User Omega

Basically when I go to push my injectors into the bores they get down to the level where the intake seal is and then there is a bit of a void ( a small gap separated by the gasket between the clam). The injectors are tight until they get to this position which is fully seated. They are very loose and would not hold a vacuum.

Has anyone seen this? What did you do? Obviously bigger o-rings would be a possible solution. The stockers are pretty tight in the bores before they get to that gap so how much bigger I don't know and who would you call to order them.

So frustrated with the extremely low quality of the MSD intake. I mean damn. I feel like I'm back in 1970 when aftermarket meant "half assed and good luck"...

rio95

Wow that sucks. Yet another quality issue. Pretty sad...

User Omega

I am just hoping its an easy fix that I am making more difficult than it has to be. I cannot be the only person to experience this.

rio95

Maybe u just need new stock o rings? Perhaps yours took a little set.

User Omega

They are all brand new. Stock size. Is there a normal used size than stock LS7 size?

rio95

Oh I dunno then.... Sounds like you may need to talk to MSD.

User Omega

Like I said, they are really tight in the bores going into the intake. Its when they are seated, they are loose. No tension at all on several of them.

User Omega

I plan on calling MSD tomorrow when they open. I am just not looking forward to what they may tell me. I have a decent amount of money invested in the porting and direct port nitrous setup...

rio95

Sounds like a possible molding shrink issue to me. I design injection molded parts for a living. Might want to try some other injectors if you know someone who has some.

I just placed an order for a mamo msd a few min ago lol. I hope I don't have this problem. Tony has the most experience with these. I'd ask him.

outhouse

Wont do any good.


Your injectors should seal in the plastic bore before they bottom out.


What you are feeling is,,,,,, your pushing the injector oring past its sealing point and there is a gap right now where the clamshell injector gasket is.


I would bet your installing them off the car.


Once you install the manifold the 10 manifold to head bolts tighten up that slack and shorten that gap greatly.


Once its tightened the injector will bottom out AND the Oring will still be in the bore sealing as it should.


Have any questions PM me, but you will see what I'm talking about after its installed.

User Omega

You are correct. I will install it on the car to see how it works out.

rio95

I can't visualize what the "issue" is here. Maybe it'll make sense once I get my intake.

Hopefully you figured it out at least.

User Omega

If you look at this image you can see the gasket that goes between the clam. You can see that the injector bores are actually 2 pieces. An upper and a lower. The gasket isn't very thin and doesn't fit the bore perfectly so what is happening here is that even though I have all of the outside bolts tightened down, the clam isn't clamping fully on the gasket that goes in between the bore sections. When I install my injector into the bore (off of the car), it presses down to where the gasket is and there is a gap there allowing the injector to be loose.

What outhouse is saying is that when you install the intake mounting - head bolts, it will clamp the gasket down and decrease the gap where the gasket is. Thus keeping the injector in the bore of the upper part of the clam because the injector will bottom out before getting into the gap area. I am hoping that this is my problem and it does seem logical. I will return with feedback either tonight or tomorrow night.

outhouse

You have it down cold, that is exactly what I was trying to say.


You will see with the clamshell bolts loktighted that the injector gasket is actually loose off the car and you can move it around almost freely with a small screwdriver.


Once its bolted on the car its gets squished at that point, to the point of you did not deburr the casting marks on the injector seat you will end up cutting the clamshell gasket.

MTBSully

Interesting. Looking forward to what you find. Everyone says you need to pull the intake to retorque clamshell bolts after a couple heat cycles anyways, so you could test the theory

Sébast19X

I have run into that issues.... Buy fast injectors spacer. Used them, that will seal properly.
Do 4 aluminum spacers to jack up the fuel rail the same level. A bit of job, but that work perfect.

Hope this help,

Seb

ChevyCobb

I could tell a difference when installing fuel rain with intake on the car versus off the car. Plus putting on the fuel rail after the manifold is already installed gives a little more room for the two rear manifold to head bolts...at least for me it was much easier to get to them and tighten

rio95

So install injectors and rail AFTER installing intake? I did my fast setup off the car and it worked fine.

User Omega

Yes, I also did my FAST rails off the car. Much higher quality there. I did not get to installing the intake the last couple days. A slight delay here figuring out the steam vent deal.