Plugging EFI Injector Ports

[DionR]

I'm nearing the end of my cam swap and getting to the point of dropping the intake back on. The thing that is killing me is that I have a Hughes FI AirGap under my bed and I would really rather bolt that on now. But I don't plan to do the EFI swap until next fall, really don't want to chance the car being down all summer while I mess with that swap so sticking with the carb for now.

Anyone ever run an EFI intake with some kind of plug in the injector ports? I see offerings for such things, but no idea how to keep them in the ports.

Here's the intake:

I don't see a good way to hold them down.

Any ideas?

 

[DionR]

Something like this:

And then maybe a strap from intake bolt to intake bolt?

 

[Professor Fate]

Might look a little bit "hillbilly", but some appropriately sized expansion plugs should do the trick. They're only temporary.

You don't want to use any kind of drive-in plug that could score the bore and cause leakage issues when removed. Plus you'd probably have to remove the manifold again to drive them out, anyway.

 

[DionR]

Might look a little bit "hillbilly", but some appropriately sized expansion plugs should do the trick. They're only temporary.
View attachment 1715888890
You don't want to use any kind of drive-in plug that could score the bore and cause leakage issues when removed. Plus you'd probably have to remove the manifold again to drive them out, anyway.

They make those small enough? Like 9/16" just as a guess.

 

[DionR]

I wonder if something like this would work, but with a plug in it:

https://www.amazon.com/dp/B08G87D95R/?tag=fabo03-20

 

[Professor Fate]

They make those small enough? Like 9/16" just as a guess.

Grainger, for example, lists them all the way down to 1/4". A little shopping around would probably get you some in the right size for a lot cheaper than what they charge. I know they've got them at the hardware store, but don't know the range they carry offhand.

 

[DionR]

The push in plugs here are kind of cool:

Threadless

Not sure if they would work. But something like that with an added small blind hole between then injector holes to hold a flat plate down so the plug couldn't be pushed out if there were a backfire or something.

 

[408 swinger]

I ordered a Cascar gen 3 carb intake and received the fuelie model. I just installed the fuel rails with injectors to plug the holes. Currently running a carb. Probably looks tacky to some, but, it serves the purpose. Plus, when we do convert, that part is already done.

 

[pishta]

Just run those rubber plugs and use a bracket to hold them in. would be easy to put a bar across the plugs and just bolt it down as they are under vacuum 99% of the time.

Fuel Injector Boss Plug

 

[67Dart273]

Just run those rubber plugs and use a bracket to hold them in. would be easy to put a bar across the plugs and just bolt it down as they are under suction 99% of the time.
View attachment 1715889196
Fuel Injector Boss Plug

What I was thinking. Drill and tap a 8 or 10 machine screw hole between the injector ports and a small flat strap

 

[AUSA66]

I used the EFI hardware ones then turned them a bit shorter & drilled as suggested above.

 

[DionR]

I ordered a Cascar gen 3 carb intake and received the fuelie model. I just installed the fuel rails with injectors to plug the holes. Currently running a carb. Probably looks tacky to some, but, it serves the purpose. Plus, when we do convert, that part is already done.

I thought about that but almost certain that they would interfere with the throttle bracket. If I have to buy parts to make that work, then I will just wait and swap the intake when I go to EFI.

 

[DionR]

Just run those rubber plugs and use a bracket to hold them in.
View attachment 1715889196
Fuel Injector Boss Plug

Saw those and others similar, but only from a company in Australia or the UK. Not sure they would be here before summer is over and I am ready to do the swap.

would be easy to put a bar across the plugs and just bolt it down as they are under suction 99% of the time.

What I was thinking. Drill and tap a 8 or 10 machine screw hole between the injector ports and a small flat strap

I used the EFI hardware ones then turned them a bit shorter & drilled as suggested above.
View attachment 1715889220

Yep, that's what I started to think about as well. Doesn't look bad and, in theory, wouldn't be difficult.

I do hesitate to mod the intake for a temporary issue. I know it's not something that would cause a problem later, just a hesitation.

 

[pishta]

you could turn some 8-10mm rod down to 7.8mm at tip and push into an injector O-ring in your injector port. Adjust height to sit flush under retaining bar. See dim E

 

[DionR]

you could turn some 8-10mm rod down to 7.8mm at tip and push into an injector O-ring in your injector port. Adjust height to sit flush under retaining bar. See dim E
View attachment 1715889356

Interesting. I'd want some kind of step just to make sure the rod couldn't slide further down and drop into the intake tract.

Thanks for that, I didn't have any idea what the sizes were.

 

[TT5.9mag]

Doesn’t that intake use stock magnum fuel rails? If so just go to a junkyard and grab some magnum injectors and fuel rails and bolt them on. Push the injectors into the holes and don’t hook them up electronically.

 

[DionR]

Doesn’t that intake use stock magnum fuel rails? If so just go to a junkyard and grab some magnum injectors and fuel rails and bolt them on. Push the injectors into the holes and don’t hook them up electronically.

Don't see a way to run the throttle linkage bracket if I do that. I could be wrong, pretty sure they would interfere.

 

[TT5.9mag]

Don't see a way to run the throttle linkage bracket if I do that. I could be wrong, pretty sure they would interfere.

For a while Mopar sold an EFI kit for the magnum crate engines with a 4 barrel throttle body. I wonder how that kit oriented the throttle linkage. Might be worth looking in to.

 

[DionR]

For a while Mopar sold an EFI kit for the magnum crate engines with a 4 barrel throttle body. I wonder how that kit oriented the throttle linkage. Might be worth looking in to.
View attachment 1715889452

That's the same kit Ehrenburg used on the Savvy Savoy project. Looks like a home built bracket using one of the TB bolts?

 

[TT5.9mag]

There ya go. Nothing a little fabrication can’t fix.

 

[DionR]

There ya go. Nothing a little fabrication can’t fix.

Still not convinced everything would clear, but it is an idea. Can't rule it out.

I do have a buddy I have been prodding to see if he could make some plugs. Have some doubt it will pan out, but you never know. Hate to ask him to cut 8 of these things, just feels like a ton of work.

 

[DionR]

I should add that I lean towards running the current MP dual plane rather than a set of injectors to plug the holes. I don't have to run the RPM right now, it's not the only intake I have.

Like my buddy said; "How much am I willing to spend now to avoid having to swap the intake later?"

Not settled, but feels like injectors plugging the holes is more than I am willing to "spend".

 

[pishta]

Interesting. I'd want some kind of step just to make sure the rod couldn't slide further down and drop into the intake tract.

Thanks for that, I didn't have any idea what the sizes were.

...turn some 8-10mm rod down to 7.8mm at tip..." the O-ring will bottom in the injector boss and the plug will be captive. OEM's have the step, not sure if they cheaped out and just through drilled that intake. In that case use larger 15mm diameter that wont even go down the boss and finish the tip to 7.8mm. You could go real cheap and just get some 5/8 square stock by 12" and bolt it tight over the bungs ( Put a sheet of gasket material under it) if the top of the bungs is machined flat.

 

[diymirage]

why not just slap some injectors in there, and use the rail to hold them down?

as long as there is no power to them they are closed, no?

 

[pishta]

correct. no power, not open. Just plumb them for water/Meth injection off your windshield washer pump.....