Buick 455 vs Olds 455

This is true, i thought about that when i listed Mondello. For those interested Mondello was one of the best performance parts sources for Olds until his son took over and now its turning more into a profit-venture than a passionate hobby. Parts are getting cheaper (and not in the good way) and ive heard complaints about their representatives. However, in the interest of fairness, they are still a major Olds distributor so i figured id list them anyway. But there's the skinny on them

 

old thread, I was looking around and was compelled to comment

Olds has a longer connecting rod, and smaller main bearing journal 3", and their 455 can be punched .125" over

Buick has a shorter rod, and large main journal 3.25"

the big journal is a disadvantage for oiling, rpm, friction

the best Olds heads will flow with the Buick heads in OEM form.

I'd wager the 2 engines are evenly matched

Buick has a better bore/stroke ratio

 

I have owned them both and in stock form they turned pretty close qtr mile times. They were both automatics I raced.

 

Just read this thread and a sbo was referenced more than a few times, I just want to clear up the confusion the op has, there is NO SUCH engine as a small block Olds.

From 260 to the 455 were machined on the same bore spacing dimension with the only difference being a shorter deck height for some of the smaller cid engines and main bearing size differences.

If you look at a sbc vs a bbc and a sbb vs a bbb for examples both of those small blocks the blocks have smaller bore centers than their bb counter parts. Here is where things get tricky, a sbb 350 has deck height of 10.188" tall with the older bbb the Nail Head had a 10" deck height. So does the deck height of an engine make it a big or a small block? And can we call a 350 Olds a small block or how about the 403 short deck Olds engine is that a small block? Now look at a bbc, is the bbc with a 9.80" deck height a small big block Chevy while the 10.200" bbc truck block is the big block?

How about Pontiac engines, all of the CIDs had the same deck heights and bore spacing except their 265 and 301 that shared the same bore spacing. If you go by main bearing size then a 400 and smaller cid would be a sb because the 421, 428 and 455 had 3.25" mains vs 3.00" mains of the others.

So no, Olds and Pontiac did NOT have a different engine platform that could be called small block.



Derek

 

This core shift you speak of, is it unique to BBB 455 or SBB 350 also?

Thanks
Gary

 

Car Craft 2001-2002
Buick 555 HP (winner)
Pontiac 501 Hp
Olds 497 Hp
The smaller bore of the Pontiac and Olds limits valve size and will shroud larger valves. A really good set of heads can improve the situation.
Buick engineers used a good bore/stroke ratio, angled plugs, wedge combustion chamber, etc. to acheive an excelent combination.
Aftermarket engineering can improve all the above however.

 

Umm that 350 diesel is one of GMs all time worst screw ups, if not THE worst screw up. That's up there with the Cadillac 4/6/8.

Back on topic, the Buick motor is the lightest of all the siblings by a good amount. The down side is the core shift issue it has.

 

Yeah but that diesel block is stronger than the Olds gas motors. That's why it gets used.

Gary, good point about the bigger valves in the Buick. The 440 Mopar has only 3.75 stroke so it has good sized valves but the torque starts getting lost or moved up in rpm with that short stroke. The stock 440s and mildly modified never seemed to leave that hard.

I wonder what a 425 Olds could be bored out to. It has same stroke as 455 Buick. Best Olds motor IMO.

 

The Olds 425 can be bored to yield around 440 cid.


There is a Buick factory internal memo (circa 1969) I posted somewhere on this Board that tested a GS 455 stage 1 car and non stage car against an Olds W30. The non stage GS 455 ran about the same time as the W30 while the stage 1 ran the quickest time.

 

The Olds never got a fair shot in that shoot out. It was the first engine built and tested, and it was done before the shoot out was conceived and didn't get quite the same cam lift, etc the others got. Not saying it would of won, or even moved up significantly, but if you look at all the builds, to Olds was slightly handicapped.

Both the Buick and the Mopar show that unshrouded valves with wide bores appear to be more favorable a combination than narrow bore, shrouded valves and long stroke.

The Pontiac got robbed on the TQ number, because it was just under the Mopar but the torque curve was already on the down slope from the start of the dyno readings. That engine was a true torque monster.

 

I like "area under the curve" measurements rather than peak torque numbers.

 

Having built both of them in stock form, I like the 455 Buick for the bigger valves and better flow, and the 455 Olds for the more traditional (shorter) oil run from the sump to the pump. The Olds is heavier, and not as susceptible to core-shift, (not as bad as the Buick) but the Buick is better in the heads. Fuel flow and usage in the Buick seems better, the Olds is a bit of a hog.

Personally, if I had my druthers on an Olds, the first generation of them were sweethearts. The last Olds I built was a 303 with 325 heads on it, and it's promising to be quite a torque monster. They were sweet, smooth running engines that were actually quite ahead of their time. They were called "Rockets" for a good reason. There aren't many cars built in 1953 that could get up to 90 mph inside 1/2 mile with a wheezy, burned out, clapped out, running on 6 1/2 cylinders smoker of a V-8. We did it regularly on a 53 Super 88 sedan until the fuel pump gave out.

 

Will a 1972 Olds 455 engine fit in a 1970 Buick skylark. The skylark has a 455 in it already but I don't know what year it is. Any help would be appreciated.
Thanks

 

You can make anything fit but a lot of things are not the same. The battery and starter are not on the same side. The radiator hookups are not the same. The wiring harness is not the same.

 

No an Olds motor will not fit in a Skylark. The Skylark will puke that Olds motor right into the middle of the garage floor and piss radiator fluid on it.

 

I put a Stage 1 motor in a '76 Cutlass, was a really fun car. Won a lot of races with that car.

 

Not to change motors (thread) But you have to admit Olds engineers were on the ball to come out with those RAM ROD 350 to mess with the Insurance company's . Those High Compression Heads those 350 ran well! And extremely RARE 200 units And the High nickel content in those blocks. And W-30/w-31 f-85 Bring big money now at Mechum. I'm Buick all the way but olds engineers were responsible for creating the best Auto Trans. Ever made. That's proven! TH-400.

 

The 464 I built for my '72 came out of a friends '72 Cutlass 442. I bet he wishes he had it back now!:grin:

 

Don't know which engine is "better", but their 1/4 times are very close.....trust me on this one