Spraying a 2 Bolt LT1 Block

What kind of hp are you guys pushing on the 2 bolt main LT1 blocks? I only want to hear from the guys who are doing this or know someone doing it.

Now, like I mentioned before, I want to hear from the guys pushing the limits of the 2 bolt blocks on and off the bottle. My plan is to build a budget 2 bolt built for some nitrous. I'm just trying to figure out what kind of limits I'm faced with etc..

Here is my basic plan in case you want to know, 355ci:
-2 bolt block, square decked, 0.030" over, ARP studs and maybe a bit of block filler.
-Stock cast crank, stock journal size, polished mains/rod journals
-6" Manley H-beam rods
-Forged SRP pistons
-Balanced rotating assembly etc...
-Largish custom hydraulic roller cam (peak at <6500) I'll limit RPM on the bottle if needed.

Goals:
430-450rwhp N/A
150-175 progressive shot

So let's hear your stories guys. If you're pushing the 2 bolt limits, I would like to hear from ya. :bow:

Mike

Your block with ARP studs is stronger than the crank you are plannning on running. BTW, the stock crank is a pretty stout piece. Use the search feature to find out more. Check out the truck in my sig. It's a late model 1pc seal 2 bolt block with studs and a short fill. Makes 504hp and 548ft# on motor plus a 225 shot of spray. I spray it off the line and generally torture it whenever possible. It's not even a performance block so I think your LT1 should be fine.

Your block with ARP studs is stronger than the crank you are plannning on running. BTW, the stock crank is a pretty stout piece. Use the search feature to find out more. Check out the truck in my sig. It's a late model 1pc seal 2 bolt block with studs and a short fill. Makes 504hp and 548ft# on motor plus a 225 shot of spray. I spray it off the line and generally torture it whenever possible. It's not even a performance block so I think your LT1 should be fine.

I searched before posting. I'm wanting to find the limits from people who've actually done it, not opinions from bench racers on whether or not I should do it. ;)

How much fill did you use in your block? Do you drive it on the street and if so, ever have any problems with overheating? I know a few guys do it on the LT1's but I have no idea how far they fill it for street use. To just below the freeze plugs maybe?

I'm not too worried about the stock crank at these levels. RPM's and detonation tend to kill cranks, not hp.

Mike

You will be fine. If your so worried why not get it drilled and splay the mains. Not much discussion here.

Time in the sig. Stock 2 bolt main block with ARP bolts, eagle 5.7" h beams, JE pistons and no block fill. Been running strong for ~3 years now.

Matt

Stock LT1 spraying almost 200, times in sig.

We also have a stock 2 bolt SBC in a vette that just went 10.98 @ 124.

You hit the nail on the head - detonation and RPM are the destroyers. Run good gas and shift early. Peak power typically occurs at a lower RPM while spraying.

At least one if not both car will be sprayed with 250 next season.

You will be fine. If your so worried why not get it drilled and splay the mains. Not much discussion here.


My plan is to build a budget 2 bolt built for some nitrous. I'm just trying to figure out what kind of limits I'm faced with etc..

Mike

I'm not 'worried'! I want to try and decide where I can safely go with my "budget". Every machine shop around here wants in excess of $500.00 just to install, line bore, line hone the new mains for a 4 bolt conversion. That does not include the price of the caps, or extra cost of the studs or any other machine work. If, after reading these posts from those that have actually DONE IT, I decide it's an acceptable risk then I'll procede as planned. If not, I'll be on the hunt for a factory 4 bolt LT1 block.

Mike

http://web.camaross.com/forums/showthread.php?t=333563

486rwhp / 571lb-ft :metal:

I have no block filler. I repaced the bolts with studs. makes power in sig.

Local guy made 634 rwhp on stock heads, rods, crank, 2-bolt, forged pistons, blower cam, stock head bolts, P600B, and a 100 shot.

Local guy made 634 rwhp on stock heads, rods, crank, 2-bolt, forged pistons, blower cam, stock head bolts, P600B, and a 100 shot.

Any idea what kind of RPM's he was turning with that setup? Can you get him to post here or have a contact email addy?

Mike

I have no block filler. I repaced the bolts with studs. makes power in sig.

Your setup is nearly indentical to what I'm looking to do. :D How long have you been spraying that setup, and how often?

Mike

It was a daily car so I imagine not TOO hard. He did blow a head gasket(or spin a bearing) and the car has been down for over a year.

Stock block bored 30 over stock 2 bolt main sprayed 250 shot and more recently new times with a 300 shot.

I built the motor in may of 02 put the spray on it about a year later. probbaly only about ten bottles through. I have been having a problem blowing up drive train parts with it. motors has about 12k on it. it used to be a daily driver now it is more of a jack stand queen.

When you're sprayin, you won't have to spike the rpm's as high as off the bottle... Nitrous is all about torque, and this usually takes more effect down low. If the mains are studded, and you don't spin it past 62-6300, you should be safe.

I've got a pal with a 96 Impala SS (LT1) with stock crank, pink rods, and no main studs that runs 14psi, and 125 shot. He's probably made 200 passes with that car with no engine problems. Now his 4L60e tranny is a different story...... ;) He's recently upgraded to a Th400 with a brake.

Stock block bored 30 over stock 2 bolt main sprayed 250 shot and more recently new times with a 300 shot.

The times in your sig are impressive, especially for a 2 bolt block on a 300 hit. :D Do you run a stand-alone fuel system for the bottle?

Mike

I spin mine to 6,400 with a studded 2-bolt block.

Thanks for everyones replies. Looks like I'll be using a studded 2 bolt block for this build.

Mike