IAC Visits Andover

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type2sam
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IAC Visits Andover

Post by type2sam » Sat Oct 11, 2008 8:22 pm

Part I:

Colin drove off into the darkness approximately 24 hours ago, so I've had some time to reflect on the Itinerant Air-Cooled session we shared.

The day started with Colin pointing out the prerequisites, namely my brake booster - laying in the driveway. I had taken the booster and master cylinder off to see if I could address the step-on-the-brakes-and-the-idle-goes-up issue I'd been having.

We went inside, got some coffee and started the session, reviewing my goals, going over the fundamentals of timing, dwell and the finer points of the design, care and feeding of hydraulic lifters. Colin corrected some invalid assumptions I had and proceeded to refine my understanding in other areas. The kitchen table session concluded with an overview of the PDSIT dual carb configuration on my bus with special attention paid to the central idle circuit.

With that, we went out to the garage to address the brakes. We replaced the round cross-section o-ring that sealed the master cylinder to the booster with the correct square-cut o-ring. We also used a thin layer of RTV on the booster as the mating surface had become pitted by rust. Once joined, Colin tested the assembled unit by playing it like some strange instrument right out of a Dr. Seuss story, determining that the booster was leaking along its perimeter where the two halves were joined. I put a rebuilt booster on the mental shopping list and we proceeded to install the unit as having brakes was deemed important.

Colin also took the opportunity to point out that my brake lever clevis pin was frozen solid with rust, brought out the PB Blaster and set things right with a thin smear of moly grease. We rolled the bus out in to the warm sunshine, bled the brakes and moved onto the valves.

I had done valve adjustments on solid-lifter VWs in the past (in fact my engine was a solid-lifter 1700 before having it rebuilt into a 2.0 with hydraulics), but I approached the hydraulic adjustment with a certain amount of trepidation. What if the lifters were air-bound? What was this magical "centering" of the lifters?

Colin reiterated the steps as outlined during our kitchen session, putting my concerns to rest and we proceeded to adjust the screws to 0 lash, then 1.5 turns in, watching to see that we were not pressing the valve stem inward. Given that this was the first valve adjustment after the rebuild (~300 miles ago), the NEXT adjustment was to be the baseline from which all future measurements were compared.

Next we moved on to the adjustment of the timing and found that we could not get the idle down to the correct level and the vacuum retard....wasn't. We pulled the distributor - and Colin observed that the distributor drive gear was a tooth or two off. It was at this point that Colin suggested for the first time that we should pull the gear and set it correctly. Understanding what you need to do if the washers slip, I quickly changed the subject :)

When the distributor checked out (advance plate movement was fine, vacuum can held from both the advance and retard sides), we popped it back in and Colin quickly deduced that it was the right-hand throttle link being too long causing the high idle.

I'll wrap this up tomorrow in Part II....

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Amskeptic
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Post by Amskeptic » Sun Oct 12, 2008 2:16 pm

Type2sam lives right on the road I used to bicycle in the fall and springs of 1975, 1976, 1977. We had a blessedly classic north east fall day.

Image

We also dodged a few potential exploding matrixes of different source issues, veering close to terminal confusion for my poor customer who was valiantly trying to keep up with my nervous prattle as I earnestly entreated his engine to please BEHAVE (non-functional cut-off solenoid for example, allowed the engine to idle perfectly even with the wire pulled off).

This was a new Boston Bob engine, and it sounded nice and tight though not yet totally broken in. Good bus, by the way. Other than weird brake behavior acting exactly like the new Mercedes panic stop brake assist servo, it was a tractable and fresh example of the finest VW bus ever made, the 1973. . . . :pirate:
Colin
BobD - 78 Bus . . . 112,660 miles
Chloe - 70 bus . . . 206,845 miles
Naranja - 77 Westy . . . 129,490 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 91 Lexus LS400 . . . 94,225 miles

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type2sam
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Post by type2sam » Wed Oct 15, 2008 2:05 pm

.....Part II

So, then we moved on to the 3000 RPM, idle and first step of the fast idle cam synchronizations. I am still amazed at how the most minor of tweaks to the fast idle links impacted the fast idle sync.

..then Central idle and mixture...

After all this was done, we went for a ride. With Colin providing the expertise, my engine went from a super-rich high idle beast to a silky smooth running, fuel sipping (sorta) machine.

The rest of the day (and evening) consisted of Colin attempting to teach me how to double-clutch (which still feels alien but I vow to keep at it), running me through the finer points of lubrication of all friction points, rust proofing and what color I should really be painting the fresh-air grille (....uh....body color?....CORRECT!!) on the nose.

To summarize the experience, on Thursday I had a bus I was confident to drive around town...with cell phone at the ready. By end of day Friday, I had a bus I was confident to drive wherever...including Transporter Fest on Sunday almost 30 miles away - something I've wanted to do for years.

If you have ever thought about engaging Colin for a visit - especially those of you ready to toss the dual solexes (no disrespect to all you Weber Progressive types out there) - I highly recommend the experience.

Thank you Colin. It was a pleasure to meet you. Safe Travels and hope to see you on the road next summer...

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RSorak 71Westy
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Location: Memphis, TN
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Post by RSorak 71Westy » Thu Oct 16, 2008 9:25 am

Welcome to the black grill club!
Take care,
Rick
Stock 1600 w/dual Solex 34's and header. mildly ported heads and EMPI elephant's feet. SVDA W/pertronix. 73 Thing has been sold. BTW I am a pro wrench have been fixing cars for living for over 30 yrs.

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Amskeptic
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Post by Amskeptic » Fri Oct 17, 2008 8:57 am

RSorak 71Westy wrote:Welcome to the black grill club!
And you ought to be introduced to the Double Clutch Club!
Colin
BobD - 78 Bus . . . 112,660 miles
Chloe - 70 bus . . . 206,845 miles
Naranja - 77 Westy . . . 129,490 miles
Pluck - 1973 Squareback . . . . . . 55,570 miles
Alexus - 91 Lexus LS400 . . . 94,225 miles

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