Holley Sniper EFI for BBD Carbs

[Mancunian]

Unless you need to keep it original i doubt if you need the heater manifold, unless Texas is a lot colder than i remember.

 

[bigwalton]

Unless you need to keep it original i doubt if you need the heater manifold, unless Texas is a lot colder than i remember.

I was thinking this same thing.

great job on the thread

 

[ag4ever]

Unless you need to keep it original i doubt if you need the heater manifold, unless Texas is a lot colder than i remember.

I’d like to keep it if possible. Not so much because it gets cold, but it assists in fuel atomization while the engine warms up.

The way the intake heater works is:

If the coolant temp is under 140, the heating element relay is triggered. Once the engine warms up, the sensor that triggers the heating element relay opens and it turns off. At this point, the coolant is circulating through the intake keeping it warm.

If this was multi point injection with the injectors spraying on the back of intake valves I would not need it. But since this is a throttle body injection system with the injector spraying above the throttle plates, there is a good chance the fine mist created by the injectors will turn into liquid as it hits obstructions. The heating element just helps it stay in vapor form while the engine warms up.

It is not essential, but it is beneficial.

 

[ag4ever]

Not much of an update, I’ve been on hold due to the intake heater issue.

I ordered a replacement on e-boy, and it came in today.

I stripped it down, and now have a (mostly) good heater. The insulation on the wire is suspect.



Interesting, during my research, I discovered that this same heating element was used in mk2 VW golfs. They refer to it as the “hedgehog” heater. Wonder why?



Notice the “Germany”? I’ll bet the AMC engineers “borrowed“ the idea from somebody else.

 

[ag4ever]

I also collected some heater hose ports for the intake. The ones on my “junk” intake were trash. I did not want to pull the ones off my original intake. Luckily the new intake had some really nice ones. But I still have these new ones as options.



I’ll probably use the Dorman 56365 (straight) and the Murray 84728 (45 degree) fittings. But I’ll decide once the intake is mounted and hoses are reconnected.

 

[ag4ever]

Intake is painted, ready for reassembly.

 

[ag4ever]

Rebuilt the intake heater with a salvaged wire from the destroyed heater because the original wire had bad insulation.





Greased the heater o-ring with some super lube.



After I installed the heater twice (forgot the paper gasket the first time).

 

[ag4ever]

I was planning to rivet the cover plate on the heater, but the 1/16” rivets were too small. I think 3/32” rivet would be perfect.

I was going to use this rivet system for jewelry Making.

 

[ag4ever]

Next, prep the new exhaust manifold.

Install the air tube plugs using copper anti seize, along with the egr tube using the same anti seize on the threads and between the pipe and fitting.

 

[ag4ever]

Then work on the stove pipe.

I had to fix one of the mounting holes as it was rusted out.



After painting with a high temp coating, reinstall with drive rivets.

 

[93_Fummins]

 

[Mancunian]

Where did you get the EGR pipe? Mine was seized solid at the manifold side and I was afraid to pull on it with no replacement.

 

[ag4ever]

Collins Brothers

 

[Mancunian]

Apparently my searching isn't up to snuff

 

[ag4ever]

I finally got back to work on this one. I might be getting close to actually installing the EFI. Go figure.

In getting it buttoned back up, I tested the charcoal vapor canister, and the purge line does not hold vacuum. So I ordered a NOS DeLorean time machine Carbon Canister.















Unfortunately, it does not hold vacuum either. It holds better, but not great. The original one holds ZERO, the vacuum gauge never moves off 0. The DeLorean one registers vacuum, but bleeds it all off in a couple seconds.

So, I just put the stock one back in and ordered a purge valve for a early 90’s Chevrolet Caprice.

The plan is to cap the carb vent port and the purge signal port. Connect the fuel tank to the canister in the stock location and purge port to the new valve.

Too bad, I was hoping to have the first time machine scrambler. (On a side note, I have a family friend that used to work at DeLorean. He would get a loaner vehicle every now and then and his favorite one to borrow was the replica time machine with the mr fusion and a fog machine.)

 

[ag4ever]

Got the exhaust manifold and intake manifold bolted on. No real issues there except I had to trim the intake gasket. It did not clear the exhaust manifold.

 

[ag4ever]

Next up is repopulating the intake manifold with all the ports and sensors.

I decided to use the 45 degree heater hose port in the front and the long straight fitting for the rear heater hose port.

Before installing the CTO valve or the heater grid temperature switch I tested them.

Heated up some water, pull a vacuum on the CTO, place in the hot water. It should hold vacuum while “cold” and flow when warm.

The intake heater switch should be NC when cold and go open when warm.

 

[ag4ever]

Got all those bolted on, new egr valve bolted on, the Holley temperature sensor installed in the factory computer temp sensor port (front one), the O2 sensor bolted in the factory port in the manifold, the power steering pump bolted back on, and the throttle bracket bolted back on.

Next up, mounting the surge tank.

I decided to mount it on the passenger fender (drivers side for you Americans ). The bottom is bolted to the fender. For the top, I am making a bracket from strap aluminum. I bent it around a 1 13/16” socket to get a nice radius. Once this is bolted in place it will be time to start running hoses.

 

[gr8dain]

Loving the progress! Looks great!

 

[spankrjs]

Does the Sniper throttle body have the low pressure vacuum port, like a GM TBI set up, for the purge canister to go to? If so, just buy a purge canister for a GM TBI truck. Two hook ups: one from tank, one to purge port. I did this on my old Tan Scrambler, plus a few Howell TBI installs, works perfect.