Connecting Rod

Tommy Sampson · Joined: 23 Feb 2009 Posts: 42

Hello all, took apart a older flathead could you tell me what the 8 6 13 on one side 16 on the other and Q 13 stamped on the bottom mean? Would like to know if this is a stock rod, it does not have a briggs stamp on it. Also the piston has a 6 stamped on the bottom and 60 on the side is this the size? Thanks for helping a newbie out.

John Matthews · Posted: Fri Apr 02, 2010 6:35 am Post subject:

Hi Tommy,

Do you have pictures? Was the engine set-up for racing?

Most flatheads built for racing will have an ARC, or Horstman rod. Also they will be ported. If the rod is cast aluminum it's probably a stock rod. Are you planning on racing this motor, or just want to put it back together and run it? If you can take some pictures it will help, some guys may have every casting mark memorized but I sure don't Laughing

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John Matthews
Heartbeat Power, LLC.

Tommy Sampson · Joined: 23 Feb 2009 Posts: 42

Hello John, I will get some pictures up. Picked this up a couple of christmas(150 bucks) ago for the kids on a fun kart. Really pushed the thing well, the clutch went out, and the crankshaft was over 3/4 so I fig I would change the crank. The more I look at these things I think I can make it work for racing. Huge class at the dirt track here, so let me know what you think,and the rod and piston that would be best. Thanks again buddy.

John Matthews · Posted: Fri Apr 02, 2010 9:39 am Post subject:

It'll be a bunch of work to make a yard kart engine competitive with the local flathead class. Go here:

http://karting.4cycle.com/faq.php?

And scroll down to where it says "flathead blueprinting". Unless it was built for racing by someone who knows what they're doing you'll be dollars ahead just buying a used motor from another racer.

On the other hand, if you just want to get out there you can put it back together and run it but you'll be way down on power compared to the other guys.

The main things to look for before you start are, is it a cast iron bore or aluminum, dual bearings (both sides of the crank), what carb does it have?

I thought you had an Animal you were working on? If so that'll be a much better starting point than a used fun kart motor.
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John Matthews
Heartbeat Power, LLC.

Tommy Sampson · Joined: 23 Feb 2009 Posts: 42

What I like about you John, no bull. It is just a project to learn some more, I am still putting the parts together for the Animal. Looks aluminum, no bearings on shaft, filp carb. Chrome gas tank and blowhousing I have a 6.5 honda on this kart now and it felt almost as fast. but your right used built one prob the way to go. Is there a way to tell if was ported? Do know a guy who could do that for me. Thanks John

John Matthews · Posted: Fri Apr 02, 2010 2:16 pm Post subject:

Sounds like a fun kart motor to me, I really wouldn't bother rebuilding it if you have the cool bore (aluminum) cylinder as they are quite easy to trash and require a special hone to prep for new rings.

The only way to tell if it's been ported is to look at / feel the ports. It'll be smoothed out where the port turns up from the block to the valve. If you really want to build this engine I'd recommend you try porting it yourself. All you need is a dremel and some sanding drums. There's a tutorial here:

http://karting.4cycle.com/faq.php?faq=new_faq_item#faq_porting

The reason I say to do it yourself is it'll cost more than buying the dremel if you have someone else do it, and the likelyhood of it ever being a really good engine with no bearings and aluminum bore is extremely low. You might as well use it to learn Very Happy

Good Luck,
_________________
John Matthews
Heartbeat Power, LLC.