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Chupa7hingy Samba Member
Joined: May 05, 2020 Posts: 54 Location: SoCal
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Posted: Sat Oct 17, 2020 6:22 pm Post subject: Oil pressure, temperature and how it relates to cooling |
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I just installed some new oil pressure and temperature gauges in my 2074 dual relief motor. As soon as I fired it up, I thought I had a problem, as the pressure was over 70psi cold (I had straight 40 VR1 for break in). When I put in the temp sensor in the relief, I noticed it had a grooved plunger and chrome spring. Recognized it as the Empi booster setup, so I pulled those and installed a stock style CB performance set and changed the oil at the same time to VR1 10-30, 40-45 cold, but down to 15-20 hot, much better, right?
Well, I'm wondering if I have a cooling problem because as I got hot, it just kept getting hotter, at least according to the temp gauge (which I'm still trying to diagnose if it's accurate or off). On the highway, I kept climbing past 220 to 240, topping out on the gauge at 260 before I chickened out and turned it off. Smelled hot (burning oil), but that was possibly because my breather hose came loose and got some oil on my heater box. Pressure was never below 15 at idle.
Questions as I try and work through this: Am I understanding that a closed relief piston pushes oil through the cooler? Then cold high pressures bypass and hot low pressures flow through? If this is the case, would putting the heavier spring in the relief put more oil through the cooler? What about using the grooved plunger with the stock spring (its taller and would have more pressure on it). Does the grooved piston do anything on a dual relief (I seem to have read it doesn't).
I know there are other things to do, like verify my temp gauge is accurate (it very well might not be), but I have to get my temp gun out of the attic to test this, just tryign to get some of the intel out of the way. Thank you all!
One thing I know will be asked, but I forgot to add earlier. It is not a full flow case. I'm also using the pressure sensor with the ISP West manifold that goes in place of the idiot light sensor and tapping into that with the idiot light.although the engine was built for me by my father-in-law, I wasn't 100% sure of all of the internal parts. I believe I have a 26 mm oil pump, but labeled as " heavy duty ". |
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Chupa7hingy Samba Member
Joined: May 05, 2020 Posts: 54 Location: SoCal
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Posted: Sat Oct 17, 2020 9:30 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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Follow-upon my troubleshooting. I took it for another drive, capping off the heater tubes, just in case there was a leak I was unaware of that might be robbing my oil cooler of airflow. While I was initially happy, because it appeared I was hovering at 220-230 this time, I was starting to smoke from the heater insulation because they were so hot
Took my temp gun, hit the case by the sensor, and was happy to see it was pretty close to the gauge reading (it showed 210 on the outside of the case, so I an guessing the actual sensor is probably no more than 10 off, if that).
I'm thinking I'm running lean... That would explain the heat issues as well, right?
I was previously having hesitation/stumbling issues prior, and increasing the idle and mains solved that problem. Maybe I didn't go far enough? HPMX duals, 55 idle and 135 mains. I think I will try and pull a plug tomorrow. They are a PITA to get to though... |
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andybla Samba Member
Joined: March 03, 2014 Posts: 630 Location: BE
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Posted: Sun Oct 18, 2020 11:23 am Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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if i recall correctly, when cold, the oil goes directly to the engine, when getting at operating temperature, the plunger opens and the oil begins to flow through the oil cooler.
i was always learned not to mess with the plunger system, that best was stock. Unless there is a high flow oil pump installed..
also, see this thread
https://www.thesamba.com/vw/forum/viewtopic.php?t=629138&start=0 |
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W1K1 Samba Member
Joined: March 04, 2004 Posts: 4921 Location: Southern AB
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Chupa7hingy Samba Member
Joined: May 05, 2020 Posts: 54 Location: SoCal
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Posted: Mon Oct 19, 2020 8:24 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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W1K1, your pics have inspired me twice now! I don't think I have a cooling problem so much as a heating one. AF gauge came today, variety of jets inbound, and I'll test the timing again before I start this weekend. Motor melted rings once already, but we discovered the mechanical advance distributor was allowing nearly double the advance it should have. Funny, it never knocked and ran great...right until it didn't, that is.
Discovering this, we were sure we found the culprit and rebuilt without much more thought about it. FF to this past week and I was sure there were no problems...until I installed gauges and saw what was actually going on inside. NOw I suspect the prior issue was a combo of too much advance AND too lean. Hope I didn't start to melt any rings this time.
Anyway, if the internals are fine, I'm sure I'll get her under control with the right fuel mix (presuming the timing is OK). If/when the time comes to redo the pistons/cylinders, I may downsize a bit to 90.5s and a smaller crank for better cooling. The 2074 is more than enough as is for this car. In the mean time, is there any way to add a cooler like W1K1's without being full flowed? Is ther any adapter that taps into the stock ports on top? |
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W1K1 Samba Member
Joined: March 04, 2004 Posts: 4921 Location: Southern AB
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Chupa7hingy Samba Member
Joined: May 05, 2020 Posts: 54 Location: SoCal
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Posted: Tue Oct 20, 2020 8:45 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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The original plan wasn't for a "performance build". In fact, my original idea was for a 1776, then I was talked into an 1835, then when cutting for an arm came into the picture, settled on the 2074 as recommended by a local VW shop. Not to hot-rod, but to have easy torque on demand for a heavier car. May have overshot for my planned driving. The recommendation was to NOT full flow as it was mostly a cruiser (although as can be read from a prior post of mine, I was sold a pressure booster relief instead of a stock setup, so I dunno...)
Original plans were to stay under 2000, and I should have stuck with my gut. Anyway, if the motor bellies up again, I'll revisit doing it different, including shrinking and making provisions for remote cooling/filtering. Parts came in today (yay!) and I'll be trying my hand at tuning the carbs this weekend. Thank you all.
BTW, here is a photo. She really deserves a solid motor.
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W1K1 Samba Member
Joined: March 04, 2004 Posts: 4921 Location: Southern AB
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Posted: Wed Oct 21, 2020 7:53 am Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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Nice
if I were to do it over.... always bigger.
Although the 1904cc was a nice bump in HP from the stock 1600 and it worked around town quite well for keeping up with modern traffic. _________________ http://www.thesamba.com/vw/archives/manuals/jim_martin_engine_build.php
1973 super
1965 squareback 1500E
1971 bay window westy- subi swap |
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Chupa7hingy Samba Member
Joined: May 05, 2020 Posts: 54 Location: SoCal
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Posted: Sat Oct 24, 2020 10:07 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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14.8 at idle, 14.7 WOT, and 15.1 at freeway cruising speed. Made up a little stand alone setup with a small toolbox and a small AGM battery. Plugged into one of the bungs on the Vintage Speed muffler, ran through the pop-out, and had my daughter read me numbers as we drove.
I currently have 55 idles, 135 mains, and 170 airs. I have a few sets of jets, so based on my readings, should I go up one or two idle sizes and one or two mains? Thinking of leaving the airs, but I have 185s sitting around too.
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Bobnotch Samba Member
Joined: July 06, 2003 Posts: 22431 Location: Kimball, Mi
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Posted: Sun Oct 25, 2020 10:56 am Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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If you're doing the jet changes to a set of Solex carbs, I'd probably bump up to a set 28 mm venturi's, then adjust my jetting. If you're running something else, then you'll have to work around them. _________________ Bob 65 Notch S with Sunroof
71 Notch ...aka Krunchy; build pics here;
http://www.thesamba.com/vw/forum/viewtopic.php?t=249390 -been busy working
64 T-34 Ghia...aka Wolfie, under construction... http://www.thesamba.com/vw/forum/viewtopic.php?t=412120
Tram wrote: |
"Friends are God's way of apologizing for relatives." |
Tram wrote: |
People keep confusing "restored" and "restroyed". |
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Chupa7hingy Samba Member
Joined: May 05, 2020 Posts: 54 Location: SoCal
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Posted: Sun Oct 25, 2020 11:29 am Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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Bobnotch wrote: |
If you're doing the jet changes to a set of Solex carbs, I'd probably bump up to a set 28 mm venturi's, then adjust my jetting. If you're running something else, then you'll have to work around them. |
Sorry, thought I mentioned it earlier. HPMX 40s. It does have the 28 venturis. |
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74 Thing Samba Member
Joined: September 02, 2004 Posts: 7394
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Posted: Sun Oct 25, 2020 8:58 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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You are running lean at 14.7:1 at WOT |
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W1K1 Samba Member
Joined: March 04, 2004 Posts: 4921 Location: Southern AB
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Posted: Mon Oct 26, 2020 12:05 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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14.8 at idle, 14.7 WOT, and 15.1 at freeway cruising speed. |
12.5-13.2 at WOT is what you're shooting for, the idle and freeway cruise at light throttle would be okay _________________ http://www.thesamba.com/vw/archives/manuals/jim_martin_engine_build.php
1973 super
1965 squareback 1500E
1971 bay window westy- subi swap |
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rosevillain Samba Member
Joined: December 28, 2005 Posts: 1290 Location: roseville, ca
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Posted: Mon Oct 26, 2020 2:45 pm Post subject: Re: Oil pressure, temperature and how it relates to cooling |
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Pop over to the Performance/ Engines forum and check out the tuning with a wideband thread. https://www.thesamba.com/vw/forum/viewtopic.php?t=293837
Not that these guys can't get you there. Beautiful car! |
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