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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sat Aug 25, 2018 7:31 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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@wildthings, what are you thinking? |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50353
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Posted: Sat Aug 25, 2018 8:42 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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hylomatt wrote: |
@wildthings, what are you thinking? |
If you have decent oil pressure at hot idle I am thinking that your relief spring is weak. |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sat Aug 25, 2018 9:00 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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@wildthings, what makes you think that the relief spring might be weak? Explain so I can learn from this please. From reading the Bentley, that spring is supposed to maintain pressure in the system and in relieving pressure, it lets oil return to the sump.
While I was checking out all the gauges, before my test drive, and readjusting my timing per some previous messages in this thread, I noticed that the oil light was on. So I shut everything down, removed the new sensor, went back to the old basic sensor and let the bus run for another 15 minutes and didn't have any problems with the lights. So I went ahead and put the temperature sensor back in and then I did my test driving.
Also, for the relief and control springs, I was looking in the Bentley at the specifications and was wondering how do I test those? Do I set it on a bathroom scale and press down until it's fully loaded? |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50353
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Posted: Sat Aug 25, 2018 9:41 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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hylomatt wrote: |
@wildthings, what makes you think that the relief spring might be weak? Explain so I can learn from this please. From reading the Bentley, that spring is supposed to maintain pressure in the system and in relieving pressure, it lets oil return to the sump.
While I was checking out all the gauges, before my test drive, and readjusting my timing per some previous messages in this thread, I noticed that the oil light was on. So I shut everything down, removed the new sensor, went back to the old basic sensor and let the bus run for another 15 minutes and didn't have any problems with the lights. So I went ahead and put the temperature sensor back in and then I did my test driving.
Also, for the relief and control springs, I was looking in the Bentley at the specifications and was wondering how do I test those? Do I set it on a bathroom scale and press down until it's fully loaded? |
SGKent posted a way to test them using a bathroom scale a month or two ago. A search should turn it up.
Good pressure at hot idle would indicate to me that the problem is probably not the oil pump or the bearings. |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sat Aug 25, 2018 9:53 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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Quote: |
74F
65mph
30psi (oil)
180F (oil)
3600 rpm
19:42 |
Pressure is low by 10 PSI. 10w30 should be fine at that temp. This is a type 1 motor and if the sender is screwed into the case then it should have a good ground. If you have it on a hose you have to run a ground wire to the strap that holds it to get an accurate reading How many miles on the case and engine?
I dib't know if the springs are weak but the two pistons may be worn and leaking oil around them. The tops get pretty banged up after tens of thousands of cycles on and off. If you had a constant PSI that was low it could be a spring but the falling PSI with RPM looks to be basic oil pressure unless the sender has a bad ground.
One thing you really should look at if you haven't is the oil pump. There are two gaskets on the pump. The first, between the pump and case you can leave alone. Don't need to pull the pump out either. But if you don't know the condition of the plate, you need to look at it and either sand it smooth or replace it if it is worn by the pump gears which happens over time. Also many new engine builders use the wrong gasket between the pump and cover. The very thin one is the one to use. It sets the end play between the pump gears and cover. If the thick gasket is used then the end play is too great and the oil pressure will be low. _________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 5:31 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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@SGKent, the case has approx 2k miles on it. The crankshaft, camshaft and maybe some other parts like rockers and pushrods might be the original items, but the oil pump gears and the cover were replaced. The two oil springs and plungers might still be original.
The original case was cracked in one of the lifter bores so I purchased a brand new Universal case and most of the parts made it from the old engine into the new one except for the ones I mentioned above. |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 6:41 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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Two photos of the engine:
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KentABQ Samba Member
Joined: September 11, 2016 Posts: 2406 Location: Albuquerque NM
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Posted: Sun Aug 26, 2018 7:01 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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I'm not familiar with type 1 engines.... but DAYUM! That looks good!
Edit: And I see you even have the correct type 1 Burger King coffee cup _________________ -Kent-
1976 Riviera, 1.8l FI chrome yellow VAN - "Chloe"
"I must say, how can you be in a bad mood driving this vehicle full of vibrant color.
Cars of today are so bland in comparison. It's like driving a celebration!" ---WildIdea
Bus ownership via emoticons:
---williamM
Last edited by KentABQ on Sun Aug 26, 2018 7:18 am; edited 1 time in total |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 7:07 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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@KentPS, thanks man! I'm picky about details so I like to get things right and complete. |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 7:26 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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okay I pulled both springs to have a look at them and try and test their load pressure as well as just measure their unloaded length.
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 9:56 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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Okay so I measured the springs and they're pressure at loaded length.
Pressure control spring
At 13/16 loaded length, it was 4+ pounds
Adjusted between 6.8-8.4 lbs to be approx 7.5 lbs
Pressure relief spring
At 1-3/4 it was just hitting 12 lbs
Adjusted between 12.3-16 lbs to be approx 14.5 lbs
I sat for about 20 minutes with the car idling and once everything got real nice and hot the oil light flickered once in awhile but it didn't come on solid like last time so I think it was good to stretch out the oil relief spring but I need to go a little further. I can tell that the pressure is up though. |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50353
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Posted: Sun Aug 26, 2018 10:20 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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If the pressure is low at idle it would be other things besides the spring as the spring wouldn't have an effect until the pressure rises.
Bearings, oil pump, and the slop of the relief pistons in their bores cause low oil pressure at idle.
Depending on your pump you can often leave the thin gasket out and just use sealant on the cover. You need to check the actual end play of your pump using a straight edge and feeler gauge.
If the relief bores are worn you can get an over sized piston and rent a tool to rework the bore.
If the bearings are loose run thicker oil or go to a larger pump and put up with the heat. |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 10:33 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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@wildthings, the modification to the relief spring has definitely improved oil pressure at 4000 RPM. It's right at 40 or just a hair under.
As far as low pressure at idle, are you talking about if it makes the original idiot light flicker? Or do I need a more specific gauge?
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 10:35 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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This is a brand-new Universal case but old relief plungers, brand new bearings, although every time I swap out the oil which I've done probably 4 maybe 5 times since the engine was rebuilt about 2k, maybe 2500 miles ago, I see swirls in the oil. Never anything chunky but I do see swirls. |
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TomWesty Samba Member
Joined: November 23, 2007 Posts: 3482 Location: Wyoming,USA
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Posted: Sun Aug 26, 2018 10:46 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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On my zero mile engine, I stopped seeing swirls after the first oil drop. Just relating my experience, can’t say if you have trouble or not. _________________ If you haven't bled on them, you haven't worked on them.
Visit: www.tomcoryell.com and check out my music! |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50353
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Posted: Sun Aug 26, 2018 10:56 am Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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hylomatt wrote: |
@wildthings, the modification to the relief spring has definitely improved oil pressure at 4000 RPM. It's right at 40 or just a hair under.
As far as low pressure at idle, are you talking about if it makes the original idiot light flicker? Or do I need a more specific gauge?
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Glad that the pressure went up at higher RPM's that makes for a good data point.
You gauge may not be accurate enough to say what your pressure actually is at idle, but the 5psi it is showing would be low in my book. Do pull the cover off the pump and check the end play for the gears. |
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SGKent Samba Member
Joined: October 30, 2007 Posts: 41031 Location: Citrus Heights CA (Near Sacramento)
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Posted: Sun Aug 26, 2018 3:54 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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Make sure the sender is grounded if it is not screwed into the case.
Make sure that you used the thin gasket on the pump cover when you built it.
this one:
_________________ “Most people don’t know what they’re doing, and a lot of them are really good at it.” - George Carlin |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 6:31 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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I didn't build the bottom end but about 2 hours ago I disassembled enough to get to the oil pump. I put a straight edge across it and used the feeler gauge like in the Bentley. The Bentley says .5-1mm of end play. I did not have that much end play on the pump gears. It was more like .06mm, really thin feeler gauge. There was a thin gasket installed but unfortunately I tore it up removing the cover plate. I'll replace it when I seal the cover plate back on. If I have less than.5mm of end play for the pump gears I don't see that causing my problem but possibly wearing out the cover plate much sooner than intended.
Anyway, that's what I've found so far. I did another test run this evening after adjusting the springs and I think it looked better while I was idling but the test run wasn't very different this time. Maybe the Springs settled back to their old shape once they were under heavy use. I'll post those numbers if anyone thinks they matter.
again, I really appreciate you guys helping me figure out what's going on. |
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Wildthings Samba Member
Joined: March 13, 2005 Posts: 50353
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Posted: Sun Aug 26, 2018 8:13 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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The way I read the Bentley is you want <.1mm of end play without taking into consideration the gasket, so according to the Bentley .06mm would be fine especially since it sounds like you still have the gasket in place.
Check what your endplay is without the gasket, if it is in the .03-.04mm range or above you may be able to run without the gasket.
Last edited by Wildthings on Sun Aug 26, 2018 9:16 pm; edited 1 time in total |
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hylomatt Samba Member
Joined: April 30, 2016 Posts: 378 Location: Florida
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Posted: Sun Aug 26, 2018 8:20 pm Post subject: Re: 1971 transporter, possible overheating, could use some advice... |
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@wildthings ok sounds good I can do that. So as far as next steps, I try new plungers in case the ones I have are worn out? If that doesn't work out, it sounds like I'm pulling the engine to look at bearings. Does that sound correct? |
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