not sure if you can do that with a hs-50 block. you would almost have to counter sink the valves and seats and then make sure the top ring doesn't interfere with the opening from the valves to piston/cylinder(rings). if the factory piston doesn't work? you could go with a aftermarket piston,but that may take some work/modifying. think it could be done,might take some work?
what ideals did you have plan that you may of thought that might work?
what ideals did you have plan that you may of thought that might work?
No angle on the valves just machine the area in front of the valves. I have been running Tec HS40 and HS50 engines for quite a few years and noticed on my aluminum cylinder engines the cylinder wall area and piston nearest the valves shows signs of blow by and discoloration down the cylinder about an inch that to me indicates flow restriction in that area. I would think that area runs hotter given the exhaust flows to that side and might account for some of what I am seeing but not all of it. The current HS50 I am building has an iron sleeve and has been honed with a deck plate, I am looking to improve flow in and out of the combustion chamber.
There is not a lot of room and on mine both valves are in a cast iron one piece insert which is cast into the head I myself would not do it. I have done it on the h50 as it is not so close.
I do think you could put a radius on the edge of the bore. I am not sure if on my h50 the relieving did anything as any flow increase is negated by the compression decrease.
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I have been thinking about how to get more power out of an HS50 and have been looking over Tec engine specs, I am wondering if a stroker can be made? I don't have a H50 crankshaft to physically check the width but the main journals are the same size the rod journal is 1/16" larger it would add 5/16" of stroke, I could make a billet rod and shorten the piston skirt then have it re-balanced. My guess is it would end up around 7 HP, there are some unknowns such as if the rod would hit the lower cylinder wall, compression ratio, camshaft alignment and I could end up with vibration issues again. I have a modified frame with the engine mount 1-1/2" lower and could still use the isolation motor mount, just some thoughts. Anyone here ever create a stroker?
Tony
Tony
two different problems with a stroker engine on a hs-50 . one side of the rod will hit the side of block(front) and the other side will hit the cam shaft between the lobes. wait three problems? if you use a h50 crank? the counter weights will hit the lower cylinder. wait again, fourth problem?
counter weights will hit the cam lobes:doah:
i think by now your really start to hate me for posting any of the information above
but you did say something that just might work?
you said you could make a billet rod.............yes:thumbsup:
if a guy could make his own billet rod in any length/dem#
i would go with a 2.815x640x.490 wiseco piston or maybe little bigger if bore size will allow it?
then take the stock hs-50 crankshaft and have it ground down .875 with the off set. making your self a poor mans stroker engine. i don't see you having any problems making the crankshaft weak at all. not with 7 or 8hp+ or maybe little more.
if you can do all that? then making a billet flywheel for it would be real easy.
purchase a animal adjustable flywheel that as the center adjustable hub. take it off and make a new hub for you tapper shaft...
this is all base on using electronic ignition(coil on the outside of the flywheel)
there is more things you could do to it. if you really want the motor to spin.......
counter weights will hit the cam lobes:doah:
i think by now your really start to hate me for posting any of the information above
but you did say something that just might work?
you said you could make a billet rod.............yes:thumbsup:
if a guy could make his own billet rod in any length/dem#
i would go with a 2.815x640x.490 wiseco piston or maybe little bigger if bore size will allow it?
then take the stock hs-50 crankshaft and have it ground down .875 with the off set. making your self a poor mans stroker engine. i don't see you having any problems making the crankshaft weak at all. not with 7 or 8hp+ or maybe little more.
if you can do all that? then making a billet flywheel for it would be real easy.
purchase a animal adjustable flywheel that as the center adjustable hub. take it off and make a new hub for you tapper shaft...
this is all base on using electronic ignition(coil on the outside of the flywheel)
there is more things you could do to it. if you really want the motor to spin.......
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ole4
could he counter sink the valves seats little and then creating a channel to the piston. thats if top ring does not interfere? and then mill the head enough to make up for the lost of CC's from channeling the air flow from the valves to the cylinder.
also maybe little porting and some stainless valves with the narrow stems installed. little bit here and there got to help a flathead run better.....:shrug:
also maybe little porting and some stainless valves with the narrow stems installed. little bit here and there got to help a flathead run better.....:shrug:
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What I need is measurements from the H50 crank, if the width across the center section of the crank is the same or narrower then any interference from the weights OD or width of each weight can be machined to clear the block, piston and cam. The next consideration would be the sizing of the crank cam gear OD, width of gear number of teeth ..ect. I machine bushing PTO HS40 and HS50 cranks on the PTO end to fit the ball bearing dimensions and shim the crank end play eliminating the retaining clip so any detail on the PTO side isn't an issue. Anyone have a H50 crank laying around for measurement?
Tony
Tony
If these pics dont show up (photobucket) here is direct link to that album Engines by Mark Detro | Photobucket
top crank is HS50 BB late model/bottom and shoved in the HS50 block is an H50 ball bearing early
top crank is HS50 BB late model/bottom and shoved in the HS50 block is an H50 ball bearing early
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That's the info I needed, markus thanks for taking the time to do that it saves me from buying a crank just to learn that. All I can do with the HS50 is improve the flow then mill the cylinder head and block to get some of the compression back. Anyone have any other ideas on how to get more power out of an HS50 without adding to the vibration issue?
Tony
Tony
I was goofing around with a BS-5 crank and one of my HS50 blocks. Looks like less cutting than the H50 midsize? The short deck height makes little room. Cutting the OD of the crank and/or trimming bottom of the sleeve, takes care of that crash.
HS50 valves are almost in the bore and with a little bigger ones cut in to the dogbone seat, REAL close.
HM valves are leaned toward the bore, sinking the bore side of the seat. Trench makes more sense there.
Unless you really sing the HS valve, I don't see a gain in flow, besides a light radius at the bore edge.
Big cam clearance can be cut in to the head.
Long side of the port is heinous, like most. I started spinning some new 5mm guides that have a chunk to fill the port, and I'd grind away the front side. It worked great on my big Kohler. Prolly easier to weld it up on an HS?
HS50 valves are almost in the bore and with a little bigger ones cut in to the dogbone seat, REAL close.
HM valves are leaned toward the bore, sinking the bore side of the seat. Trench makes more sense there.
Unless you really sing the HS valve, I don't see a gain in flow, besides a light radius at the bore edge.
Big cam clearance can be cut in to the head.
Long side of the port is heinous, like most. I started spinning some new 5mm guides that have a chunk to fill the port, and I'd grind away the front side. It worked great on my big Kohler. Prolly easier to weld it up on an HS?
How much power are you wanting to get from your HS50 ??? I have a somewhat built HS50 and it's about as far as can be taken with a stock bore and stroke , well 10 over bore .
It has a dyno 255 cam in it and ARC rod and stock cast flywheel. The intake port has been epoxied up and reshaped round to match the intake . It has stock valves but it's the big valve motor . Also has a Tecumseh Motorsports hot coil . The carb is a tec Motorsports tilly from a H50 motor motor on a long down tilted manifold, also has a custom long header . This motor is very strong and will run to the mid 7's no problem.
As far as milling the head don't do it ,it's not necessary and you won't be able to pull it over . With the cam change you lose the compression bump
and these are MF,s to pull over
It has a dyno 255 cam in it and ARC rod and stock cast flywheel. The intake port has been epoxied up and reshaped round to match the intake . It has stock valves but it's the big valve motor . Also has a Tecumseh Motorsports hot coil . The carb is a tec Motorsports tilly from a H50 motor motor on a long down tilted manifold, also has a custom long header . This motor is very strong and will run to the mid 7's no problem.
As far as milling the head don't do it ,it's not necessary and you won't be able to pull it over . With the cam change you lose the compression bump
I have a Dyno 245 cam I haven't used yet that I am going to try also ordered an ARC rod today. I have some similar intake manifolds like the one you have I made a couple one for HS40 and one for HS50 when used on a stock setup I didn't see any difference, also tried a Dellorto UA19S once not much difference there either at that time, I might not have had the right combination of parts before? I did learn recently the stock Rupp RR2 exhaust pipe is only 9/16" ID very restrictive, I made a replacement pipe with a bigger ID found that made a difference. My blocks are early HS50 with .975" exhaust valves also I do have a couple of new HSSK50 long blocks I changed up to the .975" exhaust valves. Does changing the HS50 L shaped intake port to round improve flow? Anyone sell performance coils for points ignition?
Thanks
Tony
Thanks
Tony
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Ole no I haven't run it on a bike yet but did get her mounted but still gotta build a throttle hook up . And my brothers Briggs maybe but I doubt it . I just finished rebuilding his Powell and rebuilt his raptor with similar parts as my Briggs flatty . His has the ACR long rod 4.5 and Wisco piston a 94ss cam arc flywheel. Has stock valves and 20 lb animal springs . Exhaust has a port reducer and is blended in almost seamlessly, with port work also . And Mikuni 22 for a carb .
