Anyone running the DUI Ignition??
Do you like it?
how much timing are you running and what Compresion ratio??

Doller for Doller is it better or worse than say a MSD??

Thanks
Ron R.

 

https://www.ford-trucks.com/lc/lc.ph...%2Fforddui.htm

Hear is the link.

 

Well Ron this is just my opinion....

I really like the Davis unit, and it puts out a ton of spark and its a clean set-up, and you would figure less parts less worry?

I know a few guys running them on hot rod street cars..and they seem to swear by them..They are guys that had bad problems in the past with there MSD set ups!!

But I guess it would depend on how hard you want to run your motor most of the time..Going with the Davis unit you give up Multi spark and I think rev limiting as I remember!

But to me is would seem to be a real nice street/strip unit !! JMO..

RJ

 

I also have one for my 390, just haven't installed it yet.

 

Race or strip/street?

 

street. I am putting a 390 in a 94 mustang. But no track time, just a daily driver

 

Daily driver ? Man you must be rolling in dough....LOL

 

I looked at the davis unit but its to big for the factory duel holly setup...wont clear the front carb...good luck bill

 

Hey, I've had several of those units on 351w. when I worked as a natural gas compressor field tech. They are a great unit, had thousands of hours on some of them. However, unless Davis got their poop in a group, they had a problem with the tolerances of the 5/16" oil pump drive. They just did'nt quit fit. I had to use a small file to get them to mate up smoothly (this always happened 60 miles into the sticks, not many tech lines handy). I even had one fit smooth from the factory, but it did'nt run true. After around 1000 hours (41 days of 24/7) the hex in the oil pump drive stripped out. Thank God for low oil pressure shut-downs. I will say in their defense that the engines started alot easier come -25 degrees. The reasons we went with the davis unit where... no ext. coil, hotter spark, and we kept shearing of the roll pin on the dist. drive gear on the factory Ford distributors. Not what you would call normal operating conditions, but you find out really fast what works and what works better. Lots of luck.

 

Hey Montana..thats a good testemonial..you should call Davis with your findings and ket them know about the good and the bad!! That would help us gearheads out in the future!! "IF" they take what you have to say to heart!!

Thanks for the info..its good to know there weak points!!

RJ

 

This is interesting info. Just out of curiosity what rpm were these engines usually turning at ? I assume this would be like dropping a boat in the water with enough fuel to run for a week and see what gives hahaa

 

I should include that these engines where a v8 converted to a compressor unit. You have probably come across one of these before, but these have been reconfigured to pump nat. gas. One bank (left) is the engine, and the other is the compressor. Right bank uses a special cyl. head made by the comp. manufacturer. This head uses compressor valves that act as two stage valves which do not need influence from the camshaft. That being said, one of the causes for early failure of the dist. may have been a surging, jerking timing chain. With only half of the cam lobes being used, it may have created a vibration that was unseen. Like I said not ideal conditions, but they worked long enough to pay for themselves and the maint. To answer your question Bob, they usually ran anywhere from 1700-2100 rpm. I also wondered if the constant rpm set up some harmonics at a specific rpm that was harder on parts that failed. It never let the mechanical advance flyweights rest in different positions I'm sure. They always ate they vaccum advance hook up inside the dist. That was on the ford dist.
So much for a "quick reply". I don't know if this helps anyone but I found it very upsetting after a two hour drive just see another dist. failure, so I hope someone can glean something usefull from the info. See you around.

 

Actually Im going to guess the cam had very little to do with it. I would think that a power stroke on one bank only made for some hellacious balance issues. Just curious, ever break one down and read the crank/rods/wrist pins/bores to get an idea what was taking place inside?

 

Got ya thinkin' did'nt I! Well... we had the bottom end opened up to r&r a pan gasket, and found very little in the way of bearing wear on both the mains and rods. Had too many people barking that it needed to get back in the field, so we buttoned it up and put it back in service. If I remember correctly, it had around 4700 hours on the short block. 2100 rpm... good highway number...mmmm...4700x60mph=282,000miles. Almost seems impressive, but very few start/stop or incomplete warm-ups. We had alot of power head failures mainly due to the fact that the comp. company failed to us hardened valve seats from the start. We'd pull one off, they'd warranty it, send us another just like it (hardened seats on back-order or some other lame story) and with time and money a premium we'd have to use it. In response to the balance issue, I'm sure that it had an effect on the whole engine but I did'nt have a chance to see the story unfold to date. Because the power side and "compressor" side had to have different compression pressures, the balance had to be thrown off depending on suction and discharge pressures at a specific well application. Too many variables, not enough brain power! If you are still hungry for info on these units, run a search for Grimmer-Schmidt Natural Gas Compressors. Good idea, but not enough research and developement in the nat. gas application. See ya later.

 

I rented a air compressor and jack hammer from a-z and the compressor was a small block ford running on one bank and one bank was the compressor...it seemed to run very smooth and put out lots of air..bill