odonnell

Hi guys, I recently snagged a LR fuel rail for my 951. It's one of the first variants I believe they offered and a local enthusiast told me not to run it. It only has 2 mounting brackets (goes to the manifold) whereas the later models they offer have 4 mounts, similar to a stock rail (2 go to the cam tower). From what he told me, those 2 mount points are overstressed and the threads can let go in the aluminum - he knows of 3 Turbos that caught fire after this happened in boost. Apparently the higher manifold pressure was enough to force the injectors out of the seats.

Can anyone shed light on this? I just want to make sure it's safe to run. I bought this car as a fire rescue and am not excited about the risk.

GPA951s

Think about the cross section area of the injector, it would take ALLOT of PSI to blow that small of an area out. Think about how much you need to pull on the injector when you remove it from the manifold. Now Take an Air hose with a blow gun tip on it and hold you finger over the end with a small area you can hold back allot of pressure. The Early CIS and CIS_E Injection systems on like the 5000 Turbo Quattros, Never had a Common Rail. - Our Injectors go into the manifold, Therefore they are behind a closed valve on the compression stoke, On a Direct injected car or Diesel is a different story.
I have an Early Lindsey Rail on my race/track car.
1. Make sure O rings are good and seated.
2. Make sure the bolts are long enough to engage properly and DO NOT over tighten them.

mj951

The fasteners for the fuel rail are fairly small in size and I know one of mine has stripped out on a stock rail.
I'm comfortable running a stock rail even with a stripped fastener (Loctite) because of the additional three fasteners and the reasonable force it takes to install newly rebuilt injectors into the head but I would not be comfortable running that rail with or without stripped threads.
There's a reason for the second generation fuel rail so I think you know your answer.
Bummer on the purchase but thanks for sharing the concern with those rails.

As GPA says, do not over tighten.

Noahs944

Michael,

it appears to be solid aluminum on the bottom of the rail (where the 2 mounts are on that aluminum piece). If so, surely you can bend or build some extra bracket & drill through to mount, no? I agree if LR changed to 4 mounts, there is a reason.

V2Rocket

...if solid as noted above, drill the hole all the way through and use a bolt+nut.

odonnell

Thanks guys. I don't think it's the actual pressure on the injectors causing them to strip, it's just fatigue on the 2 M6 bolts going into the intake manifold. I also have semi solid 9Products engine mounts so that isn't going to help.

I paid $70 for the rail. If someone wants it for $50 I'll probably take it, or trade for a stock rail (don't need damper or FPR or crossover rubber line).

V2Rocket

Oh, those threads...
Yes I would think adding the extra legs would only help as with the 2 leg arrangement its sort of cantilevered.

The holes on the ends are NPT?

Max Energy

Michael
I have the same one on my 2.7 944 Race car and the brackets cracked and caused a fire.
I remanufactured the brackets with 6061 Aluminum and made them stronger.
The originals cracked at the 90 deg. were it mounted to motor and caused the injectors to spay race fuel onto the hot headers.
Max

rlm328

Contact LR they may have a conversion kit for it. CEP also made a rail about the same time and they came out with the 4 point bracket.