How will gas prices affect your rodding?

av8 · September 02, 2005, 11:04:54 PM

Quote from: "1FATGMC"
Quote from: "av8"

With a 3.0 9-inch, a THM-350, and some careful ignition and Q-Jet tuning on a late-model SBC I'm figuring 18-20 mpg at cruise speeds of 65-70 mph -- not nearly so good as the BMW, but lots more smiles per mile!

Dump the 3.0 rear and the 350 auto for 3.50 gears and the 200r4 you were asking about or a 700r4 and you will have much better acceleration and better gas mileage to boot. I like the Q-jet though .

The 3.50 with the overdrive is like a 2.45 rear in 4th. That is about 18% lower rpm's on the highway or any time you are over 35-40 mph vs. the 3.00 rear.

c ya, Sum

I've been going 'round and 'round with a couple of pals on this very point. I've been for the OD autos all along but they've put up some very compelling arguements in favor of the simpler scheme in light of what I will use my truck for.

My "new" SBC and transmission are coming from a friend who has a large auto-salvage yard in the Bay Area. He's a hot rodder so understands the grade of motor I need. He's providing the motor, 100 percent complete and running good, plus a transmission, in exchange for my porting and modifications on a new French flathead block.

I'm confident I'll get a good motor but I have less confidence about a four-speed auto transmission, and I can't really afford to have one rebuilt if it takes a dive early on.

I understand the numbers and I appreciate your advice, Sum. I still have until Tuesday before placing my "order."

Thanks . . .

Mike

Crosley.In.AZ · September 03, 2005, 12:08:03 AM

Quote from: "enjenjo"I went to the HAMB drags last week, pulled a trailer with an A body on it out there, no trailer coming back. This was with the 34 Desoto, 305 Chevy, TPI, 700R4, 3.50 gear. I averaged 15 mpg with the trailer, 20 mpg without it, at 65 to 70 mph.

Congrats on the trip

1FATGMC · September 03, 2005, 12:38:47 AM

Quote from: "av8"
I'm confident I'll get a good motor but I have less confidence about a four-speed auto transmission, and I can't really afford to have one rebuilt if it takes a dive early on.

I understand the numbers and I appreciate your advice, Sum. I still have until Tuesday before placing my "order."

Thanks . . .

Mike

You can find a 700R4 cheap if you look a little. I have one I paid $100 for and I paid $350 for another complete car with a good running 305 and a 700R4. That guy you are doing the head work for should be able to find one for no more than the 350. In fact easier if he is going to get you a later year 350. Try and get him to get you a roller motor even if it is a newer one that doesn't have a roller cam in it, but has the provision in the block to run the GM spider like thing in the galley that positions the roller lifters. Now you can build a motor that gets good hp and better gas mileage than a flat tappet motor. There is a reason GM builds them.

The guy who rebuilt my 700r4 80,000 miles ago said he could do another one in the $400 to $600 range out of the car. I'm going to have him rebuild one of the one's I have now and put it and a 350 sbc in Julie's 72 Ford pickup that has a bad new 390 rebuilt motor that only gets 10 mpg. 700's can be built strong now for not that much and they will go a long way. I originally paid $200 for the one I'm using now and used it like that until it had 40,000 miles on it. Then the converter went bad (quit locking up) and while I had it out I decided to get the trans. rebuilt. I'll have problems sooner or later, but I've been so happy with it and I would never build another car that will be driven without an overdrive. I really haven't run into anyone who would go the other way back to a 350, except maybe for someone who didn't take the time to set the TV cable up right and blew the transmission up and there is no reason for that to happen. The only way you are going to get a 350 trans. to give you the gas mileage is with 2.73 or higher gears in my opinion and then it will be a dog.

c ya, Sum

sal37 · September 03, 2005, 06:37:44 AM

The price of fuel (unleaded regular) here in Newcastle Australia is the equivalent of about $US3.69/gal. With further rises expected over the next few weeks. The rising price now has me seriously considering using lpg (propane) as a fuel for my current project. Lpg sells for about $US1.30/gal. Despite having most of the stuff to set up a petrol engine I think the extra expense to go with lpg is going to save me some money, especially seeing I want to use the car on a very regular driver.

Steve

slocrow · September 03, 2005, 07:46:17 AM

Not................as it isn't an on going cost. I have noticed the roads are a little less crowded. I like that so I guess that's the trade off. Frank

48ford · September 03, 2005, 09:10:31 AM

Quote from: "1FATGMC"
Quote from: "av8"

With a 3.0 9-inch, a THM-350, and some careful ignition and Q-Jet tuning on a late-model SBC I'm figuring 18-20 mpg at cruise speeds of 65-70 mph -- not nearly so good as the BMW, but lots more smiles per mile!

Dump the 3.0 rear and the 350 auto for 3.50 gears and the 200r4 you were asking about or a 700r4 and you will have much better acceleration and better gas mileage to boot. I like the Q-jet though .

The 3.50 with the overdrive is like a 2.45 rear in 4th. That is about 18% lower rpm's on the highway or any time you are over 35-40 mph vs. the 3.00 rear.
I have to go along with Sum on this one,puling the turbo 350 and going to ad O.D. was one of the best thing I have done.with the od and a 3:75 pig it's a ball to drive and gives 18-19 on the highway.and we can here the radio at 70 mph
Russ&Irene

c ya, Sum

junkyardjeff · September 03, 2005, 06:22:29 PM

I will attend shows closer to home and the turkey run might not happen unless my 55 ford or my buddys 64 country sedan will get decent mileage,I have only put a couple of miles on it going around the block a few times but I hope to have it drivable in october and I will have a little time to check that out before it comes up. I have been tinkering with my 65 country squire to get a little better mileage and if I can get it up to around 18 or higher it might go but there is only so much that I can get with a 390,I drive 43 miles each way to work and a gas miser will be needed soon. Jeff

phat rat · September 03, 2005, 09:56:06 PM

I debated for awhile about whether or not to go 700R in the cpe but I've been happy that I did. Absolute best I ever did with the 396"/350 was 14mpg, generally it was 12-13 with the 454 crate/700R I've pulled 19 mpg generally 17 1/2-18 1/2 at todays prices that's quite a bit of difference in fuel costs.

tomslik · September 03, 2005, 10:04:55 PM

Quote from: "phat rat"I debated for awhile about whether or not to go 700R in the cpe but I've been happy that I did. Absolute best I ever did with the 396"/350 was 14mpg, generally it was 12-13 with the 454 crate/700R I've pulled 19 mpg generally 17 1/2-18 1/2 at todays prices that's quite a bit of difference in fuel costs.

well, i guess i'm just backwards.
coupe's getting 4.10 gears and a manual trans w/o OD.....

hell, i never get to go anywhere anyway...