Planet Minis

84z50r · 06-03-2006, 10:00 PM

Okay i wanna know if anyone here has decked there head too incrase compression and if so,did you notice very much of a performance increase.
And how much did you take off

SprNtrl · 06-04-2006, 08:42 AM

Is there really a point to? Im pretty sure there are pistons that can give you a decent amount of compression. Not worth ruining a head over IMO.

Kurlon · 06-04-2006, 08:50 AM

Before you dive into decking your head, see if you can get a thinner copper head gasket. That'll net you most of the gain you could safely get from decking. The over all compression increase is pretty small compared to getting a piston to match your combustion chamber.

Brent878 · 06-04-2006, 08:56 AM

I think he might be asking about decking the head after you have a high compression piston. My first thought is also to use a thinner head gasket, but how much clearance do these pistons actually have? Like on a SE piston and head, or a TB piston and race head? I already run strait race gas so bumping up the compression would be a plus for me.

I have also thought about this but haven't had time to start measureing. And what is the proper procedure to do this? I was thinking of putting clay or something on the piston and putting the head on and going through the strokes and take it off to see how much clay clearance is thier? But don't know if that is the right way of finding out.

Kurlon · 06-04-2006, 08:58 AM

You've got it right, you have to use clay or something similar to get a direct measurement of the clearances in the motor. You'll want to leave about .030" as your minimum clearance.

Brent878 · 06-04-2006, 08:59 AM

any downsides to running too much compression besides haveing to run higher octane? I know that it will put more stress on your engine but anyting to really look out for if deciding to do it. And how do you figure out what your compression ratio is?

Kurlon · 06-04-2006, 09:04 AM

The only proper way to determine your compression ratio is to cc the head and piston. Basically, you drip a fluid onto the head and piston to determine their volumes, and use that info plus the displacement to determine the compression ratio.

kane · 06-04-2006, 01:38 PM

you could use clay or also solder.

Kurlon · 06-04-2006, 03:25 PM

Problem with solder is you can't read it directly, you have to tweak the numbers you get based on the size an type of solder used. Clay, well, hit up the local kindergarden, steal some, and get'er done. :P

06-03-2006, 10:00 PM	#1 (permalink)
84z50r PM Newbie Join Date: Jan 2006 Posts: 72	Has anyone decked there head? Okay i wanna know if anyone here has decked there head too incrase compression and if so,did you notice very much of a performance increase. And how much did you take off

06-04-2006, 08:42 AM	#2 (permalink)
SprNtrl 3rd Gear Member Join Date: Jul 2005 Location: Toronto, Canada Posts: 1,183 My Mood:	Is there really a point to? Im pretty sure there are pistons that can give you a decent amount of compression. Not worth ruining a head over IMO.

06-04-2006, 08:50 AM	#3 (permalink)
Kurlon Super Moderator Join Date: Feb 2005 Location: Windham, ME Posts: 8,403	Before you dive into decking your head, see if you can get a thinner copper head gasket. That'll net you most of the gain you could safely get from decking. The over all compression increase is pretty small compared to getting a piston to match your combustion chamber.

06-04-2006, 08:56 AM	#4 (permalink)
Brent878 3rd Gear Member Join Date: Dec 2005 Location: Southern California Posts: 2,147	I think he might be asking about decking the head after you have a high compression piston. My first thought is also to use a thinner head gasket, but how much clearance do these pistons actually have? Like on a SE piston and head, or a TB piston and race head? I already run strait race gas so bumping up the compression would be a plus for me. I have also thought about this but haven't had time to start measureing. And what is the proper procedure to do this? I was thinking of putting clay or something on the piston and putting the head on and going through the strokes and take it off to see how much clay clearance is thier? But don't know if that is the right way of finding out.

06-04-2006, 08:58 AM	#5 (permalink)
Kurlon Super Moderator Join Date: Feb 2005 Location: Windham, ME Posts: 8,403	You've got it right, you have to use clay or something similar to get a direct measurement of the clearances in the motor. You'll want to leave about .030" as your minimum clearance.

06-04-2006, 08:59 AM	#6 (permalink)
Brent878 3rd Gear Member Join Date: Dec 2005 Location: Southern California Posts: 2,147	any downsides to running too much compression besides haveing to run higher octane? I know that it will put more stress on your engine but anyting to really look out for if deciding to do it. And how do you figure out what your compression ratio is?

06-04-2006, 09:04 AM	#7 (permalink)
Kurlon Super Moderator Join Date: Feb 2005 Location: Windham, ME Posts: 8,403	The only proper way to determine your compression ratio is to cc the head and piston. Basically, you drip a fluid onto the head and piston to determine their volumes, and use that info plus the displacement to determine the compression ratio.

06-04-2006, 01:38 PM	#8 (permalink)
kane 2nd Gear Member Join Date: May 2006 Location: murrieta ca Posts: 719	you could use clay or also solder.

06-04-2006, 03:25 PM	#9 (permalink)
Kurlon Super Moderator Join Date: Feb 2005 Location: Windham, ME Posts: 8,403	Problem with solder is you can't read it directly, you have to tweak the numbers you get based on the size an type of solder used. Clay, well, hit up the local kindergarden, steal some, and get'er done. :P

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