225 slant 6 Port fuel injection

[Kory Kramer]

I am new to the slant 6 but have been a gearhead my whole life. I am rebuilding a 225 slant six with my son for his 68 Duster. I am looking into installing port fuel injection instead of a carburetor. Iv'e been told that the throttle body style isn't that good due to the long intake runners used on this engine so port injection sounds better. That being said I found a manifold but I have no idea what I can get as far as a kit or individual components to get it done. I do have experience in tuning this type of system on Motorcycles so I'm not a newbie just a newbie in this engine any help would be great.

 

[pishta]

What manifold did you find? MPFI can be done with ANY intake manifold if you put the injector bungs in the head right through the water jacket, into roof of the intake port. Just drill them out .750 with a hole saw and epoxy .750 OD injector bungs into them making sure the epoxy seals the top and bottom seams. run a TB off the carb flange and your set. Use a Caddy/Buick/Olds Northstar Stainless fuel rail and cut/weld it to make it a straight 6, the spacing is perfect.

 

[rustycowll69]

where do you get the injector bungs? I'd love to see/hear more details.

 

[67Dart273]

I would not discount TBI depending on how in depth you are willing to go, and "the money." Start by reading the "stuff" on the tech page over at Binder Planet. And Pishta.........he's got some good ideas

...........Start with the "Start Here" link.......

Injection Tech

 

[my68barracuda]

I am new to the slant 6 but have been a gearhead my whole life. I am rebuilding a 225 slant six with my son for his 68 Duster. I am looking into installing port fuel injection instead of a carburetor. Iv'e been told that the throttle body style isn't that good due to the long intake runners used on this engine so port injection sounds better. That being said I found a manifold but I have no idea what I can get as far as a kit or individual components to get it done. I do have experience in tuning this type of system on Motorcycles so I'm not a newbie just a newbie in this engine any help would be great.

I run MPFI on the slant in my 68 Barracuda. I drilled the nitrous bosses in a Clifford intake to accept the injectors. Gill Welding (google that or they post over at slant six.org) is a good source for a fuel rail and other fabricated Slant Six MPFI components. For an ECU I run a MegaSquirt MS3 Pro. That ECU has extensive fuel injection, ignition timing and vehicle control capability built into it. MegaSquirt also has less expensive options. For info on MegaSquirt systems google DIYAUTOTUNE.

Tanks Inc. has an in tank fuel pump ready A body fuel tank that works well with MPFI.

Pishta, I remember that you built that head with the port mounted injectors several years ago. Did it ever make it onto an actual running engine?

 

[rustycowll69]

I run mpfi on the slant in my 68 Barracuda. I drilled the nitrous bosses in a Clifford intake to accept the injectors. Gill Welding (google that or they post over at slant six.org) is a good source for a fuel rail. For an ECU I run a MegaSquirt MS3 Pro. That ECU has extensive fuel injection, ignition timing and vehicle control capability built into it. MegaSquirt also has less expensive options. For info on MegaSquirt systems google DIYAUTOTUNE.

Pishta, I remember that you built that head with the port mounted injectors several years ago. Did it ever make it onto an actual running engine?

so, how did your conversion come out. I'm interested, but I want to hear the pros and cons, before I undertake such an ambitious mod.

 

[pishta]

**** got heavy and the build got put on the back burner. It's complete, ready for a controller and about 2 more hours of wiring but yeah...just other things popped up. Probably get it up and running in a night if I had a helper who knew MS. Trouble with MS is when you look for support, 5 guys will tell you 5 ways to get it to work and you never know which one will work with what you wired up, stuff stacks up. Also support for MS1/2 is drying up fast, everyone is jumping on the MS3 wagon. Great controller but its 5X the startup price, approaching the cost of the "bolt on" adapted units spoken about here form time to time. Looking seriously into Speed-uino now: sort of a back to 'open source' basics approach, very inexpensive and a vibrant support base. Arduino brings a powerful controller on a very flexible I/O board for like $18! From that, get another $20 plug in PC board plus passives and build your own EFI controller.

 

[my68barracuda]

**** got heavy and the build got put on the back burner. It's complete, ready for a controller and about 2 more hours of wiring but yeah...just other things popped up. Probably get it up and running in a night if I had a helper who knew MS. Trouble with MS is when you look for support, 5 guys will tell you 5 ways to get it to work and you never know which one will work with what you wired up, stuff stacks up. Also support for MS1/2 is drying up fast, everyone is jumping on the MS3 wagon. Great controller but its 5X the startup price, approaching the cost of the "bolt on" adapted units spoken about here form time to time. Looking seriously into Speed-uino now: sort of a back to 'open source' basics approach, very inexpensive and a vibrant support base. Arduino brings a powerful controller on a very flexible I/O board for like $18! From that, get another $20 plug in PC board plus passives and build your own EFI controller.

I would help anyway I can, are your questions concerning install and set up or configuration? There also is an active online support forum at msextra.com
I know a couple of guys that are running MS1 and MS2 very successfully that could also assist.

 

[my68barracuda]

so, how did your conversion come out. I'm interested, but I want to hear the pros and cons, before I undertake such an ambitious mod.

I have ran it as a race only drag car in the slant six. org race series for the past couple of years. I am currently in the process of remaking the car into one that is still race capable, but one that I can drive to the track, cross country included.
The MS ECU has been without issue. The ability to data log and adjust a/f ratios and or ignition timing with a few keystrokes on a lap top is a huge aid at the track.
I am using a locked Lean Burn distributor as a ignition timing source in place of a crank position sensor and a MSD box / MSD coil as a spark source.
The MS3 Pro has built in: rev limiters, launch controls via either fuel or spark cut, that integrate easily with either a trans brake or line locks, electric radiator fan controls, and more.
The downside is if you are doing your own install, you need to be competent in routing and running the wiring harness. There is a writing harness supplied, but the installer has to route it to each injector, throttle position sensor, air temp sensor, IAC, MAP, CLT, fuel pump, power, ground and more if you are running launch control or other options. A bad install/wire routing is not fixable with software. My install has been good, but I can see where the level of detail required is not for everyone and those folks would be better off with TB units.