Can someone tell me if there is a difference between the 20b rotor housing and the 13b rotor housing.Need to know if i can use it in a rebuild.Someone said to me that the 20b housing was stronger,find that hard to believe.

 

same

 

Same damn ting boy !

 

13b exhaust sleeves are bigger than the 20b ones.

 

Oh...ok... thanks, would account for better low down power ...Cool..

 

It also accounts for the engine choking out at high rpms. It has too much low end power, use the FD housings.

 

Also - 2 (from memory) of the thru bolt holes need to be slightly enlarged if using the 13b housings.

 

If the 20b housings are within spec, wouldn't it be cheaper and easier to just switch out the 20b sleeves with the 13b ones? I know someones done this before.

 

this is what i did, once you find the right drill bit its ease
to change out the sleeves.

matt

 

why not just port it and not waste your time trying to find an switch to different houseing? i think that would be easier and much cheaper...

 

cant port the sleeves you would cut through long
before getting it as big as a TII sleeve.

matt

 

They are the same overall , but the bolt holes on the 20B are larger , being 12mm , whereas the 13b are 10mm.

 

Since we're on the subject I have a question about fabbing up a 20B from 13B parts.

Is it practical to create a tripple rotor engine from two 13Bs and just have to find the eccentric shaft and intake and exhaust manifolds?

 

Bit more to it: the 20B has that large front intermediate housing that carries the extra stationary gear and bearing.
There is a a shop in New Zealand that produces shafts and will modify a 13B intermediate housing with the extra stationary gear and bearing. However, when you do that, the 20B manifolds will no longer fit as the custom engine is shorter than the 20B and has smaller intake runners on that housing. From memory, the shaft is about $1200USD and about $300 to modifiy your supplied housing.