302 LS-1

[Trash man]

well u could be like me and buy a 4 cylinder alero and get 26mpg "city driving"
personaly, keep ur foot outta it, and make sure the engine breaths(both in and out) efficent

[Garry]

The 3800 f-bodies don't get significantly better mileage though.

I'm a notorious gas-saver ... Driving 60mi each day to get from work and back, with german gas prices, you get practice ... I keep my MR2 around 27mpg ... I can drive a Volvo V70 Diesel the same route at around 45-50mpg (!) ... the best I've EVER had my Camaro 'vert V6 was around the 26-28mpg ballpark ... wondering what I can drive my 'Hawk once I get it registered

Instead of messing up a perfectly fine engine (though you'd probably have one of a kind there!), just drive decently ... that'll save you money without paying for it ... and regretting it later ...

[brothapig]

I have to disagree with the statement that bore vs stroke have very little to do with gas mileage. Now, it's not everything to do with mileage, but it has a lot to do with engine efficiency. If I remember correctly, it is referred to as over square and under square. As an example, a small bore and long stroke might have more mechanical advantage on the burn stroke, but more surface area and faster piston speed for friction. I guess what I'm trying to say is that engine designers today look at bore vs stroke very closely, along with a ton of other factors.

[fastTa]

I have to disagree with the statement that bore vs stroke have very little to do with gas mileage. Now, it's not everything to do with mileage, but it has a lot to do with engine efficiency. If I remember correctly, it is referred to as over square and under square. As an example, a small bore and long stroke might have more mechanical advantage on the burn stroke, but more surface area and faster piston speed for friction. I guess what I'm trying to say is that engine designers today look at bore vs stroke very closely, along with a ton of other factors.

Then you don't have a fundamental understanding of engine building dynamics. I'll try to keep this as simple as possible. Bore vs. Stroke ratios have very little to do with gas mileage as opposed to the other governing engine dynamics that signficantly effect gas mileage efficiency.

The only noteworthy bore/stroke ratio factors that play into gas mileage are the the characteristics of side loading, pump efficiency, and windage associated with a particular bore and stroke combination. Maybe 10% of the overall contributing net gas mileage factor at most.

Side loading is when the connecting rod is attempting to push the piston into the cylinder wall, most noticeable when the crankshaft is at 90 and 270 degrees. When looking at the piston specifically during a side loading observation, the skirt of the piston is being deflected slightly so that it makes more friction with the thrust side of the cylinder wall most notably on the power stroke. Generally speaking, the longer the stroke the more potential for side loading. Additionally, the longer the stroke, the faster the piston velocity at any given speed resulting is slightly additional pumping losses. Now, by your suggested theory, we should be able to increase gas mileage by reducing this friction of the increased parasitic frictional losses associated with a longer stroke. This isn't neccesarily true.

First of all you mentioned frictional surface area. I suspect you are speaking about the additional contact of the rings on the longer stroke. Well what do you think happens when you increase the circumference of the cylinder? It's true, if you were to make no other changes to a motor other than to shorten it's stroke and widen the bore, effectively numerically raising the bore/stroke ratio, you would slightly reduce some of the associated frictional and pumping losses. But, for one you won't find a reputable engine builder in the world that would not make any other changes to an engine to optimize the engine to work well with a higher b/s ratio. You touched on some simple mathematics that builders use as a rough guidline. Generally speaking, the piston ring friction in relation to the cylinder wall can me measured as increasing with the square of engine speed. With a higher b/s ratio, you must rev the engine higher to make the same power as the motor with the longer stroke and smaller bore, numerically lower b/s ratio effectively counteracting the friction that we just reduced by reducing the . The engine with the higher b/s ratio will characteristically make less torque under the curve at lower RPM's, again counter effective to increasing gas mileage efficiency.

The true gas mileage dictators are the dynamics of the camshaft, cylinder head design, intake manifold design, exhaust efficiency, and fuel management.

[Thomas L. Parker]

302 and fuel consumption

My 69 Z-28 would turn 21 MPG on the interstate at 70+ MPH. For that era, that was not bad at all. It would do around 16 MPG on Propane! At 55MPH/night, it would do 16 to 18 MPG. It really did like the higher speeds. Cruised best around 4300 RPM (Peak Torque).

On a 3.2 mile road course, it would run about 6 MPG!

Yes, I still have it!

Tom

[Joe K. 99 Zeee!!]

Here's the only 302 LS1 that I've seen, but I don't think the emphasis was on milage...

http://superchevy.com/features/camaro/0601sc_treasure/

This Fourth-Generation car was built as a salute to the original '67-'69 Camaro Z/28, which is why the Westech Automotive LS1 engine now displaces 302 ci--the same as the earlier Z/28, which terrified the competition in Trans Am racing. It's an aluminum block, produces 435 hp at 6,000 rpm, uses a special ratio T-56 transmission (2.97:1 first gear) with a Billet Hurst shifter, mounts LS6 cylinder heads modified by Advanced Airflow Engineering, has TT5 Power System headers, a cat-back exhaust, and computer calibration, with a Center Force clutch and pressure plate, a carbon fiber driveshaft, and heavy-duty 4.10:1 differential and axles from SLP.

[fastTa]

Here's the only 302 LS1 that I've seen, but I don't think the emphasis was on milage...

http://superchevy.com/features/camaro/0601sc_treasure/

I didn't read the article, but I think you're right. I think it was done just to do it. Maybe a bit of nostalgia involved. That is a good looking Camaro nevertheless.

[capncrunch]

1/8 mile times

Okay, I hear what you're saying zz4, & I hear what you other guys are saying, too. No, the 302 Z wasn't an economy vehicle, mostly because nobody bought one for fuel-economy (be like buying a Hyundai to race with), & so, the 302's spent most of their time doing what they were built for-Racing! However, I remember reading an article in 'Hot Rod' magazine, where they took an original DZ302 w/30000 miles on it, out of the car & dyno'd it. The factory called it 290hp, but Hot Rod wasn't buying it. Turns out that the STOCK 302 they dyno'd was pushing 375+hp! Also, how long did the 302 Z hold the 1/8 mile speed record, 6 or 7 years-in a row? And, as noted earlier, they made good mpg's WITHOUT over-drives (think what they would do with an OD tranny!) As I said, I 'hear' all of you, & I agree w/ ALL of you. But I don't think that it's fair to knock zz4's idea, because it sounds reasonable, when you consider all the aspects of it. By the way, thanks for the lesson in motor-physics! I am just pleased that you guys are talking American-muscle, Not rice-turbos! BTW the next-door neighbor recently got an '06 GTO w/ the 405hp, 6.0, 6 spd, (I know, built in Aussie-land BUT powered by Chevrolet!), & it FLIES! So far, he's had it up to 150mph, & it doesn't dog outta the hole, either! Long live the V-8!

[Joe 1320]

The biggest benefits from destroking the engine is reduced piston wear, reduced piston travel per crankshaft revolution, the abilty to rev higher but with a corresponding loss of low end torque. There are trade offs.....

[zz4camaro1980]

Thank you for all the feedback! Its been a big help. Im not sure if these are realistic goals, but this is what i would like to see...
1) minimum 400hp
2) high rpm (more fun to drive in my opinion)
3) minimum 30mpg

basically i want the most efficient engine possible while still being able to have some fun.
i was thinking that a mild supercharged ls-1 302 ci would be ideal.
Thanks again guys!

[Mark B]

400HP and 30mpg....


Better Get Nitrous.

[fastTa]

400HP and 30mpg....


Better Get Nitrous.

Hmmmm.......bolt on LS1's do this all day long without the help on N20.

[Jay 02 TA ws6]

Hmmmm.......bolt on LS1's do this all day long without the help on N20.

I pretty much achieved those stats before I sold mine.

[darkz711]

http://www.ttspowersystems.com/articles/7/index.htm

thats the 302 LS1. It was a prototype but it made more horsepower than the 346 even though the author of the article says it made more horsepower than a 350 but i mean that was the first thing i clicked on google. Im sure there is better info on it