Projects Track Roadster 16 yrs in the making

I am glad it turned on the light - I have to admit,
most everybody would ask what did you say lb.
Thanks, Rex

 

Yeah, I remember the high tech wheel chock at Jack’s, I have one like it here in KC, I’ll throw it away instead. Maybe open a bottle of wine in celebration too.

LB+1 and Rex,

Good points. At the moment the fuel regulator is attached to the bellhousing before the fuel rails. I’ll ask Brett about the fuel pressure issue you two raised. If I understand the present conditions the cylinders that are running “cold” are too rich. The nozzles are the brand new Ford parts.

Thanks for the input and keeping up with the TR.

charlie

 

Different heat zones impacting on the stacks thru the heads. Center different than ends yet common on both sides.
One odd ball stack in the bunch will throw the fuel trims off via ONE 02 sensor.

I still see 8 one cylinder engines.
Venturi vacuum is different than manifold vacume. You will always have venturi vacuum.

 

31Vicky,

I agree regarding your comment that one O2 sensor is reading four cylinders; and I agree that in many ways tuning this stack injector system is like trying to tune eight one cylinder engines, especially at idle.

Once the throttle plates crack just a smidgin (1/32” ?) then I believe the numbers on the laptop screen are much more reliable; i.e., have a small deviation around the mean. In the case of the IDLE values for O2, I would not be surprised if the variation around the mean was 10 times higher or more (i.e., when the throttle plates are “closed” by the return spring).

You do what you can do with the gizmos available. The new CPU is vastly more useful that the original unit.

I’m not sure I understand your “heat zone” argument. I guess you are saying that the heat soak into the Hilborn castings is different near the “inner” stacks compared to the end stacks...right?

To my mind, the Hemi is essentially a high density mass of cast iron and water, which is mostly at equilibrium. Obviously there is a gradient of heat along the lenght of the block such that areas at the “ends" are a bit cooler. However the infrared heat values were very close to each other when measuring the thermostat housing, water pipes, water hose, cylinder head surfaces. So if there are variations they are not easily detected with the infrared thermometer.

I was amazed that two exhaust header outlets (near the flange) could be so different. In my mind there can be only one immediate cause for such a difference, namely, a failure to maintain an equivalent degree of combustion in each cylinder. The air/fuel ratios must be tremendously different from cylinder to cylinder at IDLE. Surprisingly the motor seem to run fine at idle; I’m pretty sure no one could tell by listening to the engine idling at 600RPM that the A/F ratios were so wacky.

Maybe, I’m worried about nothing. But as Brett points out — if four of the plugs are being sooted-up every time the car is idling, that is not a good situation; regardless of whether the engine seems to be idling nicely.

Thanks for the post, it’s food for thought.

trakrodstr
aka charlie

 

Isn't there an exhaust crossover in the center of the heads, should/ would be hotter there. And isn't there a coolant out let on at least one head, should/would be cooler there. If there is a coolant cross over there again also. Even if they are blocked it would certainly be hotter by the exhaust crossover vs coolant cross over.
Your statement about throttle shaft bind at various temps turned that light on.

 

Charlie, Sorry to see that you and Brett are still troubleshooting TR. I would be vbery interested in why the alternator went up in smoke (sorry bad joke). If all is wired correctly there is no reason that 30 minutes after shut down the alternator is burning . . . . All I can say is - "what the He-- ?" Wish you and Brett all the best in getting TR fully up to roadworthy status.

Dave

 

Dave,

Brett and Jack both guessed that a diode in the voltage regulator (embedded in the alternator case) failed and caught fire. I spoke with a tech guy at Powermaster and without seeing the alternator, he agreed the most likely failure is a diode on the regulator circuit board.

OH well. The main thing this means is we can’t road test the Hemi this week when the daytime temps are supposed to be in the mid 50s....aaaahhhgggg!

Powermaster does not sell a “rebuild” kit for that particular series of Denso alternators, which means a trip to Powermaster and back.

Makes me want to kick my dog, but I don’t have a dog.

charlie

 

31Vicky,

There is an exhaust crossover in the center from the factory, but this is blocked when using the two separate Hilborn throttle plate assemblies. The Dodge and Chrysler Hemis have a large water manifold (crossover?) that connects the front of the two heads and receives the radiator water. In my experience Hemis are not known for water temp issues as the huge head castings contain galleys that surround the combustion chamber with water.

However, you may be right that a bit more heat in the middle of the head causes a bit more expansion of the center alum Hilborn stacks which “leak” more air when the throttle plates are “closed” (at idle).

Our current plan is to drill some small orifices in the end throttle blades so that a bit more air passes into the intake ports at idle.

I have a feeling I’m going to learn more about all this than I ever wanted to know.

charlie

 

With the butterfly's lower in the stack and closer to the heat of the motor the thermal expansion of the stack itself will affect idle quality and character. As the motor heats up and the stack ID increases slightly, the butterflys are less effective at regulating the air. At least that's what I have read...

 

Deto,

Exactly. The butterflys in my Hilborns are alum and the stack are cast alum, so you would think that the expansion events would “keep up with each other” but appearently not so. The other hidden issue is that air can be sucked around the throttle shafts, and into the port, especially if the shafts/bosses are worn. In my case the stack castings and the throttle rods are virtually brand new.

Further, if you hold up a Hilborn stack plate and look through the ports at a bright light (with the throttle blades closed)....no two ports are equivalent. Nor are any two ports symmetrical.

Finally, if you loosen the two machine screws that secures a throttle blade to the rod, you can move that sucker around quite a bit. The sprint car guys used to use cigarette paper as a “feeler” gauge to center and “equalize” all the throttle blades. This process an be repeated as often as you wish, because no matter how careful you are — a few engine hours later the throttle plates are in a different position.

So the question is: How close can we ever be to equal idle volume unless I spend a zillion dollars having all the bores and shaft bosses trued and sleeved and tricked out?

I am willing to accept financial contributions to this worthy cause....

charlie

 

Well id bet quite a bit that the center stacks are quite a bit hotter with exhaust flow being blocked by the hillborn unit. If they are that touchy and that responsive to the slightest variations chances are you'll be living with a large comprise someplace.

Here's a little thought experiment.
Centers are running hot. Hot = lean. Ex crossover is in the center & possible cause by heating that area causing more expansion on those two letting in more air.
Two ends are more than likely rich. Rich = cooler.
That could explain the temp variations of center vs ends on the exhaust.
What would concern me about that is this: since you have one 02 reading an average of 4 cylinders.....if the centers are say 3% lean the ends would be 3% rich. Not so bad and only at idle. What if the centers were 30% lean and the ends were 30% rich, that could cause a big problem really quick. The 02s would read correctly in both of those situations since it reads an average.

 

You may be on to something 31Vicky. I'll see if I can get better quality temp readings across the Hilborn flange. I agree that since we see an average O2 we don't know squat about the individual cylinder A/F ratios.

Keep one thing in mind. The duty cycle of the EFI nozzles is the same for all cylinders, even at idle. I just hope that the inner cylinders are running close to 14:1 and the outers are way too fat. Otherwise we may be damaging the inner exhaust valves or ??.

I think our next move is to drill some very small orifices in the outer cylinder throttle plates and hope the exhaust gas temp (EGT) goes way up on those cylinders as the combustion improves with more air. Then Brett can slowly seek up on a slightly rich idle mixture, just to be safe.

Given the variation in the Hilborn castings and the throttle plates I agree that we will never achieve ideal A/F ratios at idle.

You are a solid thinker and I appreciate your kind interest and input.

For the rest of this week I guess I'm going to have to be content solving the smoking alternator problem. I hope you stay with this thread.

charlie

 

Good luck Charlie, this is one of my favorite threads to follow.

Keep one thing in mind. The duty cycle of the EFI nozzles is the same for all cylinders, even at idle. I just hope that the inner cylinders are running close to 14:1 and the outers are way too fat. Otherwisewe maybedamaging the inner exhaust valves or ??.

Highly unlikely that any 1 of the 4 on either side is correct with that variation in exhaust temp. The average of the 4 may be 14.1 but if two are lean then two must be rich to satisfy the average. If two are at 14.1 but two are lean the average would be lean. If two are 14.1 and two are rich your average would be rich.

 

Thinking way outside the box for a second, could you put a sensor on each exhaust pipe, before the header collector? And move the gauge wires around as needed? Even a multi- pole multi throw switch might be possible.

I don't know how much all that might cost, or if the sensor or the gauge is the expensive part. I know the bungs are fairly cheap but would need to be welded in.

 

Trakrodstr: Thank you for starting and maintaining this very interesting build thread. The sophisticated information gained by being able to measure exhaust temps is somewhat new technology to a lot of us. I suspect a lot of engines were built and tuned "in the day" without benefit of knowing exhaust temps to the degree of accuracy we can obtain today. Performance and plug readings determined tune. If you ignored exhaust temps at idle and tuned by performance and plug condition only, you would probably wind up with a good running, long lasting engine. I guess I am saying you might be suffering from "information overload". Think of the guy who tows a heavy trailer and replaces the idiot light with a temp gauge. He has driven this combo for years without problems. The new gauge tells him he is running at 220 degrees. After years without incident, he now has a problem? I bring this up for two reasons. I tend to suffer from information overload and have a similar exhaust temp variations in my 6X2 setup. I hope to learn a lot from your excellent thought processes and attention to detail. Thanks. Keep it up.

 

BuiltFerComfort,

Your suggestion is very good. Brett and I discussed that last evening in fact. It seems that the cost would be at least $1000 for a simple thermocouple system. I think I would just buy a really top quality hand-held infrared thermometer and “shoot” each pipe carefully. But you are absolutely right that it would be great to have real time EGT readouts for each pipe. When you see the photos in the car mags showing a high-end engine build there are always EGT bungs in the header pipes, and those folks are not going to that much trouble for nothing.

Let’s see how bleeding a bit more air into the “outer” cylinders works before I get too heroic.

Stay tuned.

charlie

For the immediate

 

Right you are, and that’s why I spend time each night lying awake and staring at the ceiling....

Brett has tried to err on the side of too rich and when I pulled the plugs after the last run (up to 3000RPM) all the plugs were sooty, so we may be safe.

charlie

 

Spitbucket,

Wow what a welcome compliment. Thanks.

Regarding ‘information overload” I was shooting the breeze with Jack Presse, the roadster’s builder, this weekend. We were in agreement that the Hemi has probably been running with wacky EGT readings since the first day it was fired up using the old EFI system. I remember well Jack and I patting each other on the back and smiling because the D500 was idling so well!

Spitbucket I think you are saying that “ignorance is bliss“. Your point is well taken. I think chasing one’s tail may not be too far off the mark in this case. When I was griping about my “idle” trouble with a lady friend she said: “You just want everything to be perfectly logical all the time, and sometimes things don’t work that way.” Hummm.

Based on your thoughtful comments I will use the next few days to take a deep breath and chill a bit.

Your comments regarding reading the plugs and performance are well taken too. I would like to emphasize that once the Hemi is ”off idle”, say running above 1200RPM, you are correct, without question. Reading the plugs would be imperative to getting a proper tune.

I hope you stay with the thread and keep your keen observations coming.

charlie

 

Charlie,

You've got a lot of us with our thinking caps on. Given that the hot spot in the heads contacts the cast aluminum of the FI flanges between the center ports, would it not be feasible to remove the flange material in that spot, giving you four 2-port manifolds? Granted, it would deflate the value of the manifold, but it would certainly have an effect on the amount of heat transferred to the throttle barrels. Just my $.02 worth.

Mike

 

Charlie,
I had the same issue with my 3" Crower (mechanical) injector, Turned out to be twisted throttle shafts. Be sure your return springs are pulling back against the linkage, NOT from the opposite end of the shafts. BTW, there is a guy here in PA who re-drilled and bushed my manifold for $350. He can also make the shafts.

You can loosen the stops and plate screws and "tap" each butterfly into place, so they will all close equally. You might also consider closing the throttles completely and letting it idle off of an IAC valve (IF all else fails). Once the throttles are opened, you no longer have control of the individual mixtures, just like any other injection system.

 

electromet,

Sorry for the slow response. Sometimes work interferes with hot roodding.

As you suggest Brett and I have discussed “separating” the Hilborn stacks. This is not uncommon because you can then put a coupling “between” the throttle rod for the “front two stacks” and the “rear two stacks” which helps with equalizing throttle plate position.

I have two responses to your suggestion, one of which you anticipated.

One of my goals is to try to preserve a vintage look. On the other hand I have to be able to use the TR in the real world. So your suggestion is not out of the question.

The other response is that I an not convinced that there is that much of a temp differential along the length of the heads and thus the Hilborn flanges. The Hemis have lots of water around the combustion chamber and the engine never feels or seems “too hot”.

The exhaust crossover, through the factory cast iron intake flanges, is required for warming up an engine (carb) in super cold climates. It is not a means of “cooling” the water in the heads. I have not made careful, high resolution measurements, but I would be surprised if there is more that 10-20 degrees (F) of variation from front to rear....but I honestly don’t know. In any case, the alum Hilborn flanges block the water in a couple of areas, so maybe there is some heat difference along the length of the Hilborn flanges. And maybe that situation would modify the degree of expansion for the throttle bores and plate; but it seems to me that the fore-aft temperature differential would affect the rear cylinders more that the middle cylinders.

The truth is I don’t know what’s going on.

Thanks for reading the thread and taking time to make your suggestion.

charlie

 

exwestracer,

I contacted Kinsler a couple of years ago about this possibility. They will “blueprint” early Hilborn castings. As I remember they would not quote a price over the phone but indicated that if the unit was in good condition I could expect to pay a minimum of $1000.

There are two return springs one of which is at the front of the shaft and the second is between the third and forth stack (rear). You are suggesting that the throttle rod is acting like a torsion bar. Right? This may be a problem. As I said in the last post, some users cut the shaft and install rod couplings that are adjustable (can be “clocked”).

Adjusting the throttle plates is more or less fruitless. See my reply to “deto” a few posts back. As I said to him, you can adjust the throttle plates one-by-one then run the engine for a while. Let it cool and then readjust the throttle plates once again. This is a endless loop. The Hilborn fasteners for the throttle plate (a small machine screw) is about one half the diameter of the holes in the throttle plate. Obviously, Hilborn did not want the throttle plates to be fastener “centric” but to be bore “centric”. Thus there is an ocean of play between the two machine screws and the throttle plate.

Brett has drilled some small “air bleed” holes in the front and rear throttle plates (cold EGT readings), we will have to use trial-and-error to see if the air bleed help or hurt the A/F problem; and if the air bleeds help we will have to keep trying larger and larger holes.

Unfortunately the alternator problem had taken a nasty turn and we won’t be running the engine for awhile.

It sounds like you were able to conquer your Crower injector problems. I sure hope we can follow your lead.

charlie

 

Attending the W.O.W. show in K.C. a couple weeks ago it was a dissapointment not to see this car there. Sounds like hi-tech hell is happening for you. Keep on keepin on, I know you will. Good luck man. ~sololobo~

 

I'm gonna try to pay attention to this thread and help where I can. I have some EFI knowledge that will hopefully help.

 

deto,

Thanks, more eyeballs and ideas are welcome, especially if you have ideas about stack injection. Most of the problems arise because there is no "real" plenum to average out all the variations caused when there are eight cylinders to feed.

charlie

 

Charlie,
I just did a little work on my EFI and cleaned up a couple of items and thought I would send some pics before I put lots of road time on my roadster again.

As you can see I have not made any attempt to try to make the injection look like an original Hilborn mechanical set up as I figured I have a pretty late model motor so trying to cover the electronis of the injection would not really be worth it to me. You can also see the Kinsler shaft connector/adjusters, these were good for reducing my idle by 500 rpm at higher engine temp, and also you can see that the fuel line comes into the fuel rail on the right side of the picture and runs to the left then down to the fuel pressure regulator and back to the tank. This insures that the injectors are always getting fuel at the regulator controlled pressure without any chance of an air lock in the fuel line.
Also the small fabricated manifold below the injector tubes that takes the vacuum signal from each injector body and provides MAP to the ECU and also is connected to the back side of the fuel pressure regulator valve to provide a constant differential pressure across the injectors regardless of manifold pressure. Certainly not as pretty as yours but it works very well and I have driven the holly shit out of this car with very few problems.

Rex

 

Charlie,
Yeah, no fix for the heat expansion, but if you "zero" the throttle plates to each other, I figure that's about as close as you will get. I wouldn't bother setting them hot, you're liable to get stiction when you cold start it.

Let me know if you decide to have the shaft holes re-indexed. I'll put you in touch with the guy who did mine. BTW, I converted to slit shafts (Kinsler won't make them anymore). They clamp down a LOT better on the throttle plates. I would also get ALL the return spring pulling back on the linkage, especially if your shafts are 1/2 cut out for the throttle plates.

 

Rex,

ooops, see the next post

 

Rex,



Sorry about that empty post above....I hit the wrong button.



Regarding your EFI stack system, and your last sentence — pretty is as pretty does...you are driving “the holy shit” out of your car; whereas, I’m...well let’s just say that I’m holding something, but it ain’t a shift knob or a steering wheel.



You point out that: “ you can see that the fuel line comes into the fuel rail on the right side of the picture and runs to the left then down to the fuel pressure regulator and back to the tank. This insures that the injectors are always getting fuel at the regulator controlled pressure without any chance of an air lock in the fuel line.“



Right now the fuel pressure regulator on my TR is upstream of the fuel rails (between the tank and the fuel rails). Brett has said that he is not happy with this arrangement but that in his estimation this is a higher level issue that we can get right once we have a better baseline. So I’ll have to take his word that this is not a big issue right now. I can see that on a hot day, especially, an air lock could be a real problem.



I do see the vacuum manifold connected to your injector stacks, you have a lot more volume than my setup, which is a fact that Brett and I have wondered about. In a perfect world one could run tests with different sized plenum volumes and determining which size is best for a given engine. For right now I’m going to stick with the smaller plenum for space-limitation reasons.



The last time he worked on the roadster Brett hooked up a vacuum line to the back side of the fuel pressure regulator, so we should have a constant pressure differential too.



We are waiting for a larger capacity alternator to be delivered right now. The old one is toast, too much draw at low RPM...fried. This alternator failure, by the way popped up out of the blue and we are wondering if some of our gremlins could be attributed to a slowly failing, intermittent, alternator?



Thanks for hanging in there with our saga. It’s good to know how successful you have been with your stack system – your success means there is hope our efforts will work out. 



charlie