Head porting

[Hal]

For those of you who are considering have your head ported, or larger valves:

Don't bother.

I ran over 121 mph on a STOCK head with stock valves.

It had crower springs, retainers, and 414 cams, but the ports were completely stock.

Yes, I used a 55 shot to reach that speed, but the head still had
to flow the exhaust gasses out, and a 55 shot alone doesn't yield a 10+ mph increase in traps.

The 55 shot allowed the Red to spool up quicker/sooner, and that (IMO) is the reason for the big increase.

So, take the $ spent on head work and use it to improve something else.

If you own a 2g, a 1g head swap is a VERY good idea... even if you still have the T25.

Hal

[Van]

I'll second Hal here. It has also been shown that some head porting will also make you slower.

Stock 1G head here with some hks 264 cams.

Off topic:
121 mph, man that just rocks Hal! I can't wait until next season to see what else you can do with your set-up. I think that Red just needs that small shot up here in our thin air.
I was wondering what turbine wheel you got in that Red and if it's clipped at all?

Even John Sheperd said his car was a bit more laggy up here.

[-EpicEVO-]

Well i have a port matched head with bigger valves, and i think it only depends on your set up if it will help you or not. John shepard may have said it was more sluggish but he definatly isn't running a stock head. There is no way he would ever be able to spool that t4 with the stock head i don't care what cams.

IMO
MarK

[-EpicEVO-]

edit: Andrew was trying to use my name.

MARK

[Hal]

My car flows over 340 grams per second through a stock head casting with stock valves (3 angle valve job) at 24 psi. Others have flowed 380+.

That's a LOT of air flow capacity, so if someone is at that level (or lower), the flow through the head is NOT a bottle neck.

Hal

[-EpicEVO-]

Yeah that was andrew under my name, but anyways i think that my car as it seats right now, is slower with the ported head do to the turbo, not just the head, i have asperations of putting a bigger turbo on it so i figured i would go ahead and port match it now, with the bigger valves.

MARK

[Hal]

Oh, and Andrew... when it comes to trying new things... I doubt ANYONE running a DSM here in Colorado has tried as many things as I have:

1st to try a Frank-II (flop)
1st to actually run good with cams (webs and crowers)
1st to run a Frank-IV
1st to make water injection work (2 bar & 101 for 12.4 @ 114 mph)
1st to run a Red, yes it's not as good as it gets... but it's getting better
1st to actually run good with an EFI PMS

... and the list goes on


Now, lets define success:

1st Colorado 2g to run 12's
1st Colorado DSM to break 120 mph in the 1/4 mile

Compared to some of the national guys, not such a big deal... compared to the "locals"... pretty successful.

Hal