max hp for 2 bolt

[farmboy1466]

What's the most hp anyone's ever squeezed out of a 2 bolt main? Seems like some people think the difference between a 2 bolt main and a 4 bolt is like comparing paper to cast iron. I have heard of some people getting about 450 out of a 2 bolt 350, but I would think you could get a little more than that out of it. Just my opinion.

[cancritter]

belive l heard numbers around 500..proper build and balanceing ect cant see it no prob

[JollyBowtie]

Rpm's are the issue in the difference. Some people argue that a 2 bolt is actually stronger because there is more material in webbing. A well balanced rotating assembly is more important for keeping a motor together than the number of bolts holding the main caps on.

ROb

[J S Machine]

I've seen folks drill and tap the extra space on a two bolt main to make it a 4 bolt, and it is supposed to be stronger than the factory 4 bolt main.

[Koots]

What kind of build are you planning on?

There are lots of concerns with an engine build holding up before you worry about blowing the block apart IMO

[scarybowtie]

The 406 in my camaro was 2 bolt. It went and consistent 11.6s with the fastest pass of 11.40. It should've been around 450 hp. It had quite a few street miles, probably 50 track passes on it and had seen 7k rpms on occasion, and everything was perfect when pulled. It depends on what your trying to do. Do you have any goals? If your just wondering if 2bolt mains will hold to 450-500hp, then from what I've seen -yes. if assembled correctly.

[farmboy1466]

Not really any goals, just out of curiosity. I had a cousin that let a 327 sit around forever that I didn't know about and he didn't want to use it for a drag car because it was a 2 bolt. I knew whatever I was going to do with a 2 bolt would be far from exceeding what they're capable of.

[slowrider1983]

the two bolt will be good for around 500 if built right. major motor builds it is better to start with a two bolt block and get aftermarket four bolt caps as the outer bolts are splayed and give more strength than the stock four bolt blocks. the 400sbc blocks a that were four bolt mains were prone to cracking in the webbing that is why I found a two bolt block when I built the motor for my s10.

[TheBigMortboski]

^^What he said. I'd post a link to the ones I found on Summit, but I don't have enough posts.

[TheBigMortboski]

http://www.summitracing.com/parts/ES...n/?prefilter=1

Now I do.

[mrhp]

Roughly 400-450 horse and 6000 is safe forever in a 2 bolt properly balanced/assembled configuration. Add nitrous/forced induction and I would only use 4 bolt. Yes, 4 bolt splayed is stronger due to spreading the clamping load out.

[96ImpSS]

7000 rpm and 600 flywheel hp here with the two bolt in the Impala. 2 years and ~120 passes on it.

[Doober]

Proper engine balance and blueprinting procedures will really help your engine live. You throw an unbalanced rotating assembly in, don't check your tolerances, passages, etc., don't expect it to live long under a heavy foot.

[loudandproud]

My engine builder has thrown together some cheap 2 bolt circle track motors that have turned whole seasons of 7500+ rpm at 600fwhp with no drama...

That being said ive seen 4 bolt dart blocks come apart at 500 horse at the track... so its in the builder.

[96ImpSS]

... so its in the builder.

.....the most important statement in this whole thread ;)