Connecting rod crank diameter

markus

Well-Known Member
#21
I would contact Clements as they probably made those rods, I would also inquire at the same time as to his thoughts on running the bearings on a standard shaft.....the Motorsports cranks were treated/coated as were the camshafts.
 
#22
I would contact Clements as they probably made those rods, I would also inquire at the same time as to his thoughts on running the bearings on a standard shaft.....the Motorsports cranks were treated/coated as were the camshafts.
Is this gentleman still around?
 
#25
Skipp he is on facebook not sure if he is still on here or not . I think the ARC rod bearing part numbers were the 6391 for the 5.5 engines .
 

delray

Well-Known Member
#28
I would contact Clements as they probably made those rods, I would also inquire at the same time as to his thoughts on running the bearings on a standard shaft.....the Motorsports cranks were treated/coated as were the camshafts.
just to add to markus was saying. look up Tecumseh power 356 build. he shows the same rod and a coated crank.
https://www.oldminibikes.com/forum/index.php?threads/dyno-356-cam-extreme-build.158209/
he might too have a part number? but I don't think he is on here anymore.
 
#30
I would contact Clements as they probably made those rods, I would also inquire at the same time as to his thoughts on running the bearings on a standard shaft.....the Motorsports cranks were treated/coated as were the camshafts.
Markus my H50 motorsports crank was not treated but if I remember correctly it is smaller than a stock H50, but I'm sot sure of that.
 

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delray

Well-Known Member
#31
Markus my H50 motorsports crank was not treated but if I remember correctly it is smaller than a stock H50, but I'm sot sure of that.
ole I was wondering what was the width on a H50. I don't think the treated crank has anything to do with the bearings...either.
 

markus

Well-Known Member
#33
Markus my H50 motorsports crank was not treated but if I remember correctly it is smaller than a stock H50, but I'm sot sure of that.
How about hardened?:



I have an old karting article comparing the Tecumseh to the Raptor and in it it does state that Tecumseh was working on Plasma coating the journals that may be the black oxide coating that you see in the later years??? Regardless, I would ask clements if I had the chance, HS/OHH cranks are soft and nobody else seemed to make rods with bearing for them, just to be safe. They may even have been modified (the crankshaft) like the H50 motorsport was to fit the rod/bearing in it I dunno Never owned one of the OHV versions.
 

delray

Well-Known Member
#34
maybe to help answer your question markus if a person can run a bearing/rod on a stock Tecumseh cast steel crank. going back on Tecumseh power 356 build. he stated he ran a stock 172cc crank with the bearings/Tecumseh rod. he never use the performance crank that was coated. another good example OND ran bearings/ rod with a stock H70 crank. I even ran a billet briggs/bearing rod on a Tecumseh stock cast steel crank...no problems.
maybe one of the reasons Tecumseh use bearings in the race motors so a guy could rebuild/refresh engine for the next race/season.
 
#39
Well as usual I screwed up the pics line up , so you will have to read between the lines . I'm not really sure Michael was real familiar with the HS engines though . Or If he is like me and forgets sometimes ! lol
 
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