Grimm This has been an eye opener to me as well. If you think about it, as your HP and torque grows more stress is transferred from left to right leveraging the block up on the left to down on the right. The block cannot rotate so the stress is transferred to the block pulling outside wall away at the main web. In my case the right motor mount was loose (real loose) which may have amplified the problem causing my failure. My engine is making 525 HP, best ever, which probably compounded the torque factor here as well. Now I have to figure if either the girdle or a center mount plate would be the most effective solution. Weekender
Guys break #2 main even with a girdle if you don't run a mid plate Or they just pull the side off the block. The block is thin all over. The girdle does help but it doesn't relief the stress. I say if you are going to make some good power, then do the mid plate. If you are staying at the 525 mark, then you can consider just doing a "mid-plate" type support and use rubber mounts.
Well, seing how my engine will be up around 700, im guessing im in for this? so, can anyone post pictures of their midmount plates or custom systems they have made to prevent this stress? Pulling the side off the block!?
I own a honda motorcycle with solid lifters,and it would tick excessively in hot weather. After switching to synthetic oil about 10 years ago,it is totally silent and with over 30,000 pretty hard miles,I'm sold on synthetic. Some times it's hard to believe some of the marketing hype you see and read about motor oils. But in my case,the proof was right there in front of my face. synthetic oils have much better lubricating properties than conventional oil. I also watched a show on the history channel about motor oil,it was quite well done. Synthetics are made from a pure gas molecule,there is no microscopic contaminants in the oil like conventional oils. No matter how well refined conventional oil is it will not be totally pure of these microscopic contaminants. :3gears::3gears:
Another Broken #2 main . I think #2 goes because it is the longest unsupported span of all the mains. This block never had motor mounts on it. I've heard opinions both ways , some say front and rear motor plates will allow the block to twist and have gone as far as adding motor mounts to chassis cars to limit this. It's simple , we're stuffing 10lbs in a 5lb bag. Dave
How big was that motor? How many passes did you get out if it? How much power do you think you were making with that motor? How much pre-load do you setup on the main caps with the girdle? Another thing that I believe would help shift the load on #2 main is the 4-7 firing order swap.
Hey Dave M, that pic. looks exacly like the block I cracked, but the crack went down into the bore too. I ran home made solid motor mounts, and no mid plate. Figured 760hp on motor plus the 200 shot of the good stuff, and I guess some detonation, killed it...... Still waiting for that new "bucket" to put my 10 lbs. of Sh#* into! Gary G.
Re: Amazing story of a BBB survival The reason I was questioning my problem being cause by it being externally balanced instead of internally balanced was not only did it break the block it also cracked the crank in 7 places on #1 and 2 mains. Being that the balancer has weight hanging off it and only supported on one side unlike when you internal balance the crank and mixed with 6600 rpm. I wondered if that could cause the crank to flex/harmonic's and cause this problem? All though most of you guy's are most like internally balanced already so that blows my case apart, most likey the broken block came before the cracks in the crank Chris
Yes, The original Halo. One of Mike's first girdles I modified a few....maybe more than a few years ago.Can't remember how many motors it's outlasted.
yes it's Steel So when is the TA block going to go into production? Fish.[/QUOTE] The sooner the better!
I'd rather have the peace of mind with a new block than worry about all the crutches for the factory block. It's a 1 time expense that will cost less in the long run...Fish
