HS50 Build

[ole4]

valve spring chart. not sure how this excel sheet will copy.
White column is 26 lb spring. values are approximate you should always check seat pressure.

Pressure At Compressed Height
Height
26lb duals
0.900 8.2 9.4 7.4 5.6 20.6 38.2
0.890 8.6 9.6 7.8 6.6 21.6 39.4
0.880 9.0 9.8 8.2 8.0 22.6 41
0.870 9.2 10.2 8.6 9.0 23.8 42.4
0.860 9.4 10.4 9.2 10.2 24.8 43.8
0.850 9.8 10.8 9.6 11.4 25.8 45.2
0.840 10.0 11.0 10.0 12.4 27.0 46.6
0.830 10.2 11.2 10.4 13.4 28.2 47.8
0.820 10.6 11.6 10.8 14.4 29.0 49.2
0.810 10.8 11.8 11.2 15.6 30.4 50.6
0.800 11.2 12.0 11.8 16.6 31.4 52
0.790 11.4 12.2 12.2 17.8 32.6 53.4
0.780 11.6 12.6 12.8 19.2 33.6 54.8
0.770 12.0 12.8 13.2 20.4 34.8 56.4
0.760 12.2 13.2 13.8 21.8 35.8 57.8
0.750 12.6 13.4 14.2 23.2 37.0 59.4
0.740 12.8 13.8 14.8 24.4 38.0 61
0.730 13.2 14.2 15.4 25.6 39.0 62.6
0.720 13.4 14.4 15.8 26.8 40.0 64.4
0.710 13.8 14.8 16.4 28.2 41.2 66
0.700 14.0 15.0 16.8 29.4 42.6 67.6
0.690 14.2 15.2 17.4 30.6 43.8 69.2
0.680 14.4 15.4 17.8 32.0 45.2 70.8
0.670 14.8 15.8 18.2 33.0 46.6 72.4
0.660 15.0 16.0 18.8 34.4 48.0 74
0.650 15.2 16.2 19.2 35.6 49.2 75.6
0.640 15.6 16.6 19.8 36.8 50.4 77.4
0.630 15.8 16.8 20.2 38.0 52.0 79
0.620 16.2 17.0 20.8 39.6 53.6 80.6
0.610 16.4 17.2 21.2 41.0 55.0 82.4
0.600 16.6 17.4 22.0 42.8 56.4 84
0.590 17.0 17.8 22.6 44.8 58.0 85.8
0.580 17.4 18.2 23.2 46.2 59.4 87.8
0.570 17.8 18.4 23.6 48.0 60.6 89.8
0.560 24.2 49.6 62.2 91.6
0.550 24.6 51.2 63.6 93.6
0.540 25.2 52.8 65.0 95.6
0.530 26.0 55.2 66.4 97.4
0.520 26.6 56.6 67.6 99.4
0.510 58.2 68.6 101.2
0.500 59.8 69.8 103
0.490 61.6 71.6 105
0.480 63.4 72.8 108
0.470 65.8 74.6 bind
0.460 68.4 76.6
0.450 71.0 77.8
0.440 74.0 79.8
0.430 77.8 bind
0.420 82.2


This keeps reformatting when I save it so your on your own reading this.

 

[ole4]

Chart keeps reformatting and is un-usable. Just pm me your email and I can send the original excel spreadsheet.

 

[Rupp 72]

also see you open the area where the compression arm swings out more. that's going to totally change how the lifter rides on the tip of the compression lever. i'm guessing it will be swing to far open, more on the back side of the lever where it is round and it will try to push the compression arm lever down and out and at a angle towards the pto cover and maybe brake. it has to sit in the flat spot when fully open.

also where the cam bushing area will need to be welded up. this will help hold the arm in it's correct place.:thumbsup:

I ground the flat such that it will lay flat with the armarure fully open. And I'm just going to try the Tecumseh washer and see how that works first.

 

[Rupp 72]

Got my engine back from being bored and plated. Looks really nice, hopefully it increases the longevity of the engine especially since it'll be ran harder than normal. Also I did some porting on the intake and exhaust ports so hopefully it can breathe a lot better now.

 

[Rupp 72]

Been making more progress lately. The exhaust valve was loose in the guide and sloppy so I bought a new exhaust valve with a 32nd of an inch oversized valve stem and then reamed the valve guide accordingly to the size of the new valve stem. I also re ground the intake valve, cut both the valve seats, and then lapped both valves with fine lapping compound.

Oversized valve stem on the left.


Cut and lapped valve seats


Here is the amount of valve overlap with the camshaft installed. There is a good chance that this cam could cause the engine to fall on its face, especially at low RPM's but I'm still interested in seeing what happens anyway. Hoping for the best really.

The rest of the engine assembled.

 

[Dr. Shop Teacher]

Wow, that is a lot of overlap. Seems like you'll need to keep the revs up to keep from bogging out.

 

[Rupp 72]

Wow, that is a lot of overlap. Seems like you'll need to keep the revs up to keep from bogging out.

Yes this is going to be a race motor. So keeping the RPMs high is the intent.