| Re: [GMCnet] 1970 Tiara with Toronado FWD Question about power train [message #344724] |
Mon, 01 July 2019 13:41  |
rallymaster
Messages: 662
Registered: February 2004
Location: North Plains, ORYGUN
Karma: -4
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Senior Member |
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Jim Kanomata in Newark, CA has replacement final drive units as low as
4.10:1.
https://www.gmcrvparts.com/category-s/149.htm
Applied GMC -
38424 Cedar Blvd Newark, CA 94560
Phone: 800-752-7502
Email: mail@appliedairfilters.com
RonC
On Mon, 01 Jul 2019 12:09:54 -0600 Matt Colie via Gmclist
writes:
> Rick Daley wrote on Mon, 01 July 2019 01:15
>> I have a 1970 Ultravan Tiara. It uses the same Toronado drive
> train that the GMC motorhomes use. My mechanic tells me the engine
> is in good
>> shape. The low cylinder shows 145 and the high cylinder shows 154
> in a recent compression check. My rig weighs 8,000 lbs which is
> heavy for a
>> Tiara. They were delivered at 6,500 lbs.
>>
>> I understand the 23 foot GMC motor home weighs 10,000 lbs and the
> 26 footer 12,000 lbs give or take a few lbs.
>>
>> I recently crawled over the Cascades on Washington Hwy 20 east and
> was routinely down to 20 mph with the vacuum gauge in the deep red.
> If my rig
>> weighed 12,000 lbs I am pretty sure I would still be on the other
> side of the Cascades.
>>
>> Can anyone give me some recommendations or some threads to pull on
> improving my rigs climbing performance? (I don't have a problem
> doing 70 on
>> the flat but usually keep it at 65 or below).
>>
>> Regards,
>>
>> Rick Daley
>
> Rick,
>
> The Ultravans that I have seen that were 455 were all fit with power
> directly removed from a Toronado. Most of the standard package had
> a 2.73 final
> drive, but the 3.07 (what was shipped in TZE) was from the trailer
> tow package, and it was wrong for the TZE that day. There are
> better available
> now.
>
> We have a 9460# 23' coach, and we crossed the Big Horn (the GPS
> reported 9200msl) on the way to Yellowstone with out any real
> issues. I expect any
> naturally aspirated engine to have not put out full power over
> 8000MSL.
>
> I fully agree that you may not be getting the secondaries open.
> When we open ours, the racket is unmistakable. If the carburetor is
> still the stock
> Rochester, then the secondaries are mechanical link. You can have
> someone step on the throttle and see if they do open fully. (The
> actual throttle,
> not the air valve.) If not, fix that before you do anything else.
>
> If you ever have to do engine work, we have people that can provide
> some important guidance.
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan
> OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
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>
Ron & Linda Clark
North Plains, ORYGUN
1978 Eleganza II
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Ron & Linda Clark
North Plains, ORYGUN
78 Eleganza II
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| Re: [GMCnet] 1970 Tiara with Toronado FWD Question about power train [message #344791 is a reply to message #344789] |
Tue, 02 July 2019 18:58  |
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Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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Rick Daley wrote on Tue, 02 July 2019 19:15Thanks Matt. Frequently when I put the pedal to the floor going up a steep slope at a slow speed, I get a back fire. I suspect that is abnormal for a Rochester. As to whether the secondaries open, I don't know but there doesn't seem to be any significant increase in noise - except for the backfire.
I am on my way to Yellowstone. I have been there before in this rig - came in from the east and left out the west side. I had no idea at the time that the elevation was nearly 8,000 feet. I weigh an additional 1,500 lbs now but I don't think that means anything more than I will be moving even slower than before.
Rick,
The backfire is not normal. You should be able to pull that. Given the year and driveline, the timing would be a definite question. It should do that if we did.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: [GMCnet] 1970 Tiara with Toronado FWD Question about power train [message #344799 is a reply to message #344791] |
Tue, 02 July 2019 19:56 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Pull the distributor cap and check the advance weights and springs. Also,
vacuum hoses to the vacuum advance on the distributor.
Jim Hupy
Salem, Oregon
On Tue, Jul 2, 2019, 5:27 PM Matt Colie via Gmclist
wrote:
> Rick Daley wrote on Tue, 02 July 2019 19:15
>> Thanks Matt. Frequently when I put the pedal to the floor going up a
> steep slope at a slow speed, I get a back fire. I suspect that is abnormal
>> for a Rochester. As to whether the secondaries open, I don't know but
> there doesn't seem to be any significant increase in noise - except for the
>> backfire.
>>
>> I am on my way to Yellowstone. I have been there before in this rig -
> came in from the east and left out the west side. I had no idea at the
>> time that the elevation was nearly 8,000 feet. I weigh an additional
> 1,500 lbs now but I don't think that means anything more than I will be
> moving
>> even slower than before.
>
> Rick,
>
> The backfire is not normal. You should be able to pull that. Given the
> year and driveline, the timing would be a definite question. It should do
> that if we did.
>
> Matt
> --
> Matt & Mary Colie - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
> Electronically Controlled Quiet Engine Cooling Fan
> OE Rear Drum Brakes with Applied Control Arms
> SE Michigan - Twixt A2 and Detroit
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
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| Re: [GMCnet] 1970 Tiara with Toronado FWD Question about power train [message #344826 is a reply to message #344791] |
Wed, 03 July 2019 11:19 |
Rick Daley
Messages: 4
Registered: June 2019
Karma: 0
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Junior Member |
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Jim,
It has electronic ignition.
I am out in the wilds of north east Washington at the moment, here until after the 4th. I will see if I can get someone to look at the carb and ignition issues when I get back to civilization. I certainly have not been getting an increased noise level when I open the throttle all the way - just a downshift and an occasional backfire. The backfire isn't common or predictable.
Is there an available on-line article or discussion about the benefits of changing the final gear ratio? I would like to better understand the issues.
Rick Daley
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