Help Modifying Bosch 1600cc Injectors
 

I purchased some Bosch 1600cc injectors and didn't realize they weren't already modified to fit an FC. According to this site: http://www.rotaryheads.com/modifications/bosch-1600cc/ they have to be modified by cutting off some of the top plastic. It says he used a Dremel but to "not nick the metal". Any tips on what attachment to use or an alternative method? That seems like a risky undertaking.

I use an unmounted hacksaw blade and go very slowly.
You'll feel the blade hit the metal after sawing the plastic.
You see the grooves at the top?
Do them in two steps.
Don't get greedy and try and do this once and then pry everything off.
The plastic is on TIGHT.
Doing this in two steps allows you to pry off each thinner piece with a flathead a lot easier.


-Ted

Rockstar. Thanks Ted!

I have discovered I have to modify the bottom of the injector also... any tips there? I'm getting some vague/conflicting info on the 7 club.

As a note to anyone else, I use the hacksaw method to cut across the grooves so the plastic was separated and would spin freely and then used a soldering iron to melt a notch in each side of the plastic so it just fell off.

Most of those Bosch units run a plastic cap at the tip.
I will remove them and leave them off.
To seal the tip of the unit to the engine, I cut a length of 10mm (I.D.) silicone hose.
You can use a section of 3/8" (I think that's the SAE equivalent to 10mm?) heater hose if 10mm vacuum hose isn't easily available.

No need to worry about protecting the tip, since they are all protected in our engines.


-Ted

So basically pull off the plastic that's on there and make a pintle cap out of heater hose?

- Bore the fuel rail to 14mm. Drill is ok, ream is better. You'd like a smooth finish that doesn't snap and tear o-rings.
- Go down to the local hardware store and get a pair of E-clips that snap on to the top of the Bosch injectors in the little slots. These will keep the injector from pushing into the rail too far.
- Pop the pintle cap off the bottom. Slide new stock grommets on to the injector.
- Bolt it all together.

So the boring/eclips are for the top? If so I think (hopefully) I have that part set. If not I'm screwed because I already modified it. :dunno:

For the bottom, I can just pop the current pintle cap off and put on stock grommets?

Yes. The top o-ring diameter of the EV1 injector is 14mm. The stock injector and rail is 11mm. So, open up the rail to 14mm. You need to use the e-clip to allow the you to compress the injector against the bottom grommet, just like the stock injector does. If you've already cut up the injector, this method won't work.

If the tops are already cut, then the modified Bosch fuel injector will sit higher than the stock fuel injectors.
This is why a "custom" lower grommet is used to take up the extra space now there.
With the Bosch modified with the tops cut, the fuel rail opening will sink all the way to the newly cut top.
The stock fuel injectors use that stupid "insulation" grommet that just gets compressed and warped in that area.
We typically use the "triple o-ring" trick at the top to seal the fuel rail on the top.
I keep a short length of 10mm I.D. silicone hose or 3/8" fuel hose to cut to length just to seal off the bottoms to the engine.
The newly modified Bosch fuel injectors will sit about 1/8" higher, which means that any stock type lower (sealing) grommet will not work - i.e. not seal correctly.


-Ted

Yes, the tops are already cut. It looks like I'll give Teds way a shot (thanks again Ted). I appreciate the input though Ludwig. Perhaps someone after me will do it that way. Mine came without a top-oring so that way probably wouldn't have worked well for me anyways.

You guys might want to reconsider the use of silicone. It doesn't play well with gasoline. I realize it's not in direct contact, but any contact will quickly degrade the rubber.

http://www.goodyearrubberproducts.co...881.Page29.pdf

I planned on using the fuel hose option as that should stand up well. I'll keep that in mind about the silicone though.

Yeah, silicone hose swells like a bitch when exposed to gasoline, but in theory, the gasoline should not touch the lower grommet.
It might if you have a fuel leak from the fuel rail...
There are even some lower grommets that I've sourced that are made from silicone from the local auto parts stores.
I check my lower grommets often enough that I've never had a problem with gasoline touching them - this has been over a 5 year+ period.
But the standard warnings do apply here...
I just like the silicone hose better since it makes for a cleaner and tighter seal when cut to length.
Most fuel hose is reinforced with some kinda (Nylon?) braid, which tends to corrupt the seal a little.

Good luck.


-Ted

For the bottom of the injector for your method Ted, do you take off the pintle cap and remove that insert in the LIM?