them and the money your going to spend on nitros and buy you a good set of heads and you wont need to use the nitros

I disagree with you all of course they say stick to 150 shot or less buy our expensive ring lands. A while back one of those carcraft type magazine was dyno testing until they grenading a motor. They took a pos 350 from the junkyard put a plate system on it and had some fun. They made it over a 300 shot and then when they went for the 400 shot they purged the motor too low the cylinder pressure went skyhigh the motor jumped sideways and one of the ring lands cracked. A stock 350 possibly being able to handle a 400 shot if done properly is reidiculous if you want to use 200 or 250 just make sure you handle the ring and timing issues and everything should be ok for what you are doing. Thats my .02. O but for cheap insurance use arp main studs they are worth every penny in you investment

Originally posted by stangslayer:
</font><blockquote>quote:</font><hr />Originally posted by bigjimzlll:
ARP bolts or studs will help...but its likely that you would need to align hone/bore the mains aftr adding the new bolts/studs. Why would I need to do that? Its not like the main cap bolts have any press fit like rod bolts do... Not trying to second guess you but I just wanna know why smile.gif </font>[/QUOTE]Go to this link and look at Number 4
http://www.arp-bolts.com/pages/products/pages/mainbolts/links/how_to.html
The ARP studs/bolts have different clamping force then stock. Its not unusual for the crank not to spin after install

what is signifigant about the fourth picture? It looks as if the studs have a slightly thicker mid-body thickness than the threads. Is that right? Unless the fit between the stud and main cap hole so tight the cp must be pounded down into place, I still don't see how using differnt bolts or studs would distort the journals :confused: I must be missing something....

I've used studs without align honing or boring. The engine is in my buddy's 355 that has over 50K miles on it. It's a daily driver and he "shows off" a lot. It sees 5K quite often.

I just turned the crank while i carefully tightened the nuts in 5ft/lb increments.

I think I see how it distorts the caps though. All the clamping force is on the cap instead of pulling against the threads? Anyway, I know of others who have had success without "correcting" the main bores.

And I believe David Vizard (don't quote me) says that align honing/boring isn't necessary.

We put studs in a lot of engines & in most cases the main bore doesn't change but in a few you need to line hone.
You need to measure the bore after putting them in & see.
You are changing the clamping forces & sometimes it will distort the main bore.
You are also getting better clamping load on the fastners with studs which helps the caps stay where thy belong.
As for over an honest 500hp on a 2 bolt block, yes it can be done but we also have quite a few 350 2bolt blocks that are in the "recycle" area that came out of 500-550HP circle track deals that are junk because the caps were moving & it ruined the block & cap area.
What happens is the caps try to move back & forth or walk & this "frets the block & cap. It will actually transfer metal
from one to the other.
Yes it can be fixed but it is cheaper to get another block.
If you are planning on 600 or so HP get a real block or put splayed center caps on the stock block.
Studs help a lot but are not cure alls they just clamp better. It's that simple.
It's part of the reason GM put 4 bolts on their HP & truck engines, because the caps were moving.
It isn't because they had a bunch of extra bolts & didn't know what to do with them :D


Power does it & detonation is even worse. You will get obscene loads on the rod & main bearings under detonation, way more than with power & heavly loaded egines like trucks are very prone to detonation.

Originally posted by stangslayer:
what is signifigant about the fourth picture? It looks as if the studs have a slightly thicker mid-body thickness than the threads. Is that right? Unless the fit between the stud and main cap hole so tight the cp must be pounded down into place, I still don't see how using differnt bolts or studs would distort the journals :confused: I must be missing something.... Read what the caption says...."align hone"