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302 Cid....

1K views 8 replies 5 participants last post by  bowtie0069 
#1 ·
Is it possible to make the 302 motor a fuel efficient beast?? I know that its a V-8 and all but, could it be done?

The reason for this is because I have a 327 small journal block and a small journal 283 crank that I would love to build but, one of my dreams is to build a motor with fuel injection and was wondering if this combo would be a great start.
Can it be done with a short stroke 4" bore motor? I know that these motors are pretty strong in manual cars, (i.e. DZ 302 Z-28) but, you have to shift at med to high rpms in order to make the HP. Can this motor be tame enough to sit in front of an ovrdrive tranny and still get decent gas mileage??

Don't get me wrong, the 355 that is sitting in between the front tires is just fine but, since I have this motor just sitting here, I was just trying to see what the "pros" here would have to say about this question....
 
#2 ·
My 94 Cad Fleetwood weighs 4800 # and gets an honest 23mpg cruising at 68mph. This is the same LT1 drivetrain as the Impala SS. In a Nova weighing 1400# less I would have to think 28 mpg is possible. The Cad ran 15.8 the one time I ran it, so its not a complete stone either. For all the time money and bother involved trying to utilize an old block and crank just because you have them, to try and come up with a decent mileage combo would seem a gigantic waste of time and effort. Go find and an old 94 thru 96 Buick, Chev, Cad rwd full size V8 and you're 95% of the way to where you want to be.
 
#3 ·
:confused: :confused: :confused:

Correct me if I am wrong when I say that if you take all the electrical mumbo jumbo off the LT-1, its basically an updated "air pump".

I wanted to know if this block combo could be made streetable and provide some of the fuel economy, thats all. Or, what I could do is basically strip everything off of your CADDY and use it for parts on my Chevy II.....

:D
 
#4 ·
Hi,

I used the 3in stroke crank out of a late model 265 (LT1 style) in a 96 or 97 Lt1 out of a Camaro. Used L 5.7 rods and a set of 302 style pistons, and I used the remaining LT1 parts. My friend put it in the Camaro an kind of a nostalgia type thing, but runs very well and gets reasonable mileage, but Im not sure what.

Jeff
 
#5 ·
Jeff,

what kind of heads did he use? What was the final CID of the motor? What kind of compression was he running? You mentioned that he went a little nostalgic, which sounds cool to me, what kind of car did he put that motor in?
Is the car still running? What did he have for managing his input of fuel, carb or injected?

:D
 
#6 ·
Hi,

We used all of the parts (heads -injection- block etc) from his 96-97 z/28 camaro

Yes the car still runs

305 cubic inches ----4.030 bore x 3.00 stroke

actual comp ratio was around 10.5

I didn't have any thing to do with the electronics. I just did the machine work--decking-boring-honing-rods-balancing- heads-and I assembled the short block. He did the rest.

The car runs surprisingly well. I think its a 97 and that's why he wanted a 302, to be a anniversary version of the original 67.


Jeff
 
#7 ·
WOW, I have been thinking about building this same combo for my 63.
3" stroke x 4" bore, vortecs or E-tecs, hydr-roller cam and fuel injection. I have a 400 in my garage that I'm gonna pass on just to try and get some mileage. I drive my Nova every day and I don't need 400+hp, I think I can get close to 300hp and better mileage with this combo.

KenDog
 
#8 ·
As much as I like 302s, I dont think I would buid one, if maximum fuel milage was my main goal. I would prefer a longer stroke.

I have built several "street" type 400s that I would bet get better milage than a 302 would with comprable power outputs. The 400, would probably have much better low end throttle response.

In my opinion mileage (over simplifing this) is all throttle opening. The less you have to open it, generally the better the economy.
 
#9 ·
The biggest help for mileage is RPM--many years ago car Craft did an article on getting mileage out of a small block. Keeping the revs under 2000 was the main thing to success. The car weighed like 4000lbs, ran hard and got over 20mpg. 1 1/2" LONG primary tube headers were used (Jack Davis built them, and mine)old Streetmaster intake (pre-Performer) and a 2bbl. carb and I think a Quadrajet was also tested. Give Jack a call; he knows what they used
(909) 391-2332 He also builds the best headers around!
 
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