Hilton

Hi Marc you need up update your signature - its missing an SE

Which car are the 24lb injectors going in? Your friends' modified S4?

Hayk928

Hi Hilton

These injectors are for the modified S4. You know, it took actually a long time to choose the right size since the Design III seem to provide slightly better fuel-efficiency (spray pattern) compared to the old ones of the same size. I guess, roughly 25-30% increased fuel rate might match. Not to forget, the Design III can handle higher fuel pressure more easy - so there should still be a cushion...

Lets see how they'll work...

Signature updated

Jadz928

Great pics. I'm really happy to read you have solved your problem - it has plauged you for some time.
Bring that car over here, we'll go for a spin to get some lunch.

Hilton

I have a chance to compare injectors last night after finally getting the fuel rails off my 87.

Took pics of the fitment of the stock injector, grooved design III, and non-grooved design III with the clip that holds them in the rail.

First a comparison of all three types.. part numbers and rated flows are:

Left - 0 280 155 700 - 200cc/min @ 3bar
Center - 0 280 155 746 - 200cc/min @ 3bar
Right - 0 280 150 730 - 201cc/min @ 3bar (stock 19lb S4)



The left-most one is missing any grooves; its neck is only as wide as the grooves' internal diameter on the stock and grooved design III injector. Its also narrow higher up towards the fuel rail than the other two.

Then I fitted them to the rails with the injector pushed all the way in - the fuel rails on the S4 are the exact length that the groove on the center and stock injectors sit at the very lip of the rail retainer.

Here's close-ups of them in the rail with a clip fitted:

Stock


Grooved design-III


Narrow design-III


The narrow-necked design III has a few mm clearance where it can slip down until it touches the clip, but the o-rings look like they'll still seal.

The last thing to measure is the placement of the lower o-ring where it seals in the intake:

Stock:


Design III with grooves:


So both put the lower o-ring in the same spot, and the stock injector will protrude 2.7mm further into the intake port beyond the o-ring than the Design III. This should give the design III a further edge as its a little more room for the spray to widen before meeting airflow.

As far as I can see, the Design III with the narrow neck and no collar/grooves will also fit, and will sit so that the lower end is where the stock injector's cap sits in the intake. My own preference is for the design III with the wider collar and grooves (or cut grooves like Landseer above), just to emulate the factory fit as far as possible.

I won't get a chance to actually use these injectors for some time - still dismantling the intake and then have to send a large bag of carefully-catalogued bits for plating (curse you Rob Edwards with your photos of shiny bits .. its a disease I tell you!)

Hayk928

Today I tried to install and just noticed that five-o forgot to put the 16mm O-rings on (or in)...

My question: How difficult is it to fit the proper o-rings without breaking the slice... Can I disassemble the injector? What would you suggest?

Hilton

Not sure - I've only got used injectors to hand at the moment for experimenting with, so don't know whether you can get the plastic cap off on new ones without breaking them.

I do know on used ones they crack and break easily if you try to remove them, but they are pretty hardened and brittle from heat cycles. For new ones, you might get away with soaking them in hot water to soften then before prying?

I bought a bunch of new plastic caps and top Bosch o-rings for the used ones I'll fit to my 87 as a test, and will use Roger's 16mm lower o-rings too. I got the Design III plastic caps and standard Bosch o-rings from www.injector-rehab.com, they turned up a few days ago.

Let me know if you discover you can get the caps off - otherwise I'll need to get more caps to swap larger o-rings onto the new 30lb injectors I'm planning on needing.

kingsmen11

I'm bumping this, because I'm working on my injectors on an 89, and 87's. Thanks for the information everyone.

Hilton

As an update - it turns out the correct o-rings for the lower end of S4 injectors are 17mm, not 16mm.

After much hunting I dug up a handy Bosch fuel injector catalogue that lists the correct Bosch part numbers for injector o-rings, including the unusual one for the S4.

The correct Bosch part is actually 17mm OD, 4.6mm thickness, for the intake end of the injector on an S4. The correct lower o-ring is also a red viton one, like you get in the Porsche injector seal kit.

The Bosch part number corresponds to a box of 5 of the lower seals - so I've ordered 5 boxes, which gives me enough for 3 cars, plus one left over.

Once the o-rings arrive, and I've had a chance to measure and compare to the ones I've got from Roger, I'll post up the correct part numbers and some pictures (as well as the correct Bosch part numbers for the top o-ring, which is the same as the lower o-ring for 85/86).

Landseer

Another update, this for 24 lb injector discussion---

Here's what appears to be a good Bosch discussion and technical document.
http://www.cannell.co.uk/Bosch_Techn...linjectors.pdf

Just a note --- from this document, there is a difference in delivery for injectors that we have so-far called 24 lb injectors. (what we are using on the 85/6 cars, and performance enhanced S4 cars)

Look for the Bosch p/n 0 280 156 013 --- Hilton has pointed these out ( and Hayek used them ). These have the top slots in them already, they are OEM for an Aussi GM, and Five-O says they carry them "exclusively" in the states. They are expensive at 35 to $40 each. This injector is also the best aftermarket choice for the very prolific 6 cylinder 4.0L Jeep engine ( which Five-O seems to be capitalizing on)!! They flow about 24lb nominally. These are so-far the best aftermarket version of the design III injector for the 85/6 car I think.

The ones I used were p/n 0 280 155 931 --- These are aftermarket choice for some Corvette and Camaro applications. They are cheap at $20 each new. ( plenty of supply right now). You need to cut the top slots yourself. NOTE: They actually flow more than the above. They flow about 11% more, at 26.6lb nominally.

Wish I could sharktune the 85 to optimize the mixture using these injectors. Seems a little rich right now under some conditions. Speculating. More to follow.

John Speake

Does anyone have the P/N (Bosch and Ford) for Type 2 42# ? This appears to be the Bosch number for the 4 hole 02809 155 968 ?

Hilton

John, I'm guessing this is Adrian's car?

Looks like these are the ones:

Ford Part # M-9593-F302
Bosch Part #0 280 150 558

They have the stock grooves and EV1 connector, and are Design II (928 stock-shape injector body).

And some info lifted from the Aussie LS1 forums which came from Ford Motorsport's helpdesk:

edit: Google found this good old thread here in the 928 forum

John Speake

Thanks Hilton. Those numbers are for the old single hole pintle type, I think.

These are the ones with the 155 968 part #
http://www.blueovalindustries.com/en4540.html which are 4 hole from the pics.... I'm not sure what the Ford part number is...

Adrian already has 42# on his car, for the power he is now making with ITBs I was looking for this info on 4 hole 42# for someone in France.

MG944

anyone know the p/n for 4 hole design III 19lb injectors? looking for them for a 944.

dprantl

The ones I got a few years back were M-9593-F302 (I still have the box) and they were definitely the 4-hole design. I know because I spent some time removing the caps and bottom o-rings since I am using Pizza's injector bushings. I just ran down to the garage and read 0 280 150 558 off one of them.

I think the 558 is the stock 928 large diameter body injector, while 968 is the thinner one.

Dan
'91 928GT S/C 475hp/460lb.ft

John Speake

Thanks Dan ! I assume the 968 will fit OK with the normal large seal on the head end ?