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General Category => General Discussion => Topic started by: Sparky84 on May 24, 2020, 06:05:41 AM

Title: What Benefits of Head cleanup
Post by: Sparky84 on May 24, 2020, 06:05:41 AM
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.  (popcorn)

Cheers
Alan
Title: Re: What Benefits of Head cleanup
Post by: JMR on May 24, 2020, 08:48:58 AM
Quote from: Sparky84 on May 24, 2020, 06:05:41 AM
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.  (popcorn)

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.
Title: Re: What Benefits of Head cleanup
Post by: Pat Conlon on May 24, 2020, 10:40:31 AM
.....and unshroud the valves.
Title: Re: What Benefits of Head cleanup
Post by: JMR on May 24, 2020, 03:55:17 PM
Quote from: Pat Conlon on May 24, 2020, 10:40:31 AM
.....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.