In the last month I have received a bunch of phone calls about the parts I make and how they are used to put K or KH top ends on WL cases.
I thought that for each call I received there are many others out there who were wondering about what is involved.
So , here it is.
I know that there are many ways to do this in addition to what I have listed and think it might be helpful for others to let us know what they have done.
Also, many thanks to those that have previously posted on this subject or had discussions with me, including Dr. Dick, Panic, Patrick, Celtic Dodge and others too numerous to list.
HOW TO PUT K & KH MODEL CYLINDERS ON WL CASES
WHAT YOU ARE CHANGING
The biggest problem is that the cylinder stud by the exhaust valve is in the wrong location! This is the only machining operation involved other than for replacing cam lobes. Other than this it can be an entirely "bolt on" situation
Use a 3/8-16 threaded aluminum rod or bolt to plug the existing hole, use red locktite and tighten. Cut off and file or machine flush. Drill and re-tap using a K model base gasket for location.
The K cylinders have the valves at an angle tipped toward the cylinder bore. The angles on the intakes and exhaust are different and are also slightly different than what is used on the WR. The WL valves are in a plane that is parallel to the bore.
This was accomplished by grinding the cams at an angle and having the tappet guides at the same angle.
The best solution is the use WR cam angles with WR tappet guides While some builders have run K/KR cams with WR guides, the angle difference places a strain on the rollers and the may fail prematurely.
The positioning of the tappet adjusters to the valve centerlines is negligible on the intakes, while the exhaust are off about .045”. In actual usage this does not appear to cause any problems other than accelerated wear on the top of the adjusters.
The angles are as follows.
WL 0º 0º
WR 1.033º 3.533º
K models 1.0º 3.0º
WL cams are for bushings while WR cams have ball bearings, and will not fit in WL cases without machining them. Engineering tests have proven that a well lubricated bushing has less friction than ball bearings. Also the WR had a problem with breaking the turned down shaft on the #4 cam shaft.
The WR cam profiles are for flat tappets and will not work with roller tappets!
Also the WR tappet guides are made for the flat tappets which are wider than the roller tappets, the standard WR guides must be welded and remachined.
I recommend that for street use the hottest cam to use is the KHK profile. It is actually a hotter profile than was available in the flat tappet WR.
WR valve spring covers must also be used as the WR style tappet guides are not threaded. These use a o’ring seal and retaining screw on the guide and a rubber band seal on the slip joint.
WHAT PARTS DO I NEED?
Cam profiles with the correct WR angles for roller tappets *
WR angled tappet guides for roller tappets *
WL or K model roller tappets with adjusters (standard re-pop items)
KH cylinders require longer adjusters *
WR valve spring covers, longer covers for use with KH cylinders are also available *
Stronger valve springs for more aggressive KR profile cams *
Light weight valve spring retainers * (these use the stock keepers)
Stainless steel KR valves *, These have 45º angles, can be reground to 30º for racing applications, valve guides need to be honed
*these parts manufactured by Enfield Racing
Good luck and have fun,
AHRMA Dirt Track # 67J