Could you post your before flow numbers??
Are you planning on putting the larger valves in??

 

don't jinx me man!



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collins8:

yes, I don't have the before numbers yet, the machine shop has them (until I pay for everything I imagine). believe me AS SOON as I get them hopefully early next week I will be posting both before and after flow numbers.

It'd be interesting to have some of the "CNC" ported head flow numbers to compare with. if anybody has some numbers on the modmax heads or any of the tuner's heads available that'd be great to compare to.

I just hope I didn't waste a ton of money. (fingers crossed smilie)

later,
chris

 

well, I don't know if has been mentioned yet, but in addition to VINNIE's truck being pictured in the latest (jan) issue of MM&FF, there is an article on a JDM engine buildup with ported heads, secret grind crower cams and a magnum powers blower.



they got like 542HP and 635FT/LBS on 16lbs of boost.

I'm sortof curious as to how they got 16lbs of boost with ported heads and long tubes and only a 6lb pulley? maybe it has a small upper as well?

but anyway, the part that is really interesting to me is that they have flow numbers for the CNC ported heads!

they list these numbers:

Intake flow at .500 = 210cfm

Exhaust flow at .500 = 162cfm

I can't wait to see what my heads will do, I hope they don't suck! no pun intended!

later,
chris

P.S. if anybody else has any flow numbers available for any of the other ported heads on the market, PLEASE POST them here! thanks

 

for what it's worth, Fox Lake has some flow numbers on their website.

they list 163In&150Ex for stock '99 up PI heads

they claim Stage 2 P.I. heads flow a whopping 223 cfm intake and 195 cfm exhaust @ .500" with Mod Max valves!

all of the ported heads that I've seen seem to have REALLY large runners, meaning, they just seem to have opened up the runners as much as possible.

like this:


Now obviously this will flow lots of air, but theoretically doesn't this hurt TORQUE production?

I'm HOPING that my heads will produce good cfm's and also still retain high airflow velocity numbers, thus proving good HP and also good TQ numbers.

anyway, we'll see what happens in a few days.

later,
chris

 

Superfords, make sure that the shop uses a flow plate or clay around the intake port and a header primary on the exhaust port when they flow them, otherwise the numbers will be useless. It will choke itself at the entrance to the port, and the flow along the wallls will be lazy or dead without a clay radius to simulate the intake runner...'vena contracta.' Every good shop uses clay or a flow pate now days, but its good to make sure.

 

I have a set of heads going on my truck that flow;

.500 lift= Intake, 215.7, Exh, 185.0n JLP CNC heads BTW

WINGER

 

SMOOOOTTTTHHHHH

 

The valve only spends 1/360th of it's time at max lift. It's more important how well it flows starting when the valve lifts off the seat, and how quickly it builds velocity. The Extude Hone process is very respected because of it's ability to increase flow with minimal volume increase in the port. This helps maintain velocity even at lower rpms, and gives crisp throttle response. Some of the CNC heads flow great numbers, but have large port volumes, which kills velocity, and gives a really lazy power curve. They come on strong at the top, but the area under the curve is what counts on the street. To compare flow values on heads, you need to know the flow values from .100 to max lift on both the intake and exhaust.

 

AVG. Before Flow numbers.
Lift Intake Exhaust
.100 54.2 50.5
.200 103.4 103.8
.300 143.4 126.1
.400 162.0 138.0
.500 172.4 143.2
.550 175.5 144.7


After flow numbers
Lift Intake(CFM) Exhaust(CFM)
100 60.1 60.3
200 101.5 100.4
300 143.8 134.5
400 179.2 155.8
500 206.9 178.2
600 219.7 191.3

These are the flow numbers from a set of heads that I had a guy port for me. Looking at the low lift numbers there should be little loss of low end torque??
I have never installed them on the truck. They are just sitting in the garage.

Rob

 

superfords
Did you ever get your heads flowed ??
Thanks Dale

 

They have been flow benched. The machine shop is taking it's sweet time with everything. (I guess that's what I get for telling them I wasn't in a rush, but sheesh, it's been MONTHS!).

anyway, I called last week and the guy I needed to speak to was out of town for a week, but the person on the phone said that the heads had been tested.

he said that he didn't have the exact numbers, but...

the cfm gains he quoted me on the intake were EXTREMELY dissappointing.

he didn't give me a number on the exhaust, but did say that the exhaust side picked up "quite a bit".

I may drive over there today and play the role of the squeeky wheel and see if I can get things moving along a little faster and get some numbers to post as well. I'll update as soon as I get the info.

later,
chris

 

Yea, been there done that. I've said that a few times when I had a winter project that needed to be sent out. I kept thinking that maybe they would cut me a better deal that way. I would have to go back and start riding them as it would keep getting closer to the season to use it and it would still be far from done. I've since told any shop that's working on my project that I need it by a specific date and we agree before the work begins. Good luck with your project and keep us informed with what you're doing.

 

Yeah I'll chime in on that one.
I got my KB in Feb/03 and decided to pull the motor in Mar/03 for a freshen up and I just got my cylinder heads back 2 weeks ago. The motor is sitting in front of the truck ready to go in right now.
Thats only 9 months total, I think......Oh well its almost there.
Dale