Pontiac G8 Forum banner
1 - 10 of 10 Posts

· Registered
Joined
·
296 Posts
Discussion Starter · #1 ·
I am looking to install a cam soon and have been reading about milling the cylinder heads. I have .040 head gaskets, cam is 219/227 and I'm wondering your thoughts on milling the heads .035?
 

· Registered
Joined
·
275 Posts
Depends on your cam specs. I have the Little Lunati which is .625/.625 219/223 with stock LS3 MLS head gaskets and I went .035" milled. Thinner gasket than that probably wouldn't be safe with my cam.
 
  • Like
Reactions: sal329

· Registered
Joined
·
579 Posts
To be safe you should determine piston to valve clearance for your engine then decide how much material you can mill off of the heads. Then decide how much is safe to mill off while keeping adequate clearance (talk to a pro builder). Then have your heads milled to that spec. Then don't forget to get new length pushrods.
 
  • Like
Reactions: sal329

· Registered
Joined
·
579 Posts
To generally answer your question, if you plan to keep the engine naturally aspirated, then yes, milling the heads is an easy and cheap way to increase power potential while the heads are already off for the cam swap.
 
  • Like
Reactions: sal329

· Registered
Joined
·
114 Posts
I am looking to install a cam soon and have been reading about milling the cylinder heads. I have .040 head gaskets, cam is 219/227 and I'm wondering your thoughts on milling the heads .035?
What head gaskets are you using ? I'm undecided on which to use, but definitely want to tighten up the quench.
 

· Registered
Joined
·
5,346 Posts
I’m going to be using the Speedmaster 4.050” x .040” MLS gaskets.
Rectangle Circle Electric blue Font Gas
 

· Registered
Joined
·
3,024 Posts
Target your CR, mill the heads, then keep it cool(er)

Gen III/IV LS Performance Head Gasket(Big Bore) (straubtechnologies.com)

LS Head Gasket Replacement for MORE POWER!!!


Is there HP and RPM to be gained by replacing head gaskets on and making cooling system modifications to your Gen III/IV LS engine? Yes, and it’s been proven by Robert Yates Racing Engines in their continued development of the GM LS Spec engine for circle track racing.

RYRE pulled a track-tested engine out of a race car for endurance testing which had the OEM-type head gaskets and cooling system that was run in the car. Testing also included using the radiator right out of the race car. During testing, RYRE simulated the operating temperatures that the engine saw during races and it was noticed in the overflow tank that the engine was venting out of the radiator cap. Some head scratching went on with the results of the engine and cooling system testing. Donnie Lewis, part of the RYRE development team and Art Leniti from Arts Radiators, started researching the LS engine program and GM's focus for the engine platform; emissions legal for the EPA and better fuel economy. Donnie and Art’s research revealed that GM achieved this through heat! Increases in the operating temperature related to the fuel operating temperature and the higher the fuel mileage and less emissions due to the heat that is needed for the catalytic converter to function efficiently. As more fuel is burned, there is more energy generated. In the confined space of a cylinder, this increases the pressure and hence the temperature, which is converted via the Otto cycle and the engine design, into mechanical energy to operate the engine. The energy realized is related to the temperature difference; the higher the combustion temperature and the lower the discharge temperature, the higher the efficiency of the engine and the more gas mileage you'll achieve. In addition, to meet EPA efficiency and emission regulations, OEM manufacturers use 200 or even 210 degree thermostats.

We all know running an engine cooler will produce more HP, but sacrifices fuel economy. RYRE needed performance and reliability for their race engine. Inspection of the head gaskets revealed that GM limited the water flowing around the combustion chamber to maintain the higher operating temperature. Additional evidence of an imbalance in cooling between the right and left head was evident because of the factory plumbing. RYRE modified the plumbing to consist of equal-length lines with a T in the middle running to an expansion tank just under the radiator cap. This allows the gases to leave the heads equally.

RYRE pulled the stock head gaskets off the test engine and punched seven missing holes in the them. Being that this engine was a spec engine, power output and RPM range of power was well documented. These engines, when reaching operating temperature, had always “laid over” on the straightaways and just quit pulling. RYRE’s cooling system modifications with parts from Art’s Radiators by RYRE were quite amazing. A simple few holes and some plumbing changes to add additional cooling and release off gases allowed the engine to continue pulling through the entire RPM range! All of this was from modification to the cooling system. Additional track testing showed that the engines ran cooler on the track.


At the end of the day, Donnie Lewis of RYRE used simple physics to convert an EPA emissions engine into a 600HP NA race engine that runs to 7800RPM!!!!

Straub Tech’s relationship with RYRE has given us the opportunity to take this tech and turn it into a product for the performance LS customer. Available in small bore and large bore, the Straub Tech MLS gasket features the additional cooling holes that allow for more HP and higher RPM!!
 
  • Like
Reactions: plemon61

· Registered
Joined
·
296 Posts
Discussion Starter · #8 ·
What head gaskets are you using ? I'm undecided on which to use, but definitely want to tighten up the quench.
Well I ordered .040" I went to install them and they were .030" I didn't want to hold up the job so I have stock gaskets on now. But I think this year I'm trying another cam and torque converter and I have the correct gaskets to install as well.
 
  • Like
Reactions: plemon61

· Registered
Joined
·
5,346 Posts
Bore is too big. It creates more quench area around the entire bore. The 6.0 has a 4.0” bore. You want a gasket that is closer like what I what I listed above. Or the Cometic C5505-040. A 4.040 bore and .040” thickness.
 
1 - 10 of 10 Posts
Top