'73 RSR injectors vs. '73 RS injectors

[Matt Holcomb]

I found out today that my (new) car, a '73 RSR and '74 RS hybrid-clone, has '73 RSR injectors, which, individually, are worth as much as a set of 2.7 RS injectors, or so I've been told. One of my RSR injectors has given up the ghost -- fuel is spouting out of it -- and I need to replace it.

My options are:

1. Replace the RSR injector with another.

2. Replace all six injectors with 2.7 RS injectors.

The problem with option #1 is that '73 RSR injectors are no longer available. I suppose I could put my tweed deerstalker hat on and stick a pipe in my mouth in the hope of finding someone with a spare injector they want to sell. But, seriously, what are the odds?

So, I've taken my mechanic's advice and decided to replace the RSR injectors with a set of 2.7 RS injectors. I know that the RSR injectors have a different spray pattern, but are they that much different to the degree that the difference will be appreciable?

For what it's worth, the engine's MFI pump has been re-calibrated for a 3.0 RS engine.

[obrut]

Matt

Does your guy have an injector test rig? You can very quickly measure any flowrate differences and also eyeball the flow patterns.

[Matt Holcomb]

Ryan,

No, he'd have to send the injectors to someone with a test rig.

What would you do if you were in my shoes?

[obrut]

Back to basics, install the six RS injectors, drive slowly to a dyno shop, do a dyno run with a/f ratio - if the a/f curve is healthy and the power smooth then you know for sure that you can sleep easy.

[Adam]

I've been thinking about what you told me happened with that injector.

Why doesn't your mechanic simply install a new injector seal and put it back into the head? Did it strip the thread on the injector or something?

[Matt Holcomb]

Adam,

According to Louis, the mouth of the injector is warped and pitted.


Ryan,

Sounds like a plan.

[82SC]

call gunnar racing...I am sure they can tell you what's up...if not them try andial, and if not them brumos...

that about covers your main players...

also on gunnar there is a guy who commissioned them to rebuild a 917...throughout the project section them mention his website and how he is a master at getting hard to find parts....

if you got 5 good ones...i'd want to make it a set...

MJ

[Chuck Miller]

Maybe I'm misunderstanding you lads but...

I just took a look at my factory '73 parts book and there is NO difference between T,E,S,and RS injectors. Not sure about RSR injectors.

According to the book all (standard) MFI injectors are the same and easily purchased from your host or many other sorces.

901.110.271.00 - Injection valve

Hope this helps,

[sundaypunch]

If this is the beautiful black car that I remember from a previous thread I sure wouldn't go with the RS injectors (assuming the RSR are different). I would send them out for testing and do whatever it takes to have the proper replacement fitted.

[Early_S_Man]

Matt,

The later high butterfly or slide-valve injectors may be different, but the original racing parts catalog I have for '72 models doesn't list injectors as a special part, and this was for the engine with 86.7 mm cylinders and pistons ... the injection pump was special part, but not the injectors!