decking heads

[csracing]

Does anyone have a calculation to correlate how much material removed from the deck surface equals a certain amount of reduction in combustion chamber CCs on a stock 3V head?

 

[05stroker]

This was my experience with decking heads. I can't say the same will work for you.http://www.s197forum.com/forum/showthread.php?t=108899&highlight=max+head+flow&page=8

Do you know what cc you want the heads to be?

 

[csracing]

I'd like to be in the 46-48cc range. I see you got about 2cc's out of .020" so I'm figuring I'd need to be somewhere in the .035" range or more for what I need. Going to do some more calculations first I guess.

Thanks for the link.

 

[05stroker]

I'd like to be in the 46-48cc range. I see you got about 2cc's out of .020" so I'm figuring I'd need to be somewhere in the .035" range or more for what I need. Going to do some more calculations first I guess.

Thanks for the link.

Np , I just wish I could be more help. I was not able to find any data when I looked into this and just started taking it off bit by bit till I was where I wanted to be.

 

[Fullboogie]

Keep in mind that decking the heads affects other things, such as the intake manifold.

 

[csracing]

Keep in mind that decking the heads affects other things, such as the intake manifold.

Thanks. I had considered that so I drew up a representation of the block and cylinder heads in AutoCAD. Decking the heads 0.030" moves the centerline of the intake manifold bolts about 0.020" total, so about 0.010" per side.

 

[csracing]

I had the heads decked 0.040" after I modeled the combustion chambers in 3D and played with numbers. I was targeting 46cc's and after having the heads milled, I'm measuring them to be dead on 46cc's. I unshrouded the valves before I sent them to the machine shop so keep that in mind. I actually increased the volume of the chambers a bit before they were milled.

 

[tmcolegr]

decking he heads also affects cam timing

 

[Badd GT]

decking he heads also affects cam timing

that's interesting ,how?

 

[Wes06]

hmm, the cam is slightly closer to the crank, so assuming the chain links are the same etc. the cam sprocket will be ever so slightly retarded in timing.

However being adjustable it should be able to go back to normal range <except when fully retarded/advanced> Unless you have one of those fancy lockout gears thats adjustable

atleast thats how I could see it changing the cam timing

 

[csracing]

I have adjustable crank gears and will be degreeing the cams.

 

[tmcolegr]

hmm, the cam is slightly closer to the crank, so assuming the chain links are the same etc. the cam sprocket will be ever so slightly retarded in timing.

Correct