Freightrain

http://www.ebay.com/itm/1976-Mack-F-700-Truck-/141381348481?forcerrptr=true&hash=item20eafc2c81&item=141381348481&pt=Commercial_Trucks Interesting for sure.

About a 4-5" square tube across the back, a hole in the bottom for the inlet. Pretty simple from the ones I've seen. Don't think any one I've seen was actually a muffler. It is a real simple way to put duals on a truck.

Wow...don't seem like a bad deal for the money?

Yup, the firewall is bad enough on a std B, I can imagine yours. Even with the smallest underdash, it will stick out about 6-7" past my dash. Livable since with the shifters there you can't do anything else with the space. I have a vintage revolving light on the roof so no room for that kind of unit(though I thought of them and considered it).

I know Vintage air has one, but I was given a link to a place in Texas that has one a bit cheaper. Not quite as flashy looking box, but I don't need flashy. Link is at home, I'll get it posted. The big issue I have to deal with is getting the compressor mounted. I need to move my original filter off the front right side of engine(likely move it to frame mounted bracket) and then fab something and drive it off the waterpump. Have to mount pulley to outside of stock waterpump pulley. Checked into DCpowersales. One of the rooftop units was 330w, which equates to 27.5 amps at 12v. Wow, that will put a load on an alternator.

Sounds interesting. Might have to google them up. I've got my eye on an underdash unit for mine someday.

Congrats!

Depends on the pump. I turned mine up years ago. It ran well but only got about 4 mpg. Once diesel got to $4/gal I dialed it back and get about 8mpg now. It is not as snappy off the light but gets me there. Just a light haze out the pipes under throttle. Never got fire, but never really tried. With no oil cooled pistons I'm sure you have to be careful. Don't have the money to put a motor in it so I keep it easy on it.

Last HCEA Nat I went to was at their place in Bowling Green, Ohio. Was about 10 yrs ago, had a good time.

Saw this at Syracuse '03 and still my one of my favorite B models. Just badazz. I still wish I could get the previous owner of my B to get me pics of his old trucks. He had a fleet of B's and some other BIG stuff(like Acars).

I tjhink it will struggle to keep up 75 mph with one car on. My GCVW is around 27K lbs and 65-70 is comfortable to run with 4.10 gears. Just runs outta power trying to keep up any faster speeds and it will not pull hills well. I can use my last OD and pass someone and run it up to 75 or so on level ground, but it just doesn't have the power to keep it there.

Would that be Marcels truck? http://www.bigmacktrucks.com/index.php?/topic/36563-selling-my-mh/

Welcome aboard. Nice truck, thanks for the pics.

A picture would help of your set up.

Just so you know, 4.00 to 9.50 were the ratios available, at least from the information I've looked at. I remember Highpoint Garage having a B model for sale with 9.50 gears in it. Yowza!!!!

I know that they flip gears around in a Roadranger, but didn't know they could do it in a Mack transmission?

That duplex is likely a 9spd, I think that is the version that has OD in 5th? The 10spd is direct in 5th. Mack built them either way. Check the side of the pumkin, it should have a number stamped in the side that denotes what it is. Probably 5.xx something. When I had 4.63 and single OD, mine would run 63-65 mph. Currently I have 4.10 and enough overdrive gearing to run 85 mph. It runs along at 68 at 1800 rpm and does well with my trailer. I too was concerned with over gearing and not having enough power to pull it. All depends on your terrain. Flat land is good, hills will really slow you down.

When you get the truck, find out if any of the other three adjusters are there. Then you will have something to get your information to replace it.

Typically, the oil pump has a pressure spring, that keeps a maximum pressure limit on the pump. I don't know the actual GPH a car pump is actually capable of, but I do know a good portion gets returned to the pan as the engine is running. "Most" car filters do have a bypass built in that allows for oil to get to the motor IF the filter would clog/fail. That is for the people that NEVER change them! That is the issue, what is "Bypass" and how is it being used in these engines. I would have to investigate the workings of our old system to see what does what and how. "I think" what happens is the pump is regulated for pressure but instead of extra oil just falling back into the pan, it gets filtered and then goes to the pan. Maybe? Does anyone really know?

I agree Mike. There are somethings that aren't.

Welcome. You might get better response with your question if you post it in the driveline forum.

Mine does not bypass per say like the big unit. It's like a car. Oil from the pump goes through a pair of filters( in parallel) and back to the block to feed the engine. Nothing else to it. The valve inside is for pressure relief only to control pressure fed to engine again just like a car engine. I suppose if you could find a filter head and plumb it to the two large lines it would work fine. You could then remove the small return line.

Well apparently the oil goes through the cooler FIRST, then the filter, then the motor oil galleys. Not a big deal. Just need to confirm where that "unknown" line goes? I think the rear(left side) of oil cooler.

I relied on Phil and comparing pictures through email. Felt pretty confident and it worked out in the end.

No, should only be one relief, in that housing. Pretty sure that unknown line is coming from oil cooler. My spin on adapter had the top portion bolted on, where the pic you show is just the lower portion. Basically the oil comes from the engine block at the lowest area of the relief block(basically because the pump is bringing it up from the pan). Then it goes through relief, then the filters(or visa versa), then back into the block to feed the oil galleys. The spin on adapter also will have an oil fitting for your turbo just like your current model.