Mark

Dangit - I wrote it down...can't find it...

Searched the archives....can't find it...

My smog pump is about to die...does somebody have the correct number for the smaller belt so I can just run the fan....

BrianG

Mark:
Pull the pump, open it up and gut it. Replace the bearings. You'll still have a decent belt adjuster, and no drag.

Mark

Brian - I would do that...BUT - this is a 'temporary' thing I want to do until I convert to an electric fan...so...I figure I'll just go with the shorty belt for the time being

BrianG

I am curious as to why you would want to convert to an electric fan?

Perhaps I'm just getting old, but I really don't understand this pervasive desire to re-engineer a car as sophisticated as the 928. Especially if that means adding to the already complex and apparently failure prone electrical system in this car. <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" /> That thread about the electric water pump revealed that one would spend substantial time and effort to reduce the reliability of a critical system, which is NOT known for eating much HP, nor for being particularly fragile. Here, the proposal is to replace a simple, reliable, efficient, rebuildable system with a more complex less efficient (%age of rad shrouded) throw-away system that will cost time and money to execute.... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />

Uh..... I re-read that, and I think I AM just gettin old!! RANT OFF <img border="0" alt="[icon501]" title="" src="graemlins/icon501.gif" />

Maybe I'll just head to the garage and go iron some gaskets!! <img border="0" alt="[thumbsup]" title="" src="graemlins/bigok.gif" />

Mark

One less belt and fan = less drag on engine = more HP!

Mark

Brian - JUST IN CASE I change my mind...where did you find the pump bearings...and how much were they...

BrianG

They are just standard bearings...... available, here in Canada, at any automotive supply house. Actually, I ordered a few bearings for this timing belt project, and they did have to order a couple that were not in their stock, but I live in a town of 6000 people, and these guys don't have a huge stock.

Thom1

Hi Sharks:

See:
<a href="http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=14&t=003368&p=" target="_blank">http://forums.rennlist.com/cgi-bin/rennforums/ultimatebb.cgi?ubb=get_topic&f=14&t=003368&p=</a>

<a href="http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=14&t=002543" target="_blank">http://forums.rennlist.com/forums/ultimatebb.php?ubb=get_topic&f=14&t=002543</a>

Car Quest stores can get belts next day or same day. For my 86 model, the 20" version works perfectly for air pump elimination. Specifically: Belt 6820, 1/2" x 20", 12.5/13mm x 510mm, cost $9. They let me take the 21" belt home to try while the 20" was on order. They even ordered a 19" just in case the 20” did not work. They let me exchange belts at no extra charge. I have read and heard that the 21” works for some models, but cannot confirm that. I did not need long bolts to do the job. The fan bracket bolted back up very easily, and created tension on the belt as it became tighter.

This is just a temporary solution. The belt will stretch, and may become ineffective. There is no adjustment. I will reinstall another smog pump.

Now, who knows the specs for the BEARINGS/rollers for the smog pump??? There are needle bearings on one end. I have not dismantled the pump completely to reveal the pulley end bearings. It looks like I just whack the shaft to drive it back through the bearing from the pulley side toward the inside of the pump. Has anyone does this? Does the pulley side use needle or ball bearings? Can I order the bearings over the internet? How do I pull doughnut shaped bearings such as these? I do not have access to the back side to tap them out.

Thanks to the people who have addressed some of these issues before. I am looking for additional tips too.

Any answers would be helpful.
<img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />

BrianG

Thom:
I'm going to open my AIR pump tonight. I'll let you know what I find.

Bernie

Airpump Rebuild Procedure

<a href="http://members.rennlist.com/mgrasser/airpumprebuild.htm" target="_blank">http://members.rennlist.com/mgrasser/airpumprebuild.htm</a>

C/O Mr Grassar

Cheers

BrianG

Yikes..... these certainly are NOT the usual caged ball bearings. <img border="0" title="" alt="[Eek!]" src="eek.gif" />

This is an interesting unit... I wonder if I pipe the hose to the air-filter housing............ <img border="0" alt="[burnout]" title="" src="graemlins/burnout.gif" />

Sias

Brian, I believe it is possible to pipe the hose to the air-filter housing. Tom Cloutier is making me a Avenger II system now and that was one of the suggestions made by him when we discussed the various options.
Sias
85 928S 5 spd

BrianG

Actually, Sias, that was just a joke. If you look inside the AIR pump, you will soon see that it won't move enough air for your engine to notice the difference at the induction side. It is direct drive, meaning pretty low RPM, and awefully low volume.

Sias

Brian, agree with what you say, his suggestion was to hook up the hose rather than leaving it "open". Wish it did pump enough air like a supercharger!!! It may be noisy if left open, I don't know yet! I will be going down this path shortly when I install the new exhaust.
Sias
85 928S 5 spd

BrianG

Ah, sorry Sias.

My mechanic suggested just short-circuting the air lines and make it pump in it's own little circle.

It IS quite noisy if left open!! In fact, I thought I'd sprung an exhaust leak! <img border="0" alt="[ouch]" title="" src="graemlins/c.gif" />