What Benefits of Head cleanup

[Sparky84]

How much does the carbon buildup in your head affect performance?

What benefits would I get with a quick port n polish.

Would there be anything else I should do while it's off?

Just getting ideas at present. 

Cheers
Alan

[JMR]

How much does the carbon buildup in your head affect performance?

What benefits would I get with a quick port n polish.

Would there be anything else I should do while it's off?

Just getting ideas at present. 

Cheers
Alan

FJ ports aren't very good to begin with so any quality port work is beneficial. The head can really benefit from OS intake valves and having the seats bored to .9 of the OS valve. OS exhaust valves with the seats bored to .85 isn't a bad idea either.

[Pat Conlon]

.....and unshroud the valves.

[JMR]

.....and unshroud the valves.

That's right. Putting larger pistons in your engine also helps unshroud the valves.  The FJ head can really benefit from milling to get the compression up as well on everyday pistons like Wiseco 1314cc, 10:25CR pieces. The FJ chamber can use work too. These FJ engine heads are basically copies of the DOHC Honda's of that era.