Heymow - Lawnmower Racing Forum

Engine Help => Kohler Engines => Topic started by: DHR Motorsports on June 10, 2011, 05:19:34 pm

Title: 20hp twin....Is this a good one...??
Post by: DHR Motorsports on June 10, 2011, 05:19:34 pm
I have it already and was wondering if it is a good platform to build on and what tricks/tips really wake up these lil engines.

Thanks,
Darren


(http://i135.photobucket.com/albums/q156/Dragnova67/Mower%20racing/kohlertag.jpg)
(http://i135.photobucket.com/albums/q156/Dragnova67/Mower%20racing/kohler.jpg)
Title: Re: 20hp twin....Is this a good one...??
Post by: Burton for Certain on June 10, 2011, 05:21:10 pm
Absolutely terrible. Ill haul it to the junk yard for ya  ;)
Title: Re: 20hp twin....Is this a good one...??
Post by: DHR Motorsports on June 10, 2011, 05:46:01 pm
Pretty bad huh...... ;)
Title: Re: 20hp twin....Is this a good one...??
Post by: Caseracer on June 10, 2011, 06:01:03 pm
Darren,  That is a great engine to start with.  It should be 38 cubic inch.  The bore is 3.03 and can be bored and sleeved out to 3.375 if you want in the future.  Midwest Supercub makes steel cranks up to 3.125 stroke if you want to spend the cash.  You can get welded up cams or steel cams are available.  You can also run a roller cam if you desire.  There are stainless valves and titanium valves and a multitude of springs for them.  The factory 30 hp heads are a closed chamber design and will bolt on too.  The 30 hp also has a two barrel intake that will bolt up a two barrel carb from a 40 hp if needed.  I built a 52 inch stroker with a roller cam and I love the power it makes.

Jack Jones
Hard Case Racing

(http://i289.photobucket.com/albums/ll201/Caseracer/th_kohler.jpg) (http://s289.photobucket.com/albums/ll201/Caseracer/?action=view&current=kohler.jpg)
Title: Re: 20hp twin....Is this a good one...??
Post by: JohnB on June 10, 2011, 06:01:34 pm
 :noplease: yea, I got two of them junk motors, myself.
 
Title: Re: 20hp twin....Is this a good one...??
Post by: DHR Motorsports on June 10, 2011, 06:04:33 pm
Thanks Jack!!
Where is the place you order your parts from (Cam,lifters,springs,intake) and if you were to build one what would you order for it??

Darren,  That is a great engine to start with.  It should be 38 cubic inch.  The bore is 3.03 and can be bored and sleeved out to 3.75 if you want in the future.  Midwest Supercub makes steel cranks up to 3.125 stroke if you want to spend the cash.  You can get welded up cams or steel cams are available.  You can also run a roller cam if you desire.  There are stainless valves and titanium valves and a multitude of springs for them.  The factory 30 hp heads are a closed chamber design and will bolt on too.  The 30 hp also has a two barrel intake that will bolt up a two barrel carb from a 40 hp if needed.  I built a 52 inch stroker with a roller cam and I love the power it makes.

Jack Jones
Hard Case Racing

Title: Re: 20hp twin....Is this a good one...??
Post by: leadslead on June 10, 2011, 06:20:41 pm
the pic say vangard i can see it coming thew the paint   :P     how are the kohlers compaired to intecks ??
Title: Re: 20hp twin....Is this a good one...??
Post by: Caseracer on June 10, 2011, 06:26:34 pm
I bought most of my stuff from Midwest (JE Pistons, billet rods, 3" steel stroker crank, moly push rods, titanium valves, double springs, roller rockers, roller lifters, copper head gaskets).  Midwest also did my machine work on the block (bored and sleeved to 3.307) and assembled the bottom end and balanced the entire rotating assembly.  The roller cam, intake, carb and billet wheel (with-out fins) were bought through E-bay.  I ran a stock 20 hp for a year while I built this engine and never had an issue with it.  The factory lifters will limit you to 4500-5000 rpm and the factory rods seem to hold up to this point.  

Jack Jones
Hard Case Racing
Title: Re: 20hp twin....Is this a good one...??
Post by: wayne shaffer on June 11, 2011, 10:27:20 am
Jack did you bolt plastic fins to your billet flywheel or was that your first engine you ran? Also that Case garden tractor you have done up looks really good.
Title: Re: 20hp twin....Is this a good one...??
Post by: Caseracer on June 11, 2011, 06:53:23 pm
That is the built motor with bolt on fins. It was spun to well over 8500 without issues.  I have a lathe and made a plastic spacer to center the fin and it works so far.  That is a CASE mower from the 70's and we like them alot.  The frame is a box and needs no additional tubing to make it work.  The engine makes a bunch of power and the frame works great as is.
Jack Jones
Hard Case Racing
Title: Re: 20hp twin....Is this a good one...??
Post by: wayne shaffer on June 12, 2011, 10:56:13 am
Thanks for the info on the Flywheel fins. The tractor I was talking about was the pic. after your engine pic, but your racers are cool to.
Title: Re: 20hp twin....Is this a good one...??
Post by: Caseracer on June 12, 2011, 11:43:24 am
Thanks Wayne,  I just finished the garden tractor.  Its a 1965 model.
Title: Re: 20hp twin....Is this a good one...??
Post by: fx28 on June 12, 2011, 08:41:39 pm
Lakota Racing and Vogel Manufacturing are good sources for parts as well. With your experience you should be able to build all you the power you need. I would recommend talking to all partys mentioned on here and pick and choose what you  think you need.

nice work Jack, hope to meet you some day!!!!!!!

Chuck Miller
Title: Re: 20hp twin....Is this a good one...??
Post by: DHR Motorsports on June 13, 2011, 12:15:00 am
Thanks Chuck.

It is always to talk with people knowledgable in the arena that you are entering. You guys are a tremendous help.

Darren

Lakota Racing and Vogel Manufacturing are good sources for parts as well. With your experience you should be able to build all you the power you need. I would recommend talking to all partys mentioned on here and pick and choose what you  think you need.

nice work Jack, hope to meet you some day!!!!!!!

Chuck Miller
Title: Re: 20hp twin....Is this a good one...??
Post by: fordman21 on June 15, 2011, 08:18:20 am
I put fins on mine this year as well, I was wondering about using the plastic fan but thought it would fly apart because of the near 12,000rpm. I actually machined a billet flywheel down to practically just the fins, its from a 5hp briggs engine. It won't cool nearly as much as the plastic blades but with the alcohol I shouldn't need as much.
Nice machine Jack, very clean!  must be a handful under power.
Title: Re: 20hp twin....Is this a good one...??
Post by: Caseracer on June 15, 2011, 09:13:01 am
Thanks Ryan, IF I was turning 12,000 I would not use plastic but I'm using the factory "non-smart spark" ignition so 8000-8500 is my max.  I thought about going with the crank trigger for more RPM's but I have more now than I know what to do with. LOL  We tested that type of fan to 9000 rpm in the shop before deciding to use it. 

Jack Jones
Hard Case Racing
Title: Re: 20hp twin....Is this a good one...??
Post by: Wheelhorseracer on June 15, 2011, 09:19:17 am
I'm loving the old case you restored...
Title: Re: 20hp twin....Is this a good one...??
Post by: Caseracer on June 15, 2011, 09:43:22 am
Thanks Wheelhorseracer!  It was meant to be a pit buggy but now I don't want to use it and get it dirty!

Jack Jones
Hard Case Racing
Title: Re: 20hp twin....Is this a good one...??
Post by: Wheelhorseracer on June 15, 2011, 09:44:22 am
Too nice for that !!!