H30 piston
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The .010 over for H30's are all over ebay, like 4 sets of rings available right now and probably 5 pistons (they sold those separately usually in that size bore). Your engines parts numbers will pull up parts lists avialable online, you can use them to find the part numbers for the OS parts.
If its a 1970/80's engine block, I use the optional Mechanical release camshaft Tecumseh used an offered on post 1970 built engines, or the pre 1970 no compression release at all camshafts (they had a hole drilled into the valve seat on the earlier engine blocks for the compression release), Both maximize the compression the engine can make with stock parts. the ealry camshaft is #31317 and the Mechanical camshaft is #32197 and #32197A
If its a 1970/80's engine block, I use the optional Mechanical release camshaft Tecumseh used an offered on post 1970 built engines, or the pre 1970 no compression release at all camshafts (they had a hole drilled into the valve seat on the earlier engine blocks for the compression release), Both maximize the compression the engine can make with stock parts. the ealry camshaft is #31317 and the Mechanical camshaft is #32197 and #32197A
Hey guy's...I decided to take a different direction. I have a 3.5 Power Sport motor. I took it apart and noticed it had the boses under the flywheel for the ign assy. I drilled and tapped the boses. Then turned the crank down so the flywheel off of the H30 would fit. Now I can use the flywheel cover/recoil from the H30. That way the motor will look correct. Other than being stuck with the old style ign. Do any of you see a problem with doing this?? Thanks, Gene.
I dont see a problem with that as long as the taper is properly cut and the flywheel seats correctly. I would use the 1983 specifications of .035 btdc setting for the timing over the old .065 btdc . That is the year that the stroke and block changes occurred in that series of the small frames and the last year that they used points, and your newer H35 PS is now the same stroke as an HS40/HS50. When I saw this post I went out and dug out some flywheels to see if there was any significant changes to correlation of magnets to the key on the wheels (never really bothered with that when it comes to the H and HS aluminum wheels since they don't interchange without machine work) It appears that they all are in the same position, I even double checked with the steel wheels both small taper (1975-1979) HS and the Late large taper (1980-1984) which is supposed to be universal small frame.
Let us know how it comes out, I use the late model blocks a lot for replacements for the HS series in rebuilds, The H's with the journal change one the case side though has been a problem. While I think that there is a bushing/bearing insert that can be used to install the earlier cranks with small taper, Tecumseh never seemed to have any extensive info like that in the repair books like briggs did for some reason.
Let us know how it comes out, I use the late model blocks a lot for replacements for the HS series in rebuilds, The H's with the journal change one the case side though has been a problem. While I think that there is a bushing/bearing insert that can be used to install the earlier cranks with small taper, Tecumseh never seemed to have any extensive info like that in the repair books like briggs did for some reason.
in your first post you where asking about performance up grades. with the newer setup your using i believe you maybe able to use a ARC billet rod. as mentioned earlier by markus you have a hs-40/50 stroke now and all the newer small blocks use the hs-40/50 con-rod. dyno cams will weld up your cam for you too. 245cam would be the one for you or stock cams will buzz up 4700+ no problem also with the correct mods. if your still interested in performance mods any of us can give you part numbers...etc...
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Thanks for the extra info! And thanks for taking the time to compare parts!! Just got the rings, seals and stuff yesterday. I still have to deepen the key way. Although, the cam for the points does fit really good. A lot of the grove went away when I turned the snout down. I am going to go back with the stock cam, carb and etc for now. But it will be a little while before I get back to it. I have my Uncle's Model A to get going first. Thanks again!!! Gene.
Note that a standard HS cam (modified or not) is going to reverse intake and exhaust, and the engine will run like that, (I have one with a keihn carb sitting there) the exhaust porting is way small on the H35. I'm only chiming in with that, because we've talked about the "Bungholio" engine, and when I built one, I noted the "now" intake was anemic- and so grinding the H35 cam as Delray suggests would be the best way to do it, not using one of the many HS 245 cams in existance.
yea that’s a pretty significant amount of material to remove, looks like about the same 10 degree (I think those late models are) taper but a much smaller diameter. You can see on the small tapers where the key cut is well into the snout threads even. Hence all the problems with the snouts breaking off from people not using the correct methods to remove and install.
should be a good running engine, they dropped the upper spring retainers in that era though, if your old ones are good I would install them when assembling, I like having them on the springs. Have fun with it!
should be a good running engine, they dropped the upper spring retainers in that era though, if your old ones are good I would install them when assembling, I like having them on the springs. Have fun with it!
HA! Thanks Gene. The RT is original, I have the docs from when the original owner bought it in LA in late 66. The owner was an airline pilot, and had the car fully optioned with AC and Power Windows, both of which ancient systems I have worked on within the past two weeks. 
If you know anyone who needs a rare, NOS AC fan switch for $100 I am your man! (grin) In addition to Markus' knowledge of part numbers, history and fitment, Delray has done a bunch of hot rod R&D on these engines and been kind enough to share it with us. He mentions the cam grind and the billet rod above, but also has the scoop on improved valve components that many of us have used with great success. I think you have a cool project going on here, as I'm sure do the rest of the Tecumseh fans on here.
If you know anyone who needs a rare, NOS AC fan switch for $100 I am your man! (grin) In addition to Markus' knowledge of part numbers, history and fitment, Delray has done a bunch of hot rod R&D on these engines and been kind enough to share it with us. He mentions the cam grind and the billet rod above, but also has the scoop on improved valve components that many of us have used with great success. I think you have a cool project going on here, as I'm sure do the rest of the Tecumseh fans on here.