specific measurements

I have been doing a lot of searching here about rocket heaters , i need one for my new garage . I've seen many designs and instructions but one thing i haven't found is dimensions of the inner core . In relation to size of the stove or heater it's top measurement is 1-1/2'' ideally , does this mean the re-burn chamber has to be the same around the inside ? When using a propane tank or one with the rounded ends for the outer shell , it would be less space at the outside edge of the insulated tube , How should this be placed ? Think of it like a dinner plate inside of a large mixing bowl . Thank you in advance .

Perry MacDonald : This is an easy one, made even easier by the number of additional benefits that your post did not even ask for ! Specific measurements, materials, ratios,
and the importance of maintaining A constant Cross sectional area in your Feed Tube, Burn Tunnel, And Heat Riser are Very well explained in Ianto Evans' Great Book 'Rocket
Mass Heaters' available as a PDF Download $15. from Rocketstoves.com print ALL of the copies you can use one low price !

With~100,000~ built worldwide, most of them have been made following 'The Book' and 95% of all the First time Builds (that worked) were made following 'The book', there is
STILLno other book in any language with more rocket mass heater RMH family information !

With 'The Book" and the help of your fellow members at Permies. com you will be listening to the Throaty roar of your personal happy house Dragon in weeks ! for the craft BGIG AL !

Allen- I'm beginning to wonder if you get a commission for referrals to the "Rocket mass heaters" download.
Here's a clickable link for the extra lazy RocketStoves.com
And for the otherwise engaged low budget guys, get your internet savvy wife to find the free download of the book.

John Adamz : Thanks for putting up the link ! No I don't get a red cent ! What I get in the way of Kickbacks is being able to have the person I am talking to, have a resource
they can go to and see a picture of what I am talking about and also to present a second opinion that I am familiar with, and that probably won't change, If you were advising
someone on building a Rocket Mass Heater that was in a separate remote location who Probably also been to U-Tube and L@@Ked at a few franken-clones, what would you
want to do to insure they didn't go hareing off in the wrong direction ! Your comments and/or questions welcomed ! Big AL