Twin Cam engines have been out since 1999, so there’s big chance if you ride a Harley you’ve had to service one or more of the poorly designed OEM cam chest components. The first gen Twin Cam (99’-06’ excluding 06’ dyna) especially had numerous weak points. The spring loaded chain tensioners put a major mechanical drag on the chains which are performance robbing, cause excessive wear, and have relatively short life spans. The oil pump doesn’t scavenge (return) as efficiently as it should which can cause multiply issues one commonly being that nasty oily air cleaner. Stock cam plates are casted so they are not very strong and are prone to flex. The stock oil bypass pressure relief valve and spring are supposed to hold to a certain PSI, yet it’s still common to see them pop off prematurely as well. The second generation Twin Cam (07’ and later & 06’ Dyna) made some improvements like changing the chain tensioners to a hydraulic unit but still had its weaknesses. For example the second gen 96”/103” have eliminated the outer cam bearings in the cam plate and rely on a thin oil film fed to the bore to act as the bearing.
What’s the fix to all of this? Nowadays there are plenty of great aftermarket companies even Harley’s Screamin Eagle sector that offer an upgraded oil pump, cam plate and tensioner options. We have used them all here a Ramjet’s and can honestly say that they are all good. S&S has been a leading manufacturer in the industry for decades and their quality is relatively second to none. So about a year or so back when they first dropped their TC3 series pump & plate kit for early and late Twin Cams, we couldn’t wait to get our hands on one. The TC3 pump and plate kit fixes all of these issues and generally improves everything across the board. The cam plate is a billet plate making it much more rigid than the stock cast one to help eliminate the flex. All the passage plugs are removable so it’s easy to clean and flush the plate in the event of any contaminants entering the oiling system. On the TC3 cam plate for late model Twin Cam applications, being there is no outer cam bearings; S&S runs replaceable bronze bushings! On an OEM cam plate the spring rate for the pressure relief valve isn’t strong enough. Feuling makes a great inexpensive upgrade with a new spring and piston but you have to remove the plate from the engine to do the swap. The TC3 plate comes with not only an adjustable pressure regulator valve but it can be done without have to remove the plate from the engine.
Now, onto the oil pump. Stock ones are not very tolerant to the excessive pinion shaft run out that a lot of stock Harleys have so they can get chewed up pretty easily, and like I mentioned before suffer from poor scavenging and pressure output. S&S found a solution for all of that. Rather than having a pair of inner and a pair of outer gerotor gears (one for scavenging the other for feed). TC3 oil pumps are a three stage system. There are two separate scavenge sections, one for the flywheel cavity and the other for the cam chest. The gerotor gears also can tolerate much more pinion shaft run out without damage. Our favorite part about the TC3 oil pump is the is the preventative measures they took by designing the oil pump with a stainless steel filter screen followed by a magnetic pick up to stop any hazardous metal materials from entering you pump and eventually back through the rest of the motor!
Lastly the TC3 cam plate requires the use of a hydraulic tensioner unit, you’ll use the OEM replacement ones from the late model Twin Cam or aftermarket on both early and late kits. S&S just release their own units that are much better and beefier than stock. S&S tensioners have a larger diameter piston, thicker shoe, tighter tolerances and built in direct chain oilers! These components are the best way to go when upgrading from stock whether it be from stock parts being damaged or just for a great performance and preventative upgrade. Don’t let the lacking stock components leave you on the side of the road or cause a bigger, more costly problem! TC3 pump & plate kits retail for $674.95, the chain tensioner pair retails for $129.95. We carry these items in stock so give us a call and if you have any questions and or would like to schedule an install! Mention you saw this article in AZBIG for a 10% discount!!!
By Ramjet Racing Motorcycle Shop
13207 North Cave Creek Road, Phoenix, AZ, 85022