230SL 4 Blade Fan Spacer?!

[captainslow]

Hello!

I just saw a photo on the forum of a black and white 230 engine and saw to my dismay it has a spacer between the fan pulley and the fan itself.  I had assumed the fan mounted directly to the pulley.  I was also under the impression the only spacers were on the 280 short shaft pumps so they could get away with using the long water pump pulley.  I am working on repackaging an aftermarket HD fan clutch from Hayden on my 230 and I am trying to get the fan as close to possible as the original location.  Does anyone know the height of this spacer? If someone has a 230 laying around with the original 4 blade fan and would volunteer to take some other measurements for me that would be awesome!

[dirkbalter]

That’s what the spacer looks like.

[dirkbalter]

Some more detail. Let me know if you need more?
Material is aluminum.

[captainslow]

Dirk I owe you a beer if you are ever in Portland, and I genuinely mean that!!  Is the mounting surface in the center of the fan blades or biased to the back or front side?  I think I'm going to try and order a 5 or 6 blade metal fan.  Not to be too needy but if you have the fan handy it would be nice to know the X direction or depth of the fan (front to back) and then from say the forward lip, to the start of the blade and then the depth to the end of the blade.  I'm not sure I need pitch because that can be played with based on the number of blades.  From what I've seen the 9 blade fans are 460mm in diameter so I assume the 230 one is as well.  I just need to make sure the spinny bits don't hit the stationary bits!  I'm going to talk to Horton this week about their VS121 fan clutch to see if I can come up with a base flange that will work on a 4 bolt water pump.  If its not cost prohibitive I'd rather go with Horton over URO, they make good products in the commercial vehicle space.  I'm hoping they can provide me a clutch without a flange that just needs to be pressed together.

[dirkbalter]

The 230 air filter housing or surround is bigger than the later ones. I also installed a 9 blade fan in a 4 bolt pump and had to trim the OD of the fan a bit. The 230 fan OD is approx. 430mm. I used a visco clutch on a long water pump which made up for the spacer distance. The front face of the fan to the rear of the spacer is approx. 55.5mm.

[captainslow]

Interesting... Are you using a Uro fan clutch? I had my radiator rebuilt down at the brass works (they did a fantastic job), I had sent them the cardboard fan shroud from Buds to add the mounting tabs and they actually made a metal one for me, I didn't even have to ask!  The shroud diameter is ~ 480mm so I should be able to accommodate the larger diameter 9 blade fan if it comes down to that.  For the 230 fan, is the mounting surface of the fan passing through the center of the fan body?  To me it looks like the later 9 blade fans have the mounting surface on the forward side of the fan to accommodate the thermal clutch.  I really appreciate the info!  It would be much easier if I wasn't missing my original fan bits!

[dirkbalter]

It’s been a while but I believe my clutch is Mehle. I bought the parts from Pelican.
Yes, the fan slights over the spacer by about 11.5mm. The dimension in the picture of 55.5 gives you the dimension from the front of the fan to the water pump face. The 3bolt and 4bolt (long) pumps are the same with respect to the distance.
I dry assembled everything with the engine out and was pretty happy. After the engine was in, I recognized that the fan blades interfere with the air filter / radiator mounting shroud. The radiator is not centered relativ to the fan. There is very little room on the right side. I am surprised that yours still fits especially with an additional fan shroud mounted. Have you tried it in the car yet?

[Benz Dr.]

Why are you installing a fan clutch on a 230SL? They aren't prone to overheating so I'm sort of wondering.

[dirkbalter]

In my case, the 230 motor blew up and was replaced by a 250 motor, supposedly by the dealership in its early days. Originally, I was going to go back to a 230 motor but decided to kept and rebuild the 250. And since I am running AC, I think it is the best of the 3 versions. I also like the fan and clutch for the same reason, hoping it provides better cooling. My 280 is quiet sensitive to running hot when temperatures get to 90F or above, especially in stop and go traffic on the freeway.

[Benz Dr.]

250SL is very similar to the 230SL - same bore but longer stroke, so cooling is very close to the same. I have the same set up as yours in my car and it never runs hot. It doesn't have AC though.

Real 250SL's have the best cooling ability of all three models with the largest rad and an oil cooler.

[captainslow]

I haven't dry fit it in the car.  I'm assuming the shroud specifically provided by Buds will accommodate a 230 engine bay (that might be incorrect you know what happens when you assume).  I myself am not installing a fan clutch to improve low speed cooling mechanically, rather the NVH benefits are what I want.  I'm all for dropping the dBs on the car while maintaining the ability to pull up to ~80% of a fixed fans power.  We all have personal biases as well and mine is pretty firmly against electric cooling fans.

[dirkbalter]

You are absolutely right. We all do things for different reasons. I would just just try it. And with that being said and being careful in what I say about Bud Benz, I have experience with what I would call questionable products coming from there.