Small Block Stroker ... Gas mileage?

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73Duster422

73Duster422

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Hi guys/gals,

I'm looking at building a 422 stroker. I know it's kind of an oxymoron but, is it possible to get decent gas mileage with a stroker?

I'm aiming for 20 mpg. with 92-94 octane.


The cam that I'm looking at is a Comp Cam roller
with 274/282 duration, .538/.534 lift. 110 centerline.

Oh, forgot to mention 3.55 gears with .64 O.D. (runs like 2.27)

If anyone is getting decent mileage with their stroker, please post your results.

Thanks,
 
I can get 17+(55-75mph) out of mine, E-body 3.23's 727 and 26" tires. Car weighs 3710lbs w/me in it. Running a 770 Holley Street Avenger Crane 302-2 Hyd cam Air Gap with Doug's headers to a 2.5"h-pipe exhaust. I run 89 octane most of the time now. I'm told I can run 87 but haven't had the balls to do so yet.... I'm running Mildly Ported Iron Heads(587).

Car runs 12.7's @ 109+ or so in the 1/4 mile spinning hard to a 1.9x 60'.

I bet with some easy cruising at 55mph it would have been better.

Tom

Gears and your foot will be the limiter.LOL
 
Don't know about 20-mpg.. But with the extra cubes from a stroker, you could run compression that won't need 92-94 octane (regular unleaded) and still make good power.


This is what I see... You want a stroker... You want to run compression that will require the best pump gas... You want to run a big cam... All this = building for power.


See where Im going with this?


These cars were lucky to get 20-mpg with a stock V8.

If you want MPG, build a 318 for it and switch out engines during race season.


Not to be a jerk or anythings but your questions have unreal expectations... Im sure you could get it to do what you are asking but it would require a computerized engine management system and overdrive transmission. All of which would cost more than you would ever spend on the extra gas.
 
73Duster422,

I think 72challorange is right .... your foot is a big deal for this one.

The stroker in my 4speed Dart with 3.55s has a "life average" of 8.3mpg (there are ~1000 miles on it in ~20 months since the motor was done).....but the high is 13.5mpg doing 55mph pretty steady.

The cam is quite a bit hotter than what you are using which, combined with big ports, does not help MPG.

I think 20mpg with a light foot, in a light car, with reasonable gears can happen. GOOD LUCK!!!!!

Kory
 

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I figure the motor should make 375 ft/lbs of torque at 1800rpm. This would be a 60mph cruise speed.

I may have to back down the cam duration a bit to get the desired results.

Thanks for your input guys.
 
What are you running for gears and tires?

If you have a Tremec 5spd you should be able to get those rpms easy.

1800rpms is pretty low. I cruise at 2750 at 65 and 2500 at 55.

Tom
 
Getting close to 19 with 422, have w2 heads 528 mp solid cam tti step headers 3inch x pipe exh and 5 speed trem with .64 od and 3.55 gear
 
We don't build strokers for gas mileage we build them to stomp on big blocks..so far we're doing pretty good..:-D:-D
 
72challorange said:
I can get 17+(55-75mph) out of mine,
Click to expand...

Hah, I never...

My 408 with a 3000 slippy TCI, through 3.73's and 28" tires gets around 13 highway at 55 mph (2900 rpm's) and 8 city, and that's with a small Edelbrock 650 carb. With the 750 proform DP Holley its 8 mpg highway. However, I can run 87 octane. Edel heads, 236/242 lifting .544/.541, through 1 5/8 and 3" pipes over the axle. Best time thus far is 12.26 @ 109.59 with slicks and the Holley, and 12.73 with a Carter 750 on street tires.

One major Issue I have is the convertor. at 55 mph, it shopuld be revving about 2500 rpm's. but it's closer to 2900. At 67 mph, it should be revving 3000, but it's revving at 3500. I'm not sure how much it should be slipping, but I doubt it is that much!

I was hoping for better mpg, but I don't see it happening without a new convertor, and probably an overdrive.
 
haplo555 said:
Getting close to 19 with 422, have w2 heads 528 mp solid cam tti step headers 3inch x pipe exh and 5 speed trem with .64 od and 3.55 gear
Click to expand...


19 mpg you say ?

That's not far off the combo that I'm looking at.

Have you ever run your car at the strip?

Times?

Thanks,
Mark
 
With maybe ported Edelbrock Magnums with the chamber edges rounded off well, 11:1 compression would work fine with pump gas and that cam. Also tune the carb as lean as possible for part-throttle cruising, get the advance curve just right, and run as much vacuum advance as possible. With that setup you may be able to push 20 MPG. If anything, I'd imagine the extra mechanical advantage afforded by the longer stroke would offset, to an extent, the increase in displacement.
 
I have no stroker but a fresh 340 with 500 miles in the last month--wait--I rack the miles up quick, lol. I got 3.91 gears, 26 inch tires and a 3,000 stall tci streetfighter con. I been driving it hard and quick, just limiting my wot time to a few seconds till it gets its oil changed again, very soon I keep telling myself, lol

Its gets 8 mpg.

Good luck!
 
I have a 408 stroker motor backed by a 727 manual valve body 3500 stall and 3.91 gears and the best gas mileage since i got her on the road is 8mpg but is mostly around 5-7mpg. its hard to drive without mashing the throttle wide open.
 
Fuel injection will get you there.
 
Whoa! slightly an old thread has been stirred up here. But, any info on Stroker gas mileage is good. Now with Ontario's new 8% Tax on gas, it's even more important not to burn up too many dinosaurs.


I'm using a Tremec 5 spd OD, 3.55 gears, hydraulic roller cam duration 274/282, Lift .538/.534 and fuel injection. This combo should make mad torque down low in the rpm range.

I'll still working on the build. I can't wait to try it! No matter the mileage!
 
71dustar said:
I have a 408 stroker motor backed by a 727 manual valve body 3500 stall and 3.91 gears and the best gas mileage since i got her on the road is 8mpg but is mostly around 5-7mpg. its hard to drive without mashing the throttle wide open.
Click to expand...

LOL Therein lies your problem.
I have an srt4 turbo caliber.
If I just keep it lightly pressed on a long road trip, i get 26+ mpg.
If I switch to retard mode, I get half that.

I think the key here to good mileage lies in gearing, or even a 518 auto, or tremec manual.

of course those are all pricey, but they will help get you really close!
 
67 b-body satellite, 408 stroker, 20 miles pr. gal. has run a best of 11.93 @ 111.4 mph in the quarter.
91 octane, with a half can of lucas octane booster.
Revs. 3000rpm @ 60mph on the hwy. with 4.30 rear gear, M&H 275/60/15 rears.
j-heads ported polished, extreme energy solid lift cam, .502/.511. Crane 1.6 aluminum roller rockers.
M-1 single plan, 2" open spacer, 750 HP/DP. MSD 6AL, 1 5/8 headers.
9 1/2" dynamic converter that stalls at 4200 yet is totally streetable with a large trans. cooler, @ electric cooling fans on the rad.
9.5 compression keith black pistons, eagle I beams, eagle internal balanced crank, internal rotating weight only 1800 grams.
This same set up in my 360 got 18 mpg, best 360 et was 12.56@107mph.
In the end the 408 is obviously more efficient at cruising speed and quicker in the 1/4 by 6 tenths..
 
390 stroker - similar cam to OP - 27" tyre - 3.89 gears - 3 speed auto - 800cfm Eddy AVS Thunder - Crane Hi 6 module.

12MPG city driving in stop-start traffic.

18 MPG country driving 60 MPH at 2950 rpm.

On primaries only.
 
dodge freak said:
I have no stroker but a fresh 340 with 500 miles in the last month--wait--I rack the miles up quick, lol. I got 3.91 gears, 26 inch tires and a 3,000 stall tci streetfighter con. I been driving it hard and quick, just limiting my wot time to a few seconds till it gets its oil changed again, very soon I keep telling myself, lol

Its gets 8 mpg.

Good luck!
Click to expand...

A year later and 4,000 plus miles on the 340 and some carb adjustments it gets 11 mpg around town, I'm happy, its 30% better....good luck getting 20 mpg, with OD and 55 mph its a maybe but yeah buy a newer car for 20 mpg and drive 75 on the highways
 
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