I just dropped off a 99 head to a machine shop and told them to port and polish the intake and the head, match the ports, clean up the valves, mill the block and pressure test it if needed.

I asked about bigger valves but they said for the money it's not worth it.

Anything else I should have them do for reliability and power?



Thanks

 

You really don't want to "port" the head, except in the pockets, the ports are big enough careful work can increase flow but usually it takes someone who really knows this head. Simply port match it to the intake. If you want to bias some flow to the exhaust (useful on a turbo motor) you can run a 1mm bigger exhaust valve.

You might ask them to unshroud the intake valves and if you want more high RPM power, different cams would be in order. You can't get too crazy on the cams because the cam buckets limit lift and the head doesn't flow any better over 10mm lift anyway.

You might have the head flow tested. There are other heads out there that have been flow tested, this should give you a reasonable idea of what to expect from the head as far as flow numbers are concerned. If you don't have flow numbers how do you know what you are paying for?

Mark

 

How much does a flow test usually run?

 

Should be part of the quote on any good head work. Depends on the shop, they usually charge by the hour but somewhere between 100-250 seems normal.

Mark

 

Got the parts back yesterday.

They were suppose to gasket match the head and intake but it looks like they just port and polished it. Does it make a difference? Should I take it back and have them redo it?

Also, what is unshroud the valves? I asked them to do it but since they didn't gasket match the ports what should I look for to make sure they did unshroud the valve?


Thanks