RC550s too long?
 

I bought a set of RC550s from a member here, just went to install them and they're too long. Did I buy non-Miata RCs or is there something I am missing? I'm trying to use stock isolator, so that might be an issue.

I would search harder before posting a thread like this, but I have to leave for a racetrack in 36 hours and my motor isn't in the car, broken in, or tuned.

damn!

this sucks



this will be very impressive.




on topic, dumb question but its a place to start. Did you get the bushings from the fuel-rail to head? I tried to put my fuel-rail in without them and the injectors were too long, then I found 3 black bushings saying "wtf are these for?!" :noob::giggle:


what motor, is it built, and what turbo? I know your planning something sneaky!

do your o-ring ends seat in the rail out of the car?

do the isolators fit on the injector nozzle?

do the nozzle ends with isolators fit into the injector bores?

Matt, the o-rings pop into the fuel rail just fine. The isolators fit onto the injectors, but they seem a touch stretched. The isolator drops in with the injector attached, but the injector doesn't sit very low.

This is all i can think of. I've been running 440cc RC's for ever, I'm 99% sure they are the same size externally. They are also damn close to the factory injectors, except for the harness plug.

Yeah, what he said... ;)
His Sig says "stock".

you got me... are there missing rail spacers maybe? My vishnu rail had some weird extra spacers that fit between the bosses and the rail that like to fall off and get lost.

I have RC550s and they fit just like stock. I believe you'll have around 4mm of nozzle sticking past the isolator.

I had 550 on my car for about 5 minutes, but they fit right in place.

i thought they were too long at one point, but I forgot to put those 3 stupid as little spacer thing in between the rail and head.

What part number are they??

wat


I have zero nozzle sticking past the isolator. :hustler: Do RCs have proprietary isolators? Are the holes in the '99 head smaller than the ones for the '94?

I am using low-impedance RC550s on a BP4W ('00) head with a Vishnu fuel rail and they fit fine. I just sent them out to be cleaned, but I was using the stock isolators and the nozzle was definately sticking out past the isolator - not much though.

--Ferdi

Can you just put some washers between where the rail bolts up to the manifold to give you extra space?

here is a post I just saw about it. one of the members mention using washers to space the fuel rail.

https://www.miataturbo.net/forum/t35465/

That's what we ended up doing. We will see if it seals.

What is the part number of the injector. I have 550's in my car and they fit using factory isolators, in fact the same one's I had on my RX7 460cc injectors and the stock injectors as well. I'm using a vishnu rail.

IIRC I used the bushings from my 97 head between my 99-00 fuel rail and 99-00 head. So they should be the same size.

I dont see how too long could even be an issue unless you cant fit them between the plenum.

maybe less than 4mm, but it def stuck out.

+1

I had 0 nozzle sticking out of mine with the stocker isolator on there..

Ditto on checking the part number and going to RCs site (or googling the PN).

I used DSM RC 550s when I had my NA and they seemed a bit shorter. The low impedance ones. I ditched the rail spacers and used washer and it worked fine.

Frank