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Posted by: dax1969 Dec 14 2017, 07:08 AM

Hi guys,

Tried the search option but can't find what I'm looking for.

I know that the Cali 1976 914 2.0 has a smog pump/system to pass emission test. If such a system is not needed in your area, would you remove it or leave in place ?
Will you gain more power without this system ?

If you remove the pump should you only block of the lines with caps you can buy at AA or else or are there any other modifications needed ? Other exhaust ?

thks yr advise

krgds
Dax

Posted by: 914Sixer Dec 14 2017, 08:13 AM

All 75-76 have the smog pump and air injection system. I removed mine because it restricts the horsepower. You can cap the injection tubes. Remove all the plumbing and pump. Pump has a fan hub shaft at fails and there are no replacements at this time. Exhaust is also restrictive. Best to backdate to 73-74 exhaust. Late exhaust tend to fall apart. By removing all of that stuff you should be able to gain about 7 hp.

Posted by: 76-914 Dec 14 2017, 08:35 AM

True except the earlier heat exchangers are difficult to find and the ones on a 75-76 are most likely in good condition. I mention this only because you need good heat in Belgium. the plugs you need are std SAE pipe fittings and can be sources from most anywhere.

Posted by: McMark Dec 14 2017, 08:38 AM

If you don't need it, you can feel free to remove it.

I don't see a profound difference between with or without from a performance perspective.

The system pumps extra air into the exhaust to help burn any excess fuel while traveling down the exhaust pipe. This all happens after normal combustion, and so the pump doesn't interfere with or alter the way the engine runs. The only draw on the system is to run the pump. I have a hard time believing that a well maintained and smooth turning pump takes up 7hp, but I don't have any contrary data to support that. Regardless, that's all you're saving -- a minute amount of power to run the pump.

Leave it. Remove it. Either way won't make much difference. The process for plugging the ports in the heads is well documented in the search.

Posted by: 914Sixer Dec 14 2017, 09:27 AM

McMark,
Just going by factory specs, 73-74 2.0 made 95 hp and the 75-76 only made 88 hp.

Posted by: Beebo Kanelle Dec 14 2017, 10:29 AM

is the smog pump a rotary vane pump?

I've always thought about utilizing the smog pump to draw about 10" of crankcase vacuum.

Has anybody else thought about this?

Posted by: 914Sixer Dec 14 2017, 10:39 AM

FYI, there is a NOS smog pump over on theSamba.com $225.

Posted by: McMark Dec 14 2017, 11:34 AM

QUOTE(914Sixer @ Dec 14 2017, 10:27 AM)

McMark,
Just going by factory specs, 73-74 2.0 made 95 hp and the 75-76 only made 88 hp.

I suspect the exhaust had more to do with that than the Smog pump.

Posted by: oakdalecurtis Dec 14 2017, 11:47 AM

Hypothetically speaking, you could just loosen the smog pump swing bolt, reach in and remove the belt driving the smog pump, and leave everything else intact. That would give you all the "extra' horsepower lost by the engine from turning the smog pump while also saving wear and tear on the smog pump belt drive pulley on the front of the engine. Plus, you have the added advantage that if you ever wanted to restore the smog system for any reason, you just put the belt back on.

Posted by: dax1969 Dec 14 2017, 12:08 PM

QUOTE(oakdalecurtis @ Dec 14 2017, 06:47 PM)

Hypothetically speaking, you could just loosen the smog pump swing bolt, reach in and remove the belt driving the smog pump, and leave everything else intact. That would give you all the "extra' horsepower lost by the engine from turning the smog pump while also saving wear and tear on the smog pump belt drive pulley on the front of the engine. Plus, you have the added advantage that if you ever wanted to restore the smog system for any reason, you just put the belt back on.

Not a bad idea although we don’t need it here. If lights and brakes are working you pass tecnical inspection and get an O licenceplate

Posted by: shelby/914 Dec 14 2017, 01:25 PM

I also have a '76 which the previous owner removed all of the smog equipment. He left the air injection tubes in place and used brass caps and JB weld to plug them. Eventually one of the tubes blew out of the head taking all of the threads with it. I replaced the heads with a set of rebuilt '74s since it had previously blown a spark plug out on the other head which had to be helicoiled. Currently running '73/4 style SSI exhaust which seems to make a big difference. It also has Euro flat top pistons. Good luck.

Dan

Posted by: Vacca Rabite Dec 14 2017, 01:27 PM

Remove the belt, but also cap off the ports at the heads.
Backdate the exhaust. Will need earlier style heat exchangers and muffler.

That way you are retaining heat, finding lost HP, and can still easily bring up back to 75/76 stock with only an afternoons work.

Zach

Posted by: rdauenhauer Dec 14 2017, 05:34 PM

QUOTE(Vacca Rabite @ Dec 14 2017, 11:27 AM)

Remove the belt, but also cap off the ports at the heads.
Backdate the exhaust. Will need earlier style heat exchangers and muffler.

...& air guide tin and hanger and j tubes and ....ect.

Posted by: burton73 Dec 14 2017, 05:44 PM

This would be the 76 original paint car owned by me. Leamon changed out the broken smog pump and special Crank bracket for pulley for my car a couple of months ago and was driving it pretty hard. I have video that he texted me saying it runs great and he think he will just keep it! I tried to put it on here but could not get it to open

I personally could not find that it was any slower with the pump on of off as to the power. Not on a dynamometer but on my seat/butt dynamometer.

A picture from Lemons place.

Bob B

Posted by: mepstein Dec 14 2017, 05:46 PM

QUOTE(rdauenhauer @ Dec 14 2017, 06:34 PM)