Author Topic: Honda GXV340 Performance Help  (Read 16821 times)

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Offline westcoast racer

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Honda GXV340 Performance Help
« on: August 26, 2010, 03:01:26 pm »
Has anyone used this type of engine before?  It is an 11hp OHV engine.  Does anyone have any ideas where I can get performance parts for it?  Can it be bored or stroked?
Dan Borba

Offline Jeff Digou (Pitguy)

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Re: Honda GXV340 Performance Help
« Reply #1 on: August 26, 2010, 04:22:43 pm »

Windsor Ontario Canada<br /
Jeff Digou

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Re: Honda GXV340 Performance Help
« Reply #2 on: August 26, 2010, 08:08:54 pm »
Thanks for the web page.  Now I need to save and budget $1000 to build the engine of my dreams.  Does anyone know the difference between the GX340 & GX390?  I assume it is cc's but where does the difference come from?  Bore or Stroke?
Dan Borba

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Re: Honda GXV340 Performance Help
« Reply #3 on: August 26, 2010, 08:25:26 pm »
WOO has a parsons built outlaw.  It hasn't been on the track yet :( 

http://www.extrememowers.com/folder1/fourm/index.php?topic=2508.0

I hope to see it this year    I want  to hear it :)

Windsor Ontario Canada<br /
Jeff Digou

Offline amr5080

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Re: Honda GXV340 Performance Help
« Reply #4 on: August 26, 2010, 08:28:53 pm »
GX is a horizontal and GVX is a vertical. Hondas are hard to beat when built right on a good chasis.
Aaron Rupert
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Offline Jeff Digou (Pitguy)

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Re: Honda GXV340 Performance Help
« Reply #5 on: August 26, 2010, 08:30:36 pm »
At fog speedway   A honda has been beating up on the :censored: animal motors

Windsor Ontario Canada<br /
Jeff Digou

Offline George Herrin

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Re: Honda GXV340 Performance Help
« Reply #6 on: August 26, 2010, 10:04:30 pm »
Thanks for the web page.  Now I need to save and budget $1000 to build the engine of my dreams.  Does anyone know the difference between the GX340 & GX390?  I assume it is cc's but where does the difference come from?  Bore or Stroke?

Difference is bore.,
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Offline westcoast racer

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Re: Honda GXV340 Performance Help
« Reply #7 on: August 31, 2010, 07:39:24 pm »
Does anyone know if you can use a header like the go karts use on horizontal engines on the vertical shafts?
Dan Borba

Offline mightymowe

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Re: Honda GXV340 Performance Help
« Reply #8 on: August 31, 2010, 11:00:58 pm »
You can use a header on it but you may have to make it yourself. The GXV engines have a totaly different head from the GX engines and I dont think the ports are as nice.
David Peters

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Re: Honda GXV340 Performance Help
« Reply #9 on: September 02, 2010, 07:42:00 pm »
David,
How are they different?  Can you swap them between block styles?
Dan Borba

Offline westcoast racer

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Re: Honda GXV340 Performance Help
« Reply #10 on: September 10, 2010, 02:46:08 pm »
does anyone know if you can swap heads from a vertical to horizontal shaft GX340?
Dan Borba

Offline fx28

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Re: Honda GXV340 Performance Help
« Reply #11 on: September 15, 2010, 09:13:31 am »
I believe the oil return holes are in different positions. You can make the vertical head work good though,I built a GXV390 several years ago. You need to take some time on the head to get it right. The port is long and narrow and takes patience to open up and make the same size all the way thru. All the head parts are interchangeable, valves, springs, rockers, etc. even the rod and piston are the same, need to trim off the dipper on horz. rod. Only difference in cam is oil pump drive tang.  There is a lot of parts being developed for the GX390 motors now as they are popular in kart racing.  You should be able to build a stout motor for $1000.  you can use the stock bottom end and focus your $ on head work. I have run a reworked oem con rod for many years, they work well up to the 7500 rpm range, just make sure your clearances are right and use good oil like fhs 62r, brad penn or the like. You can stroke the crank but really is not worth it for the result and the block can be easily bored and use the 390 piston.  I would suggest talking to Tim O'Brien at EES , he helped me out alot years ago when I first started to use the Honda

Chuck Miller

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Re: Honda GXV340 Performance Help
« Reply #12 on: September 17, 2010, 01:53:03 pm »
 Chuck
When ya cut the dipper off do ya have ta plug oil holes on the rod To!
and could a horizonal head oil holes be modified so it would fit the GXV 390
I sure like the looks of the ports on the horizonal better?S
Im going ta run a tilly so no probs with carb angles!

I have run a reworked oem con rod for many years, they work well up to the 7500 rpm range, just make sure your clearances are right !!
Clearances at stock spec for rod than!

Ferris

Offline fx28

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Re: Honda GXV340 Performance Help
« Reply #13 on: September 17, 2010, 03:53:11 pm »
Ferris,   just do not open up the oil hole like you would on the horizontal. on the clearance just go for the outer limit on factory spec

I dont know about the switch of the heads, I would have to study that to see if it would work.   

Chuck Miller

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Re: Honda GXV340 Performance Help
« Reply #14 on: September 18, 2010, 10:03:01 am »
Chuck
Oh is the stock horizonal rod stronger than the stock vertical rod!
I Know theres a couple of billet Rods for the Horizonal out there!
also wandering if ya could put horizonal crank in vertical block and solve Billet flywheel issues?s
Thanks again for the info!!!
Ferris