Opinions on 403's?

[G-Body_Vet]

Yep....that's a pretty nasty pile happening right there :lol: I'm afraid to see what's in the bottom of the pan and the pick-up screen

 

[G-Body_Vet]

Got bored and decided to yank the pan and a main bearing to get a better look. The pan was nasty but there wasn't as much sludge on the bottom of the engine as I was expecting. The bearing shows a little wear from dirty oil but that's it.
I think I'm going to button it back up, save it for another project and continue to forge ahead with the 455 instead.

 

[rccktmn2]

I never had any problems with pennzoil and sludge or buildup, now the famous quakersludge is another story. I did an intake gasket on a truck with a chevy 350 that had ran the great quakersludge and it had crap built up to the bottom of the intake. Looks like you scored for sure on this one.

 

[90hurst/oldsguy]

the 403 have a bigger bore than the 455 which is a good thing. everyone pretty much hit the nail on the head about the problems with the 403. I ran quakerstate in my olds 350 and 307 and did not turn out to be pretty with the 307... Try valvoline thats what my machinist told my to use because zddp levels were a little higher than the other brands of oil. that sould help reduce on sludge buildup.

 

[L92 OLDS]

The common olds block big or small will survive very well below 5-6000 rpm, anything above that (on a stock build) and you will have some problems. The other theory is that the (not a theory) 403's are weak blocks because of the "windows" in the main webbing of the block, and that is why they make (poor high revving) performance engines because of weak mains and poor oiling. I've had 2 of these engines and never had a problem, the pistons are huge and as long as your not going to extremes (500 hp and up) you should be fine.

This

I own (2) 403's. As already noted, you will notice a big difference in available torque vs a 350 and cooking the tires will not be an issue even with a stock 403. A bump in compression with the appropriate cam will wake these motors up but watch the revs. The 403 in my 442 is a mild build that gets the car into the low 13's (maybe 12's?) and I have never had an issue with it. The bottom end was balanced and it has TRW forged pistons. If you've done your homework, you have probably already read about the high performance builds out there and guys using NOS successfully. Visit Oldspower.com or realoldspower.com for more info.

 

[Gbarrie]

Got bored and decided to yank the pan and a main bearing to get a better look. The pan was nasty but there wasn't as much sludge on the bottom of the engine as I was expecting. The bearing shows a little wear from dirty oil but that's it.
I think I'm going to button it back up, save it for another project and continue to forge ahead with the 455 instead.

I'am confused :? if you change your oil regularly whats with the sluge. Can some one please explain
Gbarrie.

 

[JDMitch32]

Nice find! The Olds engine is a very strong one. Same as the Buick SB and Pontiac's. They just need the right amount of TLC to address where the factories cut corners. These engines will surprise a lot of people if they are done right. If it needs a rebuild or just freshening up then, you can take care of some of the simple things early for not a lot of cash. I know more about the Chevy mainly because that's what I have tinkered with and owned the most, same as most GM guys and gals, but the one engine I wish I still had to this day is the Olds 350 that was in my '71 Cutlass. Simple 2 barrel and 400 transmission. That thing would flat move and with blown out Glass Packs scared the hell out of a few Mercedes' Ladies that liked to pull out if front of me. If I was half as smart as I thought was, I would have swapped that engine into the '84 GP that I bought from the little old lady down the street when the 267 crapped out in it!

 

[DRIVEN]

So what ever happened with this?

 

[G-Body_Vet]

So what ever happened with this?

Its just sitting in the corner of the garage, along with another poncho 455 and then there's still the unfinished one too. I'm real close to selling everything, including the GP. I'm too busy and losing interest.

 

[DRIVEN]

You, pull yourself together. Immediately. That's crazy talk. Now calmly go to the fridge and grab a beer. Then walk out to the garage and look at your masterpiece in progress. Do you really want someone else to finish it and take all the credit?