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Top speed for a 1978 24'er? Newbie interested.
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Picture of GirlsInPantsTour
posted
Hi,
We are on the hunt for a Barth as i think they are amazing to look at.
Since they are hard to find I have been searching all over the country. A man in Port Townsend said top speed was 55 and cruises best at 55. not meant to go over that. We would have to drive it nearly 2000 miles back to Northern Illinois.
Guess that isn't a good idea?!!!
Any help or info appreciated. This one had a 454. He is asking $12k
Thank you
 
Posts: 10 | Location: Illinois | Member Since: 05-28-2017Reply With QuoteReport This Post
Picture of GirlsInPantsTour
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sorry he said cruises best at 50mph
 
Posts: 10 | Location: Illinois | Member Since: 05-28-2017Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 12/12
Picture of Lee
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My '78-24' had a sweet spot of about 64mph, when everything sounded just right. Beyond that it was victim of the
bow wave and Mpg suffered. Keep in mind that many classic
RVs were built in the era of the national 55mph limit, and power tran combos may have been designed for that.

For planning purposes, I'd estimate about 8-9 mpg with the
454 cid/TH400 tranny combo, uphill/downhill, empty/loaded, sea level/mountains, summer/winter. A larger diameter fuel
line will probably decrease mpg☹️
 
Posts: 1403 | Location: Frederick, Maryland | Member Since: 09-12-2003Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 7/17
Picture of Mogan David
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The Barth in question probably does have an optimal cruising speed of 55 mph. However, it ought to be CAPABLE of exceeding that.
According to Wikipedia, For 13 years (January 1974[1]–April 1987[2][3]), federal law withheld Federal highway trust funds to states that had speed limits above 55 mph.

The engineer types here might know for sure...
I suppose that, during the oil embargo and double nickel speed limits, manufacturers geared and tuned vehicles accordingly.

My Breakaway, with 190hp 5.9L Cummins, seemed to cruise best @ 62 mph. Sadly, it would not go much faster than that. Later Barth diesel pushers, with newer/better transmissions, can be expected to have somewhat higher cruising and max speeds.
IMHO
 
Posts: 1891 | Location: Jackson, Michigan, USA | Member Since: 04-18-2004Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 7/17
Picture of Steve VW
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As usual, no easy answer... hmm

Motorhome handling varies a lot from one brand to another and even from one model to another. Generally, longer is better as long as the rear overhang is not too long. Tag axles are great.

We are making several assumptions:

Tires are properly inflated, balanced and in good condition. Front end is tight, alignment correct.
Ujoints are good, drive shaft is in balance
Shock absorbers good.
Chassis is level front to back.
Brakes good.

The rest depends on tire size, rear axle ratio and how fast you want to spin your engine. The shorter coaches are often around 4.10 ratio, while the larger ones like my 86 are often 4.58 ratio. With the 4.58 ratio you will see around 3000 rpm at 60 mph, fairly fast for big block. That is where I run my 86. It will easily run 75-80+ but will be turning like 4000 rpm.

The 4.10 axle will drop engine rpm about 10% so 60 mph is more like 2700 rpm.

A lot depends on driveline noise and vibration. You will often find a sweet spot as mentioned, where it seems smooth and mileage is reasonble.

So IF your coach handles well at a particular speed, smooth and steady, vibration is acceptable, fuel/oil consumption OK then run it. Tooling Along


8607-3346-33TFPOB------9708-M0037-37MM-01
86 Regal SE 33 Tag axle--"98" Monarch 37
Chev P3(7) 454TBI--------Cummins 8.3 300 hp
400 hp fuel injected-------6 spd Allison, Spartan MM
 
Posts: 3217 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 12/10
Picture of ccctimtation
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This one?https://olympic.craigslist.org/rvs/6130872296.html
I think the top speed will exceed your desire to be aboard. I had a 1976 GMC 3500, essentially the same drive train and it would exceed the speedometer limit, less frontal area but probably the same drive train, a robust, not quite bullet proof. Just
Recommendations from that experience:
1. Change oil frequently after initial purchase.
2. Change transmission fluid and filter every 5000 miles for the first two or three times.
3. Change the differential fluid immediately.
4. Change the coolant and make sure it is the right type.
5. Replace all tires unless they are under 5 years or 7 years if you are taking it home in freezing temps.

Whereas cars of this age were normally geared for 3000rpm=72mph this vehicle is probably closer to 60 at 3000. Now we are used to lots of gears and 70=~2000 engines will spin the 3K just noisier and thirstier.
Look at and print off the buyer's inspection list.
Good luck,
Tim


I was taught to respect my elders but it is getting harder to find them!
 
Posts: 725 | Location: St. Charles, MO, USA | Member Since: 10-09-2003Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 2/16
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My '75 will do at least 85 and I have a witness!!!! Smiler

When son David and I went to pick up said '75 and finally got out of Indianapolis and got on the expressway I looked at the speedo and it was at 87 miles per hour with no more noise than normal, handling was fine and the 454 was not in a strain. Since the speed limit was not 85 I slowed down but I would not recommend this speed.


Mary

Don't mess with us old folks, we don't get old by being stupid!
1968 Barth trailer, 1975 Barth Motorhome and 1985 Barth Motorhome

 
Posts: 1622 | Location: Obion, TN/Memphis, TN | Member Since: 11-23-2004Reply With QuoteReport This Post
Picture of GirlsInPantsTour
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Mary,
I got a kick out of that. :-)
We are thinking that we will just be patient and see if one comes for sale closer to home.

Seems too risky to spend $12k and not really know what we are traveling cross county in.

Thanks everyone for their input.

P.S. I am not good at being patient and really want a nice 19-24'.
 
Posts: 10 | Location: Illinois | Member Since: 05-28-2017Reply With QuoteReport This Post
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Picture of Steve VW
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Wise to shop around. Some are more "turn key" than others. A close inspection is always good when dealing with old machinery.

Good luck. Thumbs Up


8607-3346-33TFPOB------9708-M0037-37MM-01
86 Regal SE 33 Tag axle--"98" Monarch 37
Chev P3(7) 454TBI--------Cummins 8.3 300 hp
400 hp fuel injected-------6 spd Allison, Spartan MM
 
Posts: 3217 | Location: Kalkaska, MI | Member Since: 02-04-2011Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 12/10
Picture of ccctimtation
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This could be a waste of time with potential for education. There have been quite a few coaches sold on this site and some may be ready for new owners. This would give a bit of history telling when it was documented to be in some type of condition. Examples would be http://tinyurl.com/Mackscreek
And
http://tinyurl.com/85Regal
Good luck, Tim


I was taught to respect my elders but it is getting harder to find them!
 
Posts: 725 | Location: St. Charles, MO, USA | Member Since: 10-09-2003Reply With QuoteReport This Post
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My 86 cruises just fine at 70. RPMS around 3200. Of course mileage isn't so good but I've been averaging about 7.5 for our trip thus far over 4000 miles, some generator use when running, ac on 80% of the time and a motorcycle on the back. I did hit the low 80mph range for a spell trying to get clear of some traffic but I wouldn't recommend driving that speed all that long.
 
Posts: 145 | Location: Lancaster, PA | Member Since: 09-06-2016Reply With QuoteReport This Post
Picture of Crazyshakespeare13
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I have a 1974 26' foot that have a hard time even getting to the 50 mph mark....from the speeds posted above I'm guessing I might have an issue?
 
Posts: 41 | Location: Ft. Worth | Member Since: 01-02-2014Reply With QuoteReport This Post
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Picture of Kevin
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Hey Shakespeare,

Don't worry 50 miles per hour is a good safe speed. After all the National was 55 for years.
 
Posts: 2562 | Location: Northeast , Ohio | Member Since: 07-29-2012Reply With QuoteReport This Post
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Captain Doom
Picture of Rusty
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I'd check the timing and the centrifugal and vacuum advance if the engine is running smoothly.


Rusty


MilSpec AMG 6.5L TD 230HP; built-to-order by Peninsular Engines:  Hi-pop injectors, gear-driven camshaft, non-waste-gated, high-output turbo, 18:1 pistons.  Fuel economy increased by 15-20%, power, WOW!"StaRV II"

'94 28' Breakaway: MilSpec AMG 6.5L TD 230HP

Nelson and Chester, not-spoiled Golden Retrievers

Sometimes I think we're alone in the universe, and sometimes I think we're not.
In either case the idea is quite staggering.
- Arthur C. Clarke

It was a woman who drove me to drink, and I've been searching thirty years to find her and thank her - W. C. Fields
 
Posts: 8200 | Location: Brooker, FL, USA | Member Since: 09-08-2005Reply With QuoteReport This Post
Supporting Member of Barthmobile.com 7/17
Picture of Mogan David
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quote:
Originally posted by Crazyshakespeare13:
I have a 1974 26' foot that have a hard time even getting to the 50 mph mark....from the speeds posted above I'm guessing I might have an issue?


Yes, indeed.
other possibilities include very dirty air filter and/or fuel filter, damaged or otherwise-clogged exhaust, very bad spark plugs.
 
Posts: 1891 | Location: Jackson, Michigan, USA | Member Since: 04-18-2004Reply With QuoteReport This Post
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