the bolts you speak of are the main bearing caps on the crank. The 4 bolts hold up to more abuse than a 2 bolt set up.
And it isn't even April 1. If you look at the main caps on an engine most of them have two bolts for each cap. A "four bolt" block has four bolts on each of the center caps. yes a little more beef for more serous driving. That means that a lot of guys prefer them when they are building an engine.
if in fact you are in ernest... the term 4 bolt refers to the number of crank Main Bearing cap bolts at each main cap on the block, two bolt is standard construction, but for extra heavy duty, like big trucks and racing applications extra bolt bosses are cast into the block and the caps are built to accomodate two extra bolts, This is for added strength . there are even some that are Cross bolted 4 bolt.
the main bearing caps on a SBC have 4 bolts holding them in place as opposed to 2 bolt caps....it is a desired block for racing/ heavy duty applications...there's lots of thoughts and theories about 4 bolt VS 2 bolt...use the search feature on the HAMB site or plain old google it..
Man! Some of you guys think your just too good to answer a question from a guy who is attempting to learn something while on this website . Can you remember a time when you as well didnt know the answer to this question? Maybe we were alittle younger than oldfart when we asked this question......Keep in mind "A stupid question is a question not asked".
The question as to what a 4 bolt block is has been answered. As to being better suffice to say that some of us prefer to start with a 2 bolt block and convert it to a 4 bolt block as part of the machining process. Unless you are building a balls to the walls performance engine a 2 bolt block will normally hold up just fine. That doesn't mean to turn down a 4 bolt block but don't pay a premium for one if you don't need it.
It takes 2 bolts of fabric to upholster a 2 door Nash...4 bolts for a 4 door... I'm allowed to be a smartass today...it's my birthday.
I didn't know the difference between a short block and long block for the longest time. Everyone learns eventually.
Posters question has been well answered. None of us were born knowing this stuff. The OP asked a legitimate question, although I'll admit I thought maybe we were getting our collective leg pulled. But maybe he's just not a SBC guy. I've been at this a long time but there are still questions that are probably elementary to most Ford guys that I don't have a clue about. As a matter of fact my Brother-in-law is a diehard Ford guy and a real motorhead and I'm a Chevy guy (or at least that's what I'm most familiar with). We live in the same house and we ask each other "dumb" questions all the time. I'm an "old fart" now too and I don't really give a shit about asking a dumb questions anymore. I just do it. Okay, since the original poster had his question answered I came back to edit this post because I have my own dumbass question for the Ford guys. What the hell is an FE motor exactly?
You're the man Scotto. Getting fun poked at you is just a right of passage. Hell I been around for about ever and folks still poke fun at me. Old Fart is a grown man he can hold his own, trust me.
Why did the chicken cross the road?, Two(2) find two more main cap bolts. Racing for 25 years with mostly SBC engine of different configurations. My forumla has been that if you are going to rev the engine over 7500 RPMs or have more than 500 HP then you should use a four bolt main cap setup (aftermarket) to stablize the block, but you also need rocker arm stud girdles and a full roller engine, gear drive and a MSD igntion system along with a dry sump system.
....and just so you know, a 4 bolt main 350 block is no stronger than a 2 bolt main 350 block, since they're the same casting and don't know whether they're getting 2 or 4 bolt caps until they get them----despite what I've heard many "experts" say.
unless your building a power house motor its overkill. there is also a term used splayed caps (sorry for spelling guy) where the outside bolts come in at a diffrent angle.
Heathen, I think it may depend on the year and or the foundry. I tossed a junk 307 block this year to get it out from under foot, the webs measured about .0130 heavier than the 4 bolt 350 block I am using. We considered using that block when we built this engine. Anyway point is that someone with a 2 bolt block from that year as opposed to a 4 bolt block from the year mine was cast would say that 2 bolt blocks had heavier webs. Where you gain on a 4 bolt block is with splayed main caps, which is a big reason that some of us prefer to start with a two bolt block and convert to 4 bolt as part of the machining process. 2 bolt blocks are cheap.
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