After much time and testing of various combinations of valves, guides, and seats, we are happy to announce our No Lead Conversion Process, a combination of parts and cylinder head work that makes your pre-Evo Harley engine run just fine on no-lead gas.

Let’s start with the valve seats, the area of your combustion chamber most prone to overheating due to no-lead gas.

Our replacement valve seats are .060"oversize and composed of an exotic alloy of expensive minerals: 42.1% nickel, 34.12% iron, 12.3% chrome, 6. 7% molybdenum, 2.02% carbon, 1.63% silicon, and 1.13% manganese. The high nickel content allows the valve seat to expand and contract with the aluminum head.

Now to the process: After glass beading the old valve seats are removed. Your heads will be machined to a .005"interference fit at .450 degrees before installation of the new valve seats.

The seats are then matched by hand to the ports and combustion chamber. Mild porting is included at no extra charge. The seats are ground to specified height and narrowed to .060" on the exhaust and .045" on the intake, then radiused and polished into the port.

Now to the valve guides: Our cast-iron valve guide is porous and retains more lubricant. It also resists dimension changes at high temperature thus maintaining proper clearance.

Here’s the process: The old guides are removed and measured. The holes are cleaned and checked for size. The heads are again heated to 450 degrees and .002" larger guides are installed with our special sealer and solid copper gaskets. 

The valve stem to guide clearance is then machined to .001" on the intake and .002" on the exhaust. The valve guides are then machined for the stem seals.

Our valve stem seals are all Teflon with dual springs. One is used to hold the seal to the guide and the other is used to maintain proper tension on the valve stem. This positively stops oil consumption, increases vacuum in the intake port, and stops blow-by in the exhaust port.

Our new High Flow valves are the highest quality. The intake is made of solid tool steel tested at “68 ” Rockwell, with polished head and nitrided stem. The exhaust valve is made of stainless tool steel with polished head and nitrided stem, to resist distortion and wear at temperatures in excess of 2200 degrees. These valves are guaranteed for the life of your engine.

Knuckle and Panheads are uprated to accommodate 1.937" Intake valves. Ironhead Sportsters are uprated to 1.750"Exhaust valves. The valves are hand lapped to the seat for a positive seal.

Your valve springs will be tested and replaced as needed for the camshaft of your choice. So, we need to know the valve lift of your cam before final assembly to be sure adequate clearance is provided.

Stripped threads will be repaired and charged to you accordingly unless otherwise requested.

The No Lead Conversion can be done in two weeks turn-around time. Shipping time can vary according to your schedule. Please specify your preference.

Our work and products are guaranteed for one year. For an estimate on your particular application contact us directly by telephone at 805-481-6300. Or you can e-mail us.

Shovelhead with No Lead Conversion

No Lead Conversion Components

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