Hey members - I'm new to the forum with a question please. I'm converting a 2 barrel setup to a 4 barrel on a 70 455. I'm using a repro factory aluminum intake with a q-jet. I want to install the OAI air cleaner to match the existing hood on the car. My mechanic is suggesting a 1/2 inch Phenolic spacer to help with heat issues. Will that cause any clearance issues with the air cleaner? I don't want to exceed the compression of the foam. Thanks for any help.

 

I see no reason you should need a spacer, many original oai 455 cars with no spacer and no heat issues.

 

I would skip the spacer. 1/2 inch is going to get you really close to the hood and would likely need to cut the foam on the OAI top. Even then it may be to close.

 

Do you currently have "heat issues" or is this fixing a non-problem? In any case, if you REALLY have heat issues, fix the cause. A spacer is just a band aid. If the car is running too hot, did the cooling system get upgraded to match the motor? Have the carb and distributor been adjusted to match today's fuels (the stock setting assume the car is using 1970-vintage gasoline). And what was done to the engine to make it a "tribute"? Olds didn't need spacers and didn't have heat issues from the factory. The BBO cars did use a fuel return system to route some of the hot underhood fuel back to the tank. Does your car have fuel return?

 

Thanks for the quick responses, much appreciated. For some quick background - the car was made from two cars some years back. One was supposedly a real SX that wasn't salvageable, and the other a nicely optioned Supreme convertible. Tilt, power windows/locks, power seat, remote trunk, speed minder, and the hood. The entire drive train was moved over including what appears to be an L-33 2 barrel, and a turbo 400 with matching numbers and correct code. There's a 12 bolt rear with open 2.56 gears, sway bars, cut-out bumper etc. So not a real SX but a tribute. All stock except for an exhaust upgrade to a Pypes 2.5" H-bomb system that still runs through the cut-outs. As for heat, typically starts cold ok but always tough when hot. Will die easily unless feathered until it gets running a second. Doesn't overheat but once parked really heats up the hood and fenders. Has the 4 core radiator as well. As for fuel return I have to claim ignorance, as I said still learning the details. I did have the the sending unit in the gas tank replaced and that had 2 outlets - does that reference the return? Unsure of any mods to current carb and dist for modern gas as you mentioned. So, would using stock gas lines from pump to the new carb if routed properly possibly eliminate any vapor lock and no need for spacer? I certainly don't want to mess with a new air cleaner or cause damage to the hood. Thanks again for your input and help.

 

If it's never going to see cold weather, block off the exhaust heat cross-over in the intake. It will fix any heat soak problems and prevent discoloration. Use an electric choke on the carb, This will allow the use of the stock intake to carb gasket.

 

Are you saying that you have a hot start problem? If so, verify the choke is working properly. This is still the 2bbl for now, right? The few 2bbl cars I've owned have always had float height issues with the 2GC. I've often had to run the float a little lower than spec. In any case, swapping to a Qjet makes that moot.

The two-line sender is correct for fuel return. There should be three lines at the fuel pump - a 3/8" suction line from the tank, a 5/16" return line back to the tank, and the hard line to the carb. The vapor lines are separate from the pump. An engine always heats up after you stop it. That's normal since there is no airflow and no circulation through the radiator.

 

Doesn’t sound like you have a heat problem, possibly a choke adjustment issue but as JP said thats a moot point if swapping carbs. DrDan says use an electric choke..great advice..sounds like a cool car you pieced together..nothing wrong with that.

 

Thanks to all for the advice and comments. Yes, still on the 2 barrel and only a hot start issue. Sound like the best thing is to go with the swap and no spacer and see if issues resolve. Can't wait until the warmer weather.

 

Been absent awhile focused on other hobbies. This thread may be interesting to you:

https://classicoldsmobile.com/forums...g-cars-139103/

Not all that sure OAI made any difference in my ‘66 Starfire, but it was & is fun. Best I can say without A/B testing is that it didn’t hurt.

Seeing the under-bumper OAI scoops, funniest comment was from my non-car sister “Do you have front exhaust?”

Agree with others that spacer is probably a band-aid, GM didn’t need ‘em, or at least Olds didn’t. But I live in a very mild climate.

 

I agree with all said. Don't go looking for a problem that isn't there. Are you in Phoenix heat? People tend to over react. What people overlook is that whatever said car has over one hundred thousand miles without the modern over thinking. I say run it. See what happens. Go from there

 

Thanks, I appreciate the additional feedback!

 

Funny, back in my youth, I wanted to add OAI to my 66 Starfire. I even fabricated a dual snorkel air cleaner from my dad's Mercury that would have fit the quadrajet. Didn't get any further than that.