Dakota Digital CHT gauge......

...........I got it installed late yesterday afternoon on my Berg 1679 and
took off with my Fluke IR handheld gauge to see what I could find out about
its accuracy. I set the DD's upper limit at 430 deg F which is merely a
preset where the display starts flashing and then proceeded to drive at 80
mph towards Elmira on the local expressway here to see if I could get up to
430 before pulling over and using the Fluke to see the discrepancy between
the two gauges. It wouldn't reach 430 deg at 80 mph even after about ten
miles sustained! So of course, being a natural born lead foot, I gradually
opened it up to 85-90 and after another few miles it finally reached 430
(ambient temp was about 55 deg). I then killed the ignition and pulled over
on the shoulder and immediately turned the ignition key back on so that the
gauge on the dash could be seen while I was pointing my IR gauge down the #3
opening in the cylinder tin after pulling off the ignition lead from the
distributor. The result? At 394 degrees indicated on the IR gauge, the
Dakota Digital gauge was indicating 390. This is plenty close enough for me.
As I continued to monitor the two gauges as the engine gradually cooled down
for a few more minutes, The difference between them was never more than
about eight or nine degrees as the temp dropped down to about 275.

.............I'm happy with this device and feel that it's a good upgrade
over the VDO unit.

BTW...........I've never been able to drive at 80 mph for ten miles in the
past because the VDO would go over 450 deg and I didn't have the nerve to
ignore it and keep going at that speed. Maybe that's why I haven't had a
speeding ticket in the past few years............lol

"Tim Rogers" > wrote in message
...
> ..........I got it installed late yesterday afternoon on my Berg 1679 and
> took off with my Fluke IR handheld gauge to see what I could find out
about
> its accuracy. I set the DD's upper limit at 430 deg F which is merely a
> preset where the display starts flashing and then proceeded to drive at 80
> mph towards Elmira on the local expressway here to see if I could get up
to
> 430 before pulling over and using the Fluke to see the discrepancy between
> the two gauges. It wouldn't reach 430 deg at 80 mph even after about ten
> miles sustained! So of course, being a natural born lead foot, I gradually
> opened it up to 85-90 and after another few miles it finally reached 430
> (ambient temp was about 55 deg). I then killed the ignition and pulled
over
> on the shoulder and immediately turned the ignition key back on so that
the
> gauge on the dash could be seen while I was pointing my IR gauge down the
#3
> opening in the cylinder tin after pulling off the ignition lead from the
> distributor. The result? At 394 degrees indicated on the IR gauge, the
> Dakota Digital gauge was indicating 390. This is plenty close enough for
me.
> As I continued to monitor the two gauges as the engine gradually cooled
down
> for a few more minutes, The difference between them was never more than
> about eight or nine degrees as the temp dropped down to about 275.
>
> ............I'm happy with this device and feel that it's a good upgrade
> over the VDO unit.
>
> BTW...........I've never been able to drive at 80 mph for ten miles in the
> past because the VDO would go over 450 deg and I didn't have the nerve to
> ignore it and keep going at that speed. Maybe that's why I haven't had a
> speeding ticket in the past few years............lol
>
Well that's pretty neat. Now here's the link for a selector switch so you
can select any of the 4.
http://www.aircraftspruce.com/menus/...sselector.html
Scott was working on a LCD screen display for all his gauges and was
developing an auto-scroll type display for his CHT sensors so that it would
display one and then the next, etcetera, automatically. I don't know if he
ever got that far with it.
Did you get the long thermocouple sensor? How long?

I remember now the progression of my mixture gauges: 1st was oxygen sensor
after the headers and before the muffler. I had to use a three wire unit
here as the single wire almost never got hot enough to function. Next I
welded a bung on the leading part of the headers on #3 tube. It worked much
better but was still inconsistent. I think if I had been using an
inch-and-a-half muffler pipe it might have stayed hot enough, but I had
two-and-a-half all the way out. Finally, the last engine: I took a pretty
much perfect left-side heat exchanger (for a '79 bus - rare!) and welded a
bung on the head pipe about two inches from the exhaust port. This one
worked all the time and did not have the up-and-down tendencies of all the
other hookups. I expect doing this will solve your mixture reading
problems - it sure did for me. I bought a piece of RC car exhaust silicone
tubing to route the wire through so it wouldn't get the insulation burned
off and short out. I also pop-rivetted a sheetmetal channel onto the bottom
tin that acted to guide the silicone tubing in the proper position.

I intend to post some pics of that soon. Presently I can't find that series
of pics. I may need to go over to the neighbor I gave all that stuff to and
see if I can do a photo shoot! I also ran across my pics of installing new
injectors and the extra steps I took. Important note here is, when you slide
the big retainer doughnuts on the injectors, be sure to do it the hard way,
sliding them into place. Don't be tempted to take the shortcut and roll them
on! It really simplifies the job, but the doughnut might end up inside-out
in which case the rounded shoulders will be against the ridge on the
injector that they need to bear against. That rounded shoulder will allow
the injector to slide right outa there!

Look also at the head surface where the stud that the retainer fits onto
resides. Look carefully to see if the retainer is bottomed out flat against
that flat surface. If it is, it may not be exerting any retaining pressure
on the injector's big doughnut. I removed each of those studs and filed the
surface down until I could see a space between the metal retainer clip and
the head surface, that way I knew the injector was being held in snugly.
I'll try to get these posted really soon. -BaH

"Busahaulic" > wrote in message
...
>
> I also ran across my pics of installing new
> injectors and the extra steps I took. Important note here is, when you
slide
> the big retainer doughnuts on the injectors, be sure to do it the hard
way,
> sliding them into place. Don't be tempted to take the shortcut and roll
them
> on! It really simplifies the job, but the doughnut might end up inside-out
> in which case the rounded shoulders will be against the ridge on the
> injector that they need to bear against. That rounded shoulder will allow
> the injector to slide right outa there!
>
> Look also at the head surface where the stud that the retainer fits onto
> resides. Look carefully to see if the retainer is bottomed out flat
against
> that flat surface. If it is, it may not be exerting any retaining pressure
> on the injector's big doughnut. I removed each of those studs and filed
the
> surface down until I could see a space between the metal retainer clip and
> the head surface, that way I knew the injector was being held in snugly.
> I'll try to get these posted really soon. -BaH
>
>

................This is valuable information Dave. I'm looking forward to
seeing those pics.