Some belt help please

[e9Leveque]

I am beginning to reassemble the cooling system/alternator/PS pump after having taken it all apart, cleaned, new parts, etc, and I'm running into a bit of an issue.

Background: my vehicle is a 1972 euro CSi. The crankshaft pulley is one belt (162 mm), the old water pump pulley was two belt (144 outer/102 inner). I do not have AC. The two belts were previously arranged as one belt around crankshaft - outer WP - alternator, with the second belt being inner WP - PS pump. I had followed the plan for upgrading the cooling with a newer water pump, had gotten the Gen3 SFDon version with viscous fan clutch, shroud, etc. I installed the newer water pump and thermostat and given the discussion about reducing the pulley size, I had gotten a 130 mm pulley from Don. I don't think I realized that since this was a single pulley, I now no longer had a way to run my PS pump.

It would appear I have two options and I'm hoping you guys can help me decide on the best one.
1. Use my old WP pulley and just set everything back up as it was belt-wise.
2. Keep the single WP pulley and change the crankshaft pulley to a double-belt one. I don't know how easy that is to find or how obnoxious it would be to change with the engine in the car. The radiator and everything else is out so I have room, but the last time I changed a crankshaft pulley it was on an engine on a stand.

I suppose a third option is to remove the power steering, but I'm not overly concerned about the weight and I'd rather keep the PS intact.

And since I have you...
Given the suggestion of some here, I had upgraded the power steering pump, mine was making a bit of noise and was essentially caked in grime. Somehow (and I may have misinterpreted some comments/suggestions made in some of the PS threads) I ordered a PS pump that fits an E24/E28/E30 as a more modern version of the NLA E9 pump. I know that these engines have a lot of other interchangeable parts with the E9 engine, and this PS pump certainly fits into place and has the appropriate connections to hook it in. The wrinkle is that it accepts a 3-bolt pulley instead of the center-nut 125 mm pulley that is currently on the original pump. Option here I suppose is to return that pump and have mine rebuilt, or can I use an equivalent-sized E24/28 pulley?

Thanks all, I appreciate the help here. I suppose I could have just left well enough alone, but I am enjoying this process and the parts that I have thus far completed are looking and working quite well.

 

[sfdon]

The damper and crank pulley are a breeze to remove with engine in car.

Very little torque on those bolts.

BUT- the holes are NOT symmetrical…. Which you will find out when you go to install a later damper and pulley. Index and mark!

I’m in Frankfurt- heading home today.

Call if you need to discuss starting Monday.

I have 10 finished engines on stands if you want pics

 

[TomHom]

....have a nice and safe journey back!

 

[HB Chris]

You have me confused with the existing belts. The crank drives the large pulley on the WP which you call Outer, I assume that is what you mean, and then the Alt. WP drives PS from smaller pulley. (In 74 the crank drove the PS pump)

In both my e3 and e9 I have the stock configuration and have never seen the need to change pulley sizes or add a shroud (which was introduced in 74). I drove my coupe to New Mexico and Colorado in July 2024 and it was 100 degrees and it never over heated, the temp stayed at 3:00, and I used the a/c as well. The key to me at least is to have a good radiator, either new or recored, rodding them out helps but I don’t think it gets the same result.

 

[rsporsche]

it all depends on what alternator / ps bracket that is being used on the coupe. with my 3.5L, i went with the new alternator bracket which is also a PS bracket, and requires the e28 PS pump and alternator. the e28 pump runs off of the crank. with this configuration, the alternator + ps belts would be the standard e28 belts.

 

[Stevehose]

If you add the pulley to the crank hub to drive the PS pump, you'll need to adjust the PS pump alignment either through the later E12/24/28 (I think) bracket, or configure some spacers like I did.

 

[e9Leveque]

Yes, I think where I drifted off course was that I was following @rsporsche’s very thorough description and have the E28 version of things as he clearly described above, but I hadn’t stopped to consider that in changing my water pump pulley to a single rather than double, I now had no way to drive the PS pump. I’ll reach out to @sfdon when he is back and will change my crank pulley. The other wrinkle is that with many of the previous changes I have been able to swap pulleys from old part to new part, but the E28 PS pump is a 3-bolt attachment while the original is a single nut. So I’ll figure out what E28 pulley will work best based on sizing, unless someone here happens to know offhand or in your records. It looks like there were 2 or 3 options for that E28 pulley. I do have the new bracket so I think I’m ok there, but yes, I may also need to adjust some offset to ensure that the correct belt is lined up with the correct pulley.
Regarding @hbchris’s statements above, yes it’s true that the system as I bought it was likely fine. My five-blade fan did look a bit worn however, and given that with both of my previous cars (E39 and MGA) there seems to be a general statement of “add an upgraded fan”, which I had done on both of those, following that same advice here made sense. Perhaps overkill especially for my milder Seattle weather but at least now I know I’m covered.