Cox made an 0.010. You can usually find one on e-bay. It is an aircraft engine though, and no throttle for RC.



Here's a typical e-bay link:

http://cgi.ebay.ca/EARLY-COX-TEE-DEE...item256043d7e2

Go-engines makes an RC 0.060. You can get it with or without the exhaust:



You can buy it here:

http://www.shop.gotnitroonline.com/c...?categoryId=64

ACME makes an 0.05:

http://www.shop.gotnitroonline.com/c...?categoryId=60