Time for EFI on the '79

[Anthony10370]

So as some of you know, I recently rebuilt/resealed my 4.5 on the '79.

Well it's time to get it running again and I just don't feel like dealing with the CIS system, especially considering the cost of replacement parts. So I have decided to install EFI using a Megasquirt 3 and a wideband oxygen sensor.

Here are the parts that came with the kit; I go the DIY assemble main board so I had to solder all the components in place.

[dcrasta]

Looks like a pro assembly job. Keep us posted (Subscribing to this!)

[Pete R]

Seriously, keep updating. I've been thinking about doing this myself. I'm curious about the injectors. Will they fit in the CIS injector location?

[Anthony10370]

Will Do! Also the injectors will not fit because the original CIS manifold had threaded ports for the fuel injectors. I am going to have to machine the manifold shorter and fabricate the fuel rail. I am seriously considering using side flow injectors because this will allow me to affix the fuel rail directly to the manifold and install the injector from above.

[Pete R]

Originally Posted by Anthony10370

Will Do! Also the injectors will not fit because the original CIS manifold had threaded ports for the fuel injectors. I am going to have to machine the manifold shorter and fabricate the fuel rail. I am seriously considering using side flow injectors because this will allow me to affix the fuel rail directly to the manifold and install the injector from above.

that's what I was worried about. I don't want to use different runners because I have the big Euro ones. can't wait to see what you do.

[kelanel]

theres an ms3 conversion in progress on an 80 euro that you might find some good notes from since its also a cis conversion. i believe he had sleeves fabricated to thread into the runners threads. link here. one of the posts mentions using this which is equivalent to the ones fabricated. looking forward to your solutions and updates!

Best of luck,
Jonathan.

[AirtekHVAC]

I am also subscribing....very cool.

[Anthony10370]

Ok so almost a year and a half since posting on the EFI conversion. Sorry about that, I encountered unemployment and got discouraged, but I'm back working on it again. Also thanks to Kelanel for the link to the list, It's nice to see someone else's take on the EFI conversion.

I decided to go with Bosch Generation 3 injectors due to the reliability and availability and ended up buying a set of 19# and 36# injectors (36# for... future projects mwahaha), and decided to fabricate fuel rails and modify the current intake runners to accept the new injectors.

Here are a couple pictures of one or two of the intake runners being modified. I used a 7/8 bit in the drill press to drill the stops past the threads in the runners and drilled pieces of 7/8 aluminum rod with a 1/2 and a 35/64 drill bit to create the lower injector bungs. These will get brazed/soldered in to the intake runners. I also "ported" the runners below the injectors to allow for better fuel atomization.

[MPDano]

Awesome. Make sure to post how much you are spending on this conversion. Keep this thread going.

[8bender]

very nice

good luck

[Anthony10370]

Here are some of the prices I've added so far, I'll try to keep a running total as the project rolls on. All the prices I add will include taxes and/or shipping. I wont add many of the prices for things I have bought for scrapped ideas as they are hard to keep track of but I'll try to come up with a rough estimate at the end of the project. I also wont include the price of the 36lb injectors (~$100) in the total because they are for a later project.

Mega squirt 3 diy kit: $400.00 (dealer)
Wideband oxygen sensor kit: $200.00 (dealer)
19lb Bosch gen 3 fuel injectors: $48.71 (used from an online auction site)
Bosch gen 3 injector rebuild kit $18.25 (online auction site)
7/8 aluminum bar stock: $10.43 (online auction site)
3/4 brass bar stock: $13.89 (online auction site)
70 mm throttle body w/TPS: $35.70 (junk yard)
35/64" drill bit: $21.75 (industrial supply)
square steel tubing: $6.07 (hardware store)
3" cone filter: $9.50 (online auction site)
3/8" brass hose barbs: $24.98 (online auction site)
Silicon bronze TIG brazing rod: $32.48 (welding supply)
Other welding supplies: $ Approx $50.00?
EV1 EFI connectors: $FREE (a friends scrapped VWs)
Fuel pressure regulators: 1 for $8.26 (junkyard) 1 free from a friends scrapped nissan
IAT sensor W/Pigtail $8.14 (junkyard)
Steel 3/16x2" flat bar $11.93 (hardware store)
coolant hose (for intake boots) $48.25 (auto store)
coolant temp sensor: $8.00 (Pelican Parts)

Total: $956.34

Wow that adds up fast.

[Anthony10370]

Ok so I put the project down for a while again, sorry for the lapses in posting, I have been dealing with some unemployment and depression. But enough about that.

I finished installing the manifold bungs and surfaced the manifold with a flap disc since the sealing surface is internal. I made some injector retainers out of some extruded aluminum flat bar, and I am about to check the injector fitment and alignment. Once that is done I have to drill and tap the manifold for the screws to hold the injector retainers.

I then plan to drill and braze the fuel rails later today. I used a common grey high temp epoxy to make sure the bungs are really sealed to the manifold as I don't completely trust the aluminum "brazing" rod.

Here are some Pics.

[Anthony10370]

Just to clarify the fuel RAIL is made from steel tubing and brass bungs; and is being TIG brazed using silicon bronze. There is no "epoxy" on ANY high pressure part. I am going to pressure test it to 100-120 psi before installing it in the engine bay!

[AirtekHVAC]

Great work....I totally feel ya on the unemployment / depression...I am still battling it myself, although the unemployment issue is resolved....hang in there.....my 928 has been very therapeutic.

Very interested in this project...keep us posted.

[Anthony10370]

Didn't finish brazing the fuel rails today, I was able to drill and tack the driver's side rail, but after some perfect tacks I kept making horrible welds and ground off most of the material.

[Anthony10370]

I effing hate this car. I'm at my wits' end with this fuel rail build. I've bought side flow fuel rails, which didn't work, had an @$$ munching time making/fitting the manifold bungs, and have tried several different ideas for fuel rails and fuel rail bungs; the latest being some brass plumbing fittings that have a good smooth inner diameter for o-rings. My efforts at TIG brazing them have utterly failed, so I went and bought some "silver bearing solder" and flux and tried silver soldering them. Which also failed. what the hell am i doing wrong? Is this car cursed?

I will add that both the TIG brazing and silver soldering worked on test joints. I have a degree in automotive repair and have fixed hundreds of cars over the last couple years; but this car is a little (statement revised for PR)

Here are some pics of my brazing and soldering attempts.

Perfect tacks:



Is that a braze?



"silver solder"

[AirtekHVAC]

Hmmm, when brazing steel to brass or copper, I always use eutectic rod. It is a silver solder with flux coating...I do not know how to tig tho'.....is the rail aluminum, or steel? Some metals just don't like to bond to one another......

[tmpusfugit]

Both silver soldering (which is actually a lower temperature brazing) and brazing require the work pieces to be close to cherry red before the brazing rod or silver solder flows. And it will flow pretty much like a liquid, not sit in clumps like your examples. I am not certain that TIG and brazing are compatible, at least they are not in my opinion, but, I do not have a TIG so I could be wrong. On the other hand I have done a lot of brazing. The two metal surfaces have to be clean, if there is any plating it must be removed completely, correct flux needs to be used, and care need be taken to not overheat the metals, if you get them too hot the flux will burn off and the brazing material will burn/oxidize and you will have a mess. Don't think brazing is difficult, it is not, as mentioned I have done a lot of it with a normal acetylene torch. Just a bit of practice with acetylene and clean metal and I think you will be happy with the results....I use acid to clean steel to remove cad plating or galvanized flashing or zinc coating. Given you want to braze the brass to steel I would use the silver solder, but I think you will not have good results until you heat the entire joint area to the melt temps of the "solder", it will then flow. To actually use brass brazing rod you would have to approach the melt temps of the brass and that is likely to cause failure....

[Anthony10370]

Ah I see, it turns out that the flux I was using had horrible ratings, and people were saying that it was pretty useless for anything other than copper.

"Both silver soldering (which is actually a lower temperature brazing) and brazing require the work pieces to be close to cherry red before..."

Thanks for the info, I looked at the concentrations and found out that the solder I have is about 4-5 % silver, as opposed to the 50-60 % in actual silver solder; which explains why it failed my (unscientific) ball peen hammer test in the test joint.

I had the metal clean as clean as I could get it with a flap disc, but just for the hell of i I went and bought a super aggressive stainless wire wheel (the one with the knots) and cleaned the surfaces with that. I also turned the argon flow down, sharpened the tungsten way sharper than I ever would for welding steel, and turned the amperage up to about 35A.

TIG and brazing are compatible under some very specific conditions. The filler I am using is 3/32" silicon-bronze, and you have to run pure argon, and set up the welder for DCEN. You cannot use flux but the argon acts as flux.

I will also add that I avoid oxy torches like the plague.

Ladies and gentleman; I give you TIG braze 2.0

[tmpusfugit]

That looks great! Glad you found a solution and I learned something about TIG....I suspect I should avoid it at all costs, but it sure worked well for this effort....