| Author | Message | ||
     Brian Vogel Grand Master Username: guyslp Post Number: 301 Registered: 6-2009 |
Way back when the search for a new fan and viscous fan clutch came up several asked me about the fan shroud. Well, after today's session at the garage I have determined that there is (and, indeed, was) an issue with the fan blade tips of both the new and the OEM fan touching the fan shroud at almost bottom dead center. I noticed some scuffing on the interior of the fan shroud when I took it off, but chalked that up to "the accident." Upon closer examination, this set of scuffs is not a fresh set and if you look at the tips of the old OEM plastic fan the forward edge of each tip had obviously worn down slightly from contact with the shroud. The new fan is doing the same thing, but you can hear it better because the fan is metal and makes a more distinct sound. Has anyone every experienced this problem before and, if so, what was your solution. The two major connectors for the bottom of the fan shroud really don't allow for a lot of adjustment and I tried to pull it as far down as it could go before tightening down the bolts that hold them in place. I certainly don't want to leave things this way. I just don't know if an adjustment can be made successfully. Perhaps this particular shroud is warped? I can get a lower half used at a reasonable price, but am thinking I might have the same problem. Is taking out a section of the bottom center of the shroud something anyone has done? This situation doesn't have any really obvious solutions as far as I can see, particularly since it occurred with the old fan in the first place. Brian | ||
| Paul Yorke Grand Master Username: paul_yorke Post Number: 990 Registered: 6-2006 |
Engine mountings. Soft, torn, wrongly adjusted, spacer missing, engine stop missing. Radiator mounting holes elongated and rad too high. Rad wrongly repaired before. | ||
| James Feller Prolific User Username: james_feller Post Number: 287 Registered: 5-2008 |
spot on Paul. Brian, if your enginne mounts are soft and worn then the engine and thus the fan will be out of alignment to the shroud. Or indeed the shroud or rad has not been aligned correctly this can foul the fan. They are a reasonable fit as in the fan into shroud and should clear well. Neither my Spirit (Metal fan) or Turbo (Plastic fan) has ever fouled the shroud and moreover shouldnt come close unless as Paul has stated above... J | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 302 Registered: 6-2009 |
Paul, I presume the engine mounts you're referring to are the bits circled here:  Can you direct me to the correct section of the workshop manual that covers the various engine mountings and their installation? I will check the radiator, but it did not look to have ever been removed from the car in the past. Even the radiator repair shop marveled at the condition of the thing given its age. I was not particularly careful about how I positioned the radiator vertically when I put it back in on the brackets that are also the bonnet supports. Perhaps I need to loosen the securing bolts and try to bump the radiator down a bit? I just want to make sure that I've checked all of the possible culprits you've mentioned, and know what I should be seeing, before I play with the radiator. Thanks for your assistance. Brian P.S. I can post photos of all of the mounts, or at least I think I can. Unless they've either cracked or split I can't imagine these are the culprits. This car has had no oil leaks from the valve covers from all appearances and things are mighty clean "down there." | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 307 Registered: 6-2009 |
Just for completeness (and since I don't know what these things should look like) here are photos of my front engine mount and one of the two rear mounts (the second one is virtually identical). They look awfully clean and undamaged to me. There is nothing in the service history I have indicating these were ever changed.   Also, here's a shot I took of the mirror looking into the lower right radiator mounting hole. I had a bit of wiggle room to push the radiator down, but that's simply shifted the point of contact for the fan blade tips and the fan shroud once things warm up. It's also brought the fan far closer to the underside of the header tank than I'm comfortable with. I think I'm going to have to try a Hayden 2705 fan clutch, which will pull the leading edge of the fan back about another 1/4 inch and move it further away from the inward sloping surface of the shroud.  Brian | ||
| Randy Roberson Prolific User Username: wascator Post Number: 103 Registered: 5-2009 |
That front mount looks OK to me also. I changed mine and it was really obviously ratty and rotten. My fan was not hitting, though. Is the water pump good? | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 310 Registered: 6-2009 |
Randy, The water pump is fine. Doesn't allow any wiggle at all. However, I've come to the conclusion that what I really should do here is go with a Derale 19-inch (17119) or 18-inch (17118) rather than a 20-inch fan, regardless of whether using a Hayden 2705 or Hayden 2706 fan clutch. The OEM plastic fan has a very shallow blade pitch and fan depth and it's relaively "pulled-back" from the fan shroud, with little inside it. Any replacement fan blade set I found from any maker has a significantly deeper pitch to each blade and a larger fan depth. This makes the biggest difference at the leading blade tips that are inside the fan shroud and that also whirl beneath the header tank. If I step down to a 19" fan it gets me another 1/2 inch of clearance (or a full additional inch with the 18" fan). With the more aggressive pitch on the blades they're pulling more air than the OEM fan to begin with. I've just got to check again to see if I think an additional half inch is enough or if I'd prefer to have the additional full inch of clearance that going to an 18" fan would give me. I will note that I'm speaking only about Derale fan blade sets here. The pitch on Hayden blades is even deeper, making it almost impossible to get either the front or rear blade edge clearances you need using their fans with any of their fan clutches. Brian, who's found this experience has proven one of my favorite adages true, "In theory there is no difference between theory and practice, in practice, there is." | ||
| Benoit Leus Frequent User Username: benoitleus Post Number: 54 Registered: 6-2009 |
Hi Brian, when using the Derale fan, do you still use the original fan clutch ? Regards, Benoit | ||
| Brian Vogel Grand Master Username: guyslp Post Number: 327 Registered: 6-2009 |
Benoit, I posted all the gory details on the Alternate fan and/or viscous fan clutch for the "Two Series" cars thread. I did not use the OEM fan clutch since it was no longer safe/reliable after the fan self-destruct (or wobble destruct) incident. On that other thread I also posted a picture of the very simple, and clever, adapter ring that another owner had machined when he wished to use the original fan with a Hayden viscous fan clutch. I'm sure the same basic technique could be employed if one wished to keep the OEM fan clutch but switch out the fan, but "in reverse" as far as the hole patterns go. Brian |
