My c/p race race mower build


Just got started on this. Building a c/p race mower. The power plant is going to be a the biggest badest opposed twin u can get your hands on. A 46ci 20 hp pressure lubed. The 46cid was the bigest opposed briggs made till they were bannd cuz of emissions and then the vangard ohv vtwin came into place. The trans is going to be a peerless 700 to a 1 inch live axle. The flange mounts are NOT welded in yet because its going to be lower and i still have adust it. I just started on this build so that is all i have done at the moment. By the time its done there should be over a grand of work i did into it. And thats cheap. Theres a mower that i race with that the guy put 10 grand into. Thats a b/p mower, with E.C distributing parts and g team racing.
Hey offroad... Wouldnt it be better to run a briggs opposed twin 42 which is the 18 hp then run a briggs 40 16 hp oppose and switched the rods out (18's) with the 16's and then with that pop up you get shave the pistons .50 to get flush with the deck? Then shouldnt you run a ARC intek billet wheel and do what Don G did in order to adapt the wheel? Also true up the block and shave the heads .35? Also get the big intake of the briggs 20 you have there put it on the 18 and then drill jets bigger and and put Don G's air filter set up on it? Also dont forget to "enlarge and port" the block very wild that way it can breath!!!

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The plan for the motor yet have not been thought out yet. Yes, you are right. Should go to a 42ci and with the shorter stroke i can wind it up a bit more. For the first season of racing, im just gonna get a cam and port the motor and do a crank trigger ignition. That should be more than enough becuase most guys in c/p run bone stock motors in pa.

Im not running the opposed for ever beacuse in the 09 season im switching over to a single cyl OHV. Thats why im not gonna send the motor to gteam and go crazy with it.

Dons opposed twin that you just posted in those pics is the only opposed twin in the wolrd that is like that right now. and there wont be many more like that for awhile.

What chapter do you race in Nova?
Dont race much but have run with some guys in lancaster motor speedway , Kinda of a outlaw group but a good group of guys.... I ran a opposed twin one year it is bad-A** flew like hell.....

O for crank trigger ignition here what I came up with~~

But heres th epart you can get form a local auto parts store to build you ignition~~

The ford module is from a 1977 Ford bronco V8 5.0 Liter 2BBL

While we find your parts, please enter your ZIP Code at

O and for a crankshaft sensor you can use this or something similar-

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Its from a-- 1999 CHRYSLER SEBRING JX V6 2.5 Liter FI


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Its from a-- 1996 DODGE RAM 1500 PICKUP 2WD V6 3.9 Liter FI
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Ive seen that drawing at brian millers site...

I actually no some one with a 14 hp opposed that made his own. Theres thousands of different ways you can build one. Thanks for the info
Yeah no problem but also dont forget this to.... When you get a 18 and you use 16 rods and so on.... Bore that motor out .30 over because of this...

The stroke is the same as a 12 hp--3.06
The bore is the same as a 12 hp---3.44 ~~ But with is bored .30 over you have a bore of 3.74
Now you have 2 cylinders do the math out on the calculator below--\

YOU GET 67.23 Cubic Inches of motor...

You get a total of--
Your right it is but dont look to beat him with a opposed twin he will scalp you bald with his thunder twin the big TECUMSEH 20 hp V-TWIN/ INDIAN with the isky cam...
Yeah I know hes pretty good... well Hes or Superman!!! HAHA did you see the video of him wearing the superman cape???

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