MSefi.com read only forum (Jan.15,2018)

Okay,

I want to use one of my two duel plane manifolds for mpfi. I kind of have an idea on what to do. But since the runners are at different heights its kind of problematic when placing the injector bungs. I was wondering how I would go about getting everything level?

I don't want t switch to a single plane because this won't be a high rpm machine. Its going in a K5 blazer. Plus I already have 2 manifolds, three counting the one that is already on the truck.

Thanks

Colter

First off, your correct in not wanting to use a single plane on a 4x4 – been there, done that. Ended up converting my original dual plane. It can be done, you need to make the bosses different lengths, take a look at the photos on my page to get an idea:
www.mez.co.uk/ms8.html

Eliot,

I looked at your project awhile back and let me say that your setup is everything that I want mine to be. I was wondering how you compensated for the different heights of the runners? I assume you bought prefabbed injector bungs. The ones I bought are coming from Ross Racing Machine. I plan to machine my holes then install the bungs level and weld them into place. Then I will trim the excess metal that protrudes from the inside of the port. I am wondering is this a reasonable plan? Will this allow my injectors to sit at the same height in all the ports or does it even matter?

Any input you can give me will be very helpful.

Thanks,

Colter

We made the injector bungs ourselves. On the higher runners you make them as low as possible and the lower runners you make them higher. And, as you said trim off underneath.
The injectors wont be at the same height in the ports, I think we used a die grinder to blend the exit of the bung into the runner on the ones that were higher in the port.

Make sure you have your fuel rail stock and throttle body handy – to ensure you have sufficient clearance for the throttle cable and TV/Kickdown cable (if fitted)

So I guess that having the injectors at different heights doesn't effect the way the engine runs or if it did you were able to tune around it?

Make sure you have your fuel rail stock and throttle body handy – to ensure you have sufficient clearance for the throttle cable and TV/Kickdown cable (if fitted)

Good tip, I am going to modify an old holley tbi for my throttle body.

Thanks,

Colter

Runs fine, all plugs similar colour so I guess it doesn’t! - Been running like that for about 3 years. BradJ on this board has a similar setup.

Eliot,

Do you think its wise to use a hand drill on the manifold or should I use a mill to put the holes in it for the bungs? My Dad is a machinist but he doesn't have the time so I figured I would try and do it with a hand drill. But I guess I am not in any rush.

Thanks,

Colter