83 Crossfire TA

iTrader: (2)

So anyone have any thoughts on injector angle on something like a Victor Jr? Any clear reason to go one way or the other?

If it wasn’t for the runner design, I’d really try to mount them closer to the plenum then the head, but because of the curves and other packaging issues that’s not going to happen, so since I’m going down at the ports I’m debating if I’m going to go straight up and down (65* to the surface of the runner) or if I’m going to rock them back a little to point the spray further down port.

Z69

Just a thought...
But some of the imports use side feed saturated injectors.
Might make the package short enough to point them at the valves provided they're not the disc type.

FSTFBDY

iTrader: (33)

from searching other threades here I found that most say the angle isnt that big of a issue. I'm sure if you wanted to get down to the nitty gritty it would help some. At least keeping the back of the valves cooler. But hey thats why I thermal coat all my parts anyways.

I put mine in like this.
http://www.cecoatings.com/images/Car...cJrConversion/

high c

alittle off topic my bad Crossfire but tpi383 would you sell the injector bungs?

FSTFBDY

iTrader: (33)

PM me. YES I could make some more.

83 Crossfire TA

iTrader: (2)

Well, instead of working on something else last night I actually thought about it for about 5 min and this is what I came up with.

To be honest, and I’m not picking on anyone here, I’ve always felt that what most of what is done WRT to injector bungs is at best bassackwards. The fact is that most seem to drill a hole and drop a injector bung in there and then weld it up. UNLESS you build a fixture to hold the bungs in exactly the correct position or machine them after you mount them you really can’t ensure that you’re getting the same location from injector to injector, and even then, a rather large, circular weld in a small area right next to the edge of the manifold is just asking for distortion and cracking.

So instead, this is what I did:

I made a wooden fixture that holds the manifold level so I could measure it out fairly accurately and work on it with reasonable accuracy. I found that the tops of the runners were at exactly 25* and took a good look and decided that I could go 5* steeper and still have plenty of room no matter what size injectors I want to run or what I want to do with the rails/wiring, and cut out some injector mounting pads:



The idea is to end up with something that looks something like this when I add them to my runners:


The cool thing is that I first made them out of some wood and after a little measuring it looks a lot like I could aim the injectors right into the high velocity part of the port…

Next to clean them up a little and mount them on the manifold, cut the seats…

FSTFBDY

iTrader: (33)

I figured you would find something wrong with it. You always seem to. anyways... good job on the block should come out perfect.

mhaskell

Why would you want the injector closer to the plenum than the head?

Z69

To make the stream hit the back of the valve. Preferably a closed valve. It will cool the valve and help vaporize the fuel some more.
And when the valve opens. The shearing effects of the air going past the valve will further break up the fuel/droplets.
Look at the factory intakes. They have the inj. tipped over so the tip is aimed at the valve. This is supposed to help with emissions.
And also minimizes the droplet size and fuel wash on the bores.
The idea is to have vapor enter the cylinder. Not drops of fuel.
Drops don't burn well. Lots more to it.


People wonder why the cost of converting an intake is so high.
Well to do it correctly, you have to do as Mark was talking about with a jig to hold everything in alignment.
The cheap conversions will also have the bungs sitting at different heights too. Since there is nothing to hold them while welding. There's a site I found where a guy did his own 440 mopar dual plane intake. The jig he had to make took a while.
At least if you spend some time on it. You can use it for the fuel rail drilling also.

Enigma_valar

how much would that manifold support in hp range ?? like how mcuh air could it flow??

just wondering gettin some money soon and im thinking of either a stealthram or some along those line.

is the edelbrock manifold with the bongs already welded in garbage or what ??

thanks A ton

83 Crossfire TA

iTrader: (2)

Targeting injectors right at the valve is only second best for power production, but if you’re running sequential injection is great for emissions. Alternatively, you can get the same effect if you aim it in the same area and use a cam with enough overlap to get some reversion through the intake valve at low rpms, the hot exhaust gas in the intake acts like both an egr and to instantly vaporize the fuel in that area. Ford actually changed plans with their injector mountings after they managed to show that it really did work (if you look at ford’s performance applications they tend to run a slightly tighter LSA because of this from the factory).

You get the best power production by mounting the injectors as far upstream as possible assuming that everything downstream of that point is designed correctly. What happens is a combination of using the fuel as an intercooler to cool the intake charge allowing you to run more BMEP without detonation, and that the shearing action of the airflow (like what you get from the TBs in a TBI) actually results in a more homogeneous mixture entering the chamber. The extreme end of this is that some performance applications actually face the injectors upstream against the airflow to take the most advantage of this.

Since I have to pass emissions/want a decent idle AND since there was no convenient way to do it upstream I chose second best WRT to power production, which should still be at least as good as most of the other stuff out there.

Yes, basically, but as always there’s more to it. Vapor is good for emissions, it’s not good for power. Droplets are good for power if you can control their qualities, since droplets only burn on their outside surface and more smaller droplets result in more surface area the ultimate result is a faster burn, which allows you to play neat games with detonation control and timing. I did have 2 other alternative reasons to mount the injectors down there that are related to that, both have to do with stuff I’m experimenting with. The first is I want to experiment with running really big injectors with different spray patters (if you do some digging you’ll find that GM and ford have dramatically contrasting data WRT to the effectiveness of different spray patterns and use significantly different injector designs based on that data) and secondly, I hope to play with some chamber modifications to see the effects of shape changes on burn speed/direction as well as in chamber stratified charge “stuff” to run super low A/F ratios and BSFC numbers.

Heh, I measured all of my pads and I ended up with the pads at exactly the same angle to the accuracy that I can measure them (within about ¼ of a degree) and within .02” in height of each other, probably way closer then I really need to be (sorry, I’m **** retentive, it’s not that I like picking on people, it’s really that I’m good at wasting my own time taking stuff like this that far).

I’m going to bore the injector holes tonight. I intend to use a dial gauge and depth stop to set the actual bottom of the seat for the injector which should give me way more accuracy then you’d ever really need (for that matter, the tensions on the o-rings, fuel rails… will cause much more inaccuracy then that even with perfect seats).

And yea, the same jig will be used for the fuel rails, with the same spacing. FWIW, I was going to weld up my own but instead I got off my wallet and bought some holley 9/16” ID fuel rail stock, I figure that will flow more then I will ever need a set of injectors to get, and should be a good match for my Mallory regulator (rated at over 1200hp worth of fuel through the by pass).

The one in the picture, I know nothing about it. I suspect that it flows somewhere in the 260-280cfm/port range, which is somewhere in the 570hp range NA assuming that you get everything else right.

I’m using an old 2975 victor jr casting that has been welded up and heavily modified by a professional shop and was supposedly used on a big inch small block that made somewhere around 750hp NA with it. That would suggest flow numbers in the 340cfm range The fact that the flange is cut to match a 1205 gasket I have a hard time believing it BUT it is a very reputable shop and I have to admit that even externally it looks significantly different from a stock 2975, and I can tell you for sure that there isn’t a spot on the inside of that manifold that hasn’t been ground, blended and reshaped, the runner dividers extended, the carb flange totally reworked (I suspect that it was cut off and a new one was welded on, the top ½” is totally different then most victor jrs).

Honestly, I don’t have anywhere near the short block to take advantage of it right now and I got it cheap so I figure I might as well have some fun. That and it’s about perfect for the rest of what I want to experiment with…

The biggest issue that I have with the Victor EFI is that it’s based on a taller version and it’s opened up to some 1206 ports. Unless you’re running some BIG race heads you’ll have a hard time even port matching most heads to a 1206 gasket.

Honestly, for most street strip cars I see only one reason to ditch the tpi setup, and that is because it’s a pain in the *** to work on if you want to mess with the fuel system. Most people replace it well before they have a good reason to performance wise because of it’s perceived inadequacies.

For that matter, I like the stealthram for what it is.

mhaskell

FWIW, The LSx series of engines have the lowest BSFC numbers of any production engine that I know of.

The injectors are not near the plenum, and are so close to the head in fact that there is a relief machined from the head for injector clearence.




I'm not sure if you have seen the mercrusier EFI intake that I am running, the injectors are pointed to the valve and very close to the heads. Of course the fastburn heads do have raised runners. Hopefully I can get BSFC number from a dyno run soon.

mhaskell

Also you might want to run the proposed injector placement through a CFD program. It takes some training to get accurate results, but they can be spot on.

Enigma_valar

im planning on using some sportsman II or pro topline probably the sportsman. which i believe have a 1206 gasket anyway.

someone metioned hte neccisity of a plenum on a efi system ?? why?? couldnt i just do the tbi style smack dab on top ?? somone also brought up the idea using a 4.6l upper plenum.

83 Crossfire TA

iTrader: (2)

I don’t think that disagrees with anything that I wrote, and that was also the reason I gave why I’m putting the injectors where I am. Secondly, lowest BSFC numbers don’t mean that that is where you’re making the best power, and don’t necessarly mean that you’ve optimized injector location (but they might).

Honestly, I haven’t paid attention, what kinds of BSFC numbers are they seeing with the LSx engines? What about the newer designs, all of which are getting rid of the peak machined into the port for the injector?

No, I haven’t. I’ll poke around but I’d love a link/more info (hell, I’m not against hijacking my own thread with interesting but only somewhat related info).

FWIW, I ended up laying the injectors back 9* from vertical. That was as far as I could go before tools started hitting the carb flange on the plenum while trying to bore the injector holes. I could use longer bits/extensions but that put too much slop into the setup to bore accurate holes so I gave up on that. For that matter, I wasn’t sure that I’d get more then 5-6* when I originally measured it so in reality, I’m very happy with that.

83 Crossfire TA

iTrader: (2)

Pretty slick software/images there, what are you actually showing? Judging from the color gradients I’d guess that the top one is showing static pressures and the lower one is showing velocity, but I’m just guessing there based on the locations of the hot spots. What heads are those? Are they taking into account a valve blocking part of the port and if they are at what lift (obviously, neither is showing a valve in there)

I based my injector placement on a compromise between what I could actually machine accurately, what I’ve seen using a velocity probe on a flow bench and a little instinct (“best guess” after collecting as much actual data as possible usually gets me quite far in the right direction, honestly, I’ve gone against some pretty serious computer simulations based on my instincts before with great luck, seems like we still haven’t gotten to the point where simulations have any flexibility to play “what if” and come up with cool things to try)

83 Crossfire TA

iTrader: (2)

most of the new design heads that claim to be 1206’s are not. I don’t consider the sportsman a new design, they’re just big and slow, the toplines (RHS) aren’t really 1206’s, the ports are actually right around the height of a 1206 and NARROWER then 1205’s, making them somewhat difficult to match to a plenum without hogging them out and hurting the port taper and velocity.

1206’s will seal them, but if you want to mess with gasket matching I’d suggest a set of cut to fit intake gaskets or an RHS dealer that knows what they’re doing should be able get you some that fit right (I believe that they’re made for them by MrGasket, if you need them I can get them, as well as the heads…)

I have a 4bbl, 1000cfm Accel TB sitting here that I suspect that I’m going to sell off instead of use. On top of the manifold it will essentially act just like a big 4bbl will act on the manifold, which is fine.

OTOH, increasing plenum volume will increase power production till you get to the point where the plenum is large enough that the intake acts like an IR intake. The cost is responsiveness, but the responsiveness drops slower on an FI application then it does on a carbureted application (on an FI application the only issue is to get air moving, on a carbureted application getting air moving is part of the problem, you also have to get the carburetor to react to the changing air flow essentially before the carburetor sees the change to get it to react quickly).

83 Crossfire TA

iTrader: (2)

BTW, a 4.6 plenum and TB looks to be a nice, quick solution, but it's nowhere close dimention wise... I have one sitting here somewhere, if I get bored I might dig it up and take some pics...

Enigma_valar

Awesome thanks

You lost me on the gasket issue and the heads??? some more insight would be great. are you saying the sportsmans arent worth the money ona 383 or the pro toplines the numbers seem to be pretty good for both. also if i lost velocity how much would that effect the over all performance of the car im shooting for the stars kinda of on a small budget. i want hp and torque and i dont wnat ot mix and match combos fifteen times (seems like a awaste of money).

if you could measure the tb mounting point and the ford plenum id appreciate it ??

83 Crossfire TA

iTrader: (2)

You can end that there. Sportsmans out of the box are not worth the money. You end up spending real money on heads that have big ports that flow a lot like stock small port heads. If that’s what you’re looking for go for a set of ported stockers and get some velocity and flow. And by saying this I’m not ragging on stock heads, I actually think that a set of ported stockers are more then what 99% of the people that end up going with aftermarket heads really need, I just don’t see the point of paying more for heads that barely flow more and have much larger, slower ports, the only justification that I see for them existing at all is that at times its hard to get decent machine work for a reasonable price.

I like the toplines, the issue is that they have weird port dimensions. I’m a dealer so I have access to a few things that most don’t but FWIW, they all have 1.230” wide ports and the 200cc intakes and smaller are 2.100” tall and the <200cc ports are 2.225” tall. Like I said, they won’t really match the standard felpro 1205, 1206 or 1207 patters.

On the surface this might seem like a stupid PITA, but in reality it makes sense, they’re applying some of the latest technology to make a port that performs better across the board (look at the LSx ports compared to SBC ports and you’ll see the same difference)

to oversimplify things but to put them in a useable perspective:
flow=hp
velocity=responsiveness and useable low end and midrange

I forgot to but I did snap a pic using the camera phone. Nutshell this is with one of the bolt holes lined up and you can see how much the rest are off(take a look next to the upper left mounting ear, that black spot between it and the throttle bracket is the plenum, and my plenum is welded and then blended into a cloverleaf shape, not a big square like most). FWIW, even with the thing centered on the pad and even with the welded up carb pad on my intake, there are still open, exposed spaces where you can see into the plenum on both sides of the TB adaptor. (FWIW, the only reason that it’s facing backwards is that the carb pad is angled down in the front and the tb+elbow wouldn’t stay balanced on it facing forwards):

Enigma_valar

kinda of looks like it would kill perofrmance and go in the opposite direction i bet there an easy way to make it work but it looks to me like it be putting a small hurdle in the way or your airflow.

83 Crossfire TA

iTrader: (2)

Oh you could easily make an adaptor plate but why bother making an adaptor plate for something that has proven to be a restriction on the 2V 4.6's?

Enigma_valar

thats what im thinking i guess ill just throw that idea out the window. i was thinking of grabbin some pro toplines lightening heads and the gaskets from you , how much would you want for a set ? pm me if you you could

Z69

I've toy'd with the idea of the Trick Flow R box for a 5.0.
But the HSR is so much easier.