Can we start a separate topic for just EFI

In reply to Paul_VR6 (Forum Supporter) :

I guess that sounds right, I've never messed with TBI or similar so I've never thought about it....you're probably right and its probably not so bad.

The thought that's been percolating is something like a modern V8 intake, runners wrapping around a center plenum but injectors to the inside.  rough concept wise like this:

Then side mount the blower or use a small turbo or 2, have an intercooler maybe, all the modern convinces. 

This is all going to come down to a packaging exercise mostly I guess.  The body I'd like to use, mostly because its dirt cheap, has an engine bay like 29"w x 24"T then the radiator shell in front is maybe 20"w?  The engine is about 18" wide so what little space there is goes quick.  I need to assemble a pile of parts and the viable options will probably be more clear

Yeah what you're proposing could work just fine. Another (bad?) idea is there enough meat/room in the valley to install the injectors in the ports in the block? You could end up with port efi that way. Anything beyond just drilling holes from the valve side would be tricky though.

mke said:

In reply to Paul_VR6 (Forum Supporter) :

I guess that sounds right, I've never messed with TBI or similar so I've never thought about it....you're probably right and its probably not so bad.

The thought that's been percolating is something like a modern V8 intake, runners wrapping around a center plenum but injectors to the inside.  rough concept wise like this:

Then side mount the blower or use a small turbo or 2, have an intercooler maybe, all the modern convinces. 

This is all going to come down to a packaging exercise mostly I guess.  The body I'd like to use, mostly because its dirt cheap, has an engine bay like 29"w x 24"T then the radiator shell in front is maybe 20"w?  The engine is about 18" wide so what little space there is goes quick.  I need to assemble a pile of parts and the viable options will probably be more clear

 

 

Fenders or fenderless? 

frenchyd said:

Fenders or fenderless? 

Fenders, running board, hood, not sure how much hood but at least the top cover.  No working doors, it will be a step in, hence the running boards. 

The plan is a tube space/birdcage type frame so there will be frame members running through the passenger compartment and engine bay.  This is the 50s/60s part of the build, at least in my mind.  With no ladder frame under it, the body will sit maybe 4" off the ground.....so the car looks maybe 28" tall, but a small windscreen and probably roll hoops higher but visually it will look quite low. 

At least in my mind, I've never built anything like this nor honestly paid a ton of attention so it may not work in reality the way it does in my head....fender might end up looking wrong with the body that low say.....

In reply to mke :

 I like your thoughts  .  But look at the front frame of a Jaguar XKE That 6 cylinder engine weighs over 700 pounds!  Plus all the rest of the other stuff like transmission etc 

 But everything forward of the fire wall is 1 inch square tubing out of 22 gauge steel and brazed together!!!!  That's a 150 mph car that actually passed the federal crash test. 
 It weighs 22 pounds.  The suspension is heavy forgings etc etc. ( same basic frame on the V12)  

  The thing is you could use a frame like that and hide most of it  while showing off that beautiful motor  

      You can also use the Jaguar IRS   If the Dana 44 isn't sexy enough swap it for the Winters quick change ( you'll need to order it with the swing axle side plates  or just order the side plates if you buy a used one.   
 

    Are you familiar with the way some older 1930's cars mounted the blower in the front of the radiator  on the pan between the fenders?  
    The trick was they sent the drive through the hand crank hole  and had the disconnect at the vibration damper. 
  It's a subtle but clean approach.  A little less hotrod and more English country gentleman.  But every bit a walk softly and carry a big stick. 
  For sure you'd gain points for originality. 

we're way off the EFI path now 

Started a separate thread for the roadster

In reply to mke :

 where the badge bar and lower lights are is where the blower goes. I was thinking something like a 32 Ford grill shell would be in keeping with the 29  body and fenders.  Edsel Ford really made a beauty when he designed the 32.  
     If you can find a picture of the XKE frame  you'll see it's a lot less busy than your model.  The remarkable thing is the rear 1/2  is a Monique and the front frame just bolts onto the body. You could either put that type of frame into the the model A  body. And bolt them together or just set it on top of the frame.   I'll look and see if I've got  a picture of my XKE front frame.  

In reply to frenchyd :

replied on the roadster thead

In reply to mke :

I'll just leave this here. This is primitive for us, by today's standards but was done by Lawrence on a Bridgeport before the shop had a CNC...

This was like... damn near 20 years ago?  

In reply to GaryC83 :

Are you showing off the 8 ports for 8 cylinders? 

Its very neat but the injectors are spraying straight at the port wall so the main point was to setup was to hide it I guess?   

The one I saw the guy had bolted blocks to the port runners inside the V to try to get the injectors pointed at the back of the valves.  It worked I guess but I wondered about the heat on everything....but it worked.

In reply to mke :

Considering it's been street driven for 20 years and thousands of miles... it works. And yes, the point was to hide it. It's in this car.  It's got a hillborn 8 stack on it, and looks completely vintage. Even the MAP sensor is in the valley plate.  TPS is on the pedal, etc.

And yes, the shop knows to make fast flathead as well. We built the record setting XF/GR engine for Bonneville with the SCTA. Went 165.55 average and reset the record. With a NA gasoline flatty

mke said:

The one I saw the guy had bolted blocks to the port runners inside the V to try to get the injectors pointed at the back of the valves.  It worked I guess but I wondered about the heat on everything....but it worked.

Modern EFI engine bays get pretty berkeleying hot. Return style fuel system may be needed and a long prime for a hot start to prevent vapor issues. Should be solveable problems.

In reply to GaryC83 :

Its all beautiful work.

The factories go through a lot of effort to lay things out so the injectors point at the valve, pick the spray pattern and such...but I've never really known how much or what they gain for the effort.  Your results suggest they gain very little.  On the 2 blower setups I posted the injectors point at the back wall of the runner, nowhere near the valve but they ran pretty well too....but for some reason I still keep trying to get the injectors pointed at the valves because that is how the factories do it 

In reply to mke :

I suspect the reason the factories spray at the valves is to cool them down.  Burned intake valves during the warranty period are a potential expense.   There is also the issue of carbon build up. Which if too bad will lead to unacceptable pollution levels.  Another warranty issue. 
   Then race only engines I believe they are trying to stretch fuel mileage since fuel equals weight 

The closer the injector is to the valve, the more important the placement. You spray, close, at the back of the valve for the best atomization. Spray on to a closed, hot, intake valve gives the best result for the entire rev range. If you can deal with poor low speed performance, there are gains to be had by moving the injector waaay up the intake stream (even outside of velocity stacks). I don't think anything has to do with cooling (DI engines use same valves as EFI and don't have an issue)

In reply to Paul_VR6 (Forum Supporter) :

Well that shot down that theory. ;-) 

 but DI kinda shows it doesn't really matter  doesn't it?   I mean there is a world of difference between the back side of the intake valve and directly into the combustion chamber. 

DI running a few hundred psi of pressure (vs 45-60) makes the atomization issue go away. It also causes some other fun problems.

In reply to Paul_VR6 (Forum Supporter) :

 guess I'm trying to get my head around how much effort to put in to even trying to solve it.  You see a setup like GaryC83 posted that just flat ignores the "rule" about injector placement and work fine.  

I found the pics of the in V setup I saw. He said he built a couple of them, At the time I didn't think to ask how he was controlling them...those look like TBI injectors?

I'm thinking keep it simple and put the injectors in the runner pointing where they point, but maybe try the ducati shower injectors IWP-189 that spray a mist. I think at 510cc/,min they are even a useful flow rate, a little big but the means it ok to turn up the boost.  The funny thing is I had of them 12 here at 1 point when I was kind of planning a hi/low setup on the ferrari but decided it just wasn't worth the bother of trying to control 24 injectors and off to ebay they went 

GaryC83 said:

In reply to mke :

I'll just leave this here. This is primitive for us, by today's standards but was done by Lawrence on a Bridgeport before the shop had a CNC...

This was like... damn near 20 years ago?  

That's fantastic! I'm in awe. 

That in V setup is what I was thinking, super cool someone has it all mapped out!! Also "works fine" is a pretty broad brush, there are likely things that work but are likely a pita about that injector placement like massive fuel over use around idle or accel, etc. Not a big problem on a hot rod though.

Paul_VR6 (Forum Supporter) said:

The closer the injector is to the valve, the more important the placement. You spray, close, at the back of the valve for the best atomization. Spray on to a closed, hot, intake valve gives the best result for the entire rev range. If you can deal with poor low speed performance, there are gains to be had by moving the injector waaay up the intake stream (even outside of velocity stacks). I don't think anything has to do with cooling (DI engines use same valves as EFI and don't have an issue)

I spent WAY too much time researching and talking to people when I was setting up the system for the the ferrari.....not to say what I'm saying is right, only that I believe it 

RPM determines the ideal injector distance from the valve.  If you are optimizing low rpm, like say on a street car then the injector goes close to the valve, I found some tables somewhere...can't find them today of course.   6-8k the injector goes mid intake, above 10k at the top as a shower injector iirc.  But that is not the whole story.

Smooth idle  and cruise needs the fuel sprayed against a closed valve and given time to completely vaporize to get a consistent mixture, and mpg and emissions need all the fuel burned so that is what all the factories do.....spray against a closed valve.  That is generally not the best way to make hp though.  For hp the goal is to use the heat of vaporization of the fuel to cool the incoming air creating the densest charge, so limiting the DC to around 35% and timing the injection to basically be spraying into the moving air stream will  generally make more hp because the fuel is cooling the air not the port walls or valve.  I've probably seen a dozen back to back dyno results where the only change was swapping injector size to get the DC way down then retune result in 3-5%hp gain...and this is why the frankenferrari has 1050cc/min injectors rather than the hi/low setup I was originally planning.

Again, not to claim anything I just said is FACT!!!, only that I believe its true 

I just built an intake to test all this out actually  I can mount the injectors 3" 6" and ~12" from the valves. Though my power range is 5500-8500 I am pretty sure the answer.

Paul_VR6 (Forum Supporter) said:

Also "works fine" is a pretty broad brush, there are likely things that work but are likely a pita about that injector placement like massive fuel over use around idle or accel, etc. Not a big problem on a hot rod though.

Yes.  Every time there was a "man, there is a little stumble when I...." moment I was always second guessing my injector placement.  I have no idea if it  had anything at all to do with the issue but its always the 1st place my mind went.  Both setups needed idle a touch rich to be smooth and the IAC couldn't add enough to make it start well, it always needed a bit of pedal but then cruise would tolerate even a 17 afr (but I ran it at around 15) and highway mileage was better then stock.  

I guess done and running is always better than perfect and never done but I love the idea of perfect.

mke said:

I guess done and running is always better than perfect and never done but I love the idea of perfect.

At least you have looked the enemy (perfection) straight in the eye!

Paul_VR6 (Forum Supporter) said:

I just built an intake to test all this out actually  I can mount the injectors 3" 6" and ~12" from the valves. Though my power range is 5500-8500 I am pretty sure the answer.

Did you also test DC?  On all the testing I've seen this was the biggest factor with nothing making peak hp over 60%.  Spray pattern appears to matter on a couple engines too and I saw an article from honda f1? where they spent a lot of time on the pattern question.  But for sure the data sets I've seen are incomplete and may be case specific.

Edit - the iwp-089 shower injectors are 12 hole and just mist the fuel, they match what the honda data said to do with shower placement....I'm trying to remember but I think it was 7, 9, 11 holes they tried and 11 was best something like that, all specific to shower/above stack placement though.

Edit2 - the ducati 999 went to shower injectors on bikes that made peak hp at 9750.  These are the TBs I bought for the ferrari, the injectors mounted as part of the stack as that is what I was planning to do.  They didn't run very well at low rpm and on the 1098 they switched to the new ipw089 injectors and that cleared it up....well, cleared it up enough that it was ok on a motorcycle with high idle and crazy hp/weight ratio