I have a 1970 I am restoring and modifying. I was wondering about the smog pump. I am converting to tripple dellorhto carbs. Do I need the smog pump. Is there a way to bypass? Will it benefit to do so, or should I leave it alone. Any thoughts?

Mark

My understanding is all that the smog pump did back in those days was to blow cold air into the exhaust stream which may have stopped or reduced a reaction that was creating some nasty emissions. Also remember that back then we had that leaded gas which made some interesting emissions that the smog pump may have been reducing.

I would not think that it would alter the performance other that to gain the HP back that you loose running the pump. I have a 71 that the prior owner removes the pump and I am unaware of any problems.

I put out the smog pump in both my '72 240Z without any problems. I also changed - but that's not necessary - the three dic damper to a 2 disc damper (called Euro damper).

Rolf

Doehring

Did you notice any improvement in power when you removed the pump and changed the damper?

Mark

mmagnus,

soory, I can't answer that because at the same time I got rid of the original cooling fan, the original fuel pump and the original header and exhaust. In 1 Z I also changed the SU's to Triple SK carbs a little later. I also changed clutch and bushings. So the cars got a very different "feeling".

I don't think the smog pump costs much hp, but it is weight, makes things more complicated and isn't necessary. I do not even believe that it did some good to the environment because it didn't decrease the total CO2 and other emiisions, it just fooled the measuring instruments by mixing some fresh air under pressure to the engine's emissions.

Rolf

Thanks Rolf. I think I am going to remove it anyway. I am going with a similar set that you have and I think it will give it a cleaner look if nothing else.

Mark

I put out the smog pump in both my '72 240Z without any problems. I also changed - but that's not necessary - the three dic damper to a 2 disc damper (called Euro damper).

Rolf

What is a "damper"

The front crank pulley or damper. They had three different pulleys available if I remember right, a one groove, two groove and a three groove damper. L series used a one piece pulley/crank damper unit while some other manufacturers use a two piece set where the pulleys are bolted to the damper as a separate unit.

I put my smog pump in the trash can the day I got home with the car.

My smog pump was also disconnecected when I got my 240Z last year. One hose was disconnected, but what about the others. can you just cap off the places were they go into or do you need to put some kindof breather filter over them.

THe pump is removed on my 71 240Z and a 2" remaining section of hose on the air rail is plugged with a large bolt held in place with a hose clamp

I normally left the hose from the block to the air cleaner connected and blocked all the other hoses off. Best to let the crankcase vent if possible. Unless you are using a different style of air cleaner. Then it might be best to put a filter of some type on it at the block. Just my opinion.....