Thread: 400 block

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I am building a 421 CID SBC with NOS.I currently have a freshly machined 2- bolt block.I have read that this block is preferred to a 4-bolt because of web material.Would anyone recommend I spluerge for splayed caps.

Originally posted by 75 TA
I am building a 421 CID SBC with NOS.I currently have a freshly machined 2- bolt block.I have read that this block is preferred to a 4-bolt because of web material.Would anyone recommend I spluerge for splayed caps.

Oh,no here we go again. the old 400 debate.ANYONE,ANYONE? I say go for it.After all it is your money.

IMO with the 400 the 2 bolt would be stronger because there are less holes in the metal...yes, with the 4 bolt there is more metal but there are less holes.

JMO, some will say that im wrong but thats ok, everyone is entitled to their opinion.

I'm under the impression that the main webbing pulls out of the 4-bolt blocks and that it's less of a problem on the 2-bolt blocks, so I've been told.

If you're not gonna bolt a blower on it or rev it to the moon, I wouldn't think you'd need 4-bolt caps.

Originally posted by Hopper111
IMO with the 400 the 2 bolt would be stronger because there are less holes in the metal...yes, with the 4 bolt there is more metal but there are less holes.

JMO, some will say that im wrong but thats ok, everyone is entitled to their opinion.

I think this was said by myself in about two other posts last month.Hey,I know sell the block and build a 383.On paper it looks a lot better.L.O.L.

hey guys,it sounds like someone doesnt like 400's.I am pulling a 383 out of the car which this is to go into.Like most people say"there is no replacement for displacement".LOL

Originally posted by 75 TA
hey guys,it sounds like someone doesnt like 400's.I am pulling a 383 out of the car which this is to go into.Like most people say"there is no replacement for displacement".LOL

400'S are great if you like thin wall's ,blown head gaskets,and a very short rod, did I mention they crack very easily.L.O.L.

Can I ask why you think a 400 is more prone to blown headgaskets than any other engie?I know many drag racers that get as many passes on them as any other engine.Could it be these peole are blowing gaskets because of improper installation?Could you please share your reasoning for your opinion.

If you are worried about those 2-bolt main cap moving around on you just have them "pinned" any machine shop can do this....And when done is stronger than stock 4-bolts

Originally posted by 75 TA
Can I ask why you think a 400 is more prone to blown headgaskets than any other engie?I know many drag racers that get as many passes on them as any other engine.Could it be these peole are blowing gaskets because of improper installation?Could you please share your reasoning for your opinion.

Take a look at a bare 400 block look at the space between the cylinders and you will see it is much less than the space between the cylinders on say a 350 block. Then you put a couple of extra holes in the block for the (siamesesd cylinders) not to mention the extra holes in the head gaskets and you can clealy see why they are more prone to blowing out.

Originally posted by erik erikson
I think this was said by myself in about two other posts last month.Hey,I know sell the block and build a 383.On paper it looks a lot better.L.O.L.

L.O.L L.O.L L.O.L build the 400 no replacement for displacement steve morris racing built my engine when i called there to see if they had a 4 bolt block he said that they are weaker oh YEAH i run IT ON THE STREET with no steam holes every1 has an opinion call the pros!!!???

www.stevemorrisracingengines.com
231-788-5869

Originally posted by 383 chev
L.O.L L.O.L L.O.L build the 400 no replacement for displacement steve morris racing built my engine when i called there to see if they had a 4 bolt block he said that they are weaker oh YEAH i run IT ON THE STREET with no steam holes every1 has an opinion call the pros!!!???

Yeah, everyone has an opinion and it was the opinion of the pro engineers at GM that the motor needed steam holes and I'm not about to try to second guess them.

It's my humble opinion that a 400 will run just as long as a 350 if built properly and it'll make more power doin' it.

Originally posted by techinspector1
Yeah, everyone has an opinion and it was the opinion of the pro engineers at GM that the motor needed steam holes and I'm not about to try to second guess them.

It's my humble opinion that a 400 will run just as long as a 350 if built properly and it'll make more power doin' it.

And it won't overheat if properly cooled.

Originally posted by 383 chev
L.O.L L.O.L L.O.L build the 400 no replacement for displacement steve morris racing built my engine when i called there to see if they had a 4 bolt block he said that they are weaker oh YEAH i run IT ON THE STREET with no steam holes every1 has an opinion call the pros!!!???

Steve Morris is a very good engine builder and a very decent man.Here are couple things to think about.The engine was only made from 72-80.It is the only Chevy engine to use extra steam holes.If this was such a great idea why did'nt G.M. use it on any other engine?Why was there never any performance 400's offered from the factory?Why does'nt Dart,World products,Brodix,Donovon or any other aftermarket company offer the extra steam holes?The reason is it makes the block weaker and more prone to cracks.Like I said I have a bunch of these sitting around the shop with cracks in them and one has a hole big enough between numbers 3,5 cylinders you can through a golf ball threw it.The other ones have cracks down the lifter valley on the drivers side.Two of them have cracks between the freeze plugs.I had one crack on the dyno and it was a .030 over bore.The block was even sonic tested before the build and was (rocked) to the bottom of the freeze plugs.I have only had one 350 block break over the years and it was doing 603 h.p. on methanol and it was .060 over.Just ask yourself why did G.M. use the extra steam holes?Do you think there might have been an overheating problem from the factory because the walls where to thin and the coolant could not pass between the cylinders and this is why they decided to drill the extra steam holes to try and cool it down more?