The Stovebolt Site Forums The Shop Area Engine Shop YACC (Yet Another Carb Question) - 283

Greetings,

People have been over this stuff over and over, and I've been through the archives here and a couple of other places (including a great SBC forum on clubhotrod.com). I come from a world where you tune your car with a laptop, and 250 crank hp out of 112 turbo'd ci (1.8L) is no big deal, so I'm an American-iron newbie - please bear with me (or hey, just click the 'x').

My '59 3200 has a 283 in it. I use the truck for daily driving (city driving mostly), and light hauling. I'm not interested in racing it, and probably won't do much towing. Basically I want a good street driver - lots of low- and mid-range torque, decent fuel economy, pump gas (87 octane if possible), decent throttle response, and reliability.

Right now the 283 is pretty much stock, except some parts on it seem to be off an early 60s passenger car. The motor has a Rochester 2G carb, a 265/283 passenger car intake manifold, 283/327 heads (3755549 casting number), rams horn exhaust manifolds, a stock type exhaust, and stock ignition. This truck has an SM420 4-speed and 3.90:1 gears. This truck was restored about 20 years ago, and I think that's the last time the motor was opened up. It has the stock crankshaft in it, so I assume it's the stock pistons too. I haven't had the heads off to check.

I'm interested in keeping up with traffic a little better. In general, I like the 283 - forged crank, short stroke, vintage feel, what's not to like? I want to keep the rams head manifolds, because they look cool; based on my reading, it looks like they don't flow all that well, but I'm keeping them anyway. I also dig the early-type offset-bolt "Chevrolet" script valve covers, but I could give those up if someone convinced me I needed new heads.

The consensus seems to be that a smallish 4-bbl carb works great on the 283. I have an opportunity to buy an unused vacuum-secondary 600cfm Holley 4160 cheap. With that and a decent intake manifold from a swap meet or new, I'd be in business.

Here's the question I really haven't found the answer to: Is it worth it to do this kind of carb/intake swap without also swapping heads? I figure the heads can't be that bad if they were used on '60s 283 Corvettes.

I also have a number of other newbie-like questions, but these are easier to get a read on based on what's out there now, so I sweat these less. Is 600 cfm a little on the big side for an otherwise fairly restrictive intake system? Are the valve seats on my heads going to die anyway thanks to unleaded gas, meaning I should get newer ones, maybe the power pack heads? (I'm too lazy to buy lead additive.) Will aluminum heads with a suitable compression bump kill my cast pistons? Any good intake manifold recommendations for this carb on this motor?

Yeah, I know, basic stuff. Part of me suggests I should leave it well enough alone, get all the gaskets replaced (including, unfortunately, the rear main seal, the timing cover, heck even the pinion seal on the rear end), and call it a day. But I can't really leave well enough alone!

Thanks for any ideas.

-matt

The 4 barrel is a good idea. An aluminum manifold with a edelbrock performer carb work real good right out of the box. Although it,s 600 cfm you will use the primaries most of the time. Q- jet carb is my favorite but you have to rebuild one & play with it to get it right. The ram horns are great manifolds & are all you need unless you are going raceing. I take it you have dual exhaust. You might also think about a little upgrade in the camshaft.

Wups, I forgot to discuss the exhaust - after the manifolds, there's a crossover pipe running under the engine, joining the two to a single exhaust, exiting before the left rear wheel. Haven't measured the pipes, but I'd guess they're 2.25" or 2.5" ID after the crossover. There's also some kind of heat riser doodad on the RHS which I haven't investigated yet.

Also sorry that previous post was so long - wow, I must have had too much coffee last night!

You need dual exhaust on it. 2-2 1/4 pipes with whatever sound level mufflers you like. 30 inch glasspacks sound great on that.

For an intake, look for an Edelbrock Performer, but not the RPM. It's better for bottom end torque. I would go with either a 500 to 600 cfm 4 bbl or a Q-jet that has been rebuilt by someone who specializes in them. The q-jet will get you the best fuel milage, and it's primaries are sized for good milage.

The heat riser closes of the exhaust for that side, and routes it through the intake under the carb and out the other side. Helps with running a cold engine.

Dual exhaust with 2" pipes will be plenty for the 283. If you go bigger you start scrificing low end torque, which is what gets the truck moving.

Carter used to produce a 400 CFM AFB specifically calibrated for the 283. Part numbers 9400s and 9410s. Best 4 barrel you can put on a 283; unfortunately no longer produced, so you have to look.

Jon.

Thanks for all the good info, people. I will keep my eyes open for that Carter carb, and pick up that cheap Holley in the meanwhile (since I can probably turn it around for more than I will pay for it, if I don't end up using it).

Looking at my exhaust, I see it's 2" ID, which explains why it's so much quieter than my transmission. Guess I'll get into that when I get into the intake. My budget won't permit me to do anything in this area for a while, so I will have time to scavenge for cheap parts.

I also ran across a series of articles by Chevy Hi Performance, which they wrapped up into a book, but which are also available on their web site. They did a series of flow tests on over 40 cylinder heads, including 882s, the iron Vortecs, and some other budget heads. Worth a read. That iron Vortec head looks pretty nice, if I could find a cheap intake manifold that would bolt to it! Scoggin Dickey has a pretty good price, but all-new prices are just too high for me. Oh well.

One item of interest- - - -the heads for a 305 engine are exactly the same CC, and compression ratio as the 283 heads. No, they don't have the offset bolt holes, but they can be upgraded to larger valves without destroying a set of original 283 Power-Pack heads. 1.94" intake valves from a 350, and 1.6" aftermarket exhausts fit pretty well without a great deal of work, and the 305 heads will have the stellite exhaust seats on some models. I use these on claimer engines for some of the roundtrack racers who use my engines. They bring a 350 up to about 11:1 compression with flattop pistons, and they'll run 6,200 RPM with a 350 CFM 2-barrel in the claimer class. Your 283 will wind a LOT tighter with the right cam and a small 4-barrel.
Jerry

One more thing to spend some money on is an HEI distributor. It's a simple swap, all that's needed is to run a 12 gauge wire from unfused ignition. I would also put in a Crane advance kit, which gets you better milage on the highway. You get new weights, springs and an adjustable vacuum modulator. Chevy Hi Performance has an article on it that explains everything. You can pick up a used distributor for a few bucks at a salvage yard.