Cutting head for compression

Have seen posts about cutting head to raise compression on an open animal
Also have seen it suggested to cut at least .070 - .080 to make a cam work
Just how much is too much when using a 308 or mod 1 cam
I realise that the more you take off the weaker the head gets - just wondered how far you can go
Thanks for any and all input
 
I think .070" is plenty...that leaves a pretty small combustion chamber (and brings the valves closer to the piston by .070" too.)
I'd rather use a billet head (if legal at your track.)


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🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
Have seen posts about cutting head to raise compression on an open animal
Also have seen it suggested to cut at least .070 - .080 to make a cam work
Just how much is too much when using a 308 or mod 1 cam
I realise that the more you take off the weaker the head gets - just wondered how far you can go
Thanks for any and all input
I think .070" is plenty...that leaves a pretty small combustion chamber (and brings the valves closer to the piston by .070" too.)
I'd rather use a billet head (if legal at your track.)


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Is his statement about cutting the head making it weaker correct? Ive never heard this.
 
Don't know how much mine was shaved, but it is very hard on the head gasket as well as the gasket underneath the plate the valves sit on, good idea to keep a few extra on hand if you plan to run it alot...
 
Is his statement about cutting the head making it weaker correct? Ive never heard this.
They are already weak before machining. The bolt centers are very wide and too close to the corners of the head.
The #1 head bolt (closest to the exhaust port) is suspect to localized super heating from the exhaust and typically that corner of the head pulls down over time. You'll almost always lose the head gasket between the top two head bolts due to the corners pulling down. It's made even worse when using the fire ring (and similar) head gasket.
 
They are already weak before machining. The bolt centers are very wide and too close to the corners of the head.
The #1 head bolt (closest to the exhaust port) is suspect to localized super heating from the exhaust and typically that corner of the head pulls down over time. You'll almost always lose the head gasket between the top two head bolts due to the corners pulling down. It's made even worse when using the fire ring (and similar) head gasket.
Using a copper gasket instead of the fire ring gasket will help?
Also, would it be wise to remove the head and replace gasket every 2 or 3 weekends?
Currently at .095 off of head with flat top piston
 
I like the Cometic MLS gasket if (and only if) you have very flat head and deck gasket surfaces to start with.
The Flat Out Copper will work also.
The "more solid" gaskets will also help keep the surfaces from warping as badly.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
 
I like the Cometic MLS gasket if (and only if) you have very flat head and deck gasket surfaces to start with.
The Flat Out Copper will work also.
The "more solid" gaskets will also help keep the surfaces from warping as badly.


-----
🏁Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
32 years of service to the karting industry ~ 1Cor 9:24
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com
Agree MLS all the way
 
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