Leak Test and remedy

[ad67]

I leak tested a 206 with 20 metered hours and it showed a 8% leak at 80psi. Leak test was performed warm. Valve lash set cold to 0 intake and .001 exhaust. Engine performance is ok for club racing but lacks in regional races. Is my best option to simply replace the entire head? I'm ok spending extra to save time but engine builders are backed up and shipping is $$$.

 

[Chipg56]

Assuming it is coming from the valves a new head would solve the problem, but If I were you I would also have the old head repaired so you have a spare. The rebuilt head will probably last longer then new. If you don't have the time for either, lapping the valves and a new head gasket may help. I heard that some people have been using electric drills to lap valves. Don't do that.

 

["J'-remy]

a valve job is all you need to wake up an engine. a new head will need the same thing done in time

 

[ad67]

on the new head, I'm seeing some folks advertise ground or race prepped heads. Any advantage to these heads vs stock? (agree that driver, chassis etc are the focus for biggest gains).

 

[flattop1]

Its Said the heat cycled heads are better as they've already taken a set .
Post #2 is A good solution .

 

[CarlsonMotorsports]

A heat cycled head is essentially a used head that's been freshened (ie cut the seats and get the seal back to 0.)
Some are taking the head, and bolting it up to a steel plate and heat cycling it in a toaster oven. Yes, it can help, but so can having your current head freshened up. I like the idea of the valves repeatedly pounding the seat into place while running under load on the track at varying rpm. It's going to be hard to simulate that in an oven.


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