302 Chevrolet Engine Build

Dwight Southerland · 09-08-2018, 11:53 AM

Yac-
Leaving “on the mat” back then is not the same level of strain as the sustained 8000+ rpm runs of today’s cars. Secondly, we broke a bunch of rods back then, too! And if you break a rod in an engine today, it’s way too expensive to consider taking a chance.
There were only three small journal rods - early 265, ‘57-‘62 265 & 283, and the ‘63-‘67 283 & 327. There ware no special high performance forgings. The solid lifter ‘65-‘67 engines sometimes got “green” rods which meant they were magnafluxed before they were machined. All these rods are 50+ years old today. Do you want to trust them for a $10K engine?
Head casting numbers changed due to engineering changes that had nothing to do with port design. 462 changed the combustion chambers, 291 made allowance for closed crankshaft ventilation with open slots between the push rods, and 186 had the provisions for bolt holes in the end.
Just a bit of history.

09-08-2018, 11:53 AM	#29
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 1,982 Likes: 54 Liked 726 Times in 177 Posts	Re: 302 Chevrolet Engine Build Yac- Leaving “on the mat” back then is not the same level of strain as the sustained 8000+ rpm runs of today’s cars. Secondly, we broke a bunch of rods back then, too! And if you break a rod in an engine today, it’s way too expensive to consider taking a chance. There were only three small journal rods - early 265, ‘57-‘62 265 & 283, and the ‘63-‘67 283 & 327. There ware no special high performance forgings. The solid lifter ‘65-‘67 engines sometimes got “green” rods which meant they were magnafluxed before they were machined. All these rods are 50+ years old today. Do you want to trust them for a $10K engine? Head casting numbers changed due to engineering changes that had nothing to do with port design. 462 changed the combustion chambers, 291 made allowance for closed crankshaft ventilation with open slots between the push rods, and 186 had the provisions for bolt holes in the end. Just a bit of history. __________________