Author Topic: 8hp rod Idea  (Read 6972 times)

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Offline 08racernoob

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8hp rod Idea
« on: June 05, 2008, 10:11:38 pm »
Hello im  new to this forum and new to lawnmower racing
 I have a idea about the stock rod length. What if we used a shorter rod with a lower wrist pin to make up for the difference then wouldn't the less stroke allow for faster and higher revs with less stress on the rod? I think it is something like that in the honda cars (not positive though)



         after reading what i posted i feel really dumb :bash: :oops:

Offline FlatheadPuller

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Re: 8hp rod Idea
« Reply #1 on: June 05, 2008, 10:18:52 pm »
Well a short rod long piston is a bad thing. Your better off with a long rod short and lighter piston. It is easier on bottom end parts, less rod angle ratio, and its easier to rev. Just all in all its easier on the engine. The goal is to make the rods job easier to hang onto the piston.
Dennis Bazzett
Grandville Michigan

Offline 08racernoob

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Re: 8hp rod Idea
« Reply #2 on: June 05, 2008, 10:20:20 pm »
ok thanks for clearing that up i appreciate it ;)

Offline grantwt

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Re: 8hp rod Idea
« Reply #3 on: June 06, 2008, 11:50:42 am »
If your a bit of a tech geek like me you should read the wikipedia article on four stroke engines.  Down in the section called "Output Limit" it actually goes over the pros and cons of rod-stroke length.  Its fairly interesting.

http://en.wikipedia.org/wiki/Four-stroke_engine

Offline 08racernoob

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Re: 8hp rod Idea
« Reply #4 on: June 06, 2008, 12:14:10 pm »
 ;) awsome  article it explains it all

Ok another question what is the crank stroke length ? and rod center to center length?

Offline mightymowe

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Re: 8hp rod Idea
« Reply #5 on: June 09, 2008, 09:15:35 pm »
The crank stroke length is just what it says,the crank and only the crank,determines the length of stroke that the piston makes. The rod centre to centre length is the length from the centre of the big end to the center of the small end on the connecting rod.
David Peters

Offline gnnova

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Re: 8hp rod Idea
« Reply #6 on: June 10, 2008, 07:26:52 pm »
Hey the link that is posted list Jere Stahl as a reference.  I worked for him in the late 70's early 80's building headers.
Ken
SP #355
#2 SP 2007/>#2 SP 2008