Is a pontiac 400 a SB or a BB. Is it a creature of it's own?

Will SB chevy cams fit in a Pontiac 400?

I know very little about pontiacs so forgive the elementary questions.

Thanks
Mark

 

The Pontiac 400 is a completely different engine that shares nothing with the Chevy SB and BB other certain architectural features and some ignition system and starter components. It's based on the original Pontiac OHV V-8 of 1955 that I think was 370 CID. Pontiac is generally credited with developing the stamped rocker arms that Ed Cole then adopted to the SB Chevy, which was developed in the same time frame. The Pontiac V-8 was later expanded to 389, 421, 400, and 455 that most enthusiasts remember. A lot of parts are interchangeable from the original '55 to the last versions in the late seventies, just as on a SB Chevy.

When I was at Pontiac Engineering in '68 they had a set of tunnel port heads on the dynos, but they never made it to production before meeting emission standards became the primary objective for the engine developers.

I recall dropping into a dyno cell while several guys were there attending to a paritally disassembled tunnel port engine. Upon inspecting the head I went on to say something on the order of - wouldn't it be better if the pushrod tubes were cast in a teardrop section rather than just being a piece of fabricated tubing because the drag coefficient of a cylinder is 0.5 versus a teardrop's...

Well, instead of an answer, I got one of those "if we wanted your opinion kid, we'd ask", so I took that as my cue to return to my desk in production engineering. ;)

Duke

 

Thanks Duke,

The engine is in a Firebird. The fellow is looking for a cam and I had nothing to suggest, as I was not sure what components would be interchangeable.

That being said, what OEM cams did Pontiac come up with that would be a good choice?

Thanks For the insight and history Duke.

Mark

 

I ran Pontiacs for a while. A good cam for the street back then was a Cam Dynamics 286/226*---296/236*. Lobe seperation for a good idle was 110*. I'm not sure if that company was bought out or not: Comp cams might be able to grind it. OEM cams are antiques.

:chevy


[Modified by Curveit, 6:18 AM 2/13/2004]

 

Pontiac built some pretty stout hyraulic cams in the late sixties to early seventies, before tighter emission standards forced more conservative valve timing.

They're colloquially referred to as "Ram Air III" and "Ram Air IV" as I recall. They may still be available through GMPD or they may be in the GMPP catalog, or available as clones from aftermarket vendors.

There has to be a web site out there with knowledgeable people on souping up Pontiacs.

Duke