Silicone tubing question

[NorthernWaters]

I have a question about some silicone tubing that I just purchased...... The ID is 3/32. The Stock tubing on my MG has a ID of 1/8.

Will I compromise my cooling system if I use the smaller diameter ID tubing?

Thanks
..

[Chilli]

You'll be fine. I run 3/32 in a half dozen boats with no problem. As long as the water is flowing, you're good.

[egneg]

You'll be fine. I run 3/32 in a half dozen boats with no problem. As long as the water is flowing, you're good.

Sorry Mike but I disagree ... the flow rate has just been cut in half.

[longballlumber]

[Chilli]

No problem with disagreeing Chuck. The question is how much flow is required. I'm not smart enough to get into an argument about thermal absorption. LOL

Ken, you've got two options: Try the 3/32 tubing and bring the boat in after three or four laps to check temperatures before running a whole pack... or just buy some 1/8" tubing and be done with it.

[egneg]

Now I agree ... as long as temps are good you have enough flow.

[BHChieftain]

I run a mix of tubing sizes in some boats and I don't have any cooling problems,
Chief

[properchopper]

Interesting. I just posed this "optimum silicone tubing .i.d." question on another forum - didn't get any convincing answers. Reason I asked was that, while I normally use 3mm tubing on dual-pickup/independent cooling line setups, I have one on the bench (single pickup Spd .21 rudder/T-180/HRC cooling jacket with the barbs replaced with larger fittings). Since I've been schooled here that more (faster) flow is better I got to thinking that given constant pickup pressure from the rudder, the smaller i.d. would flow faster. I'm probably overthinking this and in NO WAY want to re-open the previous threads, but just want to hear some valid input.

[tlandauer]

subscribed!

[Chilli]

I've seen threads that made my brain hurt on the rates of flow and arguments on how slowing down the flow of water actually helps it absorb heat better and increases cooling. It doesn't make sense to me. I guess I should of paid more attention in physics class....

If the water is flowing and my stuff is cool, I'm happy!

unsubscribing.....

[T.S.Davis]

I asked a similar question in about 2006. I had asked basically if at some point our lineal footage of tubing could stop the flow all together. We had tubing running all over the place. Back then I think it was cooling coils. There was the speedo, the coil, two brush coolers. The debate ensued. There was a strong support for actually restricting the flow to give the water more time to do it's thing.

Certification for my day job included thermal dynamics and hydraulic calculations through tubing. I can tell for sure that I have no freak'n idea what the answer is. The mathematics are pretty daunting for a hobby. Friction loss changes as you bend your tubing too. That 180 degree bend around the speedo has different friction characteristics than a straight piece of silicone.

Some basics may apply though. Smaller diameter will increase velocity and pressure. However that does not mean more flow (volume). Small tube equates to high pressure low gpm and larger diameter equates to higher gpm at lower pressure. The simple answer is higher velocity (small tube) will move the water faster. Maybe too fast for it to transfer? I don't know. Brain hurt yet?

I do know this though. The more actual area of contact between the heated material and the water the more transfer you get. That's why we get more cooling with a jacket than a coil. A finned motor like a Neu with a jacket should (in theory) run even cooler.

[properchopper]

"Smaller diameter will increase velocity and pressure. However that does not mean more flow (volume). Small tube equates to high pressure low gpm and larger diameter equates to higher gpm at lower pressure. The simple answer is higher velocity (small tube) will move the water faster. Maybe too fast for it to transfer? I don't know. Brain hurt yet?"

That's what puzzles me. I think this afternoon to give my brain a rest I'll work on simpler stuff : Reconciling the Palestinians and Israelis, curing the World of all known diseases, and learn how to play the accordian.

[egneg]

I always choose the larger tubing to maximize flow - no such thing as to much water in FE (unless it's in the boat).

[T.S.Davis]

Sissy. Those first two are easy. That accordion though.....

I play that pipe size game every day. With fire sprinklers, for the most part, high velocity is not the way to suppress a fire. You want the volume to cool the fuel. I can turn a high pressure garden hose on a fire or blast it with thousands of gallon of water through an 8" pipe. One works better. I suppose if your putting out a match you don't need the 8" pipe. Just spit on it.

If I could just find a way to power a 1500 gpm fire pump into my cooling system. 460 volts, 200 horse. Yeah baby yeah! Might need a bigger boat. Speedo is pretty big on those.

[jetskier]

smaller ID tubing will increase pressure up stream only from where the tubing starts and will have lower flow. so if you put smaller ID tubing at the exit section, you cooling system will have higher pressure and lower flow. put smaller ID tubing on the whole system will just give you lower flow. Plus we are not talking about a pump, it's water ramming into a pickup...and that brings to another question. how much flow can the pickup intake at max speed.
So, therefore..you will get less cooling. but you will have to do some testing to see if it will compromise your system. I would just get the correct ID tubing and not loose sleep over it. my 2 cents.