Author |
Message |
Gene Kisner Samba Member
Joined: September 02, 2012 Posts: 80 Location: Fairmont, West Virginia
|
Posted: Tue May 16, 2017 5:35 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
I may have missed it, but nowhere did you mention the grade of gasoline you are running.
Your vehicle requires premium gasoline.
You can get by with 87 oct. in cool weather and/or flatland. Change to premium and check the difference in temperature. Your Thing requires 91 oct., look at the sticker under the front hood, and the poor quality gasoline available today in normally not anywhere near the pump posted rating. It is actually at best an average of a claimed oct. plus a measured oct. rating. That is what that RON+MON divided by 2 means
Low grade gas will pre detonate but you will not hear any ping or knock, it just causes engines to run hotter, especially air cooled engines. Try a couple of tanks of premium and see how it works out. The only gasoline you can believe the oct. rating is aviation gas from the airport. You can trust 100LL (low lead) to really be 100 oct. However you will not like the price of AVGAS. From $4.50 to $6.00 per gallon.
Be sure to post the results if you try this suggestion. |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Tue May 16, 2017 8:03 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
mondshine wrote: |
If you intend to use a CHT gauge that does hot have "cold junction compensation" you must avoid having the cold junction inside the engine compartment, where there are wild variations of ambient temperature. |
That's a ton of good info - thanks!
I'm using a Dakota Digital Odyssey II, which has thermocouple wire all the way to the gauge and is compensated by heating the gauge internals.
http://www.dakotadigital.com/index.cfm/page/ptype=...prd347.htm
Last edited by deafen on Tue May 16, 2017 8:07 pm; edited 1 time in total |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Tue May 16, 2017 8:06 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Gene Kisner wrote: |
I may have missed it, but nowhere did you mention the grade of gasoline you are running. |
Appreciate the info. I always buy the highest octane available, which is 93 at the station by my house where I usually fill up. I'm always amused that my vintage flat-4 car needs premium, and my modern flat-6 motorcycle (Honda Valkyrie) takes plain ol' unleaded. |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Tue May 16, 2017 8:14 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
mondshine wrote: |
If you are reluctant to drill holes, you might consider "dual gauges" like these Westach gauges. These are 10-15 years old, but they still make them.
|
Oh yeah, seen those before. Right now I'm using the DD CHT and a couple of super-cheap digital gauges from Amazon (tach and volt), temporarily sitting in a 3-gauge housing in the glovebox. I love the look of those Westach gauges, and eventually I plan to get the CHT/tach one and install it in my dash. (Then I'll sell the DD ... it wasn't cheap!) |
|
Back to top |
|
|
mondshine Samba Member
Joined: October 27, 2006 Posts: 2769 Location: The World's Motor Capital
|
Posted: Tue May 16, 2017 10:04 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
The Dakota Digital CHT gauge is a cold temperature compensated gauge.
It should give you very accurate readings.
Keep in mind that high oil temperature is directly related to RPM. Thick oil will make this worse, so knowing your oil pressure at freeway speeds is important. It will give you some indication of whether your oil cooler is being bypassed due to excessive oil pressure, and whether you can safely switch to a lower viscosity oil to keep your (hot) oil pressure in the 45-50 PSI neighborhood at 65-70 MPH.
CHT will rise and fall based on load. Unlike oil temperature, CHT changes rapidly, just driving up a moderate grade you will see CHT rise and then fall as you roll down hill. Driving with the top down increases load (due to drag) very noticeably.
So keep at it; you'll figure this out.
One thing I forgot to mention about the Westach gauges is that you can order them "off the menu". They will build gauges in almost any combination you desire. For a while, I used a 2" combination temperature gauge in my '71 Super Beetle like this:
I think it's stashed in a box somewhere around my house; I'll probably find it if we ever move.
Good luck, Mondshine |
|
Back to top |
|
|
74 Thing Samba Member
Joined: September 02, 2004 Posts: 7389
|
Posted: Tue May 16, 2017 10:34 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
I disagree on needing premium. It is based on a lot of factors whether or not you need premium.
Here are the gear calculators;
https://www.cbperformance.com/CB-Performance-Calculators-s/153.htm
and here is the link to the more air into the engine compartment:
http://shoptalkforums.com/viewtopic.php?f=32&t=90851&hilit=air+engine+compartment
I suggest doing the engine compartment air test that Eric Allred told me about where you get a lenght of hose (a cheap clear vinyl hose from the hardware store will do), and run it from the engine compartment to the passenger compartment and place the end into a water bottle. If the water is sucked up the tube while running then you are not getting enough air in the compartment. Propping the decklid and removing the tin that is in the front over the tranny (I cut the side off on the passenger side and left the side on the driver since the doghouse air exits there) helps a lot.
With a stock engine and stock carb, I never had an overheating problem though. When I went to dual carbs then there was not enough air for both 2 barrel carbs and the fan though at least in my car. |
|
Back to top |
|
|
Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
|
Posted: Tue May 16, 2017 10:34 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Gene Kisner wrote: |
I may have missed it, but nowhere did you mention the grade of gasoline you are running.
Your vehicle requires premium gasoline.
You can get by with 87 oct. in cool weather and/or flatland. Change to premium and check the difference in temperature. Your Thing requires 91 oct., look at the sticker under the front hood, and the poor quality gasoline available today in normally not anywhere near the pump posted rating. It is actually at best an average of a claimed oct. plus a measured oct. rating. That is what that RON+MON divided by 2 means
Low grade gas will pre detonate but you will not hear any ping or knock, it just causes engines to run hotter, especially air cooled engines. Try a couple of tanks of premium and see how it works out. The only gasoline you can believe the oct. rating is aviation gas from the airport. You can trust 100LL (low lead) to really be 100 oct. However you will not like the price of AVGAS. From $4.50 to $6.00 per gallon.
Be sure to post the results if you try this suggestion. |
These engines will run just fine on rot gut gas. Regular 87 octane (RON+MON)/2 is all they require as VW specced 91 RON octane gas which is equivalent to ~86 (RON+MON)/2
I ran my first Thing on sub regular Gulftane gas for as long as I could get it, never ever had a single problem with high engine temps or knocking.
.
Last edited by Wildthings on Wed May 17, 2017 1:06 pm; edited 1 time in total |
|
Back to top |
|
|
911pickup Samba Member
Joined: March 06, 2004 Posts: 625 Location: Near Goats on the Roof
|
Posted: Wed May 17, 2017 12:59 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Mondshine, I like that dual gauge setup. |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Wed May 17, 2017 4:47 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Well, i thought my timing was sorted, but after throwing the light on it this evening it's clear I'm wrong. Vacuum line off and plugged, it was showing 20* btdc at 3000 rpm. Whoooops. I adjusted it to 30*, which gives about 40* with the vacuum line attached.
The weird thing is that at idle, it's at 10* btdc whether the vacuum line is on or off. Shouldn't there be some vacuum advance at 900 rpm and a closed throttle?
Either way, I'm going to take it out for a run a little later (with my tuneup kit in the car), and we'll see how it goes. |
|
Back to top |
|
|
mondshine Samba Member
Joined: October 27, 2006 Posts: 2769 Location: The World's Motor Capital
|
Posted: Wed May 17, 2017 5:07 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
No vacuum advance at idle (provided the throttle plate is in the correct position, and idle speed has been adjusted with the bypass screw).
The distributor's vacuum advance hose should be connected to "ported vacuum", which is only available once the throttle is opened. That's why the throttle plate adjustment (the long screw which bears against the fast idle cam) is important.
Good luck, Mondshine |
|
Back to top |
|
|
Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
|
Posted: Wed May 17, 2017 8:20 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
deafen wrote: |
Well, i thought my timing was sorted, but after throwing the light on it this evening it's clear I'm wrong. Vacuum line off and plugged, it was showing 20* btdc at 3000 rpm. Whoooops. I adjusted it to 30*, which gives about 40* with the vacuum line attached.
The weird thing is that at idle, it's at 10* btdc whether the vacuum line is on or off. Shouldn't there be some vacuum advance at 900 rpm and a closed throttle?
Either way, I'm going to take it out for a run a little later (with my tuneup kit in the car), and we'll see how it goes. |
You need to rev the engine up until the timing quits advancing, 3000 rpm's may not be high enough. The exact rpm does not matter. |
|
Back to top |
|
|
74 Thing Samba Member
Joined: September 02, 2004 Posts: 7389
|
Posted: Wed May 17, 2017 10:11 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Yeah, rev it to full advance (who knows what that rpm will be but give it throttle till it stops advancing and set it in the 28-32 BTDC full advance range with the vac hose disconnected). Then warm it up and you will have to re-adjust the carb. Use the tennis ball too.
..and as mentioned above there should be no vacuum reading at idle since it is ported vacuum which is below the butterfly. You can always take a vacuum gauge and connect it to the carb to see. |
|
Back to top |
|
|
helowrench Samba Member
Joined: August 27, 2003 Posts: 567 Location: dallas texas
|
Posted: Thu May 18, 2017 4:31 am Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
deafen wrote: |
EDragnDean wrote: |
Type of oil, timing and how you set timing.
Exhaust system? Stock? Running proper heating sleds? Do you have aftermarket tin? |
Oil is dino 20w50. I think it's Valvoline.
Timing is 7.5* btdc (or as precise as I can get ...) at warm idle, vacuum hose off and plugged. (Can't do static timing b/c of the Pertronix).
Exhaust is stock.
Heater boxes properly installed and working. Heat not turned on.
The tin all looks stock to me. |
that oil looks to be way too thick,.
thicker oil actually bypasses the cooler, the way the system works (since it is set up for 10-30, the thick oil, appears to the bypass plunger as cold oil).
Try some 10W30 and see what the temps do.
Rob _________________ Current VWs:
70 bug vert for wifey
73Thing bucket o rust
73 914 1.7
12 Passat 2.5 Highway cruiser |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Thu May 18, 2017 8:07 am Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Wow, thanks again for all the input!
Advancing the timing to 30* was counterproductive - the oil got hot faster, and the top end got hot enough to start pinging after 10 minutes at 60 mph (top down), something I haven't had to deal with in years. Lucky I made it to work on time after I had to slow down to 50 mph, and I'm sure I pissed off plenty of people on the freeway.
So after work today, I'm going to back off to something in between, maybe 26* btdc full mechanical advance, and see how that goes on the ride home. (Yes, I brought my timing light, dwell/tach, and 10mm ratchet to work. Suspected something like this might happen.)
Part of my troubleshooting problem is that while the drive TO work is just fast enough and long enough to get the oil hot enough to flicker the dipstick, the drive HOME is much slower, so I lose one troubleshooting cycle per day. And with two kids, and a wife running a small business, I can almost never get out in the evening for a troubleshooting run. Oh well.
I bought 5-qt jug of synthetic 10W30 the other day. If I don't pull the screen, I can change the oil in 5 minutes, so I can get to that tonight. The screen got cleaned at the last change, so I think I'm safe.
Also, thanks for the reminder about the vacuum port not operating at closed throttle. I think I was confusing that with the vacuum retard from the DVDA, which does operate at idle IIRC. |
|
Back to top |
|
|
Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
|
Posted: Thu May 18, 2017 8:45 am Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
If it is pinging when set at 30° BTDC at 3500+ rpms I would question whether your pulley is marked or even installed correctly. Have you tried removing the pulley to see that it is properly keyed to the crankshaft? You might buy or make a piston stop so that you can accurately determine your TDC mark. |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Thu May 18, 2017 10:38 am Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Wildthings wrote: |
If it is pinging when set at 30° BTDC at 3500+ rpms I would question whether your pulley is marked or even installed correctly. Have you tried removing the pulley to see that it is properly keyed to the crankshaft? You might buy or make a piston stop so that you can accurately determine your TDC mark. |
Maybe? Hard to say. I think it's the cheaper Empi one. I know it's keyed to the crankshaft properly because I put it on myself about 12 years ago. It was when I first started trying to diagnose the overheating, and I needed something that would show me the full advance instead of just the static timing mark. |
|
Back to top |
|
|
Wildthings Samba Member
Joined: March 13, 2005 Posts: 50336
|
Posted: Thu May 18, 2017 11:01 am Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
deafen wrote: |
Wildthings wrote: |
If it is pinging when set at 30° BTDC at 3500+ rpms I would question whether your pulley is marked or even installed correctly. Have you tried removing the pulley to see that it is properly keyed to the crankshaft? You might buy or make a piston stop so that you can accurately determine your TDC mark. |
Maybe? Hard to say. I think it's the cheaper Empi one. I know it's keyed to the crankshaft properly because I put it on myself about 12 years ago. It was when I first started trying to diagnose the overheating, and I needed something that would show me the full advance instead of just the static timing mark. |
I would say to check the mark by using a piston stop then.
You could also just retard the timing two degrees at a time and see how far you have can go before the power and gas mileage drop off.
It could be your engine was built with very high compression??? Does it have problems cranking? |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Thu May 18, 2017 11:52 am Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Wildthings wrote: |
I would say to check the mark by using a piston stop then. |
Haven't ever used one of those, but it seems simple enough. And cheaper than a new known-accurate pulley. I'll look into it.
Wildthings wrote: |
It could be your engine was built with very high compression??? Does it have problems cranking? |
I doubt it - this seems like more of a budget rebuild, given the reuse of the original carburetor and distributor, unreplaced torn engine compartment seal, etc. No problems cranking at all, although it was slow to catch (5 seconds) before I adjusted the timing last night. It catches instantly now.
Definitely going to back it off by 4 degrees before driving home today. That would put it a little more than halfway between how it started (20*) and now (30*). Part of me is also wondering if I shouldn't set aside the no-name CIP1 distributor in favor of one of the Pertronix units available these days. That would set my mind at ease regarding how well (and consistently) the advance mechanisms are working. |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Thu May 18, 2017 1:19 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Yeah ... or it could be the fact that I attached the strobe pickup to the wrong spark plug wire (#2) last night. Figured this out in the parking lot at work today, and when I put it on the right wire it was 20* btdc at idle, ouch. No wonder it was pinging on the way in! Sheesh, it really has been a while since I've worked on this engine.
I reset to 28* btdc at full mechanical advance - as close as I could in the bright sun, anyway - and the drive home was uneventful. No pinging, but dipstick started flickering about 15 minutes in (60 mph, top down, 88* ambient temp). I'm really leaning toward this being an oil issue. Going to change to the synthetic 10W30 tonight (after accurately setting the timing) and I'll give it another go tomorrow. |
|
Back to top |
|
|
deafen Samba Member
Joined: April 28, 2006 Posts: 108
|
Posted: Thu May 18, 2017 5:15 pm Post subject: Re: Need more ideas to solve hot running condition (long) |
|
|
Argh ... or maybe not. Turns out I WAS measuring #1 last night, and #4 in the parking lot today. The #1 wire isn't pointed at the crank pulley, it's pointed forward and right (toward #1 cylinder, I suppose). This afternoon I was measuring the #4 wire against the BDC marking on the pulley. I have GOT to pay better attention.
Anyway, I set it to 26* mechanical, and changed the oil to 10W30. We'll see how tomorrow goes. |
|
Back to top |
|
|
|