1971 transporter, possible overheating, could use some advice...

[Wildthings]

[hylomatt]

@wildthings, I rotate the crank counter-clockwise, via wrench on the gen pully, 2 rotations and then stop at TDC mark on crank pulley for plug #1. Pop the valve cover off, wiggle the valves a little to see if they make noise or not, check them to see if any change needs to happen and if so, use my .006 feeler gauge to set the gap. Tighten it down, check it again, do this over and over until I get it right. I do both valves for that cylinder. Then I rotate the crankshaft pulley another 180 deg CC to BDC for piston #2. Do those valves and keep doing this until I'm done with #4.

I could've messed up or gotten confused this morning but that is a sound and standard method, right?

[SGKent]

what Mike (wildthings) just said. Perhaps there is something wrong with the valves, or the heads get so hot that the cylinders are sinking into them. If you can get ahold of Colin - (Amskeptic) that might be worth seeing if he can contribute anything time and thought wise. He'll be in Jacksonville Beach FL, Flagler Beach FL and Miami this fall. From Flagler Beach to you is about 160 miles. Maybe he'll feel like making the drive to assist on this one. He does charge a fee but it is his offseason, and he is close so you might get him to offer a break on this one.

FWIW I had a 1971 dual port for many miles, almost a half million. There were coast to coast trips, high-speed runs from Upland out to Lake Havasu - never once did I see anything but stability in the valve train. You will have to take it apart and look at all the culprits - case, heads, valves etc.. The only other thing I could add is as I said before - if you have two feeler gauges that you are using perhaps one is off. I usually replace the .006" blade due to it being the one that curls first. There are folks who sell just a .006" blade. Yes - that is the right way to do it. The .006" should slip thru with a little drag. The .005" should be so loose there is no drag, and the .007" should be tight and require forcing.
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[hylomatt]

Okay well the engine is coming out again tomorrow morning so I'll let you know what I find.

[hylomatt]

I pulled the engine out and spit the case looking for problems. I was able to verify that the oil pump mates well with the oil galleries. I found a couple issues. There was some glitter on the front main bearing (inside of it when I slipped it off), the cam gear is loose on its 3 rivets, and I found out why the rockers were having a problem. The head studs were pushing on the back of the rockers and need to be shortened. I'm betting they were holding the valves open some of the time. The rockers had started to cut grooves into the end of two of the head studs where they contact the #3 intake and the #4 exhaust.

I'm going to take the bottom end back to the VW shop that built it and ask them to find out what is wrong and why I'm seeing so much bearing glitter. I don't really have the experience necessary to analyze bearings and see where a problem is occurring. I don't see any bluing on the bearings nor do I see any brass showing through. When I pulled the front number one main bearing along with the end play spacers and ran my finger around its inner circumference there were metal flakes on my fingertip.

[hylomatt]

Ok it's all fixed, reassembled and back in the bus. I have good oil pressure now. I did see that trips on the interstate (~65mph) take my 10w30 oil up to 245F-ish. So today, I taped up the perimeter of my rear engine hatch, suspecting there might be some vacuum that's starving my cooling fan. On the way to work, back and forth between 60-70mph, the oil reached 230-235F but that was it. And, when slowing down and getting off of the interstate, I saw the temps drop down to 210-220F, which hasn't been normal, with it taking longer for the temps to cool down. Oil pressure was maintained throughout all of this.

With a better carb calibration (I'm messing around with the mixture), this could even be improved upon.

I was running lean before and I've enriched the mixture but waiting for feedback. I'll also check timing adustments. ATM, I'm set at 5ATDC and I checked the mechanical advance (22-25). This is a 205Q DVDA.

[Randy in Maine]

Humor me and try timing the engine (vacuum hoses off and plugged) to 30º +/- 2º when all of the centrifical advance the distributor has to offer is all in at about 3000-3500 RPMs. Let it loaf back to idle, hook up both vacuum hoses and set the idle to 850 RPMs +/- 50.

Note but do not change the timing at idle and go for a ride. Report back your findings.

[Wildthings]

[busdaddy]

Are you using a degree pulley?, or a stock one?, if stock are you sure it has the correct marks?
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[hylomatt]

@Randy and @Wildthings: I can do that but this is a newly rebuilt 205Q DVDA from tasb and a newly rebuilt carb from volkzbitz. i don't think they could be in better condition w/o a little time traveling.

I've set the timing in multiple ways,
1) all hoses off, 28-32 BTDC at full advance
2) all hoses on, 28-32 BTDC at full advance
3) retard host off, 28-32 BTDC at full advance (should be the same as #2 since the throttle valve is open and no retard vac signal)
4) all hoses off, 22-25 BTDC at full advance (what this dist is capable of)
5) all hoses on, 5 ATDC at idle (per bentley)

you can confuse yourself easily if you don't think about what you're doing or if you don't know how your dist should be behaving.

the specs for the 205Q have been published multiple times on this site but it's 22-25 deg of mechanical advance, very little vacuum advance and lot's of vacuum retard.

[Wildthings]

[hylomatt]

The difference between 1 and 4 is whether the vacuum advance is added to 30ish or used to make up 30ish. As far as the performance outcome between the two, I have not done those tests since before when I had additional problems that have since been resolved. this evening and during this weekend I will conduct some timing tests with driving.

Which tests do you want me to run? #1-5

[hylomatt]

@busdaddy, it's a stock pulley with the larger dished notch for TDC and just to the left of that is the 5° atdc small v-notch.

[hylomatt]

@randy and @wildthings, surmising based on the below information:

[Wildthings]

[hylomatt]

@wildthings, that's what I've just discovered. I came home from work and did the adjustment. i was already only a few degrees shy of 30, probably around 28 before I made a change. I took it out on an interstate test drive and it ran a little hotter but not much. Maybe 5 degrees hotter. It's hard to see that difference clearly on the vdo gauge but that's what it looked like. I'll set it back to 28-ish tomorrow morning. It's good to know all that math lines up with my equipment's condition.

What I'm fussing with now is how to tell if my air-to-fuel ratio is off. When i tore down the engine recently, the plugs seemed a little light in color but the intake valve heads where even lighter in color. Not white but light grey. So I was running lean but how do I know when it's right?

[hylomatt]

@randy, it seems i was already there, approx. see the above message.