Valve stem size

[xlfan]

I have a bare head set with casting nos 17248-07A and 17250-07. It is installed 5/16" valve guides. Could that be stock?

Does anyone know if H-D p/n 18190-08, 2.125" intake valve is 7mm stem or 5/16" stem?

[SP33DY]

0.3095"

[xlfan]

Do you mean that stem dia of 18190-08 is .3095", or that .3095" is stock valve guide in the 17248-07 and 17250-07 head castings?

[SP33DY]

Do you mean that stem dia of 18190-08 is .3095", or that .3095" is stock valve guide in the 17248-07 and 17250-07 head castings?

17248-07 and 17250-07 head castings are from a 110. They came with 0.3095" valve stems from the factory. It came with 18183-03 which is a 1.625" exhaust and 18187-07 which is a 2.08" intake valve. I have a set of these heads in the shop now, so I just double checked and measured.

Going from memory here...the 18190-08 was used in the 120R heads and as I recall it was also a 0.3095" stem valve.

[xlfan]

Thanks 0

[jsachs1]

Do you mean that stem dia of 18190-08 is .3095", or that .3095" is stock valve guide in the 17248-07 and 17250-07 head castings?

17248-07 and 17250-07 head castings are from a 110. They came with 0.3095" valve stems from the factory. It came with 18183-03 which is a 1.625" exhaust and 18187-07 which is a 2.08" intake valve. I have a set of these heads in the shop now, so I just double checked and measured.

Going from memory here...the 18190-08 was used in the 120R heads and as I recall it was also a 0.3095" stem valve.

The 1.625" ex. valves, (18183-03), used in the 110"heads are shorter (4.489") than the 1.625"ex. valves (4.530") used in the other heads that had them. The shorter 1.625" ex. valves also have a red paint dot on the stem tip. The 120 R intake valves (2.120") are .040" shorter than the 2.080" SE 110 intakes. All above have .3095" stems.
John

[xlfan]

Interesting, the 18190-08 is a 120R valve.

Would it be necessary to correct these .040" stem length differences to obtain equal spring pressure (to stock), if clearancing are checked valve to valve, coil bind, valve to piston TDC and cover clearance?

[Don D]

Once you set the protrusion at 2.0" everything comes together. The factorys vendor did just that and milled the MVA head .025 to bring back the compression. Valve to valve is liberal due to the chamber side geometry and valve angles