4mmil 72mm super cub by rdz

[05Special]

I saw the kit on ebay.. Thinking of runnin a cub..4mil crank, 72mm cub cylinders with the rdz head domes and whole nine yards come with the setup, fully ported... Anyone run that kit? it's on ebay for like 2200 worth it? I was gonna go with a 7 mil but i think it is too much...plus case trenching and all that bologna... Any input would be great guys..

[pabansheematt]

I saw the kit on ebay.. Thinking of runnin a cub..4mil crank, 72mm cub cylinders with the rdz head domes and whole nine yards come with the setup, fully ported... Anyone run that kit? it's on ebay for like 2200 worth it? I was gonna go with a 7 mil but i think it is too much...plus case trenching and all that bologna... Any input would be great guys..

to run those 72 mm pistons you'll have to bore & port the top case, at least I had to on my cheetah.

[locogato11283]

youre gonna be hillclimbing right? weve had great luck with the 4mm cubs. they will turn high rpms and have no issues. rebuilds are cheap and easy. get setup with the right swingarm and tires and youll be spankin motherfuckers up the hill.

[Animalman294]

Word..........

 

I would stick with the 4mil.

[FireHead]

I saw the kit on ebay.. Thinking of runnin a cub..4mil crank, 72mm cub cylinders with the rdz head domes and whole nine yards come with the setup, fully ported... Anyone run that kit? it's on ebay for like 2200 worth it? I was gonna go with a 7 mil but i think it is too much...plus case trenching and all that bologna... Any input would be great guys..

You gave to get your top case machined to run that setup. :thumbsup:

[rubberneck]

Any body know the dyno specs on the 4mil x 72? Is the machining and extra cost worth it over the 4mil x 68? The larger displacement would help on the bottom end I imagine. I have been told that a 421 in good tune on race gas should put me at 85-90 HP does that sound right? So what would the 4mil x 72 put out/

[shanYE west]

On average the super cubs are worth about 3-5 more hp and a few lbs of torque.

[05Special]

well I'm runnin a +6 now, with 8 paddle haulers...Probabaly won't use paddles for the climb. I'm thinkin of cutting a set of holeshot hd's...Bike will be used 80% for hillclimbing

[FireHead]

Any body know the dyno specs on the 4mil x 72? Is the machining and extra cost worth it over the 4mil x 68? The larger displacement would help on the bottom end I imagine. I have been told that a 421 in good tune on race gas should put me at 85-90 HP does that sound right? So what would the 4mil x 72 put out/

In my opinion the Super Cub is not worth the extra hassle.

 

A 421 running on race gas, setup praoperly, can brake 100hp pretty easily. :geek:

[rubberneck]

In my opinion the Super Cub is not worth the extra hassle.

 

A 421 running on race gas, setup praoperly, can brake 100hp pretty easily. :geek:

 

I assume that would be a ported 421 right? What about just cleaned up ports? Is 90 in the ballpark?

[dajogejr]

In my opinion the Super Cub is not worth the extra hassle.

 

 

Word.

You MIGHT get 2-5 HP more, a tad more torque, but that with some EXTENSIVE porting...etc.

Out of the box and with cleaned up only porting, the 68mm has better numbers.

4 mil 68 bore cub is the best bang for the money out there, bar none.

 

Weight reduction and rider skill, along with proper setup can over come that small a difference.

[shanYE west]

If I had to do my build over again I probably woulda gotten the super cub. Only because I was in the market for a new head anyways and the price for the porting was the same. So in that aspect it really only would cost me the extra coin for the case work wich is quite minimal.

[FireHead]

Word.

You MIGHT get 2-5 HP more, a tad more torque, but that with some EXTENSIVE porting...etc.

Out of the box and with cleaned up only porting, the 68mm has better numbers.

4 mil 68 bore cub is the best bang for the money out there, bar none.

 

Weight reduction and rider skill, along with proper setup can over come that small a difference.

.........plus, it's weird enough that six years down the road, you won't be able to find domes, gaskets, or pistons for it. Which means you will have a tough time reselling it.......... Just a thought. :geek: