In doing some basic engine research on my GM Goodwrench 350 crate engine (#10067353) I noticed that my engine documentation says that it has a 4 bolt cylinder and case. Is this comparitable to the L82 4-bolt main? My car originally had the L-48 in it but was burnt-up by the 2nd owner and he replaced it with the Goodwrench engine. Is the crate engine closer to the L-82 or the L-48. The original intake and carburator were installed on the GMGW engine. Unfortunately the cam from the GW engine was not swapped out during installation. For all practical purposes the engine is stock. Any ideas or guesses on the GW horsepower as compared to the original L-48? Any and all responses are greatly appreciated. Thanks to all! :)

 

L-82's were 4 bolt and L-48's were 2 bolt. But i've heard stories of both being the opposite. Probably the engines that were built at 4:30 on a Fri. afternoon :lol:.

 

I'm certainly not an expert but I have the same engine inmy 69 now. It's a basic stock replacement engine with about a 250hp rating. It's fine for a driver but you can boost it up if you want. It has a cast crank and pistons so I wouldn't go too wild but CHP magazine did a great story on this engine a few years ago and pulled 400 hp out of it. The L82 has better pistons,rods, and crank. I'm going to swap out the smog heads for WP Torquers,add a performer intake,headers, and either a 268xe or 262xe cam.That should boost HP to around 350-370.
gary

 

If you can pull the block numbers off of the drivers side rear of the motor just before the bell housing you can to to http://www.mortec.com and look up the engine numbers as well as the head numbers intake numbers just about any numbers that you want.

By the way I have/had an L-48 that was tired but being a matching number car I wanted to retain the same block so opted to build my motor rather then a crate motor. My L-48 is a 4 bolt main. The way that I hear it is if the car is coming down the line and was to have a 2 bolt main block but none were available at the time, they just swapped with the 4 bolt main. Weather that is true or not, well who knows, all I can say is that it was my gain :D
JoeB

 

I have the same engine in my car (see specs below). For several years, GM claimed that it had about 180 hp, but the actual numbers are closer to 240.
:cheers:

 

The block itself meets somewhere in the middle between that of the L-48 and the L-82. The block is stronger than the L-48's block, but not where it counts. The L-82 and GW350 both have 4-bolt mains, however the L-48 and GW350 share cast pistons and a cast crank.

The cam is the same cam as that of the L-48, and the cylinder heads have the same size valves and depending on the year, may or may not have the same chamber size. The newer ones have smaller (72cc vs 76cc) combustion chambers.

This engine probably DOES make 240 hp, assuming you run it with headers and a good exhaust system. I also believe an L-48 would put up a number very similar to that with comparable parts involved.

This engine is nothing more than an L-48 with a 4-bolt main. Having made the switch from L-48 to GW350, there was no noticeable difference in power. I would definitely reccommend a cam upgrade before you ever install the motor.

If you plan on getting real serious, however, it would be better to start from scratch with a ZZ4 4-bolt roller block, or another factory roller block. The GW350's block is 2-piece rear main(thus more prone to leaking) and also is not machined for roller llifters. ZZ4 has the one piece rear mains and accepts roller cams without retrofit lifters.

-Steve

 

Yes the block is 4 bolt main - and in that respect it is similar to the L-82 block - however as mentioned before the L-82 came with forged pistons (vs. cast in the universal replacement motor) a forged crank (vs. cast in the univ. repl. motor) It is rated at about 240 hp - but that rating is GROSS not net - all GM crate motors are rated at gross hp because they cannot tell which car, and hence which accessories or exhaust should be installed. So it is in effect probably little different than a L-48 with 4-bolt mains.

Still it is a good point to start.