In the last days I was thinking about the headwork for our project car. We try to hit the 700hp with a 2l LS block and GT40R, 4" complete exhaust system etc.

We are a little unsure about the cams but this is an other story.

The other more important thing in the moment is the head. We are planning a fully ported and polished head that shall be machined to exactly fit the 84mm bore for good breathing.
We think to take 1mm oversize valves on the intake side to get a good flow or more air into the combustion chamber with the same amount of boost - hope you understand what I mean.
On the exhaust side we want to take 0.5mm oversize valves.

Our thoughts on the headwork is to make as much power as possible with as less boost as possible.

On the other hand I heard people say that oversize valves are not a good idea on such turbo engines - but I see no reason for this?

What do you think?

 

First off we need to know what head youre running. I see you saind youre gonna use a 2l LS block...but im sure youre gonna be using a vtec head. If youre planning on using an LS head then youll definately need to get alot of work done. It would also be nice to know if this was gonna be a street car or a track only car. All these have a big affect on what type of headwork youll need. Feel free to PM me if you have anymore questions. Good luck on the build!

 

Yes it is a VTEC head from a b16a.
The car shall be used on the street but not for "daily driving". Just for having fun at the weekend. Sometimes for 1/4mile races.

Kevin

 

porting the head makes the torque hold longer in the rpm range without dropping off....

horsepower is a multiplication of torque.... the formula is torque x RPM / 5252 =HP

so if a motor makes 400 ft lb and it drops off as it revs the power will drop off...
if it holds 400 trq and has higher rpms the power is multiplied by the rpms....