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Discussion Starter #181
Keating said he could send me a blank one, but that would cause another issue as I already purchased valve covers and would need a vent. I need to find a way to make what I have work. I may have to manufacture a plate that would work with my limited tools and abilities. We shall see what comes out.
 

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While I like the baffled vents on Keating's tappet covers, you might could get away with tapping & grommeting a port, & push in a 24v breather canister with the associated U-shaped breather hose.
 

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If they would send you the plate like I show in post #180, all you'd need to do is bore and thread a hole for the breather where it needs to be. The valve cover breather system would of course be a viable option. I've even seen guy just take the stock valve covers and install breathers like you might find on racing engines. You could use the Spectre 4276 units which are on Amazon for $6.61 including the grommet. Very old school but they'd work. Of course the draft tube isn't exactly modern technology.
 

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Discussion Starter #184
Yeah the thing just needed a bit more engineering. There are other makers of that part on the market and theirs leave the vent area blank. If you want a vent you bore and thread the hole yourself. That way you don't have that extra plate on the outside. Theirs looks nice, but leaving the panel flat and just putting the threaded hole would have been sufficient. In fact, one of those is by Keating. The one you have must be a new design. Here's a photo of the other one.
I do like the vent holes they manufactured into the tappet cover itself. Too bad I am working this weekend. I would love to dive into the project. I am thinking about a thinner flat plate with a gasket, countersunk rear holes. Then cut a hole onto the plate and weld a piece threaded pipe onto it. (Thinking out loud).
 

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Discussion Starter #185
If they would send you the plate like I show in post #180, all you'd need to do is bore and thread a hole for the breather where it needs to be. The valve cover breather system would of course be a viable option. I've even seen guy just take the stock valve covers and install breathers like you might find on racing engines. You could use the Spectre 4276 units which are on Amazon for $6.61 including the grommet. Very old school but they'd work. Of course the draft tube isn't exactly modern technology.
I like the idea of the spectre vent. Here is my issue. I purchased valve covers that are ribbed. on top. I could use the vent but would have to have one of my valve covers machined or go back to stock.

Valve Cover Ribbed.jpg Valve Cover Ribbed1.jpg
 

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Very nice valve covers. Does one of those have the oil fill hole? If so, you could make a pipe with a breather cap to fit that. Here's a photo of one of those valve cover kits that has a nice size hole for the oil fill That hole is as big as the side breather pipe. Probably lots of nice breather caps that could be adapted to the top cover.
 

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Discussion Starter #187 (Edited)
Unfortunately no. I could definitely see doing it your way, but a no go. The valve covers are alike. I am still toying with the idea of making a cover and tube for the new billet tappet cover though. Just need some time off.

I do like the covers as well. The manufacturer ground some of the internal ribs to accommodate studs/nuts on the head. I like the thinking ahead, although I am using regular head bolts, it is appreciated.

Valve Cover Internal.jpg
 

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Discussion Starter #188 (Edited)
I have been looking /researching to put a mechanical fan on my 4bt. Does anyone have any sources or information of how to accomplish this? The bread truck my 4bt came from had aftermarket electric fans.

Aftermarket? This is a link to a Chinese aftermarket fan connection flange: https://www.alibaba.com/product-detail/cummins-diesel-Engine-Cooling-Fan-Adapter_60578097212.html?spm=a2700.7724857.normalList.147.3b166ab8XTYSXq

The website list a slew of fan parts as well: https://www.alibaba.com/showroom/cummins-fan-hub-4bt.html.

Again, not sure which way to go on this one (as far as which hub/fan to use). I would like to place the engine/drivetrain forward enough to allow (hopefully) the fan to fit inside the existing fan shroud. I do realized that I may need to make an allowance if the oil pan comes in contact with the front axle pumpkin.
 

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Go to Auto zone ask for a fan clutch for a 1990 Chevy p30 van, should be Duralast pn922784, I believe it takes a 88-99 Chevy 454 fan maybe others too. I've not needed a fan yet (it's winter in here PA), but this is how I plan to do mine.
 

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Discussion Starter #191
Found this Hayden Fan Clutch at Summit Racing for $38.99.


The Question is now the rotation. (The Autozone website has their fan clutch for $65.99. https://www.autozone.com/cooling-heating-and-climate-control/fan-clutch/duralast-fan-clutch-922784/268632_869176_0 ) Both are CCW Rotation. Are they looking at this from the rear of the engine? I once believed almost all engines were CW rotation when viewed from front. Both manufacturers state CCW rotation. But is that from looking at the front of the engine or the view from the rear? Both are for 4B applications.

The question really is: Is engine rotation from the perspective of looking at the rear of the engine or the front of the engine?
 

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I think you'll find neither of those fan clutches work on a 4bt. First, their pilot hole is .625". The Cummins pilot is 1.000". Second, they are reverse rotation or counter clockwise. Cummins is clockwise rotation. This has come up several times recently. Another issue is Cummins used 2 different fan hubs on the 4bt. The normal road engine like most have used 4 8mm bolts in a 50mm circle. The industrial engines used 4 10mm bolts in a 60mm circle. The fan blades also came in 2 sizes. The smaller one was 18" and the industrial was 22". All this being said, these 2 fan/clutch assemblies are about as common as hen's teeth. I've found 1 source for the 18" fan and clutch. Not sure on which bolt pattern the clutch has. That company is Mill Supply Inc. The clutch is part # 85-160 and the 18" fan part # 85-175. See photos. The clutch lists for $324.00 and the fan blade for $216.00. OUCH! Even Uptime Truck Parts who specializes in these engines doesn't show the parts. So far, I haven't been able to come up with the Cummins part numbers for the clutch units or the smaller fan blade. One possible source might be Freightliner who used these engines in many applications. You can sort of see why most either go electric or change the hub assembly to one from a 6bt Dodge.
 

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V-belt engines have a fan that rotates CW - the belt rides in the fan pulley groove. Serpentine belt engines (in most cases) have a fan that rotates CCW - because the fan pulley is driven by the flat back side of the fan belt. There may be exceptions where the fan pulley is grooved and driven by the grooved side of the serpentine belt - that would be CW.
 

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I think you'll find neither of those fan clutches work on a 4bt. First, their pilot hole is .625". The Cummins pilot is 1.000". Second, they are reverse rotation or counter clockwise. Cummins is clockwise rotation. This has come up several times recently. Another issue is Cummins used 2 different fan hubs on the 4bt. The normal road engine like most have used 4 8mm bolts in a 50mm circle. The industrial engines used 4 10mm bolts in a 60mm circle. The fan blades also came in 2 sizes. The smaller one was 18" and the industrial was 22". All this being said, these 2 fan/clutch assemblies are about as common as hen's teeth. I've found 1 source for the 18" fan and clutch. Not sure on which bolt pattern the clutch has. That company is Mill Supply Inc. The clutch is part # 85-160 and the 18" fan part # 85-175. See photos. The clutch lists for $324.00 and the fan blade for $216.00. OUCH! Even Uptime Truck Parts who specializes in these engines doesn't show the parts. So far, I haven't been able to come up with the Cummins part numbers for the clutch units or the smaller fan blade. One possible source might be Freightliner who used these engines in many applications. You can sort of see why most either go electric or change the hub assembly to one from a 6bt Dodge.
$324.00 + $216.00 = Electric fan
 

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Is it possible that the clutch will work both directions? As far as I know all 4bt fans where CW rotation (run on the ribbed side of the serpentine belt) yet these clutches listed for 4bt are the same pn as 454 Chevy which runs on the backside of the serpentine? My 4bt came with a clutch on it but it had gone bad and destroyed the fan I tried cleaning it to find a part# but gave up as it was coated with layers of grease but comparing it to a Chevy clutch the bolt spacing looked larger which is probably why the Duralast part has slotted holes but what do I know? I'd run out and measure my junk clutch but I'm on a 4day road trip.

PS I guess the Chevy fan probably wouldn't work now that I think about it or at least would need reversed maybe some one can chime in who's actually used this clutch
 

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Go to Auto zone ask for a fan clutch for a 1990 Chevy p30 van, should be Duralast pn922784, I believe it takes a 88-99 Chevy 454 fan maybe others too. I've not needed a fan yet (it's winter in here PA), but this is how I plan to do mine.
After some more research I am finding that there is a ton of misinformation around on this subject! I have found that while this 2784 clutch may fit some fan hubs however I'm not sure why it's advertised for a 4bt as the rotation seems wrong. However I believe that by turning the pilot down to .75 in or .625 one can have a mechanical fan for a LOT less money than the 300+ for the Cummins set up
 

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Yes, unfortunately some of the auto parts companies have some bad info. Not really sure where they got the idea that a 4bt and a Chevy has the same fan hub. Part of this probably stems from the fact that those early vans were originally fitted with the Chevy engine and were changed out for the 4bt. Yes Russ, the cost of that OEM Cummins fan is nuts. You could probably find a used 6bt fan hub and pulley for a '94-02 model Dodge for less than $150 and then just use the fan and clutch for it. Might get out close to half what the 4bt assembly costs. In fact, here's a complete assembly on ebay, fan, clutch, and hub assembly for $159.97 shipped. All you'd need to be sure of is shroud clearance. That fan is 560mm or 22" OD. https://www.ebay.com/itm/94-98-Dodge-Ram-2500-3500-Cummins-12v-5-9-6BT-Fan-and-Fan-Clutch/113981704444?epid=22028304901&hash=item1a89d6c8fc:g:rcsAAOSw5WRd1uMg:sc:FedExHomeDelivery!28658!US!-1
 

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So I got to thinking , all v-belt driven fans are std rotation (CW) so the 6.2 diesel and Chevy v8s older than '86 would have CW fan clutches. So I found a Hayden catalog and according to it their pn2799 for v-belt drive v8 is CW, has the same fan blade hole size and bolt spacing as the 4bt fan, and has a .75 in pilot but I can't find a spec for the bolt spacing. However it cross references to Auto zone's Duralast 922799 which has slotted mounting holes. So if the pilot was turned down to .75 leaving a 1.00 lip to center the pulley you could have a fan clutch for $37.99 with a limited lifetime warranty and use either a 4bt fan or any square body Chevy fan that has a 2 5/8in hole and 3 1/4in bolt spacing.
Don't take this as concrete as I haven't actually tried this but it looks right on paper.🤔

As soon as I get home from my trip I'll be the guinea pig and order one to try so that we can have some concrete information on this.

Glendon
 

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Discussion Starter #200 (Edited)
https://www.ebay.com/itm/94-98-Dodge-Ram-2500-3500-Cummins-12v-5-9-6BT-Fan-and-Fan-Clutch/113981704444?epid=22028304901&hash=item1a89d6c8fc:g:rcsAAOSw5WRd1uMg:sc:FedExHomeDelivery!28658!US!-1

Looking the ebay assembly is tempting, but my current shroud for the 6.2 is approx 22 inches. That fan would scrape the edges at that if it was aligned correctly. My current fan is 20 inches. So, if I purchase this assembly, how hard would it be to find a fan with the correct diameter for this assembly?
 
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