01-06-2004, 09:22 AM
Proud owner of a '66. getting ready for a transplant from a six to a 283.
Picked up the motor from an "Old Lady" driven '67 four door Chevelle.
Economy and relisbility are my main objective. I intend on keeping the 2 bbl. carb, and probably run single exhaust. I will run HEI ignition though.
This motor is leaded gas motor, anyone out there with recent overhauls on there V8 with any tips an what they have found to work best?
BTW, Happy New Year to all! Dave
01-06-2004, 01:55 PM
Dave, are you rebuilding the motor before you install it? If so, if you drop the compression ratio a bit, and use heads with hardened valve seats, you will be able to use unleaded gas. I don't know what the combustion chamber size (cc) of your heads are, but if it's lets say 64cc and you use newer 70cc or 72cc heads this should drop the compression ratio down to around 9.5 or 9.2. If I remember correctly (brain cobwebs) the 283's compression ratio was 10.5, but I don't have any manuals that old to confirm this. If your going to rebuild the entire motor, this can also be accomplished with new dished pistons, but you'll still need a set of heads with hardened valve seats. A good set of used heads with a valve job can be relatively cheap if you look around. Anyone have any experience on doing this to a 283? The HEI is a good choice, but you may have to change over to a newer intake manifold. I have an early 70's Edelbrock C3B manifold for a smallblock Chevy that cannot be used/modified to work with an HEI distributor according to Edelbrocks tech reps. I don't know the specifics as to why. You may run into the same problem with the 283 intake manifold. Why not contact Edelbrocks tech reps (Marcus Lin) and see what they think about bolting on a set of Edelbrocks Performer 72cc heads on your 283 just to see what they say...free professional advice, they are really good people there! 8)
01-06-2004, 04:00 PM
I had a 283 in my '67 chevelle before I went big block. I ran the two barrel carb for a while but wanted more power so I got a Holley 600 cfm four barrel and dual plane aluminum intake with a set of headers. I got more power and I got better gas mileage. It seems the old two barrel was so inefficient that the four barrel made it get way better miles per gallon. I never ran a HEI with it but I never had any problems with running unleaded gas. I don't think the compression ratio was too high for unleaded. I never had a problem. I still have the old 283 in my shed with only 72,000 miles on it. I was thinking of running it in a fifth gen Elco or Malibu but there's no bolt holes for the brackets so I looked into some heads for it and World heads have some made for the 305 that have hardened valve seats and accessory bolt holes. I haven't tried this yet but I think it will work. The factory horsepower rating on '67 283's was 185 hp.
01-07-2004, 08:08 AM
I always liked the 283 engines. They are a real work engine with some decent punch to them. You can wind those to 6,000 RPM with stock heads and all and not one complaint from the engine. I had one in an Old Pickup truck and it lasted a long time. I can remember doing almost 60 in 2nd gear, foot planted firmly on the floor trying to race a friend. I was a bunch younger then. If I remember correctly I won. I beat the crap out of that engine and it never complained. It was a 4bbl q-jet.
I always remember them as "Factory Strokers". Good engine, not the power producer the 327 was but still very good.
01-08-2004, 08:38 AM
When "we" built the '69 396 that I put in my '74, I asked the engine builder about the heads and unleaded fuel. He told me that the problem was way blown out of proportion, but that the real problem was with the old valves and not the heads. We used stainless valves and I haven't had any problems. The motor runs something over 10:1 compression with domed pistons and I've never had a "ping" problem on premium unleaded.
01-11-2004, 12:08 PM
Don't be a douche. I get about 13mpg with the 327 in the driver and the race car gets about 8. when i threw one some edelbrock heads it actually bumped my milage up about 3 mpg, from 12 to 15. all that crap about a smaller motor with less compression gets better milage is horse crap. look at it this way, if you got more power you can feed the car less gas to get it to move the same amount of distance/speed. bump compression to maybe 10:1 or so, run mid grade, you'll be happy. trust me.