HS50 help wanted

Biffmini

Biffmini

Well-Known Member
#1
#1
I'm wanting to build up a HS50 & have a new short block ( SCH 313C / SER 1074F ) that I think would be a good block for the build.

I'm going to need a donor engine, but I'm not sure what engine to look for.
I looking for external ignition & cast flywheel mod.
Should I be looking for a HSSK-50
I have the ARC ROD, & looking at 245 Dyno cam. Hopeing for pro advice before buying.
Also looking for Hot coil & not sure if still available. Still have a lot to learn & will be doing my homework...
Thanks in advance for any help.
I'm sure I'll need pro help for valves...
but I need a donor engine & clear path first.
 
markus

markus

Well-Known Member
#2
#2
since your going to up the power, I would be looking for a ball bearing supported crankshaft engine if possible, or buying a BB crankshaft and sidecover......you wont find those parts in a snowblower powerplant though. In addition to of course dropping some friction it keeps the crankshaft in check as its captive on the bearing so its not beating back and forth in the case like the bushing engines do.

Since your going electronic ignition, you want to look for a post 1981 engine as a donor if you are going that route. 81-84 will give you the shaft and sidecover only though since they are still points, 85-up would give you flywheel, flywheel spacer, cup, shrouding, etc... (same would apply for a bushing engine)

#34728 is the BB crankshaft number to look for for late models, Looks like it finally hit the NLA though on the replacement parts lists.

Good luck with it :thumbsup:
 
Biffmini

Biffmini

Well-Known Member
#3
#3
markus said:
since your going to up the power, I would be looking for a ball bearing supported crankshaft engine if possible, or buying a BB crankshaft and sidecover......you wont find those parts in a snowblower powerplant though. In addition to of course dropping some friction it keeps the crankshaft in check as its captive on the bearing so its not beating back and forth in the case like the bushing engines do.

Since your going electronic ignition, you want to look for a post 1981 engine as a donor if you are going that route. 81-84 will give you the shaft and sidecover only though since they are still points, 85-up would give you flywheel, flywheel spacer, cup, shrouding, etc... (same would apply for a bushing engine)

#34728 is the BB crankshaft number to look for for late models, Looks like it finally hit the NLA though on the replacement parts lists.

Good luck with it :thumbsup:
Click to expand...
Thanks, Markus: I have 3 other HS50 engines that have that have BB cover & crank, one that I think is a 83 (HS50 67124D ser 3354B)
Dark gray paint & two holes on front of block witch i believe dates it as 80's. So I should be good on cover & crank. So it looks like I'll be looking for a 85 + To get the correct flywheel & other goodies needed. Or just the correct flywheel & spacer & use pre 85 shroud, ect...
Thanks again for the info :thumbsup: if its not to much trouble do you have a part # for flywheel & spacer
 
markus

markus

Well-Known Member
#4
#4
34080 for the spacer and 611080 was a common flywheel number for the late 80's and 90's without a ring gear. There a re few flywheels that can be used though and ring gears can just be popped off if thats all you can scrounge up. I might have an excess of those parts, I am digging that box I keep that stuff in this week actually. I just parted down a couple of junkers that were both electronic ign, and I think I already have a few wheels packed away already. I can let you know in a couple of days, but they are usually pretty easy flywheels to find.
 
Biffmini

Biffmini

Well-Known Member
#5
#5
Thanks, Markus
I have a hot coil & cam on the way.
If your able to help with wheel that would great otherwise I have the numbers.:thumbsup:
I also like to have mod # for a late 80's engine so I can look up parts.
I'll be needing coil screws
 
tecumseh power

tecumseh power

Member
#7
#7
The Dyno 245 cam sounds good and makes good low to mid range power. Here's one in my OHH60. This engine is currently on a yard kart, and it is stout!

[video=youtube_share;NvRktcquKlg]https://youtu.be/NvRktcquKlg[/video]
 
FloridaMiniBikes

FloridaMiniBikes

#9
#9
That Ohh sounds mean!
Found info on the 285, and 98-T1 for the 5hp, but nothing on a 255.
10 Hp: Star 3, Star 5, & Star 6
about 20 similar specs for Briggs cams though, maybe should see about a sticky for them.
 
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tecumseh power

tecumseh power

Member
#10
#10
FloridaMiniBikes said:
That Ohh sounds mean!
Found info on the 285, and 98-T1 for the 5hp, but nothing on a 255.
10 Hp: Star 3, Star 5, & Star 6
about 20 similar specs for Briggs cams though, maybe should see about a sticky for them.
Click to expand...
If you make a sticky for them, I have cam cards for all 3 (245, 255, and 356) I can post. I also have videos of the 245 and 255 in engines running, and will have one of the 356 pretty soon.

 
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Biffmini

Biffmini

Well-Known Member
#11
#11
FloridaMiniBikes said:
Keep us posted on how that Dyno Cam 245 installation goes. I'm itching.....
...Here's some specs:
Click to expand...
Will do! FYI I'm new at this engine building...
I'll be studying, I'll need to pick up degree wheel at the least. Can use any & all help from you builders out there.
I'm gona need 18 lb springs, my big question
Is valves what to do. Being new at this this is the scarry part for me. & probably out of my league. SO PLEASE CHIME IN...
 
tecumseh power

tecumseh power

Member
#12
#12
Biffmini said:
Will do! FYI I'm new at this engine building...
I'll be studying, I'll need to pick up degree wheel at the least. Can use any & all help from you builders out there.
I'm gona need 18 lb springs, my big question
Is valves what to do. Being new at this this is the scarry part for me. & probably out of my league. SO PLEASE CHIME IN...
Click to expand...
You can use stock valves with 18# springs, although stainless valves would obviously be better. The bad thing about Tecumsehs is that you pretty much have to modify Briggs .250" stem aftermarket valves to our engines, since nobody makes off the shelf ready to run valves.

Being a flathead engine, you will most likely have to file in your valve lash to get it right.
 
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delray

delray

Well-Known Member
#13
#13
Stock valves should work just fine. You won't need to go the extreme like i did using briggs ss narrow stems and machining them to fit. Big thing is porting the bowls. Be careful on the back side where it is flat. That area can be thin. Unless you can weld more aluminum in on the backside outer area. I don't think you will have to go to that extreme either. Good thing is you got the good coil and will advance timing the correct amount for your dyno 245...:thumbsup:
 
FloridaMiniBikes

FloridaMiniBikes

#14
#14
Stock valves, 18# springs, stainless valves, .250 stem aftermarket valves??? What da.....
I got out of the military in 1982, and wanted to learn small engine repair, but no, Gov't
consulting would take care of the family. Now old and retired, I ain't got the brain cells for this,
But I'm trying. I just want to toss the cam in, hopefully correctly, and watch it work.
This is a lot more intense than Big Block chevy's, back in the 70's.
Do you think the Briggs and Tecumseh crowds would like a sticky on the dyno cams?
If so, who do I talk to, to get the OK? Hell I ain't even got my large avatar yet!
Ha ha! If I wasn't on this site, somebody would be paying me to take over a small country,
or two!
 
Biffmini

Biffmini

Well-Known Member
#15
#15
Thank you! For the info fellows.
I've done enough reading to know I have to do some fine tuning for lash... Its cozy to know I don't need to rework valves.I want performance, but I'm not going to run the devil out of it. Any ideas on springs & possible better keepers. Source?
 
delray

delray

Well-Known Member
#16
#16
retainers:dynocams DCSH102
keepers: dynocams DCSH103
Need to machine the inner spring step on the retainer little so the animal spring will clear.
Animal spring is the only short spring that i know that will work correct without getting coil bind...:thumbsup:
 
markus

markus

Well-Known Member
#18
#18
Biffmini said:
Thanks, Markus
I have a hot coil & cam on the way.
If your able to help with wheel that would great otherwise I have the numbers.:thumbsup:
I also like to have mod # for a late 80's engine so I can look up parts.
I'll be needing coil screws
Click to expand...
found a couple this afternoon :laugh: Hit me with a PM on the stuff you need/havent bought yet. Ive got enough of all the stuff here (coil extensions/bolts etc..)

 
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