with the limitations on porting and polishing in IT rules, is there any advantage to be had from doing this finishing work on an ITA CRX head?

the limitations are you can only remove material 1" from the flange, either way, d16a6 head

thanks

 

The rulebook would be the definitive source on this matter, but last I recall, porting and polishing of the head was limited to 1 inch in from the gasket.
So, the advantage I guess would be it relieves you from having to worry about those silly IT rules, cuz you aren't legal for IT anymore.

 

yes I know what the rules are. I'm asking if there is any advantage to doing port and polish work while abiding by the rules. 1" in from the gasket isn't very far, so perhaps there isn't much advantage to be gained

 

I have never done it on an IT head as I have been told the Honda ports are pretty good and have always confirmed it with a good match to the gaskets and no blockage. On the otherhand, most of this experience was before the days when dynos were so handily available to local racers and there weren't many cylinder head prep companies messing with Hondas.

Now things have changed and I have not heard really what kind of quantified gains people are finding on IT heads. I would be interested to hear if there was any real gain.

 

I imagine the psycological gain is probably as large as the horsepower gain. One less thing to secondguess or pass-blame.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by CRX Lee &raquo;</TD></TR><TR><TD CLASS="quote">

Now things have changed and I have not heard really what kind of quantified gains people are finding on IT heads. I would be interested to hear if there was any real gain.</TD></TR></TABLE>

I don't think I would believe what I was told anyway.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by metalworker &raquo;</TD></TR><TR><TD CLASS="quote">I don't think I would believe what I was told anyway.</TD></TR></TABLE>

Truth...or at least more trustworthy than any quoted numbers.

So would numbers from a flow bench be sufficient or would they need to come from a dyno? It would be easier to take a clean, stock, valveless head and get a flow bench measurement and then try a valveless ported head back to back. You get no effect of the valve grind itself but you see the max air flow, that is if the porting was a was the weakest link in the chain and the limiting factor. I guess this set-up would show the maximum capacity for effect even if it made no difference on the engine. I have a few spare used stock heads that it might be interesting to play with porting but that is if you felt the time and effort was best spent there.

Wait a minute...first you make the car run, then you develop. Developing a non-running car doesn't do much for increasing seat time.

 

Send me a head, I'll send it back with everything I know. I just won't tell you about it.

 

The perfect match-up between the intake and exhaust manifolds is what you're after. If you already have it... Skip the port matching. I didn't already have it.

Gains... I dunno. probably not much. Maybe a HP at the top end.
But if you have everything apart and are doing machine work anyway, why the hell not go ahead and do it.
JMO.