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my 9 port flow chart


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#1 _uglybob_

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Posted 04 June 2007 - 03:31 PM

hey guys
i found my flow chart for my 9 port that i got done about a year ago. i havnt seen any others i was just wondering how it compares to some other peoples heads on the forum as i have nothing else to gauge the level its at.

cheesr guys
ben :rockon:

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#2 FastEHHolden

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Posted 04 June 2007 - 08:07 PM

Sorry cant help with what you are after...but there is some good info there to build an airflow file for Dyno 2000..thanks

#3 _uglybob_

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Posted 04 June 2007 - 09:23 PM

ah kool how do i do that? do you hav that program??

#4 _monaroman68_

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Posted 04 June 2007 - 10:22 PM

I've got my flow chart in my hand and its a 173 blue head with stock ports and only had work done to the bowl and short turn .

Fiures are as follows at 28" of water.
Just will give 500 lift figures.
152.1 inlet 114.6 ext

152.1cfm @28" H2O= 235HP potential

my pre work figures where just a bit less than your starting figures.
Dave

#5 FastEHHolden

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Posted 04 June 2007 - 10:32 PM

uglybob...I do but it isn't here...when i get to that computer I can get it. :D

#6 Litre8

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Posted 04 June 2007 - 10:42 PM

To convert between different pressure flows see here

#7 Heath

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Posted 04 June 2007 - 10:46 PM

Thanks for sharing. When I have learnt enough to put this into perspective, it will be brain-food. Cheers mate :spoton:

#8 Litre8

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Posted 04 June 2007 - 10:57 PM

The exhaust/intake ratio looks very good. "They" say you should have minimum 70%. Most of the improvements come at .4"+ lift and from those numbers the port starts going backwards after .5" lift.

So, imho, a monster lift cam isn't going be an advantage but something that maximises the time when lift is above .35" to take advantage of the improved flow at those lifts. A roller would be ideal but expensive. Probably a few different flat tappet grinds that would work well too.

#9 _[BOTTLEDUP]_

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Posted 05 June 2007 - 01:10 AM

Only thing to keep into perspective when it comes to the 9 port head is that you are effectively flowing two ports, the valve itself becomes the minimum cross sectional area of the port.

The numbers you have there aren't bad, we flowed a 9 port a couple of weeks ago that put out 177cfm @ 28". The airflow potetential is there for 250 odd hp, with 100% VE (very hard to achieve with a 9 port). The exhaust figures are pretty good, Holden 6s generally are.

As Howard has mentioned, a cam with good lift numbers to take advantage of that mid lift flow would be good, dependant on the rest of the combo something approaching 0.520-0.550" net lift and ~240 duration would be good.

#10 _uglybob_

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Posted 13 June 2007 - 07:25 PM

hey guys thanks for the feed back there. i was told that flow should be good for 280 hp would you agree?
well the cam i got is the solid crow wich has .490" lift and about 240@50 dur so thats just about perfect yeh? just a bit more lift.
the idea is to build this motor and learn what i can and then go onto a roller in a bit so wiht what you said howard it will eventually hav a roller in the not too distant future!!

is there much more room for improvment with the flow specs do you think? is it bad that it starts to go down hill after 500".

id love to know how much power i could chase statisticly on this dyno 2000 thingo greg.

cheers
Ben

#11 Litre8

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Posted 13 June 2007 - 08:38 PM

You could play with rocker arm ratios to bump the lift. Larger valves and more port work may provide some flow boost after .5" lift but there is a limit to how much these will flow.

#12 _82911_

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Posted 14 June 2007 - 01:29 AM

That's reasonable flow for the vave size used.
The main reason that it hits the wall @.500" lift is the valve dia is a restriction above that point in a 9 port.
To keep the port working you will need a 1.75" valve, but to get that in there takes some serious work to both block and head.Sure, you can just throat it and stick the 1.75" in there, but it won't work unless you know where to stick it......
BTW: I would have gone for a cam with about 520-530" lift to maximize the time spent at best flow figure(both opening and closing sides of the ramp) and a bit more duration @.050' say.. 245 deg.

Cheers Greg..

#13 _uglybob_

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Posted 14 June 2007 - 07:10 PM

o well seems that it should be good enough to make some good power for now untill i bump the roller in. then i wil hav to hav another look at the valve side and some more porting and get it all much up perfect with the custom grind. i might have a look into some more rollers though howard how much higher could i go with the ratio on rockers? not real keen on parting with the ones i just bought though.

more information would be great on the bigger valve and the process required to make it work. ie the serious work to the head and block you were talking about.

thanks guys for the feedback
Ben

#14 _uglybob_

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Posted 31 July 2007 - 12:03 PM

hey guys just looking at geting another flat tappet cam now that the engine is apart again to have some more oil gallery surgery on the block (and sort out this flywheel problem) and i want to go for the best cam to get the most out of the head. i was looking on the crow cams site and the biggest solid cam looks close to to the figures suggested by a few of u guys just with a little more duration. so would it be advantageous to get this one and hav some duration taken out?
D16105
http://www.crowcams....e-Holden6.shtml
what do you think?
also want to giv it a squirt of nitrous in the near future. what do you normaly take into consideration cam shaft-wise when running nitrous?
anyfeed back appreciated

cheers
ben

#15 _1QUICK LJ_

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Posted 31 July 2007 - 03:01 PM

any cam will generaly work with nitrous, but you can optomise it for greater gains, its all about changing the cam timing events which can get complicated depending on the combo being used, but keeping it in simple terms using a little more exhaust duration say up to 10 degrees more, and a little less overlap by opening up the lobe separation a couple of degrees.

#16 _uglybob_

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Posted 01 August 2007 - 07:53 PM

ok then thats kool thanks quicklj will hav to decide how much nitrous will be used and if it would be worth while changing the grind to just use it every now and then. might even just change it later on. the cam matching the head was the main concern at the moment and optimising on the head port work.

how would the duration change to power curve? would having so much duration detracte from acceleration at all out of corners? probably a very basic thing to ask but i really dont no how those things effect different aspects of performance would really like someone to elaborate a little on it. i remember reading that 330 hp 202 in street machine kept the duration a little lower to retain acceleration characteristics.( pretty sure that is what it was).

anyfeed back appreciated.
Ben

#17 _1QUICK LJ_

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Posted 01 August 2007 - 11:29 PM

duration affects cylinder filling, as duration goes up your cylinder pressure will start to become lower after a certain point. thats where compression comes into it, once you go to a certain duration the cylinder pressure will drop unless you up the compression to counteract it, thats why big cams and low comp generaly doesnt work because the little compression that the low comp motor has gets bled off even more. so what you should be aiming to do is open the valves for longer so you can get more air and fuel in but still end up with better cylinder pressure aswell by increasing the compression.
i dont like going over about 290 advertised duration on street engines this keeps good drivability on the street. that size cam will go to 7000rpm no probs with good head flow, too many people over cam trying to get power, its all in the head and comp aswell.
i built a 202 years ago specs:
triple carbs
9 port head ported XU1 valves
278 advertised duration
10.5.1 comp
it made 161hp @wheels @ 6300rpm
it out did 3 other engines on a dyno day with same type combos but bigger 300+ duration cams they averaged around 135hp @ wheels best one made 141hp @ 6800rpm. the smaller cammed engine also made alot more torque and started to make power around 800 rpm earlier also which is very important on the street. this should give you some insight as to how a cam can affect acceleration out of a corner .ect

Edited by 1QUICK LJ, 01 August 2007 - 11:31 PM.


#18 _uglybob_

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Posted 02 August 2007 - 06:49 PM

yes so will it suit the head do you think? or is it too big. would it be worth taking out some duration? compression is not an issue as it already has 11.2 AA's told me. firgures on the chart say its increasing flow all the way up there so it should make good of the lift yeh? driveability was not something i was terribly concerned with its just to hav fun on weeks when im bak at home.
so the ones with the bigger cams where making less power, is that because the head was notup to snuff?

#19 _1QUICK LJ_

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Posted 02 August 2007 - 11:49 PM

i would go around 290-295 advertised duration with your combo as you have the head and also the comp. the biggest thing with the bigger cams 300+ duration is they really need 11.0.1+ ideally 11.5.1+ comp to really get cracking. the headflow factor also comes into play up in the higher revs.

#20 ilovea9x

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Posted 03 August 2007 - 05:28 PM

I had my J Zed head flowed tested to 480 hp
Not a figure which I think the motor would reach




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