AC pulley

[Fred Otjen]

I have two engines (both in cars) that have the AC pulley on the rear crank pulley. Neither car has or will have AC. So, I'm wondering if it's worth removing the AC pulleys and if the same bolt can be used once removed. Any inputs welcome.

[Richard Shilling]

Remove or not - it's your choice. But 'back in the day' I had a problem with a 356 engine I'd overhauled. The timing mark on the air conditioner pulley was in the wrong place. If you do switch pulleys, check the timing. Too far back to remember if the pulley bolt was the same.

[Martin Benade]

I think you are referring to a 912 pulley that is set up to drive an air pump, not a.c. the bolt is the same, and I believe the timing mark is too. The pulley is one piece so you would have to replace it with a regular one.

[Fred Otjen]

They appear to be separate pulleys. See pictures. The 912 is a '67 so no air pump and it has indications that the car AC installed at some point.

[Martin Benade]

That's a different one, I am not familiar with that style .

[Brad Ripley]

Lot of unnecessary weight at the end of the crankshaft. Buy a new pulley.

[Al Zim]

A longer rear pulley bolt was used on the 912 (i believe). If your pulley bolt does not have a flange on its edge then it is probably not a Porsche/VW bolt. Zim's stocks this bolt cleaned and plated and a new wave washer. Regarding the extra weight of a cast iron pulley on the end of the crankshaft, keeping or removing it will not make a significance in performance. VW drag racers, made an extra heavy pulley for the end of the crank so there would be more kinetic energy as the car launched down the quarter mile, al zim 2018/10/02

[Brad Ripley]

I know of only one basic design and length of the pulley bolt used in all 2-piece case engines: p/n 539-02-112. see photos below for Porsche vs VW bolt. The Porsche bolt is no longer available from Porsche -- hence the replacement part Stoddard makes. If you want an original, then according to Al Zim, you can get a restored bolt/washer from ZIMS-- but don't see anything on the ZIMS website nor a price.

[Brad Ripley]

Sorry --- that was "on all 3-piece case engines ......

[Al Zim]

A longer bolt (part number 616.102.168.00) was installed when the pulley with two grooves (one for the air pump) became standard. Without digging through the warehouse, my recollection is that this pulley was about 10MM longer. It was discontinued in 2014. Not everything we do is in our catalog! Zim's can repair front spindles when the King Pin is loose, rebuild and install brass bushings for the Link Pins, check the dimensions of the the trailing arms. We can make a concurs bolt for your oil filter top. Replace ring gears on your flywheel, resurface flywheel install positioning holes to use a diaphragm (356B) clutch on your 180MM (356A) Flywheel so you can use the 741 clutch release mechanism. We can lathe turn your brake drums centering the drum with a 4 jaw chuck rather than through the center hole then arc the brake shoes to the drum on a brake arcing machine. Head service is available, we set the interference fit on the valve guide to head, diamond hone the valve guides, measure the valve spring for proper tension, and assemble the heads. Everything is cleaned in an huge ultrasonic cleaner and we have 3 types of media for bead blasting. We will be glad to quote you on a special project. Please call about our services 800.356.2964 al zim 2018/10/03

[Steven Clarke]

Fred:
My 65 coupe had the Delanair AC system installed by Brumos when the car was fairly new. The drive pulley was identical to the one in your photos. By the time I bought the car the whole AC system was gone except for the pulley.
Eventually I pulled the engine and removed the AC pulley. Upon inspection of the stock pulley I saw that the Woodruff key slot was cracked. While this is not uncommon, no doubt the added stress from the AC compressor was an added factor.
As for the bolt, it is longer than the stock pulley bolt to account for the additional thickness of the extra pulley.

KTF,
Steve