Fuel Injector Differences - CLARITY NEEDED PLS

[Lemon98]

A few months ago I bought an M20B20 engine from which I took the cylinder head for a university project and I also bought the injectors that came off the engine too.

These injectors are numbered 280 150 716 & 944 (see picture below). However the ones that are on my car have the same long number but the three numbers above are 056.

Does this have any significance or can I send off the 944 ones to get cleaned and then swap them into my engine? So what do the three numbers represent and are they different in any way that would affect the running/tune of the engine?

IMG_20210416_134005.jpg

Thanks in advance!!

[steve_k]

from what i can gather the "944" one's come back as bosch "greens" that were used as an upgrade in the escort cosworth as an upgrade, are they single pintle or 4 pintle?

as for the others i can find anything out,

[steve_k]

have a look here

https://www.gomog.com/allmorgan/InjectorRatesBosch.html

see if that helps.

[Lemon98]

Thank you Steve, that is a really useful table for future reference and for checking specs!!

This might sound stupid but what is a pintle?

[steve_k]

Thank you Steve, that is a really useful table for future reference and for checking specs!!

This might sound stupid but what is a pintle?

no worries, i forgot i had it in my links.

a pintle is the end of the injector where it sprays the fuel from,
there's been some debate over the years about whether a 4 pintle injector is any good on an e30 engine.

[RossDavies]

Does anybody know where you can send your injectors for referb please?

[Lemon98]

Does anybody know where you can send your injectors for referb please?

There's a company called Injectortune who is also on here in the forum. I'm going to send mine to him and hope that the 944 vs 056 has no real difference lol

[Lemon98]

Something that's just come to mind is that my car was ordered from factory with a catalyser delete and being a late model (1990) the "standard" car would have come with one. Is it possible that this could be the cause of the 3-digit difference? The info that I have found online and in some books suggests that there is a difference in compression ratio between the cat and on-cat models of the later Motronic 1.3 engines.

Can anyone confirm if this is also true regarding the compression ratios?

From Steve's input I believe that they are a single pintle injector, please see the images below to confirm.

Injector_Tip_1.jpg

Injector_Tip_2.jpg

Here is the spec sheet:

image002.png

[steve_k]

yep thats a single pintle injector.

as for the cat? my G reg (1990) 325i had no cat from the factory according to the original build sheet, IIRC they were still an option in 1990.

as for a difference in compression ratio? i know there was talk that the early m20's had a slightly higher compression ratio but i dont know by how much.

[Lemon98]

yep thats a single pintle injector.

as for the cat? my G reg (1990) 325i had no cat from the factory according to the original build sheet, IIRC they were still an option in 1990.

as for a difference in compression ratio? i know there was talk that the early m20's had a slightly higher compression ratio but i dont know by how much.

Huh that's interesting, I don't know much about the options and things other than for mine it seems deleting it was an optional extra. Possibly a difference between 325s and 320s?

[omera60]

Does anybody know where you can send your injectors for referb please?

There's a company called Injectortune who is also on here in the forum. I'm going to send mine to him and hope that the 944 vs 056 has no real difference lol

Hi,

Don’t worry about these numbers. These are Bosch factory codes, they are there to identify which factory built/assembled them. As long as you have the correct spec and Bosch part number you are good to go. There is also a manufacturing date stamped on the connector side of the injector if you are curious...

Best,
Omer

[Lemon98]

Does anybody know where you can send your injectors for referb please?

There's a company called Injectortune who is also on here in the forum. I'm going to send mine to him and hope that the 944 vs 056 has no real difference lol

Hi,

Don’t worry about these numbers. These are Bosch factory codes, they are there to identify which factory built/assembled them. As long as you have the correct spec and Bosch part number you are good to go. There is also a manufacturing date stamped on the connector side of the injector if you are curious...

Best,
Omer

Hi Omer,

Thank you so much for this info!! That is exactly what I needed to know and I can now send off the spare ones to get refurbished with confidence that they are the same as my current ones.

Thanks,
Will