402 Olds?

[southernspeed]

I've got the possibility of getting a 402 Olds (4B) motor. I presume it is a 'big block'. Is it a good motor? Do they bolt up the same as a Chevy, take the same accesories? I'm running a small block at the moment and just wondered if it would make a good upgrade. Chevy big blocks are getting rare and expensive over here.

 

[diesel4me]

They arent exactly easy to find over here anymore either,especially the 1986 and older ones.Olds had a 403 V8 they used most of them in pontiac trans am's beleive it or not,also the big full size olds wagons and delta 88 and 98's.They are considered a big block,but I'm fairly sure the share the same block as a 350 olds(someone else will probably confirm or deny this)--they dont have the same bellhousing pattern as a chevy,they share the same pattern as Buick,Caddy,and Pontiac--adapter plates are available from a place like Jegs or Summit in TCI brand for about 60 bucks--.I know a few people who have used 455 olds motors in chevy pickups,they used the motor mount pads from the 79-81 "junk" 350 diesel they had before the 6.2 came out--it made it a bolt in as far as mounting the motor--the battery cables and fuel pump are on the drivers side,so you will have to do a little plumbing and wiring,but its not that difficult a swap--due to the lack of cheap chevy motors,people here are putting pontiac 400's,455's,olds motors,caddy's,buicks,into GM trucks now--nesessity is the mother of invention!.

 

[southernspeed]

Thanks for that. /forums/images/graemlins/waytogo.gif Anyone else got any info? /forums/images/graemlins/confused.gif /forums/images/graemlins/thumb.gif

 

[atho]

In my experience, the 403 is a good motor. My friend has one in a '77 Buick Electra 225 that he got from his grandma. The car is like 25 feet long, will lay a patch, and even gets 18 mpg on the highway.

 

[thor]

diesel4e hit it non the head with the trans-ams, all the mid/late 70s AUTOMATIC 400s were actually the 403 olds, 4 speed cars kept the pontiac 400.

They seem to work very well in stock applications, but not popular to build because they have week main bearing saddles. They actually cut a window in the webbing to save weight. /forums/images/graemlins/dunno.gif

Here is some more info: http://www.442.com/oldsfaq/ofe403.htm

 

[southernspeed]

OK, thanks guys. I think I'll hold out for a Chevy big block at a reasonable price (could be a long wait!!) /forums/images/graemlins/thumb.gif

 

[Aquaman]

Are ya'll talking about a 402 or a 403? There is a big difference. 402 is just a bored over 396 anyway though. Smaller of the big blocks... I like mine. /forums/images/graemlins/thumb.gif But I bet it would run better off of propane . Right now I run off of 100LL

 

[dyeager535]

He just got incorrect info on the CID. The 403 Olds is just that, 403CID, although GM termed it a 6.6L, same as the 400's. Oh well. /forums/images/graemlins/smile.gif

It IS a small block, with a huge bore and weak mains...all external dimensions are the same as the 260/307/330(?)/350 Olds motors.

 

[90v1500]

[ QUOTE ]


It IS a small block, with a huge bore and weak mains...all external dimensions are the same as the 260/307/330(?)/350 Olds motors.

[/ QUOTE ]

Your right it is a small block with windowed mains, BUT the windowed mains aren't a problem unless you run it over 6K regularly. (I've done some work on Olds motors for Street/strip cars). They do have a good bore/stroke ratio to them and make good torque motors. You could easily get 350hp and 400ft/lb from it all at less than 6K rpm. Just my .02 /forums/images/graemlins/peace.gif

 

[dyeager535]

Yeah, they may take SOME abuse, but I had for awhile a main bearing saddle that had ripped COMPLETELY out of the block.

There just isn't much support for the main bearings on these motors.

As a matter of fact, I believe ALL Olds motors 77+ used windowed mains. It works, it's just not ideal.

 

[diesel4me]

I cant remember if the ill fated 350 olds diesels had a window in the main bearing web or not--but I do remember seeing more than one with the main bearing saddle spinning around with the crank when it broke away from the block!.And some had a "window" in the block from the rods coming out the side. /forums/images/graemlins/crazy.gif
I always thought that Olds,Buick,Caddy,and Pontiac motors were pretty good--I've had a couple 401 nailhead buicks,and a 400 pontiac in a 69 GTO that ran very well,no real problems with them despite daily beatings,other than the usual weak timing chain setup in the pontiac.I never had an olds motor,but I have several friends who owned them,they were pretty fast cars,and didnt breakdown much.I hardly ever got any calls for engine parts for the Buick,Caddy,Olds and Pontiac motors as far as rings,bearings,pistons,etc---this led me to beleive they were pretty rugged motors--or maybe they just junked them all instead of fixing them?? /forums/images/graemlins/confused.gif.I miss all the good motors they had in the 60's and 70's--they dont make em like that anymore!. /forums/images/graemlins/crazy.gif

 

[dyeager535]

Yeah, you are right, the Diesels weren't windowed.

However, the process to convert an Olds diesel block to gas (it's a standard dimension Olds small block) is outrageous, and why I need to get rid of the the 350DX block sitting in my garage. /forums/images/graemlins/frown.gif