AKRA cc check

backyardhack

New member
When checking the cc of an assembled BSP engine per AKRA rules is the spark plug hole plumbed vertically or is the head gasket surface held flat?

What is the cc volume that it must hold without spilling out? Can it reach the top of the threads but not go any further?

I am aware that there is a $20 cc tool but haven't been able to find anyone selling it recently. How much difference is there between using the tool and just using the plug threads providing they have not been modified?
 

Kart43

Member
The spark plug bore is plumb, or in other words the spark plug sealing surface is level in all directions. Without the tool if you leave the prescribed amount of fluid 1/4" down from the surface you will be safe but you are not optimized.
 

Coty Morrow

New member
I just looked and that not really what I'm looking for. With the stand on his site you will have to have extra stiff to make
Spark plug plum. Surely someone is making a
Stand that when out on level surface the spark plug wil be plum
 

rebsfan4

New member
I just looked and that not really what I'm looking for. With the stand on his site you will have to have extra stiff to make
Spark plug plum. Surely someone is making a
Stand that when out on level surface the spark plug wil be plum
Check this one out.......

http://www.jcspecialty.net/img/pages/156.JPG

It's for the Animal but should work for the Clone
 

W5R

New member
When checking the cc of an assembled BSP engine per AKRA rules is the spark plug hole plumbed vertically or is the head gasket surface held flat?

What is the cc volume that it must hold without spilling out? Can it reach the top of the threads but not go any further?

I am aware that there is a $20 cc tool but haven't been able to find anyone selling it recently. How much difference is there between using the tool and just using the plug threads providing they have not been modified?
The cc volume is 26.5cc to be legal, anything under 26.5 is considered illegal, anything over 26.5 is considered leaving power on the table
 

backyardhack

New member
Thanks for the info guys. I fabricated a stand out of metal cutoffs I had laying around the garage, it isn't pretty but is fully functional.
 

DynoDon

Member
The cc volume is 26.5cc to be legal, anything under 26.5 is considered illegal, anything over 26.5 is considered leaving power on the table
Unless you plan on pulling the head every week or the engine is built for a one race deal. 26.5 will get you tossed in tech if you have carbon build up. Leaving H.P. on the table of .5 cc is a wise thing for an engine that is going to run many races and go through tech safely.
 
Unless you plan on pulling the head every week or the engine is built for a one race deal. 26.5 will get you tossed in tech if you have carbon build up. Leaving H.P. on the table of .5 cc is a wise thing for an engine that is going to run many races and go through tech safely.
I agree with Don on this one, better leave some extra for carbon build up. I usally do close to 27 cc. jmo
 

DynoDon

Member
The stand that jimmy sims sells is made by Jones and the top rail of head is level.have seen some level the lad tool
I think that there is actually an explanation as to proper procedure in the book.
 
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W5R

New member
Unless you plan on pulling the head every week or the engine is built for a one race deal. 26.5 will get you tossed in tech if you have carbon build up. Leaving H.P. on the table of .5 cc is a wise thing for an engine that is going to run many races and go through tech safely.
My bsp came out at 26.7 out of the box, and has about 6 race days total on it so far. The plan for me is to pull the head and clean everything up good every 10 races and replace any parts that are worn, such as valvetrain components or anything else.
 
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