What does 4 bolt main mean on an engine?

Four bolt mains. What holds your crankshaft in place are the main caps which also hold the crankshaft bearings. A 2-bolt cap is fastened to the block by 2 bolts, and a 4-bolt cap has 4 bolts (2 on each side). When you increase the load on the crank, you also increase the load on the main caps.

How to identify a Chevy 2 bolt main?

Im heading out to the junk yard today and wanted to see if anyone can help me look for numbers or markings other than the acutal 4 bolt main caps, i want to find a 4 bolt main engine, but want to save time and not having to unbolt every oil pan outthere, are there numbers or castings that say if it is a 2 bolt or 4 bolt…thanks guys

Is the Chevy 350 a 4 bolt main?

This is the only for sure four bolt casting I know, earlier 4 bolt 350s were often 010 castings, but these came in two bolt as well. If you are going big-block, beware tall-deck truck blocks, the 366 and 427. These heavy-duty versions all have 4 bolt caps, but extra heavy duty pistons with widely spaced rings that require the taller deck.

What is a 4 bolt main?

A 4-bolt main refers to the number of bolts attaching the main bearing caps to the block of an internal combustion engine. Four bolt mains are considered much stronger for high performance use than a 2 bolt main.

Can a 2 bolt block be converted to a 4 bolt main?

Converting to a 4 bolt main on a BBC is not worth the trouble and expense. If you truly NEED a 4 bolt main, you NEED an aftermarket block. How much power will a studded 2 bolt safely handle?

What’s the difference between a 2 bolt and a 4 bolt?

Dynamic Racing provided these pictures comparing a 2-bolt main block to a 4-bolt main block. Below is a comparison of 2-bolt main parts and 4-bolt main parts. The 4-bolt main parts are on top the 2-bolt main parts are on the bottom half of the picture. Below is a close up of the different size oil seal housings.