Thread: sbc 400 2-bolt main

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Originally Posted by 34_40

I was curious about the cracks and tried to zoom in and crop the pic. The cracks seem to have a circular shape to them before they get to the cylinder. Let's see if this worked..

I guess I could've made it larger still... but you can see the circles below the bolt holes.. Still curious.. LOL..

Those are the steam holes Jerry is talking about, they have been plugged here. I tap my holes and stick an allen screw in there. I tap those big holes above the stud as well and have pipe plugs in there with 1/4" holes drilled in them for water/steam.

Originally Posted by 1gary

Good friends-I am not preaching here,but we did get off topic in the process of four bolt main conversions somewhat.Here what I suggest directly to his question.

Sir-it is the combined situation of the 210 cc heads and the costs to convert it to a four bolt main still leaving you with a cast crank that I think you do have a combo issue.I don't think it is advisable for you to spin the engine that high to make those heads work well with that port size with only a 2 bolt main.To change to a four bolt main isn't cheap as the other posts suggest.To move to a aftermarket block in the long term is a better solution and a better financial move,but it still leaves you with a limited capability of a cast crank.The bolt main and the limited cast crank along with the cc heads is the core problem,well really the cc runner and the cast crank is.No way would I suggest you spin it up to 7,000 with a cast crank to really get the advantage of the 220 cc runners.You said you I have long rods,but no detail on what those are too.So to get back to my point,you can't really back down the rpm range because of how huge the 220's are and you can't really spin up that cast crank for very long to use those 220cc runners either.So aftermarket block,four bolt block conversion,you need to do something about that combo either sell off the heads for something smaller and do the four bolt conversion lowing the RPM's using the cast crank or replace the crank with a forged crank that can handle the high rpm and buying into a aftermarket block,but still leaving a question on which rods you have.This option being the best one.Oh one other middle price option would be four bolt conversion/forged crank.

Again-you didn't say if your intended use was to spray it and how much or any other power adders.

When you get into that size head runner,it gets expensive needing all the other parts.Those heads are not really for street use.

Man the wheels fell off on this guys question.

I think his question got answered, with some other info and opinions tossed into the salad as well! LOL... The rest is just sharing information and experiences I think..