Interesting manifold

-

Dave999

Well-Known Member
Joined
Sep 10, 2021
Messages
1,110
Reaction score
811
Location
Twickenham London UK
https://www.facebook.com/share/p/17LKmr9NYu/?mibextid=wwXIfr

Dave

571430167_10242620754360754_1149567850046546239_n (1).jpg


574842863_10242620753240726_5415755219287574399_n.jpg
 
I'd never seen one of those. speco were an aussie brand i think, i know them for their side shifted gearbox shifters, that could be used on the Aussie 3 speeds, bit like a hurst but perhaps not as good..

presume that's for 2 carter BBS?? dunno, odd shaped holes... Nifty little hot box set up though...

Dave
 
I'd never seen one of those. speco were an aussie brand i think, i know them for their side shifted gearbox shifters, that could be used on the Aussie 3 speeds, bit like a hurst but perhaps not as good..

presume that's for 2 carter BBS?? dunno, odd shaped holes... Nifty little hot box set up though...

Dave
Yeah it's scary too that for what it is, it's reasonable. Too bad it's in NZ.
 

Haven't seen this one before, no; I'll file it with these weirdos and this one.

Looks like the Speco item is configured for a pair of progressive 2bbl carbs, like Webers. That would explain the linkage orientation.

To me it looks like that hotbox arrangement…isn't. Unlike the Offy № 5041 twin 1-bbl intake, there doesn't appear to be any actual path for exhaust to circulate under the two plenums. The box itself appears to be closed on all four sides.
 
Looks like a 2×1bbl intake hogged out for a couple of Holley/(Weber) 5220/6520 2bbls., think OMNIRizon, in which case that linkage is oriented properly.
That Al-U-minimum will transfer plenty-O-heat if bolted directly to a factory exh. manny, probably better than the OE iron with the extra transfer pins cast in.
 
That Al-U-minimum will transfer plenty-O-heat if bolted directly to a factory exh. manny, probably better than the OE iron with the extra transfer pins cast in.

Nope. Latent heat of vapourization of gasoline will easily and completely overcome whatever heat manages to conduct its way over from the hotbox. To get the job done, you need exhaust heat under the plenum, not in the middle between the two plenums. Offy did this right; Speco didn't.

You're probably right about this having started out as a twin-1bbl intake, though, now I look again at the carb mount pads.
 
Hard to tell from the photos, but maybe the two "wings" extending from the hot box are fairly skinny exhaust passages.
 
Ahhhhh, the Mays (scroll down) manifold. An interesting item which was the subject of at least one published test.

I think Cain was an Australian company; might be wrong about that.

Still waiting for someone to post pics of the exceedingly rare Argentinian Penìn parallel-2bbl intake, which by all they-were-there accounts was very good.
 
-
Back
Top Bottom