Dirty Valves from butterfly system?

[Danski]

They were cleaned, perhaps not to "spotless" grade. They are at spotless now as I've just had new seals put in and the entire manifold cleaned. So time will tell if it's still happening.

[Valvebounce]

Here's a possible solution,http://www.trademe.co.nz/Brows...00488

Hey danski, You're in Christchurch aye? Like NZ? Small world huh.

[BQ.05.TD]

i removed my butterflies and did a bit of grinding and cleaning up the devider in the lower half of the runners and matched up the ports as there was a 4-5mm diffrencemade a bigg diffrence to top end power if you ask me and i cant notice and diffrence in response or lack of low end torque

were you have to match port it. and yes i assembled the intake to get this pic



this is wat the devider looks like stock. and where i have started useing the dremel is were the ports taper in 2mm for some reason

here is a better shot of the taper
Modified by BQ.05.TD at 5:42 PM 12/20/2009

[BQ.05.TD]

just found some more pics.and after you do that and get the hole welded up at each end that the shaft went through get it bead blasted to take out and edges or left over s***

this is a even better shot of the taperand after it was dremeled out on one side to see the diffrence

stock deviderstock v modded

[lcw1980]

Why not just get rid of the divider altogether? Thanks

[Danski]

This is pretty much what I just did except I took the dividing middle section back past the hole that the runner left.

You can take the whole thing out, however this will require the head to have its dividing middle bit modded aswell.

[D_Stirls]

Quote » if you ask me and i cant notice and diffrence in response or lack of low end torque[/quote]I think we have discussed this on MSN before but, the dyno disagrees with you, there's a 50% increase in torque in the bottom end. lol

http://www.nissansilvia.com/fo...rch=1


Modified by D_Stirls at 11:50 PM 12/25/2009

[lcw1980]

Wonder if BQ.05.TD has a torque graphon his engine.

Btw D_Stirls, this graph you shown us, your test just involves disconnecting\reconnecting the vaccum hose to the actuator but not removing the butterflies altogether?
Modified by lcw1980 at 6:57 AM 12/25/2009

[sjbsuperman1425]

I think we have discussed this on MSN before but, the dyno disagrees with you, there's a 50% increase in torque in the bottom end. lol

http://www.nissansilvia.com/fo...rch=1



Modified by D_Stirls at 11:50 PM 12/25/2009

who spends that much time in those low RPM's in a 1.8L anyway?

Merry Christmas everybody

[sjbsuperman1425]

Wonder if BQ.05.TD has a torque graphon his engine.

Btw D_Stirls, this graph you shown us, your test just involves disconnecting\reconnecting the vaccum hose to the actuator but not removing the butterflies altogether?

Modified by lcw1980 at 6:57 AM 12/25/2009

I know most will agree when I say that the butterflies and the bar are a HUGE obstruction to flow even if the actuator is connected to vacuum. Where you might lose "50%" low end torque by removing them, the flow in higher RPM is well worth it in my opinion. Here's my take on it:

think of aerodynamic testing for cars in wind tunnels, but in a smaller version. Put just a bar in a tube and do the test. In my brain you'd likely see the air moving past above/beneath the bar, but that air movement would most likely if not definately be slowed down or have its path altered by the disturbance from the air that hits the bar, and tumbles in all directions. I'm sure this makes since, but please, share your thoughts or expand if you can.

oh yea btw, the graph doesn't show the whole setup removed, so you may see a SLIGHT higher torque number than with the setup just disconnected at the actuator.

[lcw1980]

the sr20det had none of these butterfly thingy. how it manage to put out good low end torque?

[bentvalves]

the stroke and bore dudeman.

[meminto]

I know most will agree when I say that the butterflies and the bar are a HUGE obstruction to flow even if the actuator is connected to vacuum. Where you might lose "50%" low end torque by removing them, the flow in higher RPM is well worth it in my opinion. Here's my take on it:

think of aerodynamic testing for cars in wind tunnels, but in a smaller version. Put just a bar in a tube and do the test. In my brain you'd likely see the air moving past above/beneath the bar, but that air movement would most likely if not definately be slowed down or have its path altered by the disturbance from the air that hits the bar, and tumbles in all directions. I'm sure this makes since, but please, share your thoughts or expand if you can.

oh yea btw, the graph doesn't show the whole setup removed, so you may see a SLIGHT higher torque number than with the setup just disconnected at the actuator.

I disagree with the huge obstruction statement, but I agree that there is an obstruction..

There is only a 4cfm loss in flow with the manifold and butterflies attached, compared to the head itself..

Unless you are planning on outflowing 220cfm, keep the butterflies, if they are working as intended they are helping you

[lcw1980]

wow the euro 4 port ca18det head must suck then with lower torque at bottom end.

I'd like to keep some bottom end torque for street fun if you ask me but still this crud problem just spoils my day

[meminto]

The euro head inlet ports have a smaller cross sectional area compared to the jdm eight port..

This would provide some increased airspeed in the euro design I guess, however in comparison the flow is relative for a given lift value...

[sjbsuperman1425]

yup, might have exagerated the "HUGE" part..but i did remove my butterflies. no need for low end for me and they were more than likely not working properly.

[D_Stirls]

I was going to say that Matt had the figures actual increase in flow in the top end, and 4 cfm works out to 2.5 BHP which in my opinion isn't worth the losst down low.

who spends that much time in those low RPM's in a 1.8L anyway?

Most street 1.8 litres spend 98% of their time below 3700 rpm.

I'd like to keep some bottom end torque for street fun if you ask me but still this crud problem just spoils my day

IMO the answer to the crud problem could be water methanol injection, if you have ever seen the inside of an engine running WM injection it's spotlessly clean.

[D_Stirls]

i guess im in the 2% than

The cops really don't like imports here in Australia. so when in public view we really have to behave ourselves if we want to keep our cars un-defected.

There are a few options i was going to try with the butterflies when i was going to rebuild my CA.

1) port all the runners and increase their diameter 2mm (just enough material to allow 2mm) and then fit bigger butterflies that way they will outflow a standard manifold with the butterflies removed and you will keep the increased torque down low.

2) once again port all the runners and fit oversized butterflies to all the runners and do away with the factory TB. Effectively i will be making a individual TB manifold out of the standard manifold. This will be quite tricky because you have to do things like tap fittings to all the runner after the TB's to get a vac source for the brake booster as well as giving a place to allow the idle air to enter the system. If i was to do this i was thinking about adding a injector seat on the runners that don't have the injector seat on them. I don't know if this would overload the injector drivers though and kill them as i;m using nistune.Really though this would be the hard way to do a mulit TB setup as it would be easier to make a submainfold to accept the GTR TB's.

Having free access to a CNC machine centre is the only thing that allows me to try either of these things because i would hate to be paying for machine time to try either idea.But I won't be doing any of these ideas though as i have this sitting in my garage.

[bentvalves]

at this point im thinking the way to eliminate the crud, is to alleviate the vaccuum created behind the buttefly by drilling a few small holes in it It makes perfect sense that the oil is being drawn past the valve stem seal. Has anybody taken a look see how KA's butterfly system are designed. Nissan fixed the issue later on down the line like they always do

Greg

[D_Stirls]

If you start bypassing air past the butterflies to decrease the vacuum them you are also reducing the effect of the butterflies because you will be decreasing the intake velocity of the unclosed runner by reducing the volume of air travelling through it. If you aren't having an effect on the velocity then you won't be reducing the vacuum and if you do reduce the vacuum you will be reducing the effectiveness of the butterflies.Also two small holes isn't going to have much of an effect on the vacuum behind the valves and of you get the holes big enough to have an effect then you might as well do away with them.

Water Meth injection is a win win you get to keep your runners clean as well as all the bonuses that come with water meth injection.

[bentvalves]

agreed on water meth, have a look at KA butterflies however. CA's butterfly system will still most deffinatley do its job, air bypassing them slightly or not.

[lcw1980]

How often one have to use water/meth injection to keep it clean i wonder. It aint cheap from where i come from.

is there a stronger version of valve stem seal that can be another solution?

I think the cheapest solution is to clean the throttle body with spray-type solvents once a month and live with the 8 ports.