I have a suspected cracked head on my '87 300SDL, and have gotten a couple of leads to used #17, and #20 heads. Can these be swapped easily, without having to swap all the integral parts.
Ralph

You can put a complete #17 or #20 head on your car, the only change necessary is using the later angled injector lines. Some have bent the old lines enough to make them work, not the preferred method IMO but if it works, ...

__________________

Gone to the dark side

- Jeff

I believe the injectors themselves were different, although either ones should work just fine. also the later heads use a slightly different glowplug, so be aware of that.

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1980 500SE/AMG Euro
1981 500SEL Euro
1982 380SEL
1983 300TD
1983 500SEC/AMG Euro
1984 500SEC
1984 300TD Euro
1986 190E 2.3-16
1986 190E 2.3
1987 300D
1997 C36 AMG
2003 C320T 4matic

past: 1969 280SE 4.5 | 1978 240D | 1978 300D | 1981 300SD | 1981 300SD | 1982 300CD | 1983 300CD | 1983 300SD | 1983 380SEC | 1984 300D | 1984 300D | 1984 300TD | 1984 500SEL | 1984 300SD | 1985 300D | 1986 300E | 1986 560SEL | 1986 560SEL/Carat | 1987 560SEC | 1991 300D 2.5 | 2006 R350

Anyone know at which point in the series the changes were made, i.e., were the changes made in the #17 head or not until later, in the #20, etc?

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I believe the change happened in 1988, and the thread pitch on the injector bodies is different.

-Jason

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1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket

Tesla Model 3. 205,000 miles. Been to 48 states!
Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels.
2014 Cadillac ELR
2013 Fiat 500E.

Hmmmmmmm so No 14 injectors will NOT fit my No 18 head? I have the injectors from the 18, but just curious. I know 3.5L injectors are different than the 3.0L ones.

I too am trying to see what all needs to be done to slap on an updated head on my early short block.



What is the difference between the glow plugs? They look similar from pics. Maybe that the 3.5L ones are after-glow rated?

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

There is nothing different about the glow plugs that I know of.
I didn't know the injectors were different,

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

The PNs are different for the GPs, but the only sense I can make is that the 3.5L featured after-glow as standard equipment. 3.5L uses a Bosch 35X injector and the 3.0L uses the 36X injector.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

I did swap head #14 on my engine with #20 without any issues. I reused injectors ( glow plugs where still on it so I just made sure are working).

REused which injectors? Put the nozzles from the 14 head in the 20, or kept the injectors that were in the 20 in the 20? Supply lines?

Jay.

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On the road, currently:
'83 300D (German spec.) 168k mi. - - Wolfgang (tucked snugly away for the winter!)
'87 300D 375k mi. - finally went over to "The Dark Side"
'87 300TD 225k mi.
Cannondale 66cm CAAD5 w/Campy/Jamis Aurora
Hujsak Custom Fixie/Landshark Track Shark Custom/Ahearne Custom 29'er

Injectors (actually the injector holders) are different from the #14 to all "inclined injection" heads. The threads are different so they can not be swapped directly without machining (GSXR or SIXTO has covered this process in earier threads). The injectors themselves are the same and can be swapped into the newer holder.

Yes, the .97x glow-plugs are afterglow rated, but also dimensionally different to fit the different angle of the pre-chamber.

The easiest difference to note is the angle of the pre-chamber bore and threading causes the 603 part of the casting part number to be machined away partially.

Also injector lines, some force/bend the lines to fit the newer angle, better to find a correct set of lines as stressed steel will become brittle and eventually fail. Hopefully "eventually" will be longer than necessary.

__________________

Gone to the dark side

- Jeff

Why do the injectors have different part numbers then?

Makes sense on the glow plugs now.

Do the updated prechambers help with combustion or something of that nature?

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

The angled injectors are supposed to result in slightly more efficient combustion; I would imaging that the prechambers assist this process.

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I could be wrong on the injectors being the same, trying to remember some of GSXR's posts on the subject. Unfortunately, I sold both of my #14 heads with injectors in them, never compared the nozzles to the ones in my later head.

Also from memory, and searching some of GSXR's posts will likely yield the correct thread, the later head can be machined to fit the earlier injector holders, not sure what glow-plugs he used for the result. If not GSXR but one of the other 603 gurus, I apologize, hopefully someone here will have saved a link to post.

__________________

Gone to the dark side

- Jeff

The inclined injection change was for emissions per the FSM.

__________________

Gone to the dark side

- Jeff