Butterflies , lots of them.

[Rex Schimmer]

Doc Goggles,
Ever think of making your injectors "slide valve" style? I worked with a slide valve injector for a Mazada rotary back in the 80s and the slide valve set up always made better hps than a butterfly set up, and if your port spacing is equal with some room in between the ports it is not a hard part to make. Miss all the "cosine pie are square three bag full" B.S. on the throttle opening too. Do not work well with blowers or turbos though.

Rex

[Dr Goggles]

very interesting Rex and I guess in the application we're using it that the excess wear that slides suffer ( in comparison to 'flies)isn't really too much of a concern,....right now I'm side stepping the "stack" idea and am concentrating on a twin throttle body manifold . I just sawed the top off the stock manifold and put a kind of pent-roof top on it to add a bit of plenum volume and top it off with two of the standard TB's chimney style on top .We had a single unit on the motor in a similar config' and purely on the reasoning that there was room for two I'm doing it .

Now , another question for the gallery. This motor is a 3.8litre and the stock throttle body is 60mm, I'm thinking I'll set the throttles up so that the second one goes from 0-100% after the first one reaches about 40% , too early ?, too late ?....... any comments


In another realm , my road car is making a fool of me ........the old straight six got a set of lifters and a head the other day , now it won't even start , it'll backfire occasionally and the local dogs are hoarse from barking ,but run ? not on your Nellie!............Sick of staring at it , and having nearly scratched my scalp off it's all coming apart again ,  I know it'll be something silly , really silly and you know what?.....you're not gonna hear about it!!!!

[JackD]

No sweat "Old Timer" We will look 180 deg away while you figure it out.

[Dr Goggles]

No sweat "Old Timer" We will look 180 deg away while you figure it out.

give me a bit of credit....my stuff ups are more complicated than that.....let's just say in more modern terms ...." i needed closure".......lashings and lashings......it was to do with a miss match( that's right she wasn't married) of some rockers and the "push" ........now , I don't know how many of those hollow rods I've thrown out over the years ....and now I just need one :?yeah you can all laugh.

[JackD]

So it seems that your motor didn't measure up to the trust you placed in it.
Doncha hate that ?
Kick it again for me too. 

[hitz]

very interesting Rex and I guess in the application we're using it that the excess wear that slides suffer ( in comparison to 'flies)isn't really too much of a concern,....right now I'm side stepping the "stack" idea and am concentrating on a twin throttle body manifold . I just sawed the top off the stock manifold and put a kind of pent-roof top on it to add a bit of plenum volume and top it off with two of the standard TB's chimney style on top .We had a single unit on the motor in a similar config' and purely on the reasoning that there was room for two I'm doing it .

Now , another question for the gallery. This motor is a 3.8litre and the stock throttle body is 60mm, I'm thinking I'll set the throttles up so that the second one goes from 0-100% after the first one reaches about 40% , too early ?, too late ?....... any comments

  Dr Goggles--Your Twin throttle bodies sound like a good idea to me. The progressive linkage has got my curiosity active. If you are using a throttle position sensor to send information to an ECU for injector control are you going to be able to able to compensate in your fuel tables to keep the fuel/air ratios proper? oops! I just got it. Of course you are! Are you going to run two throttle body injectors or is it set up for individual injectors in the runners?

  I'm going to try and run my Saturn on the injectors that it came with (close to the intake valve) AND the injectors that came with the Hayabusa throttle bodies.  . It's good to hear someone else is dreaming up things to try. There is no doubt some one else has tried both of these ideas. I hope they worked. Please carry on!

  harv

   
 

[grumm441]

Quote from: JackD
No sweat "Old Timer" We will look 180 deg away while you figure it out.


Quote from:Dr Googles give me a bit of credit....my stuff ups are more complicated than that.....let's just say in more modern terms ...." i needed closure".......lashings and lashings......it was to do with a miss match( that's right she wasn't married) of some rockers and the "push" ........now , I don't know how many of those hollow rods I've thrown out over the years ....and now I just need one    :?yeah you can all laugh.

I'm just wandering if I am sworn to secrecy
G

[Dr Goggles]

I'm just wandering if I am sworn to secrecy
G

meanwhile I'm wondering if you're wandering or wondering about wandering or just wondering

....no , not yet , no-one has them in stock .......... , yeah I'm wondering too.

[grumm441]

Maybe you could try the tip (translation tip = rubbish dump)

Or take one out of the EH (translation EH = 1964 holden van)

G

[Dr Goggles]

Maybe you could try the tip (translation tip = rubbish dump)

got some...from mad Bill ,..now it sounds just like it did .........before I pulled it down ....I fear it may have suffered a "Lobe-otomy"......why ,as you asked Sunday, DID I BOTHER :x

So it seems that your motor didn't measure up to the trust you placed in it.
Doncha hate that ?
Kick it again for me too. 

kicking it and using words you won't find in the dictionary.

[grumm441]

we're not hijacking this thread like that one on DLRA are we

[JackD]

we're not hijacking this thread like that one on DLRA are we

"HIJACKING"
I kinda like the sound of that.   

[grumm441]

Uh oh
Now I'm on a watch list somewhere

G

[panic]

Re: injector placement
An injector up in the runner will have less effect on airflow at the short turn radius (than one at the manifold-head interface) since the charge has some time to "re-laminate" a bit; IIRC you need 10 × the throttle disc diameter to accomplish as much of this as will happen.
It will also vaporize more, but is that what you want? An engine with very efficient intake ports can suffer a bit of VE loss, but remember that the 12.5:1 (or whatever) air:fuel is by weight. By volume completely vaporized gas is hundreds of times larger volume than liquid and displaces air in the charge. The balance of combustion efficiency (low and consistent maximum droplet size, homogeneous mix, etc.) vs. VE (maximum charge mass) is very complex, and definitely not always in favor of complete vaporization unless maximum fuel efficiency is a high priority. Read Vizard on this.
Re: IR vs. staged or single throttle bodies.
Individual throttles can be slightly larger than the largest known-effective runner ID for a carbureted manifold since you don't need the .5-1" Hg vacuum for nozzle response. My guess would be that it's almost always between the port size and valve size + 20%. A single throttle need not total the area of the IRs since there will always be plenum volume available.
IR will always have, IMHO, better manners with high overlap than a plenum, and stronger wave tuning since superposition waves are minimized. You can still use Helmholtz by adding an air box over the stacks.