: 1994 - 1996 Fleetwood Engine Fans.



ralphb
06-28-06, 06:39 PM
I have seen some 94 - 96 Fleetwoods that have a fan shroud, and some that do not. Does anyone know the explanation for this ?

N0DIH
06-28-06, 11:40 PM
The mechanical fan is part of RPO (Regular Production Option) V08, aka, Heavy Duty cooling. This is often part of the rare V4P 7000 lb Towing Package which my car has. I have detailed much of the V4P package in this forum. Do a search for towing and V4P, it should show up. I didn't start the thread, just replied to it.

Edit: I found it.
http://www.cadillacforums.com/forums/rwd-19xx-1985-deville-fleetwood-1985/48424-making-v4p-car.html?highlight=V4P+V08

Some claim that you get 2-3 mpg better by having the electric fans, this is NOT the rule only a rare exceptions when someone is replacing a bad or locked up fan clutch. I have done extensive fuel economy testing with my V4P car with and without the mech fan and have seen no difference in fuel economy with any confidence in the data (I am a statistical green belt in training, so I like to seriously play with my numbers! I analyze them in Minitab, I trust little unless I can prove it!) In most cases the mech fan is freewheeling, and is not in full direct driven mode. Often I can actually put my hand in the fan and spin it backwards with the engine running. I do NOT recommend this!!! If you want to try, LISTEN to the fan, you can tell when it is engaged and disengaged. I don't recommend anyone put your hand in a engine driven fan while it is running...

The nice thing with the V08 cooling is that the engine temp is very stable, varying only 5-10F from subzero temps to 100F+ temps. Where the electric fan cars vary from 180F to 220F before the fans actually turn on to cool things down. So performance on the V4P and V08 cars is much more stable.

ralphb
06-29-06, 07:20 AM
Thanks NODIH ! Great details - that's what I was looking for.

BCs71
06-29-06, 02:36 PM
The nice thing with the V08 cooling is that the engine temp is very stable, varying only 5-10F from subzero temps to 100F+ temps. Where the electric fan cars vary from 180F to 220F before the fans actually turn on to cool things down. So performance on the V4P and V08 cars is much more stable.
Good info from NODIH, I would just like to point out that the dual electric fan setup can also be more reliable with aftermarket PCM programming; the car's computer tells the fans when to come on. GM made the stock turn-on temps very high for better emissions.....

Lowering the temps adds more power and reliability, as well as keeping adequate emissions and increasing longevity on cooling system components.

I~LUV~Caddys8792
06-29-06, 02:55 PM
N0DIH is the god for the Fleetwood Broughams, especially the LT1 ones.

Anyways, I had a '95 Roadmaster Limited with the Towing Package, I had the crankshaft driven fan. I didn't like it at all, because it drowned out the V8 sound.

N0DIH
06-29-06, 06:03 PM
Not! I have waay to much to learn on them!!


N0DIH is the god for the Fleetwood Broughams, especially the LT1 ones.

That is definately a sign of a bad clutch. My 76 Delta 88 when the clutch locked up I could barely do 35 mph!! That was a 100% lockup, it was completely frozen.

Mine might make a little noise at cold start, but loosens up right away so I never even hear it, you can hear it for about 1 min, then it just silences itself nicely. I rarely even know there is a mech fan there when I drive, only if I cold start and get out of the car do I hear the fan.

My 99 Burb with a 9 blade clutch fan, you KNOW that sucker is there! That thing can pull enough air to suck Niagra Falls to Ohio! But it is HD cooling too... 10000# trailer weight...


Anyways, I had a '95 Roadmaster Limited with the Towing Package, I had the crankshaft driven fan. I didn't like it at all, because it drowned out the V8 sound.

BCS71 is right on, with proper PCM tuning, the electrics do just fine at keeping things cool just as good as the mech fan. I think the overall CFM of the mech fan is more capable than the electrics, but the electrics can be more consistent and with programmability, very stable at maintaining temps.

I did try to remove the mech setup (everything!), pulled 95% of the whole mech setup and drove with only the secondary fan for around 3-4 months with no issues on temp at all. Even when it was up at 90F I had no issues (remember, AC was on, secondary fan was on also managing some airflow and that is a BIG secondary fan!) but the mpg's didn't change at all, not enough to invest $$ into a new primary fan, relay's and wiring (mine is devoid of much of that)

I~LUV~Caddys8792
06-29-06, 07:21 PM
Not! I have waay to much to learn on them!!

Well you're the god on here of them then! :)




That is definately a sign of a bad clutch. My 76 Delta 88 when the clutch locked up I could barely do 35 mph!! That was a 100% lockup, it was completely frozen.

Mine might make a little noise at cold start, but loosens up right away so I never even hear it, you can hear it for about 1 min, then it just silences itself nicely. I rarely even know there is a mech fan there when I drive, only if I cold start and get out of the car do I hear the fan.

Well I'm not positive if it was all of the time, but I distinctly remember driving down my street, when the engine was cold, with the windows down, and all I could hear was the fan over the engine. If it makes any difference, it got really lousy mileage on the freeway on a 5.5 hour straight trip from the Twin Cities into North Dakota. I was getting 18.5 MPG on the freeway and I was driving quite normally, using the CC a lot.

N0DIH
06-29-06, 11:49 PM
That is about what I get in my FW daily driving city/highway with the 3.42's.

I still haven't got much over 21 ever, a 1 time 22, but I can't repeat it.

Even without the mech fan, no change. I get around 18.5 to 19 most of the warmer months even with the AC on Combo city / highway driving.

I~LUV~Caddys8792
06-30-06, 12:52 AM
18MPG was pure highway with the 2.93 posi rear end. :(

N0DIH
06-30-06, 01:29 PM
Yikes! I am getting that city highway, are you stock PCM tune or modified?

I have made all kinds of tuning changes hoping to get better mpg, but still haven't got much better. Increasing mpg isn't so easy! No magic tune gets you 5 mpg better, I can attest to that.

I even messed with some super lean cruise tunes, still only maybe at best got 0.25 mpg better. Ok, I know, that is something, but I really need a wideband O2 to really dial that in. It isn't easy.

(If anyone wants to know what all I did, PM me)

I~LUV~Caddys8792
06-30-06, 03:05 PM
Yikes! I am getting that city highway, are you stock PCM tune or modified?

Well from what I know, it was completely stock, but the previous owner may have modded the PCM tune. He was a hot-rodder though. He was building up a '70 GTO too.

WMD
06-30-06, 04:23 PM
There was another cooling option available as well called Extra Cooling Capacity. It is neat because it is in between the Base package and the Heavy Duty Cooling package. It does not have the belt driven clutch fan, but does include the desirable upgraded more powerfull 2nd electric fan that the H.D. cooling package includes plus the extra oil cooler.
Cheers WMD












c

limo
06-30-06, 06:19 PM
18MPG was pure highway with the 2.93 posi rear end. :(

I have a 96 Fleetwood Brougham with 2.93 rear end and one 94 Fleetwood with the 2.56. The highway mileage is 16 MPG (FWB) and 24 MPG (Fleetwood). Is the rear end the main reason for such mileage difference?
Where can I get the 2.56 ?

I~LUV~Caddys8792
06-30-06, 06:42 PM
It won't make that big of difference. My Roadmaster had some other sort of underlying problem too. I'm not sure what it was though.

Come to think of it, my grandpa had a '92 Roadmaster Limited with the TBI 350 and the 2.56:1 open rear end. He'd get around 25-26 MPG on a sustained highway trip.

N0DIH
07-01-06, 01:16 AM
I am starting to think that with the small cams the LT1's have, that it works well with 2.56's, and as the rpms increase with the 2.93's, 3.08's and 3.42's, that it is just getting more and more out of it's true part throttle powerband.

Now, looking at the F Body and Y Body LT1's, they almost ALWAYS are in the mid 20's, some high 20's in mpg, even with lots of mods. The cam is larger, higher in duration, wider lobe separation (which isn't good for bottom end power, but needed to keep overlap down as the cam increases in duration) and more lift.

I would love to try a F Body cam just to see how it does in comparisson to the B/D cam. Anyone got any donations? I am hoping to get a timing chain and water pump in this summer, so maybe I'll go that much further and just do a cam swap. Or do a HOT cam. If I can get a cam in the 218/218 range, I wonder if that would be a much better choice with the gearing I have.

From what I have read somewhere in a magazine, your camshaft selection should be over 216 degrees intake duration with cruise rpm in D not OD at 65 mph is over 2600 rpm. Mine is 2600 rpm @ 65, 3100 @ 75, not in OD. So by the book (at least that one), my cam is WAAAYYY too small. Even though cruise rpm in OD is lower (1900 @ 65, and 2100 @ 75), I wonder if that reference is more accurate.

Of all the Impala SS guys I have seen, those with larger cams don't seem to be hurting for mileage like mine seems to!

Ideas? Thoughts?

Rob Benham
07-01-06, 11:57 PM
While working on mine today, the left fan came on based on engine temp and not A/C. I was working on an A/C problem, so it is not conclusive, but there seemed to be no tendency for the fans to be connected to the A,C

An my SLS, Northstar, both fans run for any selection of the A/C. Normal is 123f for series operation of the fans and 125f for parallel. (full power fans) at no time does one fan come on.

BCs71
07-06-06, 11:08 AM
I have a 96 Fleetwood Brougham with 2.93 rear end and one 94 Fleetwood with the 2.56. The highway mileage is 16 MPG (FWB) and 24 MPG (Fleetwood). Is the rear end the main reason for such mileage difference?
Where can I get the 2.56 ?

My Caprice has a 2.93 rear end with LT1 and gets 23-4 MPG with AC blasting at 70 MPH. I think the 2.93 gears are a great match for highway driving on these heavy cars.
City/combined driving is not so good at 15ish MPG. In this case (driving under 50 MPH and many stoplights) I think larger numerically gears (3.42 or 3.73) would be better slightly for MPG since I could get up to the speed limit faster due to advantage the gears would give. But Highway MPG would suffer.
I find the 2.93 to be a nice compromise -- I bet 3.23s would be best!

BCs71
07-06-06, 11:28 AM
I would love to try a F Body cam just to see how it does in comparisson to the B/D cam. Anyone got any donations? I am hoping to get a timing chain and water pump in this summer, so maybe I'll go that much further and just do a cam swap. Or do a HOT cam. If I can get a cam in the 218/218 range, I wonder if that would be a much better choice with the gearing I have.
The HOT cam is a poor choice for the B/D cars since they are so heavy. The HOT cam was really intended for the F/Y bodies which are substantially lighter. It's tendency is for HP at higher RPMs rather than low to mid-range torque to get the heavy car rolling. The popularity of an off-the-shelf solution of the HOT cam kit (and/or the cam separately) for F/Y cars has carried over to the B body crowd, and unfortunately many guys do it without research and are more than disappointed with the results because they don't have the supporting mods to go with it. 3.42 gears are borderline sufficient, 3.73s are MUCH better. A torque converter with a higher stall RPM is needed along with improved valve springs since lift with 1.6 rockers is .525" and too much for the stock pressed in rocker arm studs. Headers and a good flowing exhaust system are also ideal, not to mention PCM updating (35-36 degrees timing from what I hear).

A cam swap involves many supporting mods, it is only as good as the complete package. I learned this the hard way with my car because I went by the thinking that "might as well since I am in there doing a repair". I am now finally starting to catch up with supporting mods to make the swap worthwhile that I did back in 2003.

The F-body stock cam has been used in B bodies before, and for all the labor required I think it is kind of a disappointment being that it is less radical than the HOTcam even and yet is similar since it leans towards higher RPM performance, not low RPM torque (stock B/D body cam makes peak torque at only 2400 RPMs!!). Nodih, you're in decent shape with 3.42 gears. Not sure if the F-body cam would be a benefit or not, but I'd hate to see you go through all the labor and be disappointed. This is the reason I went with the 845 cam for mine, as it is a low to mid RPM performer. The stock B/D body cam is GREAT for torque, emissions, and still somewhat mild so it is easy on the valvetrain (longevity AND gas mileage).


Of all the Impala SS guys I have seen, those with larger cams don't seem to be hurting for mileage like mine seems to!

Ideas? Thoughts?
The bigger the cam, the more timing you through in. Some cams sing at high RPMs, which will eat gas. The HOTcam for instance will cause you to need to rev higher in order to get the beast rolling from a stop as the torque band is shifted up. I would anticipate gas mileage going down. :mad:
A torque converter could compensate for this with higher stall, which if you paid premium pricing for a smaller (9.5") high end brand unit can reduse rotaional mass and improve drivetrain losses. The big question, would the $500-$750 pricetag of the TC offset the gas mileage & performance gain?

Ahhh... the dilemma.

That said, my gas mileage sucks in my modified Caddy. Never taken it on a roadtrip to see highway mileage, but city/combined is at 14MPG.

N0DIH
07-06-06, 01:41 PM
Cam specs I would like to see on my engine would be:

I would like have a cam that is more on par with an Pontiac "066" cam or maybe a "067" cam. Leaning more towards 066 specs with a bit more modern lobe ramps.

http://www.classicfirebird.com/hand/jhand5.html

What are the specs on the 845? Is that the HOT cam? Isn't the HOT cam the one for the LT4?

BCs71
07-07-06, 10:03 AM
What are the specs on the 845? Is that the HOT cam? Isn't the HOT cam the one for the LT4?



The 845 is separate from the HOT cam although both are GM parts (#12370845).
GM Performance Parts 845 camshaft, Duration=.214 Intake/.224 Exhaust
Total lift w/1.5RR: Intake=.488 Exhaust=.509

HOTcam 218 I / 226 E 112 lsa
lift with 1.6R = .525/.525

N0DIH
07-08-06, 01:51 PM
I would like to see that cam in 208/216 duration and that lift on a 110 or at most, a 112 Lobe Separation.


The 845 is separate from the HOT cam although both are GM parts (#12370845).
GM Performance Parts 845 camshaft, Duration=.214 Intake/.224 Exhaust
Total lift w/1.5RR: Intake=.488 Exhaust=.509

HOTcam 218 I / 226 E 112 lsa
lift with 1.6R = .525/.525