Stock class K301

EBooms · #1 03-01-2014, 10:17 PM

I am currently getting a plan together for building up a 12 horse motor for my 122. I have no rules but it needs to still be usable as a plow tractor also it will still be governed at 3600 rpm. This is what im thinking so far.

second generation 10 horse head shaved
copper head gasket
"new style" mahle forged piston
1-3/8" exhaust valve {with reliefs to the head}and cleaning up the ports three angle valve job
brian miller 4000 rpm torque regrind
boring the #26 carb to .875
1" carb spacer
all of kirks ignition upgrades

my questions are I know that a 18 horse alcoa rod would be preferred but are hard to find is there another rod that would be ok to use. Also should I have bearing inserts put in the rod offset for a .020" piston pop-up.
Is there anything else i should do or anything listed that is not needed
all help is appreciated
Thanks,Evan

dvogtvpe · #2 03-02-2014, 08:26 AM

forget about the bigger exhaust valve. there's nothing there for a gain. there's allot better cam grinds out there than Millers. consider Lacota, Hackman or Zack Kerber. I'm putting a Zack Kerber cam in a stocker I'm putting together now for a guy. be a couple months before We dyno it.
Before I'd offset bore the rod I'd deck off the top of the block. piston popout in a stocker isn't as important as one would think. you also have to balance the rotating assembly if you insert the rod. you'll probably find that the piston comes up about .015 to .017 below the deck surface anyway. you also need to maintain about .025 to .030 between the top of the piston and the head.
boring the carb will help you above 3600 in hp , leave it alone and it helps the torque in the 3100 to 3300 range. you will have to drill out the emulsion tube to get more fuel in.
I've not seen a 1 in spacer in a stocker motor. I don't see then on SA motors either. I don't see it helping anything. its not legal in any stock class's for pulling.
you may want to consider a different air filter . a KT17 air cleaner with a K&N filter in it works nice.
3 angle valve job is a must. you might want to leave the ports alone if you ever intend to pull it.
stay with a mid range pump gas. race fuel kills the torque.
there's really no gains in ignition products in a stocker motor. you can put it on , it looks cool but in real dyno numbers there's nothing there so save the money. have the timing occur at the correct time is a must. its funny to watch people spend money on ignition parts only to set the timing at 20 degrees. the free thing that they can do that is actually worth something in performance is forgotten.
now if you want to get fancy consider an adjustable cam gear and play with the engine timing. I've advanced the engine cam to crank timing by up to 11 degree's in the past.

EBooms · #3 03-02-2014, 08:53 AM

I know you have recommended 18 horse rods before but do you think I need one or is a 16 horse rod good enough
also should I bump up the timing a few degrees or will it run to hot

dvogtvpe · #4 03-02-2014, 09:29 AM

the 18 hp rod was nice. they have been NLA for some time. I was still able to get the .010 us rod version but they have gone NLA to. the last couple I did I used Super Cub 5.3 length rod in them. its stock length. they did have to be balanced . I've been doing some research and the Kerber rods are lighter than the Super Cub rods so you wouldn't need to add as much weight.

austin8214 · #5 03-03-2014, 09:22 AM

What Kerber cam grind are you trying Don?

dvogtvpe · #6 03-03-2014, 06:00 PM

ZK3. you need the wide base lifters with it

austin8214 · #7 03-03-2014, 06:33 PM

Quote:

Originally Posted by dvogtvpe

ZK3. you need the wide base lifters with it

I think you'll be happy with it. I have one in a .030 over 14 HP. I was happy with the results.

dvogtvpe · #8 03-03-2014, 07:01 PM

We'll see what kind of numbers we come up with. He said If I wanted to do My own grinds He would do them for Me.

austin8214 · #9 03-03-2014, 07:34 PM

Quote:

Originally Posted by dvogtvpe

We'll see what kind of numbers we come up with. He said If I wanted to do My own grinds He would do them for Me.

Yep he is a good guy to work with. Very helpful. My 14 came up just short of 20 HP and 29 lbft of torque. On what the dyno owner called a very conservative dyno. Good luck with your build.