building horsepower in a cub

joshratliff · Oct 7, 2013

crazy question but what is the best way to build horsepower in an older red cub?....don't wanna go overboard or anything but I would like to have a little fun with it, I have a couple of them and one needs an overhaul...both are used for gardening, a big sweetcorn patch, and pulling wagons around on the farm and little odd jobs

old · Oct 7, 2013

Not a whole lot you can do to any flat head engine to get much if any more HP out of one due to things like the valves hitting the head so upping compression is not easy. Also hard to bore out much if any so as I said not much you can do with out spending very big $$

the tractor vet · Oct 7, 2013

Oh there is a little ya can do to make it a SUPER CUB . (10 use the pistons from a 184 cub lowboy also the head and the carb . (2) have it balanced .Then IF ya want to get carried away then ya can install a bigger intake valve , have the cam rebuilt and Blueprinted and the lifers reground or replaced . You can latterly double the pony power on a cubby. So yea ya can perk them up .

gene bender · Oct 8, 2013

Yes depends on how much money you want to spend there are hi-dome pistons for them and like tractor vet says its only money. Dont need to worry about hitting the pistons as the valves are in the block and there is room to put larger valves in.

Anonymous-0 · Oct 8, 2013

For a time in the 1960's, M&W made a set of .090" oversize pistons for the C-60 block...so they'd safely bore at least .090".

Anonymous-0 · Oct 8, 2013

Pappy had a Cub when I was a kid that we'd do custom mowing jobs with around town. It would run circles around an "average" Cub. Of course, Pappy had swapped over the governor off a C-60 power unit off a 50-T baler, and had drilled out the carb jet slowly and in steps until the carb would actually feed enough fuel to the engine to use the RPM's the governor allowed.

One evening, Pappy was on the way to a mowing job when he saw the guy at the local high school mowing with their Cub. On a lark, Pappy dropped in behind the schools' Cub and started mowing the next mower width of grass...caught up with, and passed the school's Cub, all the while doing a perfect job on the mowing. When he reached the next street, Pappy shifted the PTO out of gear, raised the mower deck and shifted into 3rd and continued on to his mowing job. Two days later the school superintendent called and asked him to work up specs for bidding a 140 with a Woods 59 to be the school's next mowing tractor, as their Cub "suddenly" wasn't big enough for the job.

Hendrik · Oct 8, 2013

Super Cubs actually were built (in France). See link.
Good luck on your venture.
Older thread on Super Cubs

jbp · Oct 8, 2013

The easiest way is to drop a 184 engine in your cub. They use a counter balanced crank shaft, domed pistons, bigger manifold and carburetor,2400 RPM governor and possibly some other things. They are rated at 18 horsepower versus 10 for a regular cub engine.

The 184 will handle a 60 inch mower deck in tall grass that would stop a regular cub dead in its tracks.

I always wanted to build a muscle cub too.
Joe

old · Oct 8, 2013

Safely or just be able to. That is two different things. Seen many engine bored to the point that they ran hot due to lack of metal and or have the sleeve crack if one gets hot.

the tractor vet · Oct 8, 2013

You worry to much . Ya know that you bored it to much is when you stick your hand in #1 and go all the way to #6 with out touching anything , And when you make sleeves up to fill the gap that the sleeves have to have flat sides to fit. You would go bonkers being around watchen us go to the DARK SIDE on engine building . A M M 4 cylinder with 855 Cumming sleeves Allison pistons with Farmall rods with john deere valves , and Oil all Over with big block Chebby pistons a Farmall H with 806 .060 over pistons in it . Never a good thing with me , a progressive size book a set of calipers and a large bottle of C/R and time to think . Can get pretty preverted .

old · Oct 8, 2013

I come form a time of some crazy idea as to building HP and seen many a 6 or V-8 run one time in a 1/4 mile and have it blow all apart due to having to much done with to much metal removed

the tractor vet · Oct 8, 2013

Well if ya can't WAIST and engine on each and every pass then ya should not be playen . Of the engines i have run in the 51 years i have been wrenchen i have lost two , my first engine That i bought from one of the socalled best lasted till the fourth break in pass when it came unglued . That was when i started to build my own . And in 1964 i unleashed a 390 FE Ford tri power that was a monster that was never beat and never came unglued . And i had a M M engine break a crank that we had welded up and off set ground , i knew that one would break as the people that did the weld and grind did it wrong and there were crow feet cracks at the oil holes when it came back . I was over ruled on not wanting to use it and i put it in and it lasted about 20 pulls before it broke . We never tried another 7.750 stroke again.

old · Oct 8, 2013

One thing that got me back in the 60s was when Nascar did the 6 and V-8 had to run in different classes all due to the fact the 6 was eating the 8 in the 1/4 mile. Am ans always will be one who prefers the 6 cylinder because it will out class the V-8

Anonymous-0 · Oct 9, 2013

That has to be one of the dumbest things you have said over and over again.

gene bender · Oct 9, 2013

you got something all mixed up NASCAR didnt run drags and no six would beat a v8 unless something was realy wrong in a drag. Now are you talking about the 51 Hudson in nascar.

old · Oct 9, 2013

You best go back and look at things. the 6 ate V-8s alive and will still do so. Sorry did many drags and won and ran 6

Anonymous-0 · Oct 9, 2013

When did you last see a COMPETITIVE inline six cylinder run in Top Fuel? When did you last see a COMPETITIVE inline six cylinder in a Funny Car? While I'm a fan of certain sixes, I know that the V8's are head-and-shoulders above an inline six in high-RPM situations. With shared rod journals in the V8's, the crankshaft is shorter than the average six...which means they can usually rev higher and make more power.

Anonymous-0 · Oct 9, 2013

Forgot to mention...the C-60 used in a Cub isn't a sleeve motor. And the blocks had enough "meat" between the cylinders to bore .090" over without requiring sleeves.

old · Oct 9, 2013

Back in the 60s when they change the rules so the V-8 and the 6 could no long run on the same race and that is what killed the 6 cylinder in drag races. Sorry I have built many straight 6s and none have been slow. Have one sitting behind me in this office 292 Chev that when done will eat most cars. Sorry old school drag guy and done many

john *.?-!.* cub owner · Oct 9, 2013

Not sure what 6 cylinders and V8s have to do with the original question, but when you talk of putting in larger valves you will also have to bore the passage way through the block to the manifold to get any improvement, remember, the valve is simply cut into the block, so the entire passage is the same reduced size.

building horsepower in a cub

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