interesting head flow theory

[burgo]

http://mototuneusa.com/homework.htm
http://mototuneusa.com/the_2007_superbike.htm

this guy beleaves making the ports smaller is the way forward. i think his theory is basically filling the areas of the port that have low velocity so that altho he is reducing the size of the port it doesnt effect the flow but does increase overall velocety of the port. or something like that lol

[Stuart]

i read in the vizzard SOHC ford gneing book (its applicable to the ohc gm engines) that he "ramp ported" the bottom of the intake ports and found good gains. I tried it on a std 1.2 head with plastacine and a flow bench and it did give a bit of extra flow but nothing HUGE, but hey every little is important when your chasing numbers.

i suppose its as mixed a theory and opinions as the running in of engines lol

[S_Gault]

stuart send me the flow bench data coz youve totally missed the point

ive done the ramp port on pintos etc... it doesnt increase the flow.. the flow stays the same proving the point that port is non restrictive and too big for the valve size.

what it does do is increase the port velocity, which you cant measure unless youve the correct pitot tubes and the 3d modelling software.

on a nova head that you describe the short turn is just about perfect and if you ramp the port as you describe you will loose flow.

but the first post has the jist of it

[Stuart]

need the data recoverd from a hdd full of porn.... so that could take some time lmao.

the flow did increase by a margin..... but maybe i was blind that day.... :roll:

might spend the afternoon messing about with Gt power just to try and recreate it

[S_Gault]

gimme the numbers,

what bench were you using and what test pressure and i'll convert my numbers

[Stuart]

dont you read? the hdd that the data is on has failed, its full of porn so its gonna take some intresting recovery strategy lol.

it was at 10" of pressure on a superflo 110 bench though.
air temps are needed too ;o) or dont they bother you lol

[burgo]

but the first post has the jist of it

woohoo does that mean im cleaver??? or just that i read stuff properly??

[_JH_]

i read in the vizzard SOHC ford gneing book (its applicable to the ohc gm engines)

I have that too. Haven't looked through it properly, but it looks quite interesting. Just need to build a DIY flow bench now (don't start steven lol)

[S_Gault]

i have flowcom with my flowbench.. so it does the number crunching smart guy.

if you werent using it and your were using a pressure drop of 10inches then at the numbers you would be measuring the small increase you say was none as its barely within the limits of error.

what bore adaptor were you using and how was the head fitted to it? i suspect you may also have offset the head on the bore the second time.. as much as 40thou will have an effect due to less bore shrouding.

your so critical when anyone questions you... you seriously cant be wrong, especially when it comes to me, coz i seem to catch you out so often

[S_Gault]

oh and the vizard book has some good data about rocker ratios, it relates directly to GM engines although the numbers are a bit different.

derek.. nothing wrong with diy flowbench, ive done it , just its easier to compare bench to bench with an industry std, but from a tuning point of view, it makes zero diff.

I had to buy one as I do development work on superbikes and they want to compare like with like

[Stuart]

never moved the head off the bore adaptor "smart guy" :P so that avenue of trying to shoot down is f**ked...... after i used the temp correction factors and all that crap the numbers were bigger... but meh ill jsut dig the spreadsheet off the old hdd at some point. But i suppose us mere mortals CANT possibly see improvements that youve not seen.....

[S_Gault]

if your talking about a couple of cfm gain etc on the numbers you get with a 1300 nova head, its extremely doubtful, especially if your not using the flowcom as there are too many variables . I do believe truly that you may have seen a small gain, what im saying is its prob not an improvement as its outside the error limits of the bench at that test pressure.

all im saying is Ive been down these blind avenues before, it would save people time and effort if they actually belived me,

keep your fecking pants on man... you really have a thing about my posts and espically if i dont agree with you.

well im here to tell the truth from fact and past work , not what i picked up second hand from someone else

[_JH_]

well im here to tell the truth from fact and past work , not what i picked up second hand from someone else

In that case can you answer my question here then? :)
http://www.novaload.net/forums/viewtopic.php?p=525259

You sometimes take great delight in telling people they're going wrong, but you don't follow it up by telling them how to go right. maybe thats why you get treated like this.

[Stuart]

You sometimes take great delight in telling people they're going wrong, but you don't follow it up by telling them how to go right. maybe thats why you get treated like this.

:+: thats the puppy!!

[S_Gault]

coz there are no books that do it derek..

ask a specific question about them and i'll answer it

[_JH_]

Perhaps you could have mentioned that at the time then! lol

Going to make some throttle bodies with them next year instead, so don't worry your pretty little head about it.

But thankyou for your offer of help