Who makes the TAD and SW Diesel Serpintine pulleys?

[evm1024]

OK, may be I'm tired.

I wrote 3/8 npt up above and should have written 5/8" UNF. Just change that in your minds.

PS Hey mods, can I change those posts? It has been over 30 minutes.

[evm1024]

OK, got some time tonight.

First on order is the temp sender. Trying to use the old one was a bit of a kluge because it was too big for the port in the head and I cobbled together an adapter. I got some slight leaks that way.

Knowing what thread the port was cut to is also a problem. At least one source indicates that it is 5/8" UNF. However, most temp senders are NPT. And 3/8" NPT 5/8" UNF are close to each other (if you know UNF and NPT then you know the differences)

It turns out that west marine had 2 of the senders I was looking at in stock. This boat uses a dual station sender (2 gauges, on at the helm and the other below) and 3/8" NPT would fit so I picked one up on the way home from work. ( WM # 1654854 | Mfg # 18-5897 ) Plus I had some rewards coupons in my pocket.


Back on the boat I pulled the header tank and drilled a 1/16" hole in the thermostat ( Slant 13478 ) The idea here is that air can escape and that in a cold engine some hot water gets through. More on that later.


With the header tank still off and the temp sender not installed I put a funnel into the port on the head and poured 50/50 antifreeze into the head until it started to come out of the hole in the thermostat.

At that point I reinstalled the header tank topped off the port in the head. Then I installed the temp sender and filled up the header tank.


With the fill cap still off I (moment of truth) started the engine. Amps up to 40 at idle, a few bubbles working their way out of the expansion tank fill. Top off coolant as needed and when the coolant started to expand I put the cap back on.


Letting the engine warm up gradually I kept taking a look at temps with the IR temp meter. No leaks and perhaps a slight mositure around the temp sender. Perhaps it needs another 1/4 turn when the engine cools down again.


Up the rpm and the alternator is putting out 80 amps into at 95% full 700ah LiFePO4 bank (100 amp alt). The regulator is set to 13.9 v.


Temps keep rising and eventually settle at 180 degrees (via the gauge). The IR temp meter reads 185 on the head bolts - Ran it a full rpm with no load and the temp stayed rock steady. The return coolant temp went from about 90 F at idle to 110 or so at near WOT with the gauge reading rock steady.


Ok, back to the hole I drilled in the thermostat. When using the original thermostat the temp would rise and rise and go up to about 210 F then after a time fall back to 185 F. This was always something that worried me (was it sticking, faulty etc).

The reason this happens is that with a thermostat without a hole there is no warmed coolant on the temp sensing (wax) side of the thermostat. So the thermostat stays closed until the conduction from the hot side to the cold side is great enough to allow the thermostat to open (and it does in a rush). It looks like it is stuck then releases.


And in my case because i removed the heater circuit there is more or less no coolant flow until the thermostat opens up which can cause localized hot spots in the head.


By drilling a small (1/16") hole in the thermostat I now do ger some coolant flow from the hot side to the cool side when the thermostat is closed. This allows some circulation in the head while the engine is coming up to temp and of greater value to me it allows the wax pellet to cause the thermostat to open in response to the coolant temp. No more "sticking" - the temp just rises to 180 F and stops there.

[evm1024]

Well, I think that we can call the serpentine belt conversion a success!

Pulleys bought, adapter made, belt installed, pump installed and full amps (more or less) without belt slipping.

It does look nice to see that wide belt moving at low rpm.

The ratio from crank to alt is about 1 to 3 so at 1800 RPM cruise we will be turning the alt at 5400 RPM.

And at 1000 RPM the alternator could still produce significant output.

I'll have to discharge the batteries to 50% SOC and set the "bulk" to 14.0 v and then see what current the alt will put out.

As a point of reference - when the alt was producing 80 amps the alt case was at 176 F after 10 minutes.

Need to get a few more photos and then call this thread done.

[evm1024]

Looking good - as always with things boat, if you uncover one area another problem crops up. The starter has decided it it time to be rebuilt.

I get a a little weeping around the temp sender in the head. The sender is 3/8" NPT and perhaps the head is 5/8 UNF after all. I'll see if I can source an adapter to fit a smaller diameter sender.

Here is a last photo of the full system. Hopefully this thread will be of use to someone who wants to piece together a serpentine kit for their 4.236.

[Jd1]

I notice that you are not using as spring loaded tensioner for the belt. Can you tell me how much belt deflection you see when the engine runs and the alternator is charging ? Also, how much belt tension are you using (how did you measure it)

[evm1024]

Tad recommends that you use the same tension as with a Vee belt:

"Belt Tension should be, so that without undue pressure, the belt can be depressed 3/8 of an inch at the center of the longest span as shown in the image below."

I've always wondered what force in pounds this implies - An old rule of thumb is that if the belt slips under load when wet it is too loose. I'm not sure where I got that from. It might have been my dad who was a mechanic when I was much younger.

Run the alt at loaf and watch the amperage. Then splash some water on the belt and pulleys. If the amperage goes down then the belt is slipping.

[Jd1]

Thanks, I will try that test.
Any details of how much belt slap you get under load ?

[evm1024]

The belt only appears to vibrate back and forth perhaps 1/2" or less on the longest span. Nothing to hit of course so no slap....

[Jd1]

Thanks for that info!
This brings out another interesting question though ..... I also have the +-1/2" movement but I get an occasional (frequently) noise that I previously called 'slapping' but it has a sort of snapping whip kind of feeling to it. I assume this to come from the belt as it whips back and forth between + 1/2" and - 1/2" and back again. It is not constant but maybe 20% of the time and intermittent. I use a 10 rib J section belt which is fairly flexible (to be able to wrap around the small alternator pulley). What kind of belt are you using ? I would think a heavier belt would do less snapping/slapping.
In any case, thanks for the info on the play in the belt - at least I know this is to be expected.

[evm1024]

Originally Posted by Jd1

Thanks for that info!
This brings out another interesting question though ..... I also have the +-1/2" movement but I get an occasional (frequently) noise that I previously called 'slapping' but it has a sort of snapping whip kind of feeling to it. I assume this to come from the belt as it whips back and forth between + 1/2" and - 1/2" and back again. It is not constant but maybe 20% of the time and intermittent. I use a 10 rib J section belt which is fairly flexible (to be able to wrap around the small alternator pulley). What kind of belt are you using ? I would think a heavier belt would do less snapping/slapping.
In any case, thanks for the info on the play in the belt - at least I know this is to be expected.

Ages later I check back...

I'm using a K6 belt. I'm not hearing any of the "slap" but then again I have not gone looking for what you describe. I'll be on the boat this coming weekend and take a listen.

[Federico993]

Someone knows a cheap pulley kit for Volvo D2-40 engine?

[DougR]

Originally Posted by Federico993

Someone knows a cheap pulley kit for Volvo D2-40 engine?

What type of pulley are you looking for? How much power does it need to transmit?

[Federico993]

I am looking for a K6 or J8 pulley kit

[DougR]

Penta sells a pk4 140mm pulley #3582415. And they used to have a pk5 116 pulley #21178943, but I don’t know if that one is still available.

Company B&B Mfg. in the US can probably make you whatever you want..
-BBMAN.com-