Western RS/RL Model Help

[Mr Black]

I am fitting a Western RS model hood to an Australian R Model. I like the RS/RL hood shape but we don't have the Westerns in Oz so working out fitment has been interesting.

One thing I want to know is how much higher the cab sits on a RS700 compared to a R700. Is there someone out there with a RS600/700 that would be willing to measure the height of their cab mounts? The measurement I am after is the distance from the top chassis bolt on the mount to the top of the mount. The mount on a standard Oz R model is basically level with the top chassis bolt but I am sure the RS cab sits higher. I have some Series 1 Superliner mounts that sit about 4 inches higher than standard but would like to know the proper height of a RS/RL cab.

Hope someone can help.

Thanks

[j hancock]

There is a posted RS brochure you can check out.

It shows RS at 66" between top of cab and top of rails.

A R-700 ST has 65.2"

A RD-600SX brochure has 62.8".

A R-607RS "Flintstone" is 61.3"

http://www.bigmacktrucks.com/index.php?/topic/32773-rl600ls-rs600ls-brochure-r-600/?hl=%2Brs+%2Bbrochure

http://www.bigmacktrucks.com/index.php?/topic/32702-1977-mack-r-brochure-r700-r700st-r747st-r-700/?hl=r700

Jim

[Mr Black]

Thanks Jim - that has been very helpful.

There is a posted RS brochure you can check out.

It shows RS at 66" between top of cab and top of rails.

A R-700 ST has 65.2"

A RD-600SX brochure has 62.8".

A R-607RS "Flintstone" is 61.3"

http://www.bigmacktrucks.com/index.php?/topic/32773-rl600ls-rs600ls-brochure-r-600/?hl=%2Brs+%2Bbrochure

http://www.bigmacktrucks.com/index.php?/topic/32702-1977-mack-r-brochure-r700-r700st-r747st-r-700/?hl=r700

Jim

[Mr Black]

There is a posted RS brochure you can check out.

It shows RS at 66" between top of cab and top of rails.

A R-700 ST has 65.2"

A RD-600SX brochure has 62.8".

A R-607RS "Flintstone" is 61.3"

http://www.bigmacktrucks.com/index.php?/topic/32773-rl600ls-rs600ls-brochure-r-600/?hl=%2Brs+%2Bbrochure

http://www.bigmacktrucks.com/index.php?/topic/32702-1977-mack-r-brochure-r700-r700st-r747st-r-700/?hl=r700

Jim

Hey Jim, do you have any idea of when the RS/RL brochure was printed? The reason I ask is that the combination of cab + hood has an overall length of 106.75 compared to 119.00 for the R700 in the other link you have provided. That is over 12 inches difference whereas my understanding is that the difference in hood length between a R600 and R700 is much less than that (probably around 7 or 8 inches). I guess I am trying to work out whether a R700 hood is the same length as a RS/RL700 hood. The only explanation I can come up with for why there is over 12 inches difference between the trucks in the 2 brochures is if the RS/RL brochure was printed prior to the cab update so that some of the extra inches in the R700 brochure are from the back of the cab and not all 12 inches are in the hood. Any thoughts?

[2stacksuperdog]

The pictures make it look like the R700 has the +3 cab

[Mr Black]

The pictures make it look like the R700 has the +3 cab

Thanks 2stack, I agree based on the pictures. I can't see a year on the RS/RL brochure but it appears (to me) based on the specs that it would be new enough to also have the +3 cab. Certainly galv cabs were not available in Australia prior to the +3 cab but maybe it is different in the US. Assuming the RL/RS in the brochure has the +3 cab also, I just can't work out why it would be over 12 inches shorter than the R700.

[Lmackattack]

I don't have exact measurements but a rs700 hood should be about the same length as a r700 hood.The difference will be taller hood hight on later model rs700

A rs700/r700 hood is about 10-12" longer than that of a r600 hood.

As far as how far off the frame the cab sits....my rs700 was about an inch lower than the 2 superliners that I measured. I was able to use a superliner air ride cab set up on my rs700. If I recall the cab is about 5" higher than a standard r model.

[Mr Black]

I don't have exact measurements but a rs700 hood should be about the same length as a r700 hood.The difference will be taller hood hight on later model rs700

A rs700/r700 hood is about 10-12" longer than that of a r600 hood.

As far as how far off the frame the cab sits....my rs700 was about an inch lower than the 2 superliners that I measured. I was able to use a superliner air ride cab set up on my rs700. If I recall the cab is about 5" higher than a standard r model.

Thanks for this. The RS700 hood I have is the later one so is taller through the centre - like the one in your picture.

The chassis I am using doesn't currently have a R700 hood but has the holes pre-drilled in the chassis for the cab to be moved into the R700 position (as our Superliners in Oz were essentially R700 models with a different hood so every chassis was predrilled for long and short hoods - I understand the Superliner in the USA was a different beast). The next cab mount position on the chassis is less than 12" away so it concerns me a bit that the RS700 hood may be slightly different in length to a R700 hood. However, my Superliner chassis mounts haven't arrived yet and I understand that they are offset a bit as compared to standard R600 mounts so the difference could in the mounts themsleves. I guess I will know in a few days once the mounts arrive.

[Whiskymack]

Hello,

From memory I'm pretty sure that the BBC for later model RS/RL700's was 117 inches, very slightly shorter than the Eastern model. I think the same applied to the 600 as well; the western hood was fractionally shorter than the Eastern model. Also, hood length changed when frame mounted intercooling came in in the early eighties, I think they added an inch or two to the front of the hood to make room for the intercooler which sat in front of the radiator. Because Western model 700's were phased out before this I don't think they ever added the extra length. I guess a lot will depend on when your frame was made.

The other possible fly in the ointment is that the Superliner (US) was longer than either the RS700 and the R700. I think the BBC for the series 1 was 121 inches.

I suspect that the Australian version may also be longer than the R700 but I can check it tonight when I can get a look at my specsheets.

[j hancock]

I believe the RS brochure date is 1985. The R-700ST brochure is 1977

Jim

[Mr Black]

Hello,

From memory I'm pretty sure that the BBC for later model RS/RL700's was 117 inches, very slightly shorter than the Eastern model. I think the same applied to the 600 as well; the western hood was fractionally shorter than the Eastern model. Also, hood length changed when frame mounted intercooling came in in the early eighties, I think they added an inch or two to the front of the hood to make room for the intercooler which sat in front of the radiator. Because Western model 700's were phased out before this I don't think they ever added the extra length. I guess a lot will depend on when your frame was made.

The other possible fly in the ointment is that the Superliner (US) was longer than either the RS700 and the R700. I think the BBC for the series 1 was 121 inches.

I suspect that the Australian version may also be longer than the R700 but I can check it tonight when I can get a look at my specsheets.

Thanks for your input. I raised the concern because I am worried the RS700 hood won’t fit once I move the cab back into the standard R700 position (it is currently sitting in the standard R600 position). I really don’t want to have to fit the cab in a non-standard position given the holes in the chassis are pre-drilled for R600 and R700 positions. I know Australian R models have the same cab positions as Eastern USA models (because we originally imported the Eastern hoods from the USA for Australian models). However, I can’t work out whether Western cabs sit in the same spot on the chassis as Eastern (and therefore Australian) cabs.

I was first alarmed when I took a few measurements. My RS700 hood is about 22cms longer than the R600 hood that is currently on the truck. However, the distance between the pre-drilled holes on the chassis for R600 and R700 mounts is only 17.5cms. That means that the hood appears to be approx 4.5cm too long. Of course there are other things that may be relevant here. For example, firstly, I am told that the R700 mounts have a slight offset from the mounting bolts whereas the R600 mounts do not (although I am still waiting for the R700 mounts to arrive to confirm whether that is true). Secondly, the RS models mount on the radiator whereas my R600 mounts from the chassis.

I guess I will work it out in the end but was just hoping to find some comfort that the R and RS model cabs sit in the same spot on the chassis (despite having other differences such as height) before I take this much further. It could be that this project is too much problem. I am raising the cab height and preferred to use a RS hood because of the lower guards – so that the space between the tyres and guards doesn’t become excessive. However, it could be that the differences between R & RS models just make it not worth trying!!!

Any further input would definitely be welcomed. Thanks!!

[Lmackattack]

Another place to measure that may help figure this out is to measure what a r600 is from center of front wheel to front of cowl...then measure what a r700 and rs700 is....if I was up around my truck ...rs700l....I would measure for you..

[Mr Black]

Another place to measure that may help figure this out is to measure what a r600 is from center of front wheel to front of cowl...then measure what a r700 and rs700 is....if I was up around my truck ...rs700l....I would measure for you..

Agreed, I think that would help. Unfortunately I don't have access to a RS700L as we didn’t get Westerns in Australia. I may have another problem anyway, which I didn’t think of until one of the posts above. I have a front mounted intercooler and it sounds like the RS700L hood may interfere with that. I have this truck parked up off-site so can’t check out how much space I need in front of the radiator to accommodate the intercooler for a few days. Do you recall if you have any space between your radiator and the front of the hood on your RS700L?

[steve p]

mr black, mate where are you in oz for a start ,what do you have to start with ,photos would be a help to work out your plan of attack .look on hcvc web site restorations my 797 is on there steve

[Mr Black]

mr black, mate where are you in oz for a start ,what do you have to start with ,photos would be a help to work out your plan of attack .look on hcvc web site restorations my 797 is on there steve

Hey Steve, I am in Brisbane. I have come across your R797 on HCVC - very impressed. Your fabrication skills are exceptional. Unfortunately I don't have your skills so need to stick to using genuine parts!! So, to answer your question, the following is what I have:

• '85 R686 with EM6 and Maxitorque box
• USA Western hood from a RS700L - this was originally bought for a R700 project that didn't go ahead so I figure I may as well try and use it on the R686 as part of its restoration
• Series 1 Superliner cab mounts (which are about 4 inches taller than standard R600 mounts)

The intention is to move the cab back into the R700 position using the Superliner mounts. I will be picking up a remote system to move the gear stick back and the longer R700/Superliner steering shaft. By the look of it, there doesn't appear to be much more to moving the cab back (other than exhaust and other pipe/electrical extensions).

What I am not sure of is whether I can make this RS hood work. I guess it comes down to whether the cab on a Western sits in the same spot as a standard R and whether the Western hood will accomodate the front mounted intercooler. Will take some pictures next time I am at the truck.

Where are you in Oz? Is the R797 finished? Would be great to see some more pictures.

[Whiskymack]

Thanks for your input. I raised the concern because I am worried the RS700 hood won’t fit once I move the cab back into the standard R700 position (it is currently sitting in the standard R600 position). I really don’t want to have to fit the cab in a non-standard position given the holes in the chassis are pre-drilled for R600 and R700 positions. I know Australian R models have the same cab positions as Eastern USA models (because we originally imported the Eastern hoods from the USA for Australian models). However, I can’t work out whether Western cabs sit in the same spot on the chassis as Eastern (and therefore Australian) cabs.

I was first alarmed when I took a few measurements. My RS700 hood is about 22cms longer than the R600 hood that is currently on the truck. However, the distance between the pre-drilled holes on the chassis for R600 and R700 mounts is only 17.5cms. That means that the hood appears to be approx 4.5cm too long. Of course there are other things that may be relevant here. For example, firstly, I am told that the R700 mounts have a slight offset from the mounting bolts whereas the R600 mounts do not (although I am still waiting for the R700 mounts to arrive to confirm whether that is true). Secondly, the RS models mount on the radiator whereas my R600 mounts from the chassis.

I guess I will work it out in the end but was just hoping to find some comfort that the R and RS model cabs sit in the same spot on the chassis (despite having other differences such as height) before I take this much further. It could be that this project is too much problem. I am raising the cab height and preferred to use a RS hood because of the lower guards – so that the space between the tyres and guards doesn’t become excessive. However, it could be that the differences between R & RS models just make it not worth trying!!!

Any further input would definitely be welcomed. Thanks!!

Hi,

I checked my spec sheets and BBC for the RS700 was definately 117 which makes it two inches shorter than the R 700 at 119 inches.

Thge Australian Superliner has 91 inches from wheel centres to back of cab and 35.6 inches from bumper to wheel centres. Given that the bumper is set well forward of the hood, if you reduce this dimension to 28 inches which seems to be standard on US models pre frame mounted intercooling, you get 119 again.

My guess is you would be best off getting exact hood dimensions for an Australian R700, including how much clearance there is at the front for the intercooler and compare with your RS hood. Then you should know if it will fit or not.

By the way, if your main issue is that you want to reduce clearance between tyres and fenders then, as a last resort, perhaps a late model US R 700 hood could be your answer if the RS hood doesn't fit. From about the mid 70's the US R700 rode higher and the fenders were deeper. I have never seen one of these hoods on an Australian R 700.

Check this out:

[steve p]

mr black i'm in bris the 797 is work in progress ,more photos to come as work proceeds[time and money].superliner 1 used the 700 mount, superliner 2 used a fabricated mount that was taller,just remember mta was manufacturing parts to suit our conditions and needs so they are uniquely aus

[Mr Black]

Hi,

I checked my spec sheets and BBC for the RS700 was definately 117 which makes it two inches shorter than the R 700 at 119 inches.

Thge Australian Superliner has 91 inches from wheel centres to back of cab and 35.6 inches from bumper to wheel centres. Given that the bumper is set well forward of the hood, if you reduce this dimension to 28 inches which seems to be standard on US models pre frame mounted intercooling, you get 119 again.

My guess is you would be best off getting exact hood dimensions for an Australian R700, including how much clearance there is at the front for the intercooler and compare with your RS hood. Then you should know if it will fit or not.

By the way, if your main issue is that you want to reduce clearance between tyres and fenders then, as a last resort, perhaps a late model US R 700 hood could be your answer if the RS hood doesn't fit. From about the mid 70's the US R700 rode higher and the fenders were deeper. I have never seen one of these hoods on an Australian R 700.

Check this out:

Hi, thanks for this info – it is greatly appreciated. As I do the maths in my head, I don’t think the RS hood will work in the standard R700 cab position. When I get the chance to get back to the truck, I will work it out properly but it doesn’t sound promising.

Yes, my main concern is the height between the tyres and the fenders once I lift the cab up to a more modern height. The truck will be put to work once restored so I want it sitting up higher so it doesn’t look like a pumpkin truck. However, with the Oz hood, the space starts to become excessive as the fenders already sit quite high. The RS hood is the obvious answer to that problem but seems to create a number of other problems. Another solution would be to use a Series 1 Superliner hood (which, in Australia, will bolt straight on in the R700 position) but I would rather not stray too far from what the truck actually is – but I guess it is an option.

The picture of the R700 you sent looks great. I wonder if they made a version that would fit around the front mounted intercooler. Not sure if I want to go through the trouble and cost of importing another hood from the USA though!!

[Mr Black]

mr black i'm in bris the 797 is work in progress ,more photos to come as work proceeds[time and money].superliner 1 used the 700 mount, superliner 2 used a fabricated mount that was taller,just remember mta was manufacturing parts to suit our conditions and needs so they are uniquely aus

Hi Steve, yes definitely some differences between USA and MTA models. My thoughts were to get the cab in the R700 position and at the height I want it, and then just fabricate whatever is needed at the front to get the hood in the right position. However, I think the front mounted intercooler is going to be a project-killer.

Since you are in Brisbane, is there anyone you can recommend to do some of this work (ie. picking up the cab and moving into the R700 position)? I see that you do most of the work yourself so you may not know anyone. I have regular mechanics for our trucks but this is more within the domain of modification/fabrication.

Thanks

[steve p]

mr black the best way to deal with this issue is to give me a call and organize a time,it's too hard to do this by messages steve 0423524565

[Mr Black]

mr black the best way to deal with this issue is to give me a call and organize a time,it's too hard to do this by messages steve 04235245

Thanks Steve - sounds good. I will give you a call. Cheers