'83 6.9 engine questions?

[6point9diesel]

Just wanted to run this past you fellas to see if I have this right. As far as I can tell the differences with the '83 model 6.9 are as follows:

1. injector pump
2. injectors
3. head gaskets

For some reason I thought the 83s had a different cooling setup. Are the heads different than the later models? If they do have different heads, do the later model heads fit? I've also heard that they have a lower compression ratio than the later models. Is this right?

I know when I got my banks kit the turbo wasn't suggested for the '83. I can't see this being because of the fuel injection system, but maybe the head gaskets. Can someone clarify for me?

Paul

 

[F350camper]

From what I understand, the 6.9 heads use smaller head bolts and thus the heads wont interchange. Not sure about the compression ratio.

 

[6point9diesel]

Rob,

Thanks for the reply. Are you referring to the differences between the 7.3 and the 6.9?

I think I may not have been clear enough.

I'm of the understanding that there are some key differences between the '83 6.9 and the later model 6.9's. I'm wondering what those difference are.

Or do you mean the early 6.9's had different head bolts than the later 6.9's?

Thanks again,

Paul

 

[F350camper]

ahh, sorry my bad. Yes I was refering to 6.9 vs 7.3. So, ok, I know nothing about any of your questions...

 

[6point9diesel]

Paul

 

[towcat]

'83 had different head castings versus the rest. "the warden" just went through his. he can tell you about the nuances.

 

[Agnem]

That would be news to me. The main difference between the 83' "A" engines and the subsequent year "B" engines, is the pistons and glow plug system. I've not noticed any other differences myself. There were some other internal changes over the next 3 years, such as the cooling jets being bolted in instead of pressed in. The Weep hole in the injection pump, and some other really minor changes like the dips stick tube were the others.

 

[The Warden]

That would be news to me. The main difference between the 83' "A" engines and the subsequent year "B" engines, is the pistons and glow plug system. I've not noticed any other differences myself. There were some other internal changes over the next 3 years, such as the cooling jets being bolted in instead of pressed in. The Weep hole in the injection pump, and some other really minor changes like the dips stick tube were the others.

Mel, according to the Ford 6.9l update issued in '85 (I thought you had a copy of it; someone scanned it in as a series of .pdf files back in the TDS days), the precombustion chambers are different on the "A" engine as well as the pistons. AFAIK the difference is strictly internal, so without part numbers, you can't tell the difference between the two precombustion chambers without cutting one in half. The update actually said that "A" heads won't work properly with a "B" engine or vice-versa, although I can't remember the exact reason (and I'm at school; I'll check the bulletin when I get on my computer at home this evening) beyond the difference in precombustion chambers.

Also, not all "A" engines have the early glow plug system. I think that was limited to trucks actually built in the '83 model year...and the "A" engine was also used in early '84's. I have an "A" engine in my truck with the later glow plug system (currently non-op pending switching to 7.3l plugs).

I can't remember if the oil cooler change occured with the switchover to "B" engines or if that was at a slightly different time...again, have to check the update

 

[6point9diesel]

Thanks guys!

So the '83 pistons...were they higher or lower compression? I thought I heard the '83's were a lower compression engine.

Thanks again!

Paul

 

[Agnem]

Yes, the A engines had a lower compression by just a tad. Better for turbocharging!