Gaps in the tinware

That is a California exhaust with twin manifold preheater tubes, right? Never seen one of those in the flesh before. Regarding the hole facing the flywheel it is not critical, seal it the way you see fit. Have seen the cast mark, but never the machined hole before. Is it for a flywheel trigger related to F.I., or diagnostic socket?

J.

Yep, I've got one of the special cars ;-)

Well 1974 wasn't suppose to come with FI, and the wiring harness would suggest that my car did not come with FI. I think that hole held a sensor that was related to the diagnostic test socket, the VW computer tester would using that sensor to judge engine speed, compression and ignition timing if I'm not mistaken.

Chris

You are correct, my euro spec 74 had the diagnostic plug and the sensor in the hole you show in the pictures. The flywheel had two metal pins poking out on the backside, that swept past the sensor.

My car was a dual port 1300, the most common engine in northern europe I think. Mine had dual intake preheat pipes too. It was limiting my choices in aftermarket exhausts to zero. :)

I'm okay with the dual-preheat system in my car because it looks pretty cool and plenty of volks have never seen one in person, But the pre-heat pipes on my manifold have rust damage and the passenger side has two pinholes in one of the tubes that I artfully repaired with JB- weld about...8 years ago. But changing from the 'special' dual-preheat manifold to a single pre-heat stock one is pretty simple really. Besides the tinware, all you need is a different muffler/header for a single-preheat system, a single pre-heat intake manifold, and then replace the top two studs in the rear cylinders that are longer with regular length. There is no difference in the heads that I am aware of, the whole deal is contained within the special muffler and intake manifold combination.

The EGR system is a separate headache but by the time I got this car the EGR had been removed, the EGR port capped off at the muffler(yes it has taper-threaded hole for it) and the carburetor wasn't the original, so the EGR control circuit wasn't drilled out, although the boss to accept the vacuum fitting for it is present on every 34pict-3 I've handled. I wish I could get my hands on an ORIGINAL German 1974 carburetor. I know from experience that having a good, original casting re-bushed is better than any of the new brazilian carburetors

Chris

Duct tapes works too but not the cheap stuff.

Tony

I have seen the flywheels but never the sensor.

Very few dualport 1300's in Norway, more 1200 and regular 1300 + 1500 and

1600's We also had the 1300S also refered to as the GT in some markets. Basicly a stock 1200, late style body, linkpin front with disks, swayaxle rear and a dualport 1600. In fact the fastest T1 ever built(Stock/Factory).

It was limiting my

J.

Looks like a CA engine with that dual heater riser. I have only worked on one of these changing the intake manifold boots.

JB Weld should plug up that sensor hole on the block, if you want to. VW used a sensor there for diagnostic purposes but I don't think that the techs really used that big computer to plug in to the car. I think that sensor would determine the crankshaft thrust bearing, or case wearing out, but I might be wrong on this.

Are you going to try to rebend some of the tin to get a tighter fit? Or some Silicone or RTV? OR ??? In pic # target8 it does look like some of the tin got snipped off. Hmmm do I see Anti-Seize on the exhaust studs? ;-)

I think it's bad Karma not to.

Tony

I don't think Karma cares here in Chicago one way or the other with the application of Anti-Seize on the aircooled exhaust studs! lol It is still a good idea to use it as long as the nuts don't loosen up. I believe I have tried it both ways and still those studs & nuts rust up well. HEAT is my friend along with penetrating oil. ;-)

I usually buy the Anti-Seize >> Is it bad karma to put anti seize lube on the exhaust studs?

You are supposed to use copper coated or copper nuts on the exhaust. No seizing. Brass might work too.

Jan

dave AKA vwdoc1 wrote:

HA, no seizing huh............. Tell that to the back of the Rabbit Exhaust Manifold Studs! Yes I do use those special nuts, Brass I think, on the water-cooled but not on the aircooled exhaust studs. I might try those special nuts at one of the next muffler/heater box change and see how they last. Thanks Jan.

I use brass (or copper if I can find them) nuts on all my exhaust junctions on my vw's.... i usually get em from aircooled.net

Copper! Kinda makes sense to me. I still have a bit left in a can of copper-based anti-seize I got ... holy cow, while in the Air Force in the sixties. Man, did I luck out or what?

It really works. I doubt I'd find that stuff today.

Ehh? You can get either copper or aluminum anti-seize paste at any auto parts store.

in stick form too. 8^) Even amazon.com has the copper anti-seize. I too need to buy some more since I am scraping the bottom of my last bottle. ;-)

But it ain't radioactive.

I just took a Rabbit engine apart for the fasteners (beautiful, high-grade allen-heads). Didn't see any copper anything. Everything came apart quite easily. After PB Blaster applied over two days. :)