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Hello! I'm glad I found this site, looks like there is lots of useful information here. I am the proud owner of a brand spankin' new (to me) 1970 Oldsmobile Cutlass 4dr hardtop. She still runs and drives, and the engine (Rocket 350) runs perfect. She needs a little brake work before I register it, but it should be minor. After I get her on the road, I plan to slowly start doing some mods. I am decently mechanically illiterate, which is why I joined here, so I can avoid doing stupid crap with my money :P My goal with the car is to have something I can show off to my friends who are driving a Corrola, something powerful, fast, and loud Something I can use to paint the intersections with rubber. I love classic cars, and honestly thought Oldsmobile would be my last choice of a project, ("It's a granpa car" etc) but I fell in love. I am doing this on a part-time job budget, keep that in mind.
My plan so far is to first get a new Intake Manifold and replace the current 4bbl carb (I believe it is just a stock one) with a new 4bbl. After that, I'll replace the exhaust headers and get a new muffler/chop it off and leave it open
Maybe when I am quite a bit more confident I would look at doing some more internal engine things.
My first question I suppose is, will leaving everything else stock, and only upgrading the intake and carb with that latter, result in a loud banging noise and lots of smoke?
Here's some really bad pics of when we picked it up.
Thanks for reading! I can't wait to get her on the road!
Welcome to the site, congrats on the new to you project. If it were me I would leave the stock intake and carb on it and do the exhaust work. The carb and manifold you chose are not a good match to your stock engine. Just wait until you start upgrading the internal parts and then plan your engine build around compatible performance parts. Adding the parts you describe alone will not result in banging noises and it will not gain any yield in additional performance.
I would start off doing a complete check of the ignition and fuel systems. Do a compression check to make sure the motor is healthy. Dual exhaust is great because it lets the motor breath a little easier.
one of the easiest way to pick up some "oomph" IMO is with a rear gear change, car probably has a highway gear in it now. If you like to cruise at 80 mph leave the rear stock but if you want to burn rubber a 3:55 rear ratio or higher (numerically) will really make a difference. Best bet is to find a complete rear drum to drum and put it in.
I would also recommend a shift improver kit for the trans, after a fluid an filter change.
I agree with oldcutlass to leave the intake and carb as is if its already a four barrel, the Qjet is a superior carb to the edelbrock. If anything I would consider doing a "poor mans" ram air setup similar to the W31 setup.
Cool car btw, the 4 door hardtops are super cruisers!
IMHO- The car will be quicker, more responsive and get better gas mileage with a properly working quadra jet carburetor like the one your car came with instead of that Edelbrock carb.
Ok, I guess I'll stick with the Qjet for now, thanks for replies! Dual exhaust is definitely on my list, and after the fluids and filters etc are done, and a compression test, that is what I'll do. I'm not sure what gears I have in my car now, but will look int getting the 3.55. Also, I have one of these: http://www.supercarsunlimited.com/im...2316large1.jpg But it says Oldsmobile 350 rocket, and it only has 1 of those things going off the side. What is a W31 setup? And a "poor mans" ram air?
Looking under the engine, there seems to be some "makeshift" fixes, that make me cringe, so I will be tidying all that up.
I agree with the others that you should retain the original carb and intake. Swapping those to aftermarket parts will not improve performance any and will just lighten your wallet.
I also agree that a rear gear change is the best bang for the buck performance modification. Since your car is a 1970, it should have an O-Type rear (12 bolt cover and 10 bolt ring gear). There are not a lot of gear options for those so looking for an entire rear with a better gear ratio and posi would likely be about the same cost as regearing and installing a posi in the O-Type.
FYI, the standard no-cost ratio in '70 was 2.56:1. Both my 70 Supreme and my 71 convertible originally had that ratio and the 70 ran quite well with it (I drove with that rear all through high school and most of college). Swapping in a lower ratio rear made a HUGE difference, though.
I agree with the others that you should retain the original carb and intake. Swapping those to aftermarket parts will not improve performance any and will just lighten your wallet.
I also agree that a rear gear change is the best bang for the buck performance modification. Since your car is a 1970, it should have an O-Type rear (12 bolt cover and 10 bolt ring gear). There are not a lot of gear options for those so looking for an entire rear with a better gear ratio and posi would likely be about the same cost as regearing and installing a posi in the O-Type.
FYI, the standard no-cost ratio in '70 was 2.56:1. Both my 70 Supreme and my 71 convertible originally had that ratio and the 70 ran quite well with it (I drove with that rear all through high school and most of college). Swapping in a lower ratio rear made a HUGE difference, though.
So what's the lowest gearing that they made for this year/wheelbase? What would my options be? Can I get them off any other 3rd gen cutlass?
The O-Type was used from 1967-1970 in all the Cutlass lines. The lowest gearing from the factory was 4.66:1 but you could get the dealer installed 5.00:1 gears if you wanted. The factory had three series of carriers for the spread of ratios, with 2.56-2.78 using one, 3.08-3.23 using another, and 3.42, 3.91, 4.33, 4.66, and 5.00 using yet another.
Nowdays Richmond Gear makes 3.42, 3.90, and 4.10 gear sets but the footnote shows they are designed to fit the factory 2.93-3.23 carrier only. https://www.richmondgear.com/wp-cont...n1.pdf#page=32
This means you would need to buy a new gear set and a different carrier to do a gear swap. That's why I said it's about the same price to find a complete rear that already has gears and posi.
The good news is that a rear from any 68-72 GM A-Body will fit under your car:
Olds Cutlass or 442
Buick Skylark, Gran Sport
Chevrolet Chevelle, Malibu, El Camino, Monte Carlo
Pontiac Tempest, GTO, Gran Prix
Locating a factory O-Type posi carrier can be difficult and expensive, but there are modified Ford 8.8 posi carriers that can be used with the Richmond gears.
Keep the Q-Jet as advised. Replace the timing chain and gears.
I agree with these! Replacing the timing chain is just good insurance.
Do yourself a favor and do not replace the Q-Jet with an Edelbrock. They are easy to swap parts on, but they are very hard to dial in. A properly rebuilt Q-Jet is a way better option!
I've thick headedly struggled with Edelbrock carbs for a while now, and it's not worth it. They are finicky. It's infuriating. Have the Q-Jet rebuilt. If you're going to spend money anyway, that's a much better use.
I agree with these! Replacing the timing chain is just good insurance.
Do yourself a favor and do not replace the Q-Jet with an Edelbrock. They are easy to swap parts on, but they are very hard to dial in. A properly rebuilt Q-Jet is a way better option!
I've thick headedly struggled with Edelbrock carbs for a while now, and it's not worth it. They are finicky. It's infuriating. Have the Q-Jet rebuilt. If you're going to spend money anyway, that's a much better use.
Is there a rebuild kit I can get to do it on my own? Or do you mean send it away to someone?
You can get a rebuild kit from most auto parts stores that will work to refresh the carb - I usually get them from NAPA. For a more complete "rebuild" I have heard folks say the kit from Cliff Ruggles has more replacement parts and better quality gaskets. If your carb needs more in-depth work such as throttle shaft bushings and you're not familiar with QJets, it may be better to send it out to a reputable carb guru.
November 18th, 2016, 10:06 PM
Something I can use to paint the intersections with rubber. I love classic cars, and honestly thought Oldsmobile would be my last choice of a project, ("It's a granpa car" etc) but I fell in love. I am doing this on a part-time job budget, keep that in mind.
