Author Topic: mechanical DDC  (Read 681 times)

Offline birdarchitect26

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mechanical DDC
« on: October 24, 2017, 06:15:52 AM »
What years did DD switch to electronic control. I'm almost certain my bus (1973 MC7) is mechanical, aka no DDC. The bus WAS converted by MCI in 1984. How can I tell? I don't see a box anywhere, although there is a large box on the forward wall.

The question arose because I think my Jake brake is not working. I hardly let the engine reach operating temps. The bus has been sitting for months because of a fuel issue, now solved!

I'll post a pic of the bay

J
1973 MC7 Challeger
8V92Ta MCI conversion

Online chessie4905

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Re: mechanical DDC
« Reply #1 on: October 24, 2017, 06:21:00 AM »
Look for wiring harness coming out of valve covers, not just single wire for Jake's.
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Pennsylvania-central

Offline luvrbus

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Re: mechanical DDC
« Reply #2 on: October 24, 2017, 06:47:03 AM »
The DDEC sets on top of the governor if you have a throttle cable,air hoses, cylinders and linkage on the governor you have a mechanical engine
Life is short drink the good wine first

Offline B_K

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Re: mechanical DDC
« Reply #3 on: October 24, 2017, 07:57:54 AM »
As far as I know the "DDEC" (Detroit Diesel Electronic Control) engines came out in the mid to late '80's.
I have worked on an '87 or '88 that was DDEC and have worked on them all the way up to '94 that weren't.

But just because a bus was built before then does not mean it is not have a DDEC engine swapped in to it.
I have worked on a 1973 MCI that had an 8V92 DDEC in it.
Also there are a number of older buses that have been converted to DDEC like Boomer's Silversides with a 6L71 DDEC. (and I know Clifford has done a few too)
;D  BK  ;D

Offline Boomer

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Re: mechanical DDC
« Reply #4 on: October 24, 2017, 09:39:28 AM »
Don't know what the official date would be from Detroit, but I saw my first 60 Series engine in '86  at a training class and bought my first three in '87 (trucks).  Not sure about the first DDEC 2 strokes, would be interested to know.
'81 Eagle 15/45, NO MORE
'47 GM PD3751-438
'65 Crown Atomic, NO MORE
Vancouver, WA USA

Offline luvrbus

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Re: mechanical DDC
« Reply #5 on: October 24, 2017, 10:13:25 AM »
DDEC's came on the market in 1985 for the 2 strokes fwiw
Life is short drink the good wine first

Offline Gary Hatt - Publisher BCM

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Re: mechanical DDC
« Reply #6 on: October 24, 2017, 06:29:26 PM »
My Eagle is a 1967 when LBJ (Lady Bird Johnson) ran the White House and it came with a DDEC.  Does that help?  :D

Of course, it did have an engine swap somewhere along the way from an 8V71 to a 60 Series.   ;D

The Electronic engines are great because they are full of surprises. There is never a dull moment. You never know when they will shut down on you for no apparent reason in heavy traffic, on hills, or sometimes when traveling thru one lane construction zones with no place to pull over as happened to me yesterday.  Thankfully, she started right up again each time.

The mechanical engines were very boring to drive. They just ran and ran and ran and ran and ran. 
1967 Eagle with Series 60 Power Plant
Gary@BusConversions.com