:UW Neuspeed adjustable cam pulley for 8Vs by Dan Barnes PHOTOS BY THE ALJTHOR To use a metaphor less tired than the one about the air pump, let us say that an engine is like an orchestra. All the parts must be tuned together, playing the same song, to the same rhythm. If that is the case, then the camshafts are the sheet music, the master plan followed by every player, and the framework for any changes or improvisations. The three basic characteristics of a cam are its lift, duration and timing. The proper choices for all of these depend on the design of the intake and exhaust manifolds, the ports and the compression ratio, to name just a few of the variables. The problem is complex, and many volumes can be written on camshaft design. However, there are some general rules that enthusiasts can use to select a camshaft, and with most common engines there is plenty of experience in the marketplace to draw upon. A camshaft's lift and duration are fixed, ground into the profile. Changing them requires changing the cam itself. The third, timing, depends on the camshaft's drive apparatus, which in some cases is quite easily modified. For instance, Neuspeed recently introduced an adjustable cam timing gear for BV fourcylinder Volkswagen engines built from 1975 through 1998 (all VW chassis from MKI through MKIII, but not the New Beetle, Golf IV or Jetta IV) Camshaft timing adjustment is an important tool for the engine tuner, as attested to by the increasing use of variable timing mechanisms at the O.E. level in high-performance engines. Most of these 126 european car
applications have separate intake and exhaust camshafts. but changing timing is still useful on singlecam engines, which have intake and exhaust lobes on the same shaft. In general, advancing the camshaft on single cam engines will give better low-end torque. while retarding the cam will give better high-end power. Thus. within a moderate range, an engine's power characteristics can be changed as desired. As a simple modification for a street-driven car, an adjustable cam timing gear has several advantages over a cam swap. The cam gear is less expensive. It is easier and simpler to install, and requires no valve adjustment, a necessary procedure when changing the cam on an engine that doesn't have hydraulic tappets. Another use for the adjustable cam timing gear is to restore the original timing when a cylinder head has been milled. as is sometimes done to raise compression. The Neuspeed cam timing gear allows adjustments up to 7 degrees of advance or retard. These are camshaft degrees, which equal twice as many degrees of crankshaft rotation. Thus, valve events can be made to occur up to 14 degrees earlier or later in the suck-squeeze-bang-blow cycle. The main gear and teeth of this Neuspeed part are machined from 7075 T-6 aluminum and hard anodized black to eliminate wear and protect against corrosion. All markings are laser-engraved on the gear. The inner hub is machined from 6061 T-6 aluminum and hard anodized red. It features locking stainless-steel threaded inserts for the adjustment screws and comes with a hex wrench to make the timing adjustments Installing the gear is straightforward and should be well within the abilities of anybody who has basic hand tools and the ability to read the clearly written instruction sheet. The only special tool required is the timing belt tension adjuster The one Neuspeed uses in its shop is VW tool number T1 0020, made by Hazet. I photographed this installation as performed by Aaron Neuman at Neuspeed Though it usually takes him considerably less time, Aaron recommended that first timers should allow as much as an hour and a half to understand everything and take their time to avoid mistakes. Using hand tools should add only a few min- At a Glance What is it? Neuspeed adjustable cam timing gear, P/N 3-62.10.21 What does it fit? VW SV four-cylinder sohc engines. 1975-1998. What does it do? Changes cam timing relative to the crankshaft. Allows engine power to be moved from low rpm to high rpm or vice versa. Neuspeed 3300 Corte Ma I paso Camarillo, CA 93012 (805) 388-7171 (805) 388-0030 www.neuspeed.com june 2000 121
utes to the time required with air tools because of the small number of fasteners involved. Camshaft timing should be adjusted only after the installation is complete. Adjustments are made by loosening the four adjustment bolts and rotating the camshaft (not the engine) to the desired position. Always make adjustments with the engine at TD C, and torque the four adjustment bolts to 10 lb-ft afterward. Some show enthusiasts li ke to leave the cover off the timing gear, but it is safer when working on the engine to have it on. The cover also prevents the entry of dust which accelerates the wear of the cam drive apparatus. Test drive the car immediately after work is completed to ensure no mistakes were made. This cam timing gear will fit any VW 8-valve motor 1975-1998; this installation was done on a 2.0L engine in a MKIII-chassis Cabriolet. On this engine, Neuspeed says retarding the stock cam four degrees will add about 5 hp to the top end. With a Neuspeed street cam, the use of the adjustable gear is not recommended, because that cam's powerband is very broad and the gear will add only about 1.5 hp. With radical cams-i.e., those having duration on the order of 280 degrees-the adjustable gear may help bring back some low-end power. The changes would likely be a few horsepower redistributed, but Neuspeed has not dyno tested such configurations. The Neuspeed adjustable cam timing gear for VWs appears to be a quality, long-lasting product, is easily installed, and has impressive fit and finish. It may be an affordable alternative to a cam upgrade for a mild street car and provides another element of tuning freedom on more ambitious projects. It could also be viewed as a service part in some cases, as it wil l restore proper timing for engines on which the head has been milled. If you find yourself with any of these needs, it should be an excellent solution. 1. First remove the strut tower brace, if fitted, and then the intake tube. Any extra wiring should be pulled clear of the upper timing cover. 2. The upper timing belt cover is freed by the removal of two bolts. 3. Put cylinder #1 attop dead center on the compression stroke. This can be done on manual transmission cars (on a level surface only) by putting the car in fourth gear and pushing it slowly. With an automatic, a wrench must be applied to the crankshaft. The first indication, sometimes difficult to see, is the timing mark on the crankshaft pulley, which aligns with an arrow molded into the plastic lower timing cover. Another method is to remove the green plastic plug from the transmission bellhousing and look for a marker on the flywheel. Neither of these methods can indicate whether the engine is finishing the exhaust or compression strokes. 128 european car 4. 1993-up 2.0L engines have a plate behind the cam timing gear with a mark that must be aligned with the mark on the front ofthe gear labeled " QT." Earlier engines have a mark on the rear ofthe cam timing gear that is aligned with the front edge ofthe upper surface ofthe head. In either case, be sure to mark the rib ofthe belt that aligns with the mark on the cam timing pulley. Wite-Out works great for this. 130 ~
<011 128 E 5. Loosen the timing belt tensioner pulley. 6. It is important to keep tension on the belt to prevent it from jumping a cog on the intermediate shaft. A bungee cord to the underside of the hood works well.lfthe belt slips a cog on the intermediate shaft, the distributor will become unsynchronized, causing very poor running and the check engine light to come on. 7. Remove the cam gear retaining bolt. If an 1m pact driver is available, it will be the easiest method. If only hand tools are available, jam the sprocket against something, while being careful not to damage it. In either case, never use the belt to hold the sprocket while loosening or tightening the bolt. It is advisable to stuff a rag in the lower timing cover to prevent the Woodruff key on the camshaft from falling in, as retrieving it from there is both labor-intensive and non-optional. Slide the cam timing gear off the camshaft. 132 ~ <011 130 8. Ensure that the Neuspeed adjustable cam timing gear is set straight up, at zero degrees, and the four adjusting screws are tightened. Then slide the gear onto the cam, being careful thatthe Woodruff key is not pushed out of its slot. Torque the center bolt to 58ft-lb. Do not use the beltto prevent it from rotating. 9. Replace the belt. The mark made earlier should line up with the timing mark on the new pulley. 10. Adjust the belt tension to the proper specification for your engine, and tighten the tensioner bolt. Any VW tool supplier should have the necessary tool. ~ AUTOMOTIVE PERFORMANCE SYSTEMS. INC. 3300 Corte Malposo Camarillo. CA 93012 805.388.717 1 tel 805.388.0030 fax info@neuspeed.com WWW.NEUSPEED. COM