Model 71 Cub Engine Questions

[gearheadmike]

I got a model 71 cub with factory 7hp it will be getting a rebuild do to age/smoking. Still runs good tho lol. Does anyone make any type of performance parts?

Like cams/bigger valves/Over sized piston/Upgraded carb/header/Air Intake/Crank/Flywheel. Etc?

This is going to be my Show/Parade tractor and has no attachments. Also i want to keep the original 7hp. So no im not slapping a 12 or bigger engine in lol.

[Randy Littrell]

They really don't make much in the way of high performance parts for a 7hp, not really any demand.

That 7 will do what ever you need in stock form, if you need more power, a larger engine would be your best bet.



Randy

[sir_lancealot]

If I remember correctly, they don't make the parts to rebuild an original 7 hp engine. It'll be an 8 hp engine after it's rebuilt with the parts that are available.

[J-Mech]

Originally Posted by sir_lancealot

If I remember correctly, they don't make the parts to rebuild an original 7 hp engine. It'll be an 8 hp engine after it's rebuilt with the parts that are available.

Well..... kind of. They don't make piston for the small bore. But the 7hp still has a shorter stroke. It will still be a 7hp.

You don't need any "performance" parts for a parade tractor. Besides..... you'd likely crap your pants at the price anyway. It's a tractor, not a show car.

[gearheadmike]

It's most likely going to need a hone if so idk if they make a .010 piston for this my dad had a kohler k series 10-12hp. But i remember seeing .010 on the piston.
This is going to be a show tractor lol frame will be powder coated along with what ever else i can do. The local car show at the same time has a small engine/tractor show that ill be bringing it to.

I read some that the l head on these if shaved don't flow good but a good valve cut 3 way/porting & polishing and header or straight through muffler and carb work helps.

[ambrola]

I have a rebuilt engine that menthos had done. I am not got a use for it if you just want to do a swap?

[J-Mech]

Originally Posted by gearheadmike

It's most likely going to need a hone if so idk if they make a .010 piston for this my dad had a kohler k series 10-12hp. But i remember seeing .010 on the piston.

It will need bored. No, like was said, if it has the original 7hp piston in it, you have to bore it to the newer size. Pay attention.

Originally Posted by gearheadmike

I read some that the l head on these if shaved don't flow good but a good valve cut 3 way/porting & polishing and header or straight through muffler and carb work helps.

Oh god. Here we go again.

[ambrola]

Originally Posted by J-Mech

It will need bored. No, like was said, if it has the original 7hp piston in it, you have to bore it to the newer size. Pay attention.




Oh god. Here we go again.

ROTFLMAO

[mhasewinkle]

Originally Posted by gearheadmike

It's most likely going to need a hone if so idk if they make a .010 piston for this my dad had a kohler k series 10-12hp. But i remember seeing .010 on the piston.
This is going to be a show tractor lol frame will be powder coated along with what ever else i can do. The local car show at the same time has a small engine/tractor show that ill be bringing it to.

I read some that the l head on these if shaved don't flow good but a good valve cut 3 way/porting & polishing and header or straight through muffler and carb work helps.

On your performance questions. The things you have read is only for high rpm for this engine. If this is a show/parade tractor then put a straight pipe on it for it to be louder. Everything else you won't see a difference for show/parade. On your rebuild have the block bored/honed out. Just honing it won't work.

[J-Mech]

Originally Posted by mhasewinkle

On your performance questions. The things you have read is only for high rpm for this engine.

Not true. Those things will help any engine. How much??? If you know how to do it, it will gain you at least a horse. Thing is... for a parade tractor, it's not worth the work.