i dont drive my car hard, never will... i have a 63 impala with 283/pg stock combo.. its a 2bbl car right now.. compression is good lookin to do some mild upgrades and hopefully pull a lil more mpg somehow, all while being low budget..... was thinking somethin like: 305 heads or somethin else 300hp cast iron or aluminum quadrajet / 4gc / edelbrock 500fcm? distributor upgrade of some sort, im all over the place on this one keep the rams horns i have maybe a really mild cam? this car doesnt get revd over 3500 LOL.. low n slow cruiser.... tryin to magically pull 21-22mpg any ideas or advice?
Swap in a 230 6 cylinder? Actually, I don't see why 21-22mpg should be a problem with the 283 if it were all stock and in perfect tune.
better spark for sure . HEI swap is easy. dual exhausts, an RV torque cam like the Comp 252. don't think heds will help much. the idea for efficient is to keep fuel/air mixture velocity high, burn it hot and get it out of there. I think keeping the 2bbl is doable. if you never stomp on it, why need a 4bbl? for highway mileage, think about a 200r4 swap, more advantageous to use gears to keep the engine in it best rpm range rather than the 2 gears of the PG. 200r4 fits in the same space as the pg, but the rear mount moves back. maybe even a t350.
what rear end are you using. 3:08 is real common--can't remeber if 2:73 is available or not----got 21 in a 57 wagon years ago, but I ran a rejetted 2bl carb. good luck
I would start with the distributor first. The stock engine is already pretty good. Rear gear could be an issue.
get an overdrive, I get about 17 mpg (highway) with a 700r4 behind a 283 with a edlebrock 4bbl in my wagon. I stomp the loud pedal a lot too. I think I could do even better if I changed my rear end ratio. I think it's too low with the overdrive and I'm not in the proper rpm range when crusing. I've got rams horns on mine as well and a HEI. Check on your bearings etc. also, for better "rolling resistance"
You should be able to get 21 easy on the road with proper gearing, but not in town running stoplight to stoplight. I have hit 23 mpg with my 283 in a 56 chevy with a T5, fifth is overdrive, and a 3:08 gear driving a steady 60 mph.
I hear good things about 305 Vortec heads for power on small cube mills. I suppose the improved combustion chamber design couldn't hurt efficiency and they would have hardened valve seats. X2 on the Comp 252 grind. Don't forget your mileage goes up if you keep the car waxed. Just cuts right through the air.
Depending on the rear axle ratio, the 200-4R trans sound like a good idea, or maybe even a TH350 with a lock-up converter. How stock and how many miles on the 283? It may be due for a camshaft anyway. Also check the timing gears and chain for wear. This can retard the cam timing slightly which doesn't tend to help mileage. Make sure the distributor advance, centifugal and vacuum, are working properly. If you've still got a heat riser, make sure it's not stuck closed. But maybe one of the easiest and cheapest fuel mileage mods you can make would be to install a vacuum gauge in the car where it's easy to see while driving. Make sure it's connected to full manifold vacuum, not ported or off-idle vacuum. Then always try to drive while maintaining the highest possible vacuum reading. As far as fuel mileage is concerned, low vacuum BAD, high vacuum GOOD!
If you are determined to keep the powerglide this car is going to get poor mileage and no engine modifications are going to result in much of a measurable difference.
its a 88k mile bone stock from 63 ..... idk about teh trans swap because i wanna remain stock parts for now... i think a 200 or a 700 wuold be the choice if i do swap... from what i know the th350 has the same final ratio so it just adds a 1st gear from what i understand... carb is givin the old leak down issues and REALLY is a bitch to start, then i have to keep idle high to have it not die at stoplights.. this could also be something to do with ignition.. so if nothing else im due for a carb rebuild. i had read a lot the 305 heads would flow slightly better and have the hardened valve seats so thats why i had thought of those, plus they are cheap... maybe thats not true im no opposed to keeping the 2bbl, but would sorta like a 4bbl just cause.... it gives me more "show worthy" options for intake manifold and all (i know you guys dont all care about this).. chrome or endurashine... altho i could paint up the stock manifold nicely i guess..just am sick of the chevy orange,. i do wanna keep the oil filler tho because i plan on chroming the script valve covers.. i have dual exhaust already as well
I ran a 283/PG combo in this '63 Impala back in the 80's and could knock down 21 MPG on the highway. About the only mods, I had were a free flowing dual exhaust with the old rams horn manifolds, an Edelbrock Streetmaster with a freshly rebuilt Rochester 2 barrel adapted to the four barrel manifold and a fresh tune up. Granted, it wasn't a stop light bandit by any stretch of the imagination, but a great daily driver back then.
Here's a recent NYTimes article on the subject. Running on the primaries of a 4-bbl may work in your favor too. http://wheels.blogs.nytimes.com/2010/06/29/performance-at-the-pump-goes-extreme/#more-60341
for some odd reason i had never thought of a 2bbl adapter onto a better 4bbl intake.. taht might make a lil sense.. maybe a $50 swap meet performer with the stock 2bbl carb rebuilt could work for me.. hmm
You may get better mileage with a O-jet than the 2bbl. The primaries on the Q-jet are pretty small, around 220 cfm if memory serves.
Not in my opinion..especially when there are small bodied electronic ignition distributors out there, that look a hell of a lot better and still run an external coil that looks correct all the HEI's on what are supposed to be period correct or traditional builds look like a dam eye sore
I like the old converted Mallory units,,or even better convert your old points one to elecrtonic..it will look correct..because it will be OEM just the guts inside will be changed GMC BUBBA here on the hamb might have stuff for ya too well tuned points will work too..but the electronic ones i think pack more punch
Well now we're getiin' somewhere! With 88k it's probably due for a timing gear and chain set, if it hasn't been done already. This will put the cam timing back where it belongs. The standard TH350 probably won't help much, but the TH350C with the locking converter could, at least at steady 40 mph and above. Overhaul the carb and make sure the choke is working properly and that the heat crossover in the intake manifold isn't plugged. The stock points type distributor, IF IT'S IN PROPER WORKING CONDITION, should work fine in this kind of engine. At 88k miles the dist. shaft and bushings may be worn and the mechanical and vacuum advances might be cashed. If you don't have someone local who's up to the task, get in touch with Bubba's Ignition in Indy here on the HAMB. If you don't want to fuss with points, I'm sure there an electronic conversion kit available that will fit the stock style distributor. Just be a little suspicious of some of the "too cheap" imported replacement distributors that you might see online or at the swap meets. And put a vacuum gauge in the car now, drive it a while the way it is now and watch the vacuum readings. As you make changes to the carb and ignition watch how it affects your manifold vacuum.
Fix the carb, and give it a good tune up (this could keep you busy for a while if you haven't messed with old cars much). If the stock ignition system is working properly it will be fine for a stock engine. Gearing is where you'll find mileage, I assume the car has 3.08 rearend gears. Add an overdrive automatic transmission, drive it for a month taking accurate records about the mileage, and then get back to us.
The TH2004R is the way to go for an automatic OD swap. I put one in a '63 for my dad several years ago, and there was nothing to it. The length is the same as your Powerglide (unlike the TH7004R, which would require cutting down your driveshaft), and I fabbed up a simple trans crossmember out of parts of an old, unused aftermarket one for a '55-'57 we had on hand. It could always go back stock, though I have no idea why anyone would. Powerglides are for restos and drag cars. The same car has a mild, iron head 350 with an "RV" cam, iron Q-jet manifold, rams horns, an Edelbrock 600cfm carb, and HEI (I hate the look, but it works great). If you want a more traditonal look, use your stock distributor with a Pertronix Ignitor (the magnetic pickup bolts up to the bottom of the rotor, and the module/trigger bolts up where the points were). They are $79 or so from Summit, and basically any speed shop or restoration parts dealer carries them. When I did the swap, I swapped out the 3.36 rear gears for a 3.70 chunk I had lying around, and the car STILL gets 20+ mpg. Remember, the TH2004R has a .67 overdrive ratio...this reduces the 3.70 down to 2.479!
Sometimes you have to get past what you see as ugly and go with function. I swapped in an hei that I picked up from Scott White Performance on Ebay and with a good set of wires and plugs picked up two mpg on my 71 GMC 3/4 ton running a performer intake and Holley spread bore carb with dual exhaust on a bone stock 79 350. That is gong from 10 to 12 but that makes it a huge jump. The big plus is that it starts one hell of a lot easier than it ever did before. I've run it for over 10,000 miles so far. When you are looking at gas mileage improvements in a car like that it takes looking at the whole picture and what you may have to add or give up to get it. Some of the things guys here like for "looks" sakes cost fuel mileage as compared to other things. Bias tires will cost mileage over radials, point type ignition usually costs mileage over electronic ignition unless the guy tuning the point style ignition is hell for good at what he does and you stay on top of it. The simple things that a guy can do. Having the car in the best state of tune you can have including fresh ignition parts, distributor set up right and carb at the top of it's game. Plus making sure that the timing chain and gears are in good shape with no slack in the chain. Properly aligned front end. Out of alignment causes extra drag on the front tires. Run quality gas. Actually try different brands to see which gives the best mileage but I have proven on more than one rig that one brand sold by a national chain of minimarts of the same name costs 2mpg on one of my rigs plus most cars run piss poor on it. They are usually the cheapest gas in town. You may not like the looks of radials but they are worth extra gas mileage. Clean air cleaner filter.
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