76olds

I need to ask,... what's the difference between a Nascar Olds block and a regular Olds run of the mill block?
455? 350? What blocks were available at what CID.

Thanks
Eric

joe_padavano

The NASCAR block was a factory race part cast in the mid-70s when Olds actually ran Oldsmobile motors in Cutlass stock cars. AJ Foyt was one driver who ran these. The block was much beefier than stock and had four bolt mains (as shown below). Typically run with Batten heads.

wr1970

Were these also only 350 dx blocks?

76olds

Just talking out loud here,
I thought I heard here that the Nascar block had a higher nickle content. For those here that know cast and steels!!
If someone were to take a block of P-20 material which is between 38-45 rock well, tried to duplicate a 350 block with 4 bolt mains for kicks, would the P-20 be somewhat close to the casting of the Nascar block?

Thanks
Eric

joe_padavano

Not even close. Completely different casting. For one thing, diesel blocks were two bolt and had a massive boss in the front timing area to mount the injector pump.

joe_padavano

In the interest of keeping that Parts Wanted thread on track, I've moved this discussion to it's own thread.

wr1970

Well this is my opinion only Eric. I am not buying in to the high nickel content story period on any Oldsmobile motor. There is no evidence to prove it anywhere that i know of with the exception of Mondello. Joe Mondello didn't provide any proof. Thanks Joe p for explaining that. I was under the opinion that the Nascar block was designed from the dx. Alway good to learn from your info.

joe_padavano

I'm sure some of the engineering done for the diesel block was applied to the NASCAR block.

wr1970

Joe did Nascar have mains as a DX?

joe_padavano

No, but the DX does have enough meat in the webs to machine for four-bolt mains.

anthonyP

Very interesting subject. Was the last Oldsmobile engine used when the '76 & '77 Cutlass bodies was no longer allowed for NASCAR racing?

I cannot recall the maximum engine size for NASCAR after the 426/427/428 engines were banned, only that the aero cars were limited to around 350 cubic inches after the 1970 season.

Does anyone remember the driver who raced a '70 Cutlass in NASCAR. I saw his name and the car mentioned in an old Motor Trend magazine in the race results section, but now cannot find it.

Were Chevy engines exclusively used in every NASCAR '81-'88 Cutlass, or did any of the teams use an Oldsmobile engine?

76olds

Thanks for posting the web thickness differences Joe. Due to the small web casting in the street production blocks were their many other differences that you know about ?

Eric

joe_padavano

Differences between what and what? DX and NASCAR? Or production gas blocks?

76olds

Production Gas blocks , webbing differences

Inline

Question out of interest: in what timespan was Oldsmobile block used at Nascar?