Imo000

How can a injector be more secure without a clip? Carl's rails use bolts to hold the rail brackets and that's about it or has his pruduct been updated since? I've raised my concern years ago when Carl first offered his extruded aluminium fuel rails but not too many people though it was anything to worry about. That mindset different now days and for a good reason.

Bill Ball

Kevin: That is the question. SOMETHING was wrong with the clip/injector/rail. The clip unseated the day before while breaking free the harness plug on that injector. The clip reseated with that "positive click". Thought it was OK. But, you are right, it should not have dislodged so easily.

GregBBRD

For my new intake system (which requires new fuel rails) we had the rails drilled and tapped outboard of each injector opening and had stainless steel plates water jetted out to hold the injector into the rail. Two stainless screws hold each plate in place.

I believe these pieces are identical to what Hans supplied with his intake runners and fuel rails. I'm also guessing that his supercharger kit will use the same pieces.

The only way these injectors will come out is if the injectors breaks in half.

Not securing the injectors to the rails is a mistake, in my opinion.

Imo000

First thing I've noticed with Hans's CAD drawings were the injector retaining tabs that you've mentioned.

vanster

Red car and the white donor are on their way to GB
Note the clever shrink wrapping. Brilliant idea, wasn't mine.

Bill Ball

Van: Good move!

Chalkboss

That looks like a Woudsma wrap!

Martin's928

The fuel rails from 928MS bolt through the billet body of the rail to the intake manifold and are very secure. In my setup, I'm confident they cannot move or allow an injector to move.

Imo000

What's holding the injectors in the rail when the rail comes loose from the manifold?

Martin's928

Ahh, I understand your point! Redundancy. I really can't say what the probability of the mounting system of the rails failing only to suggest it seems extremely unlikely. It's not a particularly stressed mounting system and, to my eye, appears more than robust enough for the job. The only thing I could think of was if one of the mounting bolts worked it's way out through vibration. I used blue Locktite to minimize this risk. I am in the habit of routinely checking my high pressure fuel system (since I built it and worry…..) and those rails are really solid.
Perhaps Carl could comment on the engineering aspects?

zekgb

Bill: Did the injector unseat from the clip or did the clip unseat from the rail? Looking at the rails on my spare engine it appears that there is at least some variance from port to port as to how much meat there is on the flanges that retain the clips. Any chance that plating the rails caused some issue with the flange?

vanster

One thing to keep in mind is that an S4 manifold vs an S3 manifold, the injectors are in plain site.
The S3 requires removing the outboard part of the manifold to check for leaks. The engine will not run with the manifold removed.

GregBBRD

Both cars have arrived here.

I pulled off the wrap and looked at the car.

That barely even qualifies as a fire, compared to others I've seen....

The tough part will be finding a pretty firewall pad and good intake tubes.

zekgb

Linderpat had some intake tubes available a while back, not sure if he ever sold them.

Rob Edwards

Stopped by Greg's today, it's full court press on Van's car.

A little sobering to see what a 'minor' fire touches. Check the ABS harness at bottom right. Pristine 32 year old factory harness label to the right of the grommet, bare charred conductor barely 2 feet away:



The engine had a mix of Greg's braided PFTE and kevlar fuel hoses on it- hottest part of the fire was near injector 8- the LH harness was a toasty mess nearby but the kevlar just laughed it off: