Lmackattack

thanks for the part number rick. I bought the alt from my mack dealer on sat installed the pully and all looks good so far. I am also going to use the gen mount bracket and use a pipe spacer to keep the alt from bouncing around. I will also need to get a set of shorter belts as the alt is trying to hang off the engine to far with the genarator belts. simple fixes but lots of running around. one other Question I see the positive post that goes to the batt cables ground post to the frame rails then there are 2 posts and Im not exactly shure what they do. what would I hook those posts to???

Hi Kevin I agree with rsmartyn. Those older diesels are great on fuel economy. be carefull as adding to much fuel will lower mpgs and may cause high EGTs. If you do mess with the fuel screw I would get an EGT guage to make shure you dont get to melting pistons. I have the 283 tip turbine and with a few twists of the fuel screw It makes the EGTs get pretty high at the end of 5th gear On a med pull I might have to let up some times..However here in the flats of the midwest It shure does pull good and can keep up with a 300 maxidyne at the same gross weight. Part of the problem with my 283 and the smaller maxidines is that the intercooling/charg cooling (if equipped) is not the most effective. The IC is just part of the issue but it does play an important part in temps. The 237 has no IC and that may render your adding extra fuel. just be carefull what ever you decide. My friends day cab R model 300 maxidyne with a 9 speed got around 6.1 mpg hauling mail from Chicago to NY and 6.5 MPG hauling an empty trailer from NY back to Chicago pretty good economy if you ask me.

I went to my mack dealer tonight and the parts guy found the same alt that I borrowed from the yard. Its a leece neville. They have a sale on them this month for $140. + tax. that sounds like a good deal to me?. I can make it bolt up easy to the gen bracket so I think I will be going back to buy it tomorrow morning. I can get a smaller pully if need be from a local rebuilder so we will see if it works right? for refrence the local electric repair shop wanted to charge 200 for a "new rebuilt" altanator. Trent

you will pick up a few mph up top but it will also make the low gear taller. most of the 9 speeds I have driven had between 4.64 - 5.02 rears. on 11r22.5 tires. all were great in the mud but I do remember having to realy use that low gear some times. I know 4.17s will work but it makes the truck more of a highway cruiser. from my experince I can easly tell the diffrence if the truck had 4.64 rears or 5,02s. cant give much input on the tire dia diffrences as I have not driven many dirt trucks with tall 24.5 tires

a 9 speed low low gear is 10.69 I think there is a "B" version with a lower ratio but most 9 speeds I have seen had the 10.69 ratio. with 4.17s and low pro 24.5 you will have a ok low gear but not as deep as a 2 stick 6 speed. I have a 9 speed waiting to be rebuilt and will be installing it in my mack with 4.17 rears. It should be fine for most applacations but it wont be the best in the deep mud. I chose the 9 speed for the OD gearing and the extra gears in between. I want to use all of my maxidynes power just my .02

thanks for the tip. I test fitted a altanator out of a junk R model tonight and it looks like it may work for me. I just hope they can get a part number off of it? It looks like I will be able to make a long bolt and get a pipe spacer like you said you made. I will have to see if the pully is the right size for the applacation. this alt has a 2 slot pully that looks identical to the old genarator. if all goes well It should work. this was 2 easy so far LOL.. knock on wood Trent

I have changed over to 12v system but need still to install a Altanator. I know Larry and Rick Harper talked about a difftent bracket or a fabricated pice to align the pullys. that seams easy to fabricate but what I would like to know is if I can use a altanator from a R model. tipical story at the dealer. they need a vin # ,part number, or a old altanator to compare. My B model Vin # wont work as it had a genarator. any tips? Thanks Trent

never driven one but my garbage man says besides the terrible ride the truck has been great. its just a local HD delevery truck in my opinion. Garbage, spotter intercity etc.. I would not want to drive one over the road for long trips. I dont wear my seat belt in a rig and I think I would have a broken neck from hitting the top of the cab in one of those LOL. they are fast and versitile but just not something I would want to own for a toy. I would however get one for company use for landscaping or a small busness thats where they would make money

Thanks for posting the pics Thad. looks like a straight truck to build off of. I think I saw that truck on truck paper or truck trader?? that is pretty far to get it lots of $$$ that could be spent on restoring it. Im shure you can find another RS that is close to you for a little more that runs and can be driven home. I always tell people that im lucky I dont own a trailer because I would have lots of junk at the yard I would need to restore someday. I think your right Rob, 72-73 ish was the changeover year to the larger cabs. I like the small cabs just as much as they are simple but the extra few inches in the later cabs shure are nice when you are going to the truck shows with tools the girlfriend and the dog all in the same cab LOL I have seen Johns (bulldogbred) truck pull. He turned me on to truck pulling last year. That 300+ in his ride was pretty impressive for an older 2v motor. Cant wait to see his E7 400 pull this summer. He is right that some of these older motors have more grunt than the new elctronics do. I turned up my 2v this winter and hope to get some of these big cats at the next pull event.

I cant open the pics So I cant see its condition but I can tell you from experience that if the truck needs lots of work you will run in circles trying to restore it to orginal form. My first B needed so much work the I ended up geting another B model and used parts from both to make one good truck. If I did it all over again I would have found a truck that cost a little more but was in better condition. I love working on trucks but I just dont have deep pockets to do frame offs like the pros do. I got real lucky with my RS as it was a O/O truck and was maintained well over its life. I think it was only neglected for its last few years. It has been much more fun to build off a straight truck than to have to fight with other peoples hack jobs and temp fixes. I dont have my mack book in front of me but I think The 866 and 865 needed diffrent transmissions. one was a maxidyne and could use 5 gears the other needed more gears as it did not have a flat toru curve of the maxidyne. For some reason I always here of rod bearing problems with the older V8s? post a pic on here if you can I always like to see a nice looking RS

Thats exactly why I like to push start things its easy to drag something around to start it but you never know what going to happen when it comes to life LOL. I put a few scratches in the cross member doing it this way but I like my trucks to have a few war scars. makes them more fun to drive not worring about everything around you. I found why my new batt and starter was haveing an issue cranking. seams that the PTO idler gear that I took off another trans was not meshing like it should and it was binding. I took it off and she cranked over with a fresh charge on the batts. Whats the status on the engine? last I heard it was stuck or something? ever find the issue? Trent

the seat and my paints are fine however my friend got a real good look at the windshield. when the 4 feet slack in the chain ran out. LOL. I had a chain wraped around the rear crossmember and had the bucket over the frame to push it along. when it took off running I tried to keep up but she had a little to much unburnt fuel that needed to be burned off first LOL. I think the rear tires on the loader came off the ground LOL. I pulled it this way incase she was a runaway so I could stop it. after I got things back under control I lifted the tandems off the cround and went thry the gears. boy did that 711 sounded good wound up again Trent

do those bumpers fold down to be able to open the hood? I know the roo bars do with the pull of 2 pins. Trent

got the old B fired up today. Its been about 3 years sence I herd it bark. I think it got excited too as it almost pulled over the rubber tire loader I was running that was chained behind her when it fired up. My friend popped the cluch and mashed the pedal in a high gear, it blew a big black cloud and starrter running away faster than the maching LOL. he got it out of gear as the rpms came back down and all was good. Boy does it feel good to drive it again. I have a isse with the PTO gear and the clutch pedal adjustment but it looks like an easy fix? Trent

nice looking Rig!! going to build a model of it?

the 7 speed is a fast transmission (.60 overdrive? will have to check my books.) you likely will have slow rears so it wont be 2 fast. I think it was David that said that the fast drive train speed helps reduce stress and shock in the mud? The 7 speeds I have driven were all pretty good and the 2 low gears did help startup on a hill, at least a little better than the 2 stick 6 speeds

I have tinkered with my pump to flow a little more fuel. I noticed that the EGTs rise to 1000 fairly quick now. Thats ok because Im just bob tailing to shows and stuff. I dont think I could pull a long hill loaded as the EGTs will get to high. It is fun for bob tailing around and my Butt dyno tells me HP is up. From what I have learned from others is that If you want to properly get more HP you need more air when you add more fuel. Most newer high HP diesels are running hi boost to keep EGTs down and keep emissions in check. higher Boost will burn the extra fuel and keep EGTs down. the intercooler should be able to keep up for most adjustments but be carefull. Injector size may become a issue depending on the powere you want. my advice is to get a cheep, used slightly larger turbo and up the fuel flow a little. Then see where the EGTs settle on a pull. The extra boost from a larger turbo should be able to burn the extra fuel added and the injectors may be fine for the powere. As you know many of us dont have a dyno to prove our results and none of us will tell you its 100% safe. just be smart, make little adjustments AND WATCH YOUR GUAGES

looking good. dident you make a great looking green/white RD mack a few months ago? I havent seen many DM800s like that from my aera. lots of U models and DM600. I just won a R model kit on ebay yesterday and bought a RS700L resin hood. I plan to recreate my RS mack after I finish the Astrailian V8 Valuliner conversion kit that im working on. What kind of paint do you use? I started to use the model masters water base paint a few years back and love how easy it is to airbrush not to mention fix my mistakes

great stories guys. I can relate to the steering wheel breaking fingers. My RS has manual steering and I will never for get how fast that wheel moved the first time I slowly rolled over a curb!!!

find a real low gear and I bet it could that 600HP is for the big roads. I dought he used all 600 ponys to pull that more important how much weight was on the drives and what suspention did it have?? regardless its good to see a Mack in the News Trent

not shure if I read the post correctly but I think you will find some small issues trying to put later style interior parts in the early cabs. I know the rear wall is a few inches closer to the front so the headliner may not fit properly. door panels should fit fine and the Radio console should fit with no major modifacation. But I think your biggest issue is finding a full used good interior. I have been looking for a black interior for a year with little luck. No longer made and salvage yards want to sell the whole cab intact. Trent

Its diffrent for shure. not my sort of taste, but I truely can apreciate the vision (no pun intended) behind it.

wow! nice truck. Im shure your grandpa is proud of that machine. How long has he owned it?

Great news Rob! I remember the pics on the old BMT site when you started tearing it down. hope to see it at a truck show soon!! Trent

I think the later V8s were pretty good i.e E9 sieres I hear of bearing issues with the early versions 865 or 866 V8s My company I work for has a 440 V8 with 480,000 miles on it with out a rebuild. besides the basic stuff that wears out its been a good engine. It does have excess blow by now and will need a rebuild soon . The down fall with the v8 is that if it does break something . its likely big$$$ to fix. Alot of people will pull the tired V8 out and put a fresh 400HP E7 in its place. not my style but for saveings I can understand the reason.