Reply With Quotei had a 71 chevelle that i use to race a lot.it had bbc two bolt and i use to bang the shit out of it with a 400hp nitrous kit and never had a problem.if your not making big hp a two bolt will be fine.
I'm looking to put a BBC in my flat to race in the River racer class. I was going to have a guy build me a tame 454, but I found a freshly built one. Its in a guys boat now with only few hours on it for a reasonably good price. (he lost his job and needs to sell it) It is only a 2 bolt main block vs the 4 bolt I was going to have built. I do not know enough about engines to know if a 2 bolt is necessarily bad at the slower speeds (90-100mph)compared to a 4 bolt. I'm not trying to set records here, just play at the races. Anybody give me some back ground of pros vs cons? thanks for your reply.
i had a 71 chevelle that i use to race a lot.it had bbc two bolt and i use to bang the shit out of it with a 400hp nitrous kit and never had a problem.if your not making big hp a two bolt will be fine.
I was running a 2 bolt in a 427 550 hp with no problem in an 18 Cole Starfire with V-drive. It was a great ride!
I've been told a 2 bolt is no problem up to 600hp, anything over that, you might want to consider converting the 2 bolt to a 4 bolt. The blocks themselves are identical.
HBjet
I'm running a 2 bolt 454 with stock caps, a cast crank, stock 3/8 rods with ARP bolts, and a 2 750's on a 8-71 blower running 12 lbs. boost. I beat the crap out of it all summer. Stayed under 6400 rpm and had zero bearing problems. I tore it down last week, the crank is perfect, bearings are going back in. It's the high rpm with heavy parts and short rods that causes a problem. And even then, the rod or piston will fail before the main caps.
F.U.
Go ahead and use it. The next time it needs line bored or honed, put some aftermarket 4 bolt caps on it. They are better than stock anyway.
Fired up,Four bolt mains are nice but not necessary,the post from detroit jim address'the rpm question.Depending on how many rpms you turn, it should be fine.The critical thing is that everything is balanced properly and you have a good harmonic balancer.I have also heard that some people stud the 2 bolt main caps.DEL51
Firedup, I am in agreement on the 2 bolt main block for the use intended, I have ran several 2 bolts over the years and needless to say I have punished them severely, and I never had a failure due to the 2 bolt main, be it a chevy or a ford, as was posted earlier, the failure usually occurs in the rods, pistons, or some other dumb part, before the 2 bolt will, in 98 we blew both of our pro gas motors (Fords), and being the hi points race ,we had to have an engine to keep going, the only block we had was a 2 bolt, so, we took the crank,rods, heads & pistons and stuck em together in that little old 2 bolt and twisted it in excess of 8500 with over 15 to 1 compression, and went on to win 3 races in a row, we lost the "junkyard dog", as I named it, at Witchita, but it was nothing to do with the 2 bolt, the rough water in the shutdown was the culprit as we lot an oil line and destroyed it, so , as others have said have a good time with your engine.
Thanks JDL and all the rest. I feel alot better knowing a little more.
The Fire Guy.
I want to throw in my .02 here. I think the 2 bolts are plenty strong for just about anything you want to do with it except for the extremly high HP/RPM motors. Having said that, I want to ad that if your motor is built to correct specs and clearances, your right foot and common since will have more to do with how long your motor will last than how many main bolts you have. I'm not saying you should putt around and baby it, I run the living $h!t out of mine(2-bolt) every chance I get. Watch the water ahead, keep from catching air and unloading/loading the engine suddenly and get a rev limiter. A sound, relativly inexpensive, lightly beefed engine will hold up extremely well.
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