Hello! Log in or Register   |  Help  |  Donate  |  Buy Shirts  See all banner ads | Advertise on TheSamba.com  
TheSamba.com
 
Need more ideas to solve hot running condition (long)
Page: Previous  1, 2, 3, 4, 5  Next
Forum Index -> Thing/Type 181 Share: Facebook Twitter
Reply to topic
Print View
Quick sort: Show newest posts on top | Show oldest posts on top View previous topic :: View next topic  
Author Message
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Fri May 26, 2017 7:10 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Tennis ball didn't do the trick. No fan blockage. I think I'm officially out of options that I can deal with in my driveway. I'll still get my gauges installed (probably on the Monday holiday, since I'm out of town Sat/Sun), but I don't think there are are any more changes that i can make myself.

Guess i'll get off the stick and get the cooling system stuff, then take it to Hicks and say "fix it". I've been meaning to take it there anyway to get an estimate on bodywork and paint, but I was hoping to have the mechanicals all sorted first. Ah well.

Thanks for all your help, everybody, and I'll keep following up as things move along.

On the question of flaps: I saw this kit for $155 shipped, and it looks really nice (all the important stuff is OE, and it's been cleaned up and powdercoated). Any thoughts? The only other complete kit is on eBay for $110, but it doesn't look to be actually refurbished. I've got a Mexican thermostat on the way.

http://www.awesomepowdercoat.com/thermostat_flaps.html

Oh, and I'm also considering a 356 generator pulley setup. I guess it runs the fan 20% faster? Anybody done that before?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Wildthings
Samba Member


Joined: March 13, 2005
Posts: 35915

Wildthings is offline 

PostPosted: Fri May 26, 2017 7:16 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

deafen wrote:

Oh, and I'm also considering a 356 generator pulley setup. I guess it runs the fan 20% faster? Anybody done that before?


You don't have a "power" pulley on there now do you? Your pulley should be 7" in diameter.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Fri May 26, 2017 8:04 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Wildthings wrote:
You don't have a "power" pulley on there now do you? Your pulley should be 7" in diameter.


Nope, it's stock size (I think it's an EMPI 8779).
Back to top
View user's profile Send private message Gallery Classifieds Feedback
74 Thing
Samba Member


Joined: September 02, 2004
Posts: 3434

74 Thing is offline 

PostPosted: Fri May 26, 2017 10:12 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Time to drop the engine, pull the heads, and figure out the compression ration, and pull the oil pump and see what camshaft you have in there.

I had a similar experience years ago. I bought a rebuilt 1600dp that was supposed to be stock with stock compression. It would ping and run hot. I tried everything, and finally built my own engine to replace that one. When I tore that one apart the heads had been flycut so much that my compression ratio was 9.5:1 with a stock camshaft-no wonder it would ping once in a while and ran hot.

Good luck-your engine compartment does not look too pushed in from your photo. Def tear that engine apart and see what you have.

Your tire size still is not helping the cooling. Going to smaller tires or running a smaller 356 generator pulley will speed up the fan.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Mon May 29, 2017 6:47 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

helowrench wrote:

Thinking outside of the box.........
It is possible that the relief piston is stuck in bypass mode. It happens kinda rarely. Might be worthwhile to look up how to troubleshoot and eliminate that.


I just now pulled the rear relief plug (on my way to installing the temp sender), and the piston dropped right out. It is slotted, if that makes a difference. The spring appears to be stock.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Tue May 30, 2017 5:17 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

I finally got all my gauges finished yesterday - CHT, oil temp, oil pressure, tach, volts. The wiring ain't pretty, since i intend to eventually put them into the dash plates and right now they're in a cheapie plastic housing in the glovebox, but they work.

And of course, today I can't drive the Thing to work, and tomorrow it's going to rain. But Thursday I should be able to finally get her out for a commute and get some real data. Woot.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Bashr52
Samba Member


Joined: July 16, 2006
Posts: 5195
Location: On the Hill In J.C.
Bashr52 is offline 

PostPosted: Tue May 30, 2017 6:03 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

I'll ask again in case it was missed, do you know what trans/gearing you have? Is it still a stock Thing trans? What size are your rear tires? Any idea what RPM you are running at highway speeds?

The reason I ask is a "freeway flier" trans will let you run lower RPM at highway speeds which in turn turns the cooling fan slower...
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Tue May 30, 2017 7:20 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Bashr52 wrote:
I'll ask again in case it was missed, do you know what trans/gearing you have? Is it still a stock Thing trans? What size are your rear tires? Any idea what RPM you are running at highway speeds?

The reason I ask is a "freeway flier" trans will let you run lower RPM at highway speeds which in turn turns the cooling fan slower...


All good questions! Unfortunately, I have few answers.

I'm assuming it's the stock transmission. The engine was rebuilt in its original AM case, and reused all of the externals (carb, distributor, coil, etc.) So following that line of logic, if the transmission was functional, it got reused. But I have no proof of that fact. Is there a way to test the gearing at rest? With my Jeep, I was able to at least determine the R&P by turning a rear wheel and counting driveshaft rotations, but there's no driveshaft, so ...

Rear tires are 27x8.5R14, so it's slowing down the engine by ~5% from the stock 185SR14.

I finally got a working tach installed last night, so as soon as I can get it out on the road I'll have a an answer to that last question.

On another note - I'm thinking about replacing the oil pump with the CB unit that hangs a filter off the side. When I pull the oil pump to do that, will I be able to determine if the cam is stock vs. upgraded?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Wed May 31, 2017 8:56 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Okay, I've got new data points, and they don't look good. At all.

1 - CHT quickly got to 400+ on the 5-mile drive to the freeway, running between 45-55 mph.

2 - CHT climbed all the way to 480 within 7-8 minutes at 60 mph. I got off at the next exit.

3 - Around this same time, the Berg dipstick started flickering, and the oil temp gauge was around 225. (It's hard to be precise, since it's just got a big blank gap between 220 and 260.)

4 - Once off the highway, CHT stayed above 400 when in motion, dropping into the 390s when stopped.

5 - Oil temp stayed at 220 or above the entire rest of the drive.

6 - Oil pressure was 40 at cold idle, got as high as 60 under load cold. Hot idle (mind you, VERY hot idle) was less than 10 psi, but more than 5. Cruise pressure was around 20 psi at around 2000-2100 rpm., which seems okay.

7 - 60 mph = 2100 RPM. That seems really, really low. But I haven't checked to make sure the tach is properly calibrated - it was showing hot idle around 650 RPM, and I'm pretty sure I set it to 850 with my real dwell/tach a couple weeks ago. I should be able to cross-reference them tomorrow night.

8 - CHT was 30-40 degrees hotter with the tennis ball. Which makes a kind of sense - at 1900-2000 RPM, the fan isn't starved yet, and opening the lid with the top down creates a venturi to suck in hot cooling air.

9 - I clearly didn't tighten the oil pressure sender enough, because there's oil all over my tin now. Sad At the end of the day I'll see if I can get it any tighter, then check the oil level and top off if I have to.

10 - Even at 480 CHT, there was no audible pinging, even when I floored it in 4th at 50 mph on the offramp.

So to me, this seems like I've got a cooling problem (tin/fan/RPMs/etc), not a heat-generation problem (timing/compression/etc.) But I'm definitely out of my depth. Probably time to hand it off to a professional.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Wildthings
Samba Member


Joined: March 13, 2005
Posts: 35915

Wildthings is offline 

PostPosted: Wed May 31, 2017 9:40 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Since your oil and CHT go up together, I think it has to be a lack of cooling air for some reason. CHT and oil temps don't usually track each other all that close as the heat for each has different causes.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Wed May 31, 2017 11:33 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

I used a gear/RPM/MPH calculator (https://www.blocklayer.com/rpm-geareng.aspx), and have determined that there's either something wrong with the tach, or this tranny is geared ridiculously tall.

Using the specs listed at http://ww2.whidbey.net/jameslux/181spec.htm, the stock tranny's 4th gear is 0.93 and the R&P is 4.12. If I plug those in, along with the 27" rear tire height, the engine should be turning close to 2900 RPM at 60 mph.

To get even close to the indicated 2100 RPM I saw this morning, I need to drop to 3.88 R&P and 0.82 4th gear, the tallest combo I can find by googling around. And even that would only drop the RPM to 2400 at 60 mph. Of course, if the tach is correct and this is some bizarre super-duper-tall gearing, that would explain all of my overheating, now, wouldn't it?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Wildthings
Samba Member


Joined: March 13, 2005
Posts: 35915

Wildthings is offline 

PostPosted: Wed May 31, 2017 11:55 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

deafen wrote:
if the tach is correct and this is some bizarre super-duper-tall gearing, that would explain all of my overheating, now, wouldn't it?


If you have decent power in high gear I would doubt that your tranny is geared too long, unless you have a fairly large engine build. Also with long gearing you would also have a tendency to use the lower gears more thereby keeping the revs up and the fan spinning nicely.

Low rpm's would also tend to lead to low oil temps, not high oil temps.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Wed May 31, 2017 12:17 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Yeah, I'm leaning toward "inaccurate tach". It's a super cheap digital unit I got on Amazon and wired up through the diagnostic harness. Next step is to check it against my known-good dwell/tach, and then to swap in the analog Westberg as a secondary check.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
74 Thing
Samba Member


Joined: September 02, 2004
Posts: 3434

74 Thing is offline 

PostPosted: Wed May 31, 2017 12:17 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

If that tach is right the gearing and tire size are the major source of your problems.

You can determine your gear ratio by jacking up the rear and putting it in gear and counting the revolutions of the rear tire compared to the revolutions of the crank pulley-do a search.

You need to be in the 3.5k - 4.5k rpm on the freeway for proper cooling at cruising speeds.

Is your CHT installed under the #3 spark plug?
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Wed May 31, 2017 12:31 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

74 Thing wrote:
You can determine your gear ratio by jacking up the rear and putting it in gear and counting the revolutions of the rear tire compared to the revolutions of the crank pulley-do a search.


Yeah, that makes sense. I'll definitely give that a shot.

74 Thing wrote:
Is your CHT installed under the #3 spark plug?


Yes. I removed the gasket from the plug so that it wouldn't change the depth.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
74 Thing
Samba Member


Joined: September 02, 2004
Posts: 3434

74 Thing is offline 

PostPosted: Wed May 31, 2017 12:48 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

https://www.thesamba.com/vw/forum/viewtopic.php?p=6877375

Here is a thread on the gear ratio.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Wildthings
Samba Member


Joined: March 13, 2005
Posts: 35915

Wildthings is offline 

PostPosted: Wed May 31, 2017 2:25 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

If your tach was set to the 8 cylinder setting and was reading 2100rpms your engine would have been turning 4200rpms. If it were on a six cylinder settings your actual rpms would be 3150.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
deafen
Samba Member


Joined: April 28, 2006
Posts: 105

deafen is offline 

PostPosted: Wed May 31, 2017 2:50 pm    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Wildthings wrote:
If your tach was set to the 8 cylinder setting and was reading 2100rpms your engine would have been turning 4200rpms. If it were on a six cylinder settings your actual rpms would be 3150.


I'm literally smacking my forehead. It was on the 6 cyl setting. Thank you!

So that should be fast enough to keep things cool. Which brings me all the way back around to the tin, flaps, and/or fan.
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Bashr52
Samba Member


Joined: July 16, 2006
Posts: 5195
Location: On the Hill In J.C.
Bashr52 is offline 

PostPosted: Thu Jun 01, 2017 4:30 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

deafen wrote:
Wildthings wrote:
If your tach was set to the 8 cylinder setting and was reading 2100rpms your engine would have been turning 4200rpms. If it were on a six cylinder settings your actual rpms would be 3150.


I'm literally smacking my forehead. It was on the 6 cyl setting. Thank you!

So that should be fast enough to keep things cool. Which brings me all the way back around to the tin, flaps, and/or fan.


3100 is still a bit low, you'd like around 3500 or more on the highway. I have a 3.88 and .89 4th in my Thing, but I also have a 2232 and the power to pull taller gears. I cruise around town in 3rd, and 4th is more an overdrive for the highway.

3.88 from a bug and .84 from a bus is an available gearing for cars that will be doing a bunch of high speed highway cruising, but the 3.88 and .89 is more common.

What is the code on the side of your trans? That will show what that car SHOULD have in it (or at least did from the factory Laughing )
Back to top
View user's profile Send private message Gallery Classifieds Feedback
germanbilly
Samba Member


Joined: October 18, 2013
Posts: 321
Location: Victorville
germanbilly is offline 

PostPosted: Thu Jun 01, 2017 9:22 am    Post subject: Re: Need more ideas to solve hot running condition (long) Reply with quote

Just a thought, You had said there was a rats nest in your fan housing. Did you clean the oil cooler? I mean Clean, Clean. not one piece of straw, dirt, lint. The cooling fins are very small and if they are not all clean the oil cooler will not work.
GB
Back to top
View user's profile Send private message Gallery Classifieds Feedback
Display posts from previous:   
Reply to topic    Forum Index -> Thing/Type 181 All times are Mountain Standard Time/Pacific Daylight Savings Time
Page: Previous  1, 2, 3, 4, 5  Next
Page 4 of 5

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum

About | Help! | Advertise | Donate | Premium Membership | Privacy/Terms of Use | Contact Us | Site Map
Copyright © 1996-2016, Everett Barnes. All Rights Reserved.
Not affiliated with or sponsored by Volkswagen of America | Forum powered by phpBB