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Guessing at 6-8 inches!

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I would like a real measurement of an R700 hood.

The pictures I have found are confusing, some make look like the difference is only 4", some look like 6" and some look really long unless there are different length hoods?

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Those are sweet dimensions. Do you have those drawings for a 1995 rd688s? 228" wheelbase? Does Canadian spread tandem have the same turning radius as the closer set American tandem with same wheelbase?

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Looks like 12 in difference to me according to drawing

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Let me toss a handful of dirt a question in the ring - do you relate R600 and R700 Eastern R-model hoods? From what is written above looks like you do that. But I'm pretty sure the measurments of RS600 and RS/RL700 Western Valueliners would differ.

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I found in my copybook a figure of 54-1/4 length of after '82 Eastern R-model hood. I remember I checked out the one on my R688ST of 1988 and it was to that size. So Keith's figure is the same dimintion, just with 1/4" difference due to the particular hood or the particular measuring band (I once got such issue with 2 different bends:))

Also I see a figure of 53-3/8" for a pre-82 Eastern R hood. It was in series before the chassis mounted after cooler took place.

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On 12/30/2018 at 4:10 PM, JoeH said:

Those are sweet dimensions. Do you have those drawings for a 1995 rd688s? 228" wheelbase? Does Canadian spread tandem have the same turning radius as the closer set American tandem with same wheelbase?

I don't have a 1995.  The link is for a 2002 RD with a 210" wb. It is as close as I have.  The 2002 spec sheet doesn't list the turning radius.

All else being equal, I believe the US and Canadian spread would have the same turning radius because the 228" wb is at the center of the suspension for both examples.

https://www.bigmacktrucks.com/tutorials/article/214-2002-mack-rd600-dimensions/

 

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The blue 86 RD688 hood differs from my 85 RS688LST

6a1b5aa52a53a1a51bd0fe6bdd557070.jpg

08d2412c9e90f831cb7474fbc319bc73.jpg

My real goal is to find out how much longer a RS712LST hood is than my 85 RS688LST

I have been thinking about turning this truck

6899ff8a6447427522da606a8b807420.jpg

Into a close copy of this truck

6e49c1b5032dea3eb56707c6b1f6daef.jpg

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The blue 86 RD688 hood differs from my 85 RS688LST

6a1b5aa52a53a1a51bd0fe6bdd557070.jpg

08d2412c9e90f831cb7474fbc319bc73.jpg

My real goal is to find out how much longer a RS712LST hood is than my 85 RS688LST

I have been thinking about turning this truck

6899ff8a6447427522da606a8b807420.jpg

Into a close copy of this truck

6e49c1b5032dea3eb56707c6b1f6daef.jpg

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10 hours ago, Quickfarms said:

The blue 86 RD688 hood differs from my 85 RS688LST



My real goal is to find out how much longer a RS712LST hood is than my 85 RS688LST

I have been thinking about turning this truck

6899ff8a6447427522da606a8b807420.jpg

Into a close copy of this truck

6e49c1b5032dea3eb56707c6b1f6daef.jpg

That's why I pointed out the difference knowing you have Western R which is almost a different story to East one along the hood, frame rails, front spring hangers etc.

Of possibilities to make RS700 of RS600 you can note the position of the front cab support brackets on these two pictures you posted. Looks like the spring hangers together with battery boxes and air tanks are positioned the same. But for the longer hood the cab is moved backwards. So the mounting points on RS700 are close to the rear edge of the battery box cover and RS600 has them near the front edge. To move the cab you would probably need those brackets themself (But they might be the same), move the rear cab support cross member, put new cab floor panel with a different hole for the shift lever, that lever as it's different, make the steering shaft longer (or different?) and so on. Probably could be done having a correct hood but not a one day work. And sure worth some extra investigation on a subject of purchasing a solid RS700 truck instead.

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Those 1.75 inches is an interesting point. That means you can't use RS700 hood combined with CMAC. At least without modifications.

Alastair, a pleasure to deal with your technical knowledges about Mack design. I too appreciate such approach in modelbuiding.

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Now to add to the confusion

 

The hood on my 1975 RS685LT and my 1985 RS688LST both measure 54.25" and the distance from the grill to back if can on both trucks is 105"

 

The 1975 hood is a flat top

 

The 1985 hood has the raised center

 

The 1985 RS688LST has the air to air after cooler mounted in front of the radiator

 

The 1975 was built in Hayward

 

The 1975 was built in Allentown

 

 

 

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On 1/5/2019 at 5:40 AM, Quickfarms said:

Now to add to the confusion

 

The hood on my 1975 RS685LT and my 1985 RS688LST both measure 54.25" and the distance from the grill to back if can on both trucks is 105"

 

The 1975 hood is a flat top

 

The 1985 hood has the raised center

 

The 1985 RS688LST has the air to air after cooler mounted in front of the radiator

 

The 1975 was built in Hayward

 

The 1975 was built in Allentown

 

 

 

That does add to the confusion!

But there may still be an explanation......

I think your last line was meant to be 'The 1985 was built in Allentown'.

This would make sense because I believe Hayward closed in the early 1980's and all production of Hayward models was transferred east.

The hood ridge appeared roughly about the time the RS600L got the Value-liner moniker but can also be found on some very late model RS700's.

I have also seen it on a few metal dash RS700's so I imagine that replacement hoods from about 1978 also had this ridge. I think the ridge may had served as a strengthening rib but I'm not sure.

As regards the fact that the hoods and BBC seem to be the same on both your trucks despite the spec sheet dimensions saying otherwise, this is my best guess:

On RS700's, pre Value-Liner RS600's and first Generation Super-Liners the back edge of the hood comes right up to the outer edge of the cowl and you often see paint/hood chips on older trucks. On later 1980's models there is often a gap between the back end of the hood and the outer edge of the cowl. I would say this gap is about an inch but I don't know if it is as much as 1.75. I always imagined this gap was to stop the hood and cowl bashing together on trucks with air ride cabs but maybe it killed two birds with one stone by moving the hood forward a bit to make space for the rad mounted intercooler. Just a guess though.

You could try measuring from the bumper to the back of the cab as I think hoods tend to move around a bit as well. 

 

 

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I have a '78 rs712 long frame with neway air ride if your interested Quickfarms.

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I have a '78 rs712 long frame with neway air ride if your interested Quickfarms.


Where is it located and what are the specs and how about some pictures

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It measures 246" from center of the front axle to the center of the back axle. It has been stretched 25" and could easily be put back to the original length. It is a single frame except where it was gloved in the rear. The thickness is a 1/4", has round housings with no carriers. I would like to keep the fuel tanks. Asking 1200.00 located in Wheatland Nd. 701-730-4577 Mark

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It measures 246" from center of the front axle to the center of the back axle. It has been stretched 25" and could easily be put back to the original length. It is a single frame except where it was gloved in the rear. The thickness is a 1/4", has round housings with no carriers. I would like to keep the fuel tanks. Asking 1200.00 located in Wheatland Nd. 701-730-4577 Mark
image.jpeg.84317bac72f29ac4cf0233b28a035396.jpeg
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Thanks for the offer but it would be a little hard to get to my place in Southern California and it is a bit more of a project than I currently have the time for.
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