I just discovered that all the parts are available for a complete OAI system for '68 & '69 W-machines (from air cleaner assy to the scoops). I'm planning to eventually run a Performer RPM intake on my SBO and I know that it raises the carb just a bit. But is it enough to cause interferrence w/ the hood on my '68 Cutlass if I use the OAI air cleaner?

Also, any opinions on the OAI kit from TPP (PN: CW1776T)? I'm not going for "factory correct", just a "factory look". Thanks.

 

I'd be surprised if the RPM on an SBO raised the air cleaner higher that is is on a stock BBO in the same car.

 

I would be surprised as well, however don't big blocks have a much shorter motor mount on the frame? Regardless, one could always recess the air cleaner base to make it work.,,or use bb mounts?

 

NOOOOOOOOO!

Must be time for the weekly motor mount tutorial. Again, the CRANK CENTERLINE is in the exact same place for both BBO and SBO. Since the BBO has a taller deck, the carb flange sits higher (yeah, Toro intakes excepted). Look at the oil pan to crossmember clearance - the BBO can't sit any lower than the SBO.

 

Aye, didn't think about the W30s being a little taller than the W31s, that might be enough of a difference. Jeg's site on this manifold only states a height problem w/ the T/A's shaker scoops (understandable......not much tolerance there to change much).

http://www.jegs.com/i/Edelbrock/350/...11#moreDetails

Also states:
Manifold height: (A) 4.80'' , (B) 5.80''; Carb pad height = 5.30''
View Manifold ''A/B'' Measurement Guide.

If I knew how much taller a BBO was at the intake seal surfaces (front/rear) compared to a SBO, and the A/B dimensions of a stock BBO 4-bbl manifold, then I'd know for sure if I'd be pushing the envilope w/ this combo. $850 is no small chunk of change to drop on what is essentially a CAI kit for a car, even though it's one of the coolest ones on the planet. I just don't want to end up w/ an unworkable combination.

 

I'd put the system together with the stock intake the put some 2" tall chunks of play dough on top and close the hood and see what you get.

 

I have the same set up including the performer intake on my 68, all on the original G block. I have no clearance problems but it is close. You will not be able to use the hood insulation though.

 

Are you running the Performer, or RPM Air-Gap for big blocks?

The RPM-AG is ~0.6" taller than the Performer for the big blocks (5.54" vs 4.95" at the carb pad), while the Perf-RPM for the small blocks is in between at 5.30" If you are running the Performer, and if the G-block is less than (5.30-4.95=) 0.35" taller (from crank/cam C/L to the intake front/rear seal surface) than the SBO block, I could still be in trouble. If its the RPM-AG you are running, then I should be clear no matter what.

A good sign though is, that Edlebrock does not warn that the RPM-AG creates hood clearance issues on a '68 442, unless they are assuming a low-rise air cleaner is being used in place of the OAI air cleaner (which seems unlikely).

 

Sorry for more apples vs oranges but SBO/RPM works fine with 68 OAI in the red 70. Yes, the red 70 has 68 OAI system.

I would check the clearance w/ normal air cleaner (same height as OAI I would believe) & intake in place using clay, foam, etc like jag mentioned. If you have 2" or so you should be good to go w the RPM.

 

It must be really close because my stock air cleaner with a Performer slightly rubs. Of course this doesn't apply to the original poster's question because we're talking BB vs SB

 

I'll check that too, however I currently have a 2bbl intake/carb/air cleaner on the car now, so that adds another level of fruit to veggies comparison.

Did a little digging, can't seem to find the dimensions of the crank and/or cam C/L to intake seal surface for the two blocks, but found that the deck heights (measured from the crank C/L?) is 9.33" for the SBO and 10.625" for the BBO. This difference (1.295"), assuming the intake seal surface relative to the decks is the same dimensions / geometry between the two blocks, would result in the SBO intake seal surface being ~0.916" lower (closer to the crank) than on a BBO. This is larger than the 0.35" dimension I calculated in the post above indicating that even if Nilsson is running the Performer intake (and not the RPM-AG), on his BBO, I should be OK, in fact I should have a tad over 1/2" more clearance to the hood (over an inch more if Nilsson is running the RPM-AG).

 

Doesn't that 39 deg refer to the cam/lifter/pushrod angle, not the cylinder C/L angle? All Olds V8s are 90-deg cylinder angles, no?

 

I did the math wrong and deleted the post , and yes I was using the 39 degrees as the internal angle and that isn't correct

 

I'll try to redeem myself, you are absolutely correct:

 

Must be a slight mounting height difference between the reproduction OAI and the stock cleaner. I had to alter the mounting height of my stock cleaner to keep it from rubbing. No problem with the TPP OAI.

 

No problemo. I'm still a nooby here and half of my posts thus far have been wrong. I find that everytime I'm forced to scratch my head I learn something new.

Thanks all for the feedback here, unless someone drops a bomb and all my assumptions made here go out the window, I'm confident now that I'll be OK w/ a Performer RPM on my SBO w/ the TPP OAI system in my '68 S.