my 9 port flow chart
#1 _uglybob_
Posted 04 June 2007 - 03:31 PM
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
#2
Posted 04 June 2007 - 08:07 PM
#3 _uglybob_
Posted 04 June 2007 - 09:23 PM
#4 _monaroman68_
Posted 04 June 2007 - 10:22 PM
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
Posted 04 June 2007 - 10:32 PM
#7
Posted 04 June 2007 - 10:46 PM
#8
Posted 04 June 2007 - 10:57 PM
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]_
Posted 05 June 2007 - 01:10 AM
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_
Posted 13 June 2007 - 07:25 PM
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
Posted 13 June 2007 - 08:38 PM
#12 _82911_
Posted 14 June 2007 - 01:29 AM
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_
Posted 14 June 2007 - 07:10 PM
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_
Posted 31 July 2007 - 12:03 PM
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_
Posted 31 July 2007 - 03:01 PM
#16 _uglybob_
Posted 01 August 2007 - 07:53 PM
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_
Posted 01 August 2007 - 11:29 PM
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_
Posted 02 August 2007 - 06:49 PM
so the ones with the bigger cams where making less power, is that because the head was notup to snuff?
#19 _1QUICK LJ_
Posted 02 August 2007 - 11:49 PM
#20
Posted 03 August 2007 - 05:28 PM
Not a figure which I think the motor would reach
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