thinkin of pullin the cleveland back out

[ugly74]

I'm not sure what the deal is. timing's right (36* total), carb (1850 holley) is tuned about as close as a carb can get. and yet, all I can squeeze out of this thing is five (5!) mpg. ?:?
don't get me wrong, she sure runs sweet. oodles of power. barely give 'er any gas, and it'll run up hills in 2nd that I'da had to drop to 1st with the 302. I love that I have to feather the gas goin around corners, lest the rearend try to come around;D
but I burned up and entire main tank just going to work and back. (50ish miles)
and I just can't do it. if I can't afford to drive it...what good is it?
I have a Mustang in waiting that would love to have this motor (but it'll be awhile for that) with some 4.56s and a 5 spd.
so I'm gonna refurbish my ol' 302.

anyone want a PS bracket for a stock pump and some sweet Sanderson headers for a C into eb project?

 

[NYLES]

I'm not sure what the deal is. timing's right (36* total), carb (1850 holley) is tuned about as close as a carb can get. and yet, all I can squeeze out of this thing is five (5!) mpg. ?:?
don't get me wrong, she sure runs sweet. oodles of power. barely give 'er any gas, and it'll run up hills in 2nd that I'da had to drop to 1st with the 302. I love that I have to feather the gas goin around corners, lest the rearend try to come around;D
but I burned up and entire main tank just going to work and back. (50ish miles)
and I just can't do it. if I can't afford to drive it...what good is it?
I have a Mustang in waiting that would love to have this motor (but it'll be awhile for that) with some 4.56s and a 5 spd.
so I'm gonna refurbish my ol' 302.

anyone want a PS bracket for a stock pump and some sweet Sanderson headers for a C into eb project?

Man that sucks! Having to pull it

 

[dead road]

how much you want for the parts. I'm going 71 boss 351 into 71 baja. Sand drags and car shows only so no concern on fuel economy.

 

[fordfan]

Don't pull the Cleveland yet! I have a '69 with a cleveland and it seems to get really good mileage....better that a 302 with a c4! This cleveland is the 2v version with a small cam, ballanced, an aluminum 4 barrel intake and an eldebrock carb. The trans is a np435 with 3.50 gears and 33's. The cleveland and the M motors are some of the more efficient engines made and if the fuel/air ratio is right it should do fairly good (unless it has a real radical camshaft). If it is a standard displacement (not stroked) it should do at least as good as a 351 windsor. Same displacement; same fuel ratio = close to the same mileage. Those cleveland engines really seem to breathe easy and run really free. The one in my 69 is hard to start off with the 435 and not spin the tire, and it really loves to scoot up a hill (on the hwy - not offroad). I love it! Like Dead Road: "how much for the parts you don't need?"

 

[broncnaz]

Most likely its way overbuilt for your driving needs hence the poor mileage. But what gearing, tranny and tires size are you running?

 

[Madgyver]

Is it 4V or 2V heads?

 

[bludorbronc]

sounds like the power valve is shot, just letting gas go right thru. isnt the exhaust burning your eyes.

 

[ugly74]

it is a bit overbuilt. it idles fairly smoothish, but it's still pullin real strong at 6500 rpms. I haven't wound it faster than that, but it could, and feels like it wants to. also, I'm runnin 32" tires, 3.50s, and a c4. and the heads are 2V, with a little bit of port and bowl work.
I think before I through in the towel on this, I'll build another carb and see how it does.

 

[NYLES]

it is a bit overbuilt. it idles fairly smoothish, but it's still pullin real strong at 6500 rpms. I haven't wound it faster than that, but it could, and feels like it wants to. also, I'm runnin 32" tires, 3.50s, and a c4. and the heads are 2V, with a little bit of port and bowl work.
I think before I through in the towel on this, I'll build another carb and see how it does.

Quickfuel

 

[Madgyver]

The 1850 should work well with the set-up, Unless something is wrong with the carb.
Have you look at fuel delivery? if there is any leaks along the run.

How big is you cam?

 

[broncnaz]

If the power valve is bad more than likely your idle is way rich and adjusting the idle mixtures screws results in no changes.
I'd say other factors are involved like gearing, maybe torque converter slippage, and overall engine build. Probably just to mismatched for the mileage game.

 

[buckintone]

it is a bit overbuilt. it idles fairly smoothish, but it's still pullin real strong at 6500 rpms. I haven't wound it faster than that, but it could, and feels like it wants to. also, I'm runnin 32" tires, 3.50s, and a c4. and the heads are 2V, with a little bit of port and bowl work.
I think before I through in the towel on this, I'll build another carb and see how it does.

6,500 rpms? that'll eat some gas

 

[ugly74]

The 1850 should work well with the set-up, Unless something is wrong with the carb.
Have you look at fuel delivery? if there is any leaks along the run.

How big is you cam?

cam's not huge, .508 intake and exhaust, not a whole helluva lot of overlap.
it's pretty torquey right from idle, but really wakes up right around 4000rpm.

you're right, the 1850 should run nice on this thing.

 

[ugly74]

If the power valve is bad more than likely your idle is way rich and adjusting the idle mixtures screws results in no changes.
I'd say other factors are involved like gearing, maybe torque converter slippage, and overall engine build. Probably just to mismatched for the mileage game.

it probably is a carb issue. but it's not the power valve, as the idle mix screws are turned out 1.25 turns. I can turn them out more maybe 1/2 turn more if I wanna, but if I turn them down to 1 turn, it idles rough. so...

I'd thought about parasitic loss through the trans being the culprit (it's freshly built, with a new converter), but I ruled it out, cuz this thing seems to move so easily, even with the tall gearing and 32s

 

[ugly74]

6,500 rpms? that'll eat some gas

I don't even wanna think about how many gallons to the mile this Fn pony get's when I'm putting the spurs to 'er! ;D

when I calculated the 5mpg, I was driving fairly calm. shifting at no more than 4k, and kept it under 70mph. long stretches too, no traffic, only 2 stoplights.

 

[rustbucket]

What's your stall speed?

 

[OX1]

@ $3.50 a gallon your running .70C a mile right now.
If you manage 10 MPG, now you'll be .35C a mile.

Figure out true yearly mileage and even see if it is worth the effort, dollar wise

 

[Madgyver]

I think it's a carb and torque convertor issue. I've experienced less gas mileage with a Cleveland and an automatic C6 compared to manual trans..

 

[broncnaz]

it probably is a carb issue. but it's not the power valve, as the idle mix screws are turned out 1.25 turns. I can turn them out more maybe 1/2 turn more if I wanna, but if I turn them down to 1 turn, it idles rough. so...

I'd thought about parasitic loss through the trans being the culprit (it's freshly built, with a new converter), but I ruled it out, cuz this thing seems to move so easily, even with the tall gearing and 32s

moving easily or even new a converter doesnt mean the converter is blame free. Stall speed may be a issue. or its just a loose converter but you dont really feel it due to the power of the engine.

 

[ugly74]

so...the stall speed may be too high? or just slips too much through the rpm range? I guess I'm not too savvy on automatics maybe.

I'll go home and take it for a spin to warm it up. to measure the true stall speed, you basically just stand on the brake and give it gas and see where the RPMs come up to, right?