Heymow - Lawnmower Racing Forum

Engine Help => Honda and Clone Engines => Topic started by: nor66 on November 23, 2013, 09:42:41 pm

Title: 420 head?
Post by: nor66 on November 23, 2013, 09:42:41 pm
Will the 420 clone head fit the Honda GX390 block without any problems?
Title: Re: 420 head?
Post by: George Herrin on November 23, 2013, 11:06:03 pm
YUP Same thing.
Title: Re: 420 head?
Post by: nor66 on November 23, 2013, 11:23:55 pm
Thank you George! I thought they were but wasn't sure.

Hey what size bore is Jake running?
Title: Re: 420 head?
Post by: mowvette on November 23, 2013, 11:39:05 pm
Now some secerts are just kept in the family.... :lol:...One too many questions....lol
Title: Re: 420 head?
Post by: George Herrin on November 24, 2013, 07:33:42 am
A big one!!!
Title: Re: 420 head?
Post by: nor66 on November 24, 2013, 10:10:12 am
Hey you can't blame a man for trying!

I know there are some differences in between the real Hondas and the clones, I am just trying to figure out what all of them are.


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Title: Re: 420 head?
Post by: George Herrin on November 24, 2013, 10:52:25 am
To be honest I have not found enough differences that amount to anything. Demensions bores etc are alll very close Everything we have is 100% clone and have had no problems with it at all well except the one  deal with the head but that was a part of racing.
Title: Re: 420 head?
Post by: Darkviper on November 24, 2013, 11:32:39 am
dose 420 have bigger valves then 390s just a question.
Title: Re: 420 head?
Post by: George Herrin on November 24, 2013, 11:42:55 am
nope
Title: Re: 420 head?
Post by: Darkviper on November 24, 2013, 11:44:50 am
whats difference between the two heads.
Title: Re: 420 head?
Post by: George Herrin on November 24, 2013, 11:56:09 am
NONE. ONLY difference between the 390 and 420 in bore!!! To answer the question as to whats in Jakes motor, alot of one off parts that were never built to even go into a honda motor!!! Will i go into detail NO!! Does he have stock valves yes n no!! Stock diameter but they are stainless and longer to accomodate the cam!!! Why not bigger diameter you ask because we dont like what it does tried it and didnt like it. How big is the cam? Lets just say there aint nothing inside that wasnt whittled on for clearances. I know I have said I have no secrets but in this case I reckon I finally do. Parts interchange from clone to honda, I have found with those I have worked with everything interchanges. I have noticed the clone cranks n pistons in a  true honda block pops out the top. Meaning the piston will have to be milled off some. Each one is different a bit so no one set amount works on every setup.
Title: Re: 420 head?
Post by: nor66 on November 24, 2013, 11:58:12 am
It looks like there isn't any difference between them at all.... The bore seems to be the only thing I see.... Except one is Japanese and the other is Chinese . I have read that the clone carbs have a bigger bore than the Hondas



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Title: Re: 420 head?
Post by: mowvette on November 24, 2013, 07:09:10 pm
I have one of the 420's on my supermod single and ran it this weekend, our last race for the year, and ran it with the supermod twins. Got 3rd, out of 4 of us racing. Not bad against the twins. And I knew it had a blown pan gasket but still ran it. Oil over everthing now and it still held its on...
Title: Re: 420 head?
Post by: nor66 on November 25, 2013, 10:52:21 am
I have watched a few of the singles run with the twins and they are pretty impressive.


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