Mill decisions

OK Quarterhorse, I couldn't ignore this thread for another minute.

In Jim Szilagyi book "How to Build a Big Inch Small Block Mopar" he states that the LA block can support up to 430 hp continously. Later on he states 500 hp. He's a Mopar engineer and most likely has/had access to data that we will never see. Having said that, this is what I know:

There is a member here who is running close to 550 hp naturally aspirated with a stroked stock 360 block. He did have a problem with a broken crank and has replaced it with the addition of a stud girdle and has not had any more problems. I might add that all internals are forged too and he races this car pretty often.

I'm with Moper when he states that aftermarket 4 bolt main caps are a bad idea as the main webs are too thin. Drilling this out does not help matters and may only serve to weaken the block.

So, my opinion is that a stock block can support 500-550 hp if:

1. You are using a premium rotating assembly consisting of all forged parts. The rotating assembly must be balanced even if the maker says that it's "pre-balanced". A top quality harmonic damper must be used.

2. The machine work must be impeccable!! Everything should be magnafluxed before assembly and the block should be blueprinted including align boring. Sonic checking the cylinder walls is must.

3. Use a stud girdle and top quality studs.

4. Block prep! Grind off all casting flash, parting lines, etc. Don't leave any stress risers.

5. Half fill the block with Hard-Blok or whatever.

I also think that making 500+ hp on E-85 or methanol will be easier on the block than doing the same on gasoline. Why I think so is for another post.

Now, will this block be 100% reliable with another 200 shot of juice? No way. Will it run? Hell yes, and really hard too for awhile. Mr. Szilagyi states that for 650+ hp applications, the R3 block is the only way to go. Main webs designed for 4 bolt mains, serious cyl wall beef, etc. The block itself even weighs about 50 lbs more than 340/360 LA block. Unfortunately, I don't think anyone can tell you for certain that "10 200 hp hits and she's a goner". You might get 1 shot or you might get 50 or 100, but it will go away and it won't be pleasant.

Hope this helps.