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Trip Report [message #171029] Sun, 27 May 2012 21:51 Go to next message
Jon payne is currently offline  Jon payne   United States
Messages: 495
Registered: May 2008
Karma: 1
Senior Member
First, thanks to all of those who responded to my post about the Onan. I am going to take a closer look at the field winding terminal ends.

Just came back from a short trip, 120 miles, to a local state park, Turkey Run. This is the first drive over 5 miles since the install of the Rockwell Aluminum Intake so I was anxious to see how it performed after a good heat soak.

We started out this morning, OAT around 85 degs and I noticed I could not reach 60 mph easily. In fact to do so I really had to open the throttle. Normally I can easily cruise 70 MPH. but today it required a lot of throttle to reach 60 and noticed too the engine temp would rise. As I backed off the throttler and reduced speed to 55 MPH the temp would drop to near normal. Normal temp the gauge reads about a third between the 1/4 mark and the 1/2 mark on the gauge. When I would reach 60 or so temps would rise to the 1/2 mark. As I slowed down to 40 or less, like going through a town the temps would return to "normal".

I am thinking that I have a timing issue. When I replaced the intake I removed the distributor and perhaps I did not get the timing right. At the time I was certain I timed it to 8deg TDC but maybe I was on the 4deg mark instead. Could this be the reason for the lack of power? I'm also thinking the mechanical advance could be stuck. Does this sound like a possibility? Note that the distributor is a Dick Patterson that I installed three years ago.

There was another issue I was experiencing. When stopping at a light then accelerating, the engine would hesitate, pop, hesitate, pop several times. I know this could be related to heat but I never experienced it this bad with the cast iron manifold. Could it be related to the first problem?

To summarize, could the lack of power be due to improper timing or a stuck mechanical advance?

Does the hesitation and popping I described sound like a heat issue or could it be related to the timing issue?

What about the high engine temp? I am thinking that if the timing is not correct or the mechanical advanced is stuck, the increase throttle is cause the engine temp to increase.

Thank you all in advance!

Jon


Jon Payne
76 Palm Beach
Westfield,IN
Re: Trip Report [message #171031 is a reply to message #171029] Sun, 27 May 2012 22:08 Go to previous messageGo to next message
Dennis S is currently offline  Dennis S   United States
Messages: 3046
Registered: November 2005
Karma: 2
Senior Member
Jon,

Yes, retarded timing can cause loss of power and higher engine temperatures. A stuck mechanical advance or failed vacuum advance could both be contributing.
When you set you timing, remember to plug the vaeuum line to the distributor advance.

Dennis

Jon Payne wrote on Sun, 27 May 2012 21:51

First, thanks to all of those who responded to my post about the Onan. I am going to take a closer look at the field winding terminal ends.

Just came back from a short trip, 120 miles, to a local state park, Turkey Run. This is the first drive over 5 miles since the install of the Rockwell Aluminum Intake so I was anxious to see how it performed after a good heat soak.

We started out this morning, OAT around 85 degs and I noticed I could not reach 60 mph easily. In fact to do so I really had to open the throttle. Normally I can easily cruise 70 MPH. but today it required a lot of throttle to reach 60 and noticed too the engine temp would rise. As I backed off the throttler and reduced speed to 55 MPH the temp would drop to near normal. Normal temp the gauge reads about a third between the 1/4 mark and the 1/2 mark on the gauge. When I would reach 60 or so temps would rise to the 1/2 mark. As I slowed down to 40 or less, like going through a town the temps would return to "normal".

I am thinking that I have a timing issue. When I replaced the intake I removed the distributor and perhaps I did not get the timing right. At the time I was certain I timed it to 8deg TDC but maybe I was on the 4deg mark instead. Could this be the reason for the lack of power? I'm also thinking the mechanical advance could be stuck. Does this sound like a possibility? Note that the distributor is a Dick Patterson that I installed three years ago.

There was another issue I was experiencing. When stopping at a light then accelerating, the engine would hesitate, pop, hesitate, pop several times. I know this could be related to heat but I never experienced it this bad with the cast iron manifold. Could it be related to the first problem?

To summarize, could the lack of power be due to improper timing or a stuck mechanical advance?

Does the hesitation and popping I described sound like a heat issue or could it be related to the timing issue?

What about the high engine temp? I am thinking that if the timing is not correct or the mechanical advanced is stuck, the increase throttle is cause the engine temp to increase.

Thank you all in advance!

Jon



Dennis S
73 Painted Desert 230
Memphis TN Metro
Re: Trip Report [message #171033 is a reply to message #171029] Sun, 27 May 2012 22:15 Go to previous messageGo to next message
Bob de Kruyff   United States
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
Senior Member
Jon Payne wrote on Sun, 27 May 2012 20:51

First, thanks to all of those who responded to my post about the Onan. I am going to take a closer look at the field winding terminal ends.

Just came back from a short trip, 120 miles, to a local state park, Turkey Run. This is the first drive over 5 miles since the install of the Rockwell Aluminum Intake so I was anxious to see how it performed after a good heat soak.

We started out this morning, OAT around 85 degs and I noticed I could not reach 60 mph easily. In fact to do so I really had to open the throttle. Normally I can easily cruise 70 MPH. but today it required a lot of throttle to reach 60 and noticed too the engine temp would rise. As I backed off the throttler and reduced speed to 55 MPH the temp would drop to near normal. Normal temp the gauge reads about a third between the 1/4 mark and the 1/2 mark on the gauge. When I would reach 60 or so temps would rise to the 1/2 mark. As I slowed down to 40 or less, like going through a town the temps would return to "normal".

I am thinking that I have a timing issue. When I replaced the intake I removed the distributor and perhaps I did not get the timing right. At the time I was certain I timed it to 8deg TDC but maybe I was on the 4deg mark instead. Could this be the reason for the lack of power? I'm also thinking the mechanical advance could be stuck. Does this sound like a possibility? Note that the distributor is a Dick Patterson that I installed three years ago.

There was another issue I was experiencing. When stopping at a light then accelerating, the engine would hesitate, pop, hesitate, pop several times. I know this could be related to heat but I never experienced it this bad with the cast iron manifold. Could it be related to the first problem?

To summarize, could the lack of power be due to improper timing or a stuck mechanical advance?

Does the hesitation and popping I described sound like a heat issue or could it be related to the timing issue?

What about the high engine temp? I am thinking that if the timing is not correct or the mechanical advanced is stuck, the increase throttle is cause the engine temp to increase.

Thank you all in advance!

Jon

It definitely could be timing but I'm suspecting a massive vacuum leak due to intake manifold issues that many have experienced.


Bob de Kruyff
78 Eleganza
Chandler, AZ
Re: [GMCnet] Trip Report [message #171048 is a reply to message #171029] Mon, 28 May 2012 04:13 Go to previous messageGo to next message
USAussie is currently offline  USAussie   United States
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
Senior Member
Jon,

I've got one of Dick's dizzie's (Australian for distributor) in Double
Trouble; the sheet that came with is noted to set the initial timing at 12°
@ idle (600 rpm).

Here's a link to a photo of the sheet that came with it.

http://www.gmcmhphotos.com/photos/member-galleries/p32021-dick-paterson-s-di
stri.html

Pull the dizzie cap off and check / lube the mechanical advance pivot points
with a modicum of Synpower grease then hook up your timing light and set the
timing as per the sheet that came with your distributor.

Regards,
Rob M.
 

-----Original Message-----
From: Jon Payne

First, thanks to all of those who responded to my post about the Onan. I am
going to take a closer look at the field winding terminal ends.

Just came back from a short trip, 120 miles, to a local state park, Turkey
Run. This is the first drive over 5 miles since the install of the Rockwell
Aluminum Intake so I was anxious to see how it performed after a good heat
soak.

We started out this morning, OAT around 85 degs and I noticed I could not
reach 60 mph easily. In fact to do so I really had to open the throttle.
Normally I can easily cruise 70 MPH. but today it required a lot of throttle
to reach 60 and noticed too the engine temp would rise. As I backed off the
throttler and reduced speed to 55 MPH the temp would drop to near normal.
Normal temp the gauge reads about a third between the 1/4 mark and the 1/2
mark on the gauge. When I would reach 60 or so temps would rise to the 1/2
mark. As I slowed down to 40 or less, like going through a town the temps
would return to "normal".

I am thinking that I have a timing issue. When I replaced the intake I
removed the distributor and perhaps I did not get the timing right. At the
time I was certain I timed it to 8deg TDC but maybe I was on the 4deg mark
instead. Could this be the reason for the lack of power? I'm also thinking
the mechanical advance could be stuck. Does this sound like a possibility?
Note that the distributor is a Dick Patterson that I installed three years
ago.

There was another issue I was experiencing. When stopping at a light then
accelerating, the engine would hesitate, pop, hesitate, pop several times. I
know this could be related to heat but I never experienced it this bad with
the cast iron manifold. Could it be related to the first problem?

To summarize, could the lack of power be due to improper timing or a stuck
mechanical advance?

Does the hesitation and popping I described sound like a heat issue or could
it be related to the timing issue?

What about the high engine temp? I am thinking that if the timing is not
correct or the mechanical advanced is stuck, the increase throttle is cause
the engine temp to increase.

Thank you all in advance!

Jon

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Regards, Rob M. (USAussie) The Pedantic Mechanic Sydney, Australia '75 Avion - AUS - The Blue Streak TZE365V100428 '75 Avion - USA - Double Trouble TZE365V100426
Re: Trip Report [message #171219 is a reply to message #171029] Tue, 29 May 2012 10:18 Go to previous messageGo to next message
Jon payne is currently offline  Jon payne   United States
Messages: 495
Registered: May 2008
Karma: 1
Senior Member
Guys,

Looks like I found the cause of the lack of power during cruise which I was not able to go much more the 60MPH without having my foot to the floor. As you will see the brake booster vacuum line is split at the manifold fitting. When I replaced the intake I was going to replace this hose but when I went the the local parts stores, neither Autozone or NAPA had hoses with right wall thickness. I think NAPA said they could order one but I need to check with them again.

Does anyone have a source for this vacuum hose?

http://www.gmcmhphotos.com/photos/misc/p44337-vacuum-leak.html

Jon


Jon Payne
76 Palm Beach
Westfield,IN
Re: [GMCnet] Trip Report [message #171222 is a reply to message #171219] Tue, 29 May 2012 10:34 Go to previous messageGo to next message
jhbridges is currently offline  jhbridges   United States
Messages: 8412
Registered: May 2011
Location: Braselton ga
Karma: -74
Senior Member
I buy it off the local parts house (Slack Auto Parts, been there since 1928).  I'll go look on the hose if you want, but it's standard stuff.
 
--johnny
'76 23' transmode norris
'76 palm beach

From: Jon Payne <embrep@sbcglobal.net>
To: gmclist@temp.gmcnet.org
Sent: Tuesday, May 29, 2012 11:18 AM
Subject: Re: [GMCnet] Trip Report



Guys,

Looks like I found the cause of the lack of power during cruise which I was not able to go much more the 60MPH without having my foot to the floor. As you will see the brake booster vacuum line is split at the manifold fitting.  When I replaced the intake I was going to replace this hose but when I went the the local parts stores, neither Autozone or NAPA had hoses with right wall thickness. I think NAPA said they could order one but I need to check with them again.

Does anyone have a source for this vacuum hose?

http://www.gmcmhphotos.com/photos/misc/p44337-vacuum-leak.html

Jon
--
Jon Payne                                 
76 Palm Beach                         
Westfield,IN
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Foolish Carriage, 76 26' Eleganza(?) with beaucoup mods and add - ons. Braselton, Ga. I forgive them all, save those who hurt the dogs. They must answer to me in hell
Re: Trip Report [message #171223 is a reply to message #171219] Tue, 29 May 2012 10:38 Go to previous message
roy1 is currently offline  roy1   United States
Messages: 2126
Registered: July 2004
Location: Minden nevada
Karma: 6
Senior Member
Jon Payne wrote on Tue, 29 May 2012 08:18

Guys,

Looks like I found the cause of the lack of power during cruise which I was not able to go much more the 60MPH without having my foot to the floor. As you will see the brake booster vacuum line is split at the manifold fitting. When I replaced the intake I was going to replace this hose but when I went the the local parts stores, neither Autozone or NAPA had hoses with right wall thickness. I think NAPA said they could order one but I need to check with them again.

Does anyone have a source for this vacuum hose?

http://www.gmcmhphotos.com/photos/misc/p44337-vacuum-leak.html

Jon


Napa is a good choice. Those thick vacuum hoses usually last a long time. that would be why the auto supply places don't stock them. If you are close to a pick ur part or similar wrecking yard there should be some available .


Roy Keen Minden,NV 76 X Glenbrook
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