Anyone know what size holes I need to drill for injector bosses? Is it a straight thru hole, or does it have features (counter bored, grooved)? I got this neat little GM intake with cast injector bosses that are not drilled out ... yet, and I need to mount 40lbs/hr (GM style) injectors. I searched here and everywhere, but I can't find an answer. Thanks!

 

We just had an M1 mopar manifold converted, but i cant find their info. Call up Hogan's 805-928-8483,theyre local and probably have all the info you need.I know you would want to have some sort of fixture to insure proper angle and symmetry cylinder to cylinder.Not much help-- but i know someone'll have that info on this board.

 

I measured the OE LT1 injector bores at about .540 to .545". It's a good idea to put a bevel at the top of the bore so the o-rings don't get damaged, as well as a 'step' at the bottom of the injector bore to limit how low the injector sits in the manifold.

 

To do it correctly you need bungs and they should be welded in.

bret

 

Well I found out no bungs are needed and it is a simple machining job. My machinist will be using an LS1 intake as a sample and will have it done by next week ... as well as facing off the carb/throttle body mount. The weld in bungs are mainly for sheet metal intakes or if you need to change the angle of the fuel spray.

Thanks all!

 

Bite's tongue on that one

..move along everyone nothing too see here
what was the name of that movie? blood on the tracks ...hahaha

 

 

Nice one Hawk....

Must be I waste my time making $10 injector bungs on a CNC machine here.... god I wish I had actually converted some single planes to EFI before.... hmmm

Bret

 

MSD sells a cutter for a mill. Its expensive, but its designed to do just what your're after. Maybe you can find someone to go in with you, or an interested machine shop.

http://www.msdignition.com/fuel_10.htm

 

Production tool supply makes a injector bung drill.

 

No worries guys, it is done! This is not a standard carb intake that I am using, it is an LS1/6 GMPP intake exclusively designed for EFI. It already has the bosses for the injectors ... unlike standard carb intake without bosses that require the injector bungs to be welded ... they are undrilled for those who want to convert an LS1/6 engine to carb. Otherwise you would have to plug those up. My machinist used an LS1 intake to get all the dimensions and it came out great! Edelbrock makes this intake for GM and they will be releasing it as mine is now, drilled for injectors without the need for welded in bosses.

Since some of you don't understand what I am talking about, here you go:
http://www.gmpartsdepot.com/store/pr...ategory_ID=11&

Thanks to the others for your help! No thanks to the others.

 

Yeah we got you with that intake... only way to go other than the FAST on a LS1.

Most intakes don't give you enough material to use that MSD tool and get a good injector angle at the valve.

Bret