I have a chance to buy an Offenhauser Dual Port intake (Sbc -Qjet). Wondering if anyone is using or has used one in the past. If so, How well did it perform? Thanks

 

I've used a bunch over the years... was a great design 30 years ago..... last one I used was on a Jeep 6-cyl of all things, a CJ-7, about 12 or 15 years ago.

They ran great in their time, and were real well made as far as casting quality and general quality control. Didn't really produce as much power as lots of others would have, which would probably be even more true now; but it gave good driveability.

Look it over carefully to make sure it supports all of whatever accessories and stuff you might need; if it's old, it might not have all the bolt holes you need. In particular look for the A/C strut bracket next to the carb, the throttle cable bracket bolt bosses, and the alternator bracket bolt boss.

 

Thanks RB, It has all mounting bosses except the alternator up front. It's kinda shaped odd up front, like they used to put the oil filler neck there. Isn't there an alternator bracket that locates on a manifold bolt? Also, Will it still mount up to my 305 heads/block contours? I'm hoping to use it if I can. I been told the dual plenum 360* makes great torque.

 

Different of the alt systems over the years have worked different ways.... they have never used an intake blot though. The early ones that first used the RH alt mount (starting in 69) had that top bracket to go to a stud (instead of a bolt) on the water outlet. Those also had the little mount tab for it onthe water pump in a different place, farther out to the front. Later styles have a boss on the very front edge of the intake, and later water pumps require a little spacer about 1" long to use them onthe earlier bracket arrangement.

If it's a SBC manifold, it will bolt to a 305. Then all you have to do is figure out how to bolt everything else to it.

 

Oh.... and there did used to be an oil filler up front, in fact the round place on the block and the intake up at the front edge was put there to accomodate it. They used to have a road-draft tube to slightly evacuate the crankcase, at the back, next to the dist, and the oil fill used a push-in breather cap to supply fresh air in; then for a couple of years they used a sealing oil cap like we have now, and they added PCV back by the dist where the road draft tube had been; then in about 68 or so (LJ blocks) they eliminated the road draft place in the block, and put the PCV in the VCs like it is now; then in about 69 they put the oil fill in the VC also, and eliminated the tall fill tube in the front of the intake, but lots of intakes still had the boss for it cast into them up until about 71.

 

You also need to check it to make sure an HEI will fit without hitting anything.

 

Thanks men for all the info, I think I'm going to buy it anyhow just for the uniqueness of it. Probably won't modify it. But the design of a Q-jet feeding 16 ports will make one interesting conversation piece among hot rodders!