Author Topic: VW air cooled guys? (Read 5122 times)

Don R · « **on:** July 26, 2019, 03:09:36 pm »

Working on a dune buggy bought by a friend. She has way too much money in it and has been taken advantage of by mechanics. #1 was leaky spring loaded pushrod tubes. Someone tried to silicone them and loaded the pushrods and oil screen with gobs of silicone. I had to scrape the pushrods there was so much on them. Silicone in the oil pump screen. #2 was a cable end in the right rear intake port, didn't make it past the valve. #3 was lower cylinder shrouds over and under the cylinders. #4 one spring clip missing on the throwout bearing, #5 the coil feed has naked spade connecters, two crimp joints, two soldered shrink tube joints and 4 sizes/colors of wire. #6 alternator wire rubbing the fan belt. #7 fuel hose against header, #8 rear poly trans mounts torn and flopping. Multiple loose nuts rattling around on the cylinders?? Odd size nuts on motor mount bolts, Excesss clutch cable folded forward and poking something every clutch movement. Electric fuel pump on a stock carb with no regulator. Brakes are a big Q? but first things first. 1970 drums probably original, I can't wait to break my long breaker bar on a rear axle nut. Where's the 5' cheater? L0L! The things I get myself into.
Is a stock 1500 or 1600 carb OK on an 1835 kit with dual port heads? It measured 92mm bore. Previous mechanic relieved her of the holley weber that was on it.

Gordon · « **Reply #1 on:** July 26, 2019, 05:01:29 pm »

Wow... I drove a '74 VW bus for almost ten years, took it on dozens of cross-country trips, was the main mechanic on it the entire time, and I still don't even know where to start with all that!

Scott S · « **Reply #2 on:** July 26, 2019, 07:26:34 pm »

Any idea what cam is in it? I'd go for dual Solex/Kadron carbs. Be easier to tune than jetting the stock carb and run better, too.

scottly · « **Reply #3 on:** July 26, 2019, 10:16:23 pm »

The first car engine I rebuilt was the family 1959 VW bus, with the 36 HP 1200cc engine and crash-box 1st gear trans, in high school auto-shop. It had sucked a valve, which in turn knocked a hole in that piston as well as trashing the head. My dad found a used head and piston, and I did my first proper valve job as well as replacing the guides. I also was allowed access to the community college shop, where I bead-blasted the heads and case (never again

) and recondition the big ends of the rods.

The Holly/Weber was actually a Pinto carb; it was a progressive 2 barrel carb that was perhaps better than the 250 and 350 CFM Holly "Bug spray" carbs? It should be OK with a stock carb, but will run out of breath early.
The typical electric fuel pumps used on VWs were Facet pumps (square looking things), and didn't make enough pressure to require a regulator.
The axle nut does need a 5 foot cheater.

Make sure it is tightened back up after removal, lest the splines wear.
Most dune buggys based on the stock chassis, like the Meyers Manx, had the "pan" and therefore the wheelbase shortened by about 14", IIRC, which would explain the too long clutch cable.

70CB750 · « **Reply #4 on:** July 27, 2019, 05:25:51 am »

My dad's first car was VW air cooled

He sold it in 1974.

Gitano · « **Reply #5 on:** July 27, 2019, 06:30:23 am »

This thread is bringing back some fond memories - my first car was a very well used '64 bug. The turn indicator stalk was a plastic toothbrush handle screwed onto a broken stub on the steering column! But, I didn't care. I had wheels!

Scott S · « **Reply #6 on:** July 27, 2019, 07:37:17 am »

I've had a bunch of Bugs. Drove them daily for years. The only one left is Ruby, my '63 rag top. I'm the second owner; had her since '94.

Don R · « **Reply #7 on:** July 27, 2019, 09:33:38 am »

Thanks for the tips, If it was mine I'd go with webers or at least dual solex. This lady was taken advantage of at every turn. She has 10K in it. I'm hoping she can get the previous carb back from the last guy that worked on it. I'm thinking I'll have $200 in parts, no labor cost.

Don R · « **Reply #8 on:** July 28, 2019, 12:04:02 pm »

Scott that bug is amazing. My brother has enough good parts for one more dual port engine. I'd love to find a nice body but around here they're few and far between.
I was second in line a couple years ago on a sweet no rust ever bug. My buddy got there first. He said he'll never build a rusty car again.

Don R · « **Reply #9 on:** July 30, 2019, 09:44:02 pm »

The rear brakes adjusted up OK without removing the drums. I'm almost ready to put the engine back in. Jeez I hope most of the oil leaking is over with, my brother took the carb apart. I think he's feeling pretty nostalgic working on a VW with me. We did quite a few back in the day. He kept a 6V and a 12V engine ready to swap out.
No more big surprises in the motor, I trimmed the Taiwan fan housing at the bottom to fit the Brazil engine case, added a few screws here and there. I gave it a drink of Rotella and since I got wrong spark plugs I put the autolite ones back in. The dual port heads take a long 12mm? thread oddly enough a cb750 plug is one of the options for it.
Oh, there was a missing spring clip on the throwout bearing.

Don R · « **Reply #10 on:** August 01, 2019, 08:53:55 am »

We checked the carb, it was clean inside. I added a fuel pressure regulator and filter. New NGK's, it still won't idle below 2K rpm. It may be time to check the compression valves and cylinders appeared good. My biggest fear is that the dorks (PO) that worked on it got the cam timing wrong. I really don't want to split the cases. My brother has a carb hanging on the wall at home we might try that one. I did liquid check the valves, they were sealing good.
We didn't turn up his old cutaway bellhousing so we couldn't start it on the chevy engine test stand. At any rate it isn't that hard to remove from the buggy. I really want it done and out of my shop I have a quick 750 project in mind.
No good deed goes unpunished.

scottly · « **Reply #11 on:** August 01, 2019, 06:45:13 pm »

Hey Don, on those later Solex PICT carbs the idle setting is a bit different from most carbs. They use a by-pass idle system, which literally by-passes the closed throttle blade. There are two recessed adjustment screws on the left side of the carb as you are facing it. The large one is for the amount of air that flows past the throttle, and the smaller one is the mixture screw. The screw on the end of the throttle lever is for setting the fast idle cam when cold and the choke is on.

Don R · « **Reply #12 on:** August 02, 2019, 06:33:15 am »

Last night I noticed there is a low speed on the right side, the check ball is frozen. It apparently should move and allow air in to operate a couple circuits. It seems to come apart like a Weber jet, I'll try to pull it apart.
A guy on the carburetor appreciation society facebook page was using old water pump pliers to remove jets without crushing them. (like for the wire spring hose clamps.)

Don R · « **Reply #13 on:** August 02, 2019, 12:12:29 pm »

Rarely have I ever worked on a vehicle so unwilling to be repaired. If I believed in that #$%* I'd think it was haunted by the spirit of what it was once. I got some free 5/16" fuel hose and it's almost impossible to slip it on a barbed fitting. It needs a new pilot jet that I ordered off ebay.
I got under it today and what the welder missed in quality he made up in quantity. Oh my. I've welded 12" sch 40 pipe and had less of a cover weld.

Scott S · « **Reply #14 on:** August 02, 2019, 06:32:13 pm »

Are you aware of www.thesamba.com ?

Don R · « **Reply #15 on:** August 02, 2019, 09:43:06 pm »

Quote from: Scott S on August 02, 2019, 06:32:13 pm

Are you aware of www.thesamba.com ?

I've been there but forgot until I was searching the carb. I found what I needed to know.
Thanks for the reminder. I searched VW powered motorcycles there once.
My VW powered design would have webers and a small alternator so the tank can sit low and not look awkward. blacked out and as clean as possible. Hidden wiring and plumbing etc.

Scott S · « **Reply #16 on:** August 03, 2019, 03:16:58 pm »

Her bike would run better AND get better gas mileage with dual single throat carbs.

Don R · « **Reply #17 on:** August 04, 2019, 08:14:03 am »

Agreed, but she has over $10K in a $4K car. I can't bring myself to tell her she needs to spend a few hundred to get what her previous mechanic took off. I'd consider publicly shaming the guy but he's probably just stupid.

Don R · « **Reply #18 on:** August 06, 2019, 03:53:57 pm »

I got the jet and no improvement. Still no low speed circuits just accel pump and main jet. I removed and plugged the fuel cutoff solenoid port and no change. I also tested it off the carb.

Don R · « **Reply #19 on:** August 10, 2019, 12:12:06 pm »

It will start and run barely, the cylinders look good, valves adjusted and seal, oil leaks fixed but it still runs like poo below 2500 rpm. If I can get it revved up the right bank seems to light up and fire. 3 and 4 are black since I flooded it 1 and 2 look new. I'm baffled. I attempted to remove the right intake but it's overlapped with the main intake tube and I wasn't willing to loosen everything else.
Edit,

The kicker is 1,2 and 3 have 55 pounds of compression and 4 has 65. Throttle blocked open, plugs out, cranking good. This is with a 92 mm big bore cylinders. She now remembered it gets so hot they had to wait for it to cool down before driving it further. I'm assuming the extra shrouds and undersize carb caused it to overheat and took out the rings. I'm recommending a full 92mm replacement cylinder and piston kit. Just because it doesn't cost that much more than replacement rings and I'll feel better about it.

dave the welder · « **Reply #20 on:** August 13, 2019, 07:32:37 am »

good call on replacing pistons and jugs as a set

Scott S · « **Reply #21 on:** August 13, 2019, 07:47:43 am »

The 92mm pistons run hotter because the cylinder walls get so thin. The 94mm pistons will run cooler than most 92's.
They do make a thick wall 92, or I think you can step down to 90.5 bore, depending on how the case was machined. I've been away from the VW world for a while.

Make sure the little deflectors are between the cylinders. Run the "sleds" tin to direct hot air out the back.
Some aftermarket shrouds don't have the correct vanes inside, to direct air down over the cylinders.

Any idea what cam is in it? Is it a doghouse oil cooler? Use foam to seal around the cooler and force air through the cooler and not slip past it.

Don R · « **Reply #22 on:** August 13, 2019, 08:17:30 am »

It is a doghouse cooler, I tightened up the tin around it but a PO cut a hole in the 36hp type fan housing

I made a carbon fiber cover but he tore up vanes inside. I'll replace that when I determine who makes the best one and take a good look at the shrouds. The recent thinking is avoid the type 3 cylinder shrouds but they have proponents also.
(I've been spending time on the Samba) On a buggy, directing the hot air out the back may be advantageous so it doesn't recycle.
I think the 34 carb has to go, it can't afford to run lean. The 90.5 kit is a good idea if the case and heads are machined correctly for it. I'd go 1600 or maybe a set of 88's if it wasn't already cut for the 92's.

Scott S · « **Reply #23 on:** August 13, 2019, 01:38:14 pm »

If the vanes are missing, that's a huge problem.

Don R · « **Reply #24 on:** August 14, 2019, 07:58:42 am »

It's like my wife said, no good deed goes unpunished. I'm pulling the engine back out for round 2. I wish we had recovered the cutaway trans case we used to have so we could start it up before putting it back in.

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Author Topic: VW air cooled guys? (Read 5122 times)