Guys, can I take a 6.0 block and open it up to 4.030" on a 250 hit? Are you guys o-ringing the blocks for this much power? Stroke will be a 4.100" Callies crank, billet caps.

Thanks!

 

I have a 4.030" bore, and it's been o-ringed in preparation for a 500 hit or more.

 

My main concern is cylinder wall thickness. Not that it will fail but I don't want to risk any distortion of the bore.

Any more comments?

 

Mine a at 4.060 bore (and 3.72 stroke). It was an ARE block that they supposedly sonic tested for thickness. I have run 300+ through it at over 700+ rwhp many many many times. The same bottom end is now refreshed and I will be hitting it with ALOT more. We will see if it holds.

When it was refreshed the machine shop said the bores looked great and where still round. All we did was a diamond hone to fresh it up. Bores still checked right at 4.060 The deck surface was wavy as hell..but the machine shop said that was likely heat cycling and miles on a new block. We decked the block square again. Hopefully it will stay in shape better this time around since its well seasoned.

 

I was kind of worried at first, that's why I got a good used block.

 

Yea I agree. I am doing a new GM block but it will be heated and decked prior to assembly.

 

Oh...one other thing. I have not oringed...just Cometic gaskets. When I removed the head you could see where some gases where bypassing the fire ring ever so slightly. Never had any coolant issues or crank case pressure issues so it had to be very very slight. I suspect it was due to the deck surface moving a bit. But those gaskets held very very well. I have probably sprayed 600-710rwhp at least 150-200 times over the 18 months that motor was together. Never pulled the head. The main bearings where shot...completely...but those damn gaskets held on for dear life.

 

Depending on how the customer uses the motor, we will recommend that the motor be pulled and re-freshed once a year. We do this on all of our race cars and it greatly extends the life of a motor.

 

I have a 4.030 x 4.000 motor that I've hit with a 300 plan on hitting it with more... stock style gaskets, none of that cometic stuff. Still hauls ***...

 

this is my philosphy now as well

 

I've got a 6.0 iron block bored .030 over, 4.00 Callies Crank, 4.030 Diamond pistons, 6.125 Crowler rods and cometic head gaskets spraying 300 also, never had a problem with the motor. Ran a 9.23@149.1 on a 1.32 60ft at the Thunder Shoot Out. I agree about freshening the motor before the start of racing season.

 

What are the specs on your motor? Cam specs, heads, etc.

 

are you guys pushing water on these big shots?

what are you running for bottle pressures?

 

I run a 408 and am the builder of Elite Hotrod's motor also. I run 300 worth of bottle with cometics and have never had a problem. I play on running 450 next season on the same setup with a individual fuel system for the nitrous.

6.0 motors are tough. I don't think you will have any problems. I would only sonic test it for a 4.06 bore at any rate. Once the sonic test comes back good spray it with as much as you want.

The camshaft and CC of the chambers play a big roll in this setup also. If your dynamic compression ratio is to high, then when you try and spray a big shoot the cylinder pressure will be to high and take out something prematurely.

Elite Hotrod has a 244/248 612/615 on a 113LSA on XER lobes.
Heads are CNC S3 13.8 Static compression 6.0 heads.

Mine is 245/250 630/615 on a 112LSA on non XER lobes
Heads are LS1 casting ported and polished cut .030

We both make over 700 to the wheels through an auto and a 9in.

 

NOS is the name of a company, nitrous is a product they sell that makes your car go fast.

 

Actually I believe NOS is an abreviation for Nitrous Oxide Systems, just so happens to also be a company

 

Oh yeah, and you should be good to go Mikey

 

i wondered how long it would take! [NAWZ]

 

Mikey, you will be able to get away with the 4.030" bore. It would be a lot safer though if you went only to like a 4.010" bore. This would leave the walls pretty thick and keep you from having any distortion. You should be fine running a Cometic gasket without o-ringing, unless you are planning a larger hit down the road. We've gone up to a 300 hit with no o-ring's and Cometics.

 

Thanks Chris. We are going with the 4.030". Customer says he does not plan to spray more than a 200 shot of NAWZ...hahaha

Funny thing I posted the NOS to bring the dick heads out of the walls....haha...it worked