Water - Fuel - Separator - Theory - ????????

[Scott06]

But I'm talking about an I/O, hence it being in the I/O section

In my particular case, a carbed 3.0.

Generally speaking, running relatively high octane fuel, in relatively low compression motors, is not advised. Mainly because the spark, without the extra compression, sometimes isn't enough to ignite the fuel.

When an engine calls for higher octane fuel it is because the compression ratio is higher and or the ignition advance is greater and the engine will be more prone to ping /detonate / preignition which left unchecked will severely damage an engine. There is no harm nor ill effect running 91 or 93 in and engine that calls for 87, fuel will ignite just fine if the engine is in good working order. Only your wallet will empty faster...

on the original 3.0 pump mounter filter this will in the same way as other filters separate water , on my 1990 that the original ceramic element was in for many years, the spring on the bottom was rusty from water accumulating there.

 

[emilime75]

Guys, I'm fully aware of the benefits of higher octane fuels and their anti knock/pre detonation characteristics, but there's a trade off when used in lower compression motors and "less than aggressive" ignition timing.

An "octane" rating is simply the detonation rating of the fuel, nothing more. It doesn't necessarily mean it's higher in quality and will make more power. On the contrary, if your engine can't take advantage of that characteristic by using higher compression and/or tuning with aggressive timing, it's actually less efficient, meaning it actually has less energy when ignited than a lower octane fuel. This is the down side and is due to the additives needed to raise the octane rating. The result is slightly reduced power and efficiency, in our case GPH.

If you want to take that further, the same additives that give it the high octane rating and prevent it from igniting/detonating at lower temps, i.e. knocking/pre-detonating, make it ignite slower. This means from when the piston comes up on the compression stroke, and the spark plug fires, it will actually take a little longer to ignite and combust than a lower octane fuel. This can be a benefit in some cases, as it is with the whole pre-detonation issue, but if your engine isn't having those problems then you see absolutely no benefit. In fact, you're again possibly losing performance because, in essence, the ignition timing is being retarded.

So, while no, running higher octane fuels than what your engine needs worn hurt anything...mechanically. it will hurt performance and efficiency slightly, possibly to little to notice. Either way, there's no point to it, unless the motor needs it. It's money wasted.

 

[GA_Boater]

Folks - What does octane have to do with emilime75 installing a water separator/filter? Have you decided to install one or forget about it?

 

[emilime75]

I have, it was ordered before I even started this thread. I understand its importance, was just looking for some more insight... but then the thread got derailed, partially my own fault.

 

[Lou C]

I have read that the only 'true' water separating filters are the Racor with the bowl, or possibly similar ones made by Sierra and others, they (Racor) are a lot more expensive and the bowls can be tough to get off, but if you have had a water problem in your fuel are probably the best way to go, if you have the room to install one.

 

[Grub54891]

The spin on work fine if you service it annually, or if you get a lot if water quickly, any filter will allow water through. It certainly won't Hurt to put one on of any kind.

 

[GA_Boater]

I have, it was ordered before I even started this thread. I understand its importance, was just looking for some more insight... but then the thread got derailed, partially my own fault.

I didn't want to say that.

 

[robert graham]

I cut my cartridge filter open once several years ago just to see what was inside....looks for the most part exactly like an automotive oil filter....pleated media....I'm confident the media materials are different but very similar. My motor is a 90HP with a 12 gallon portable tank so water intrusion is not much issue, but an inboard/outboard, built-in tanks water can be a real killer issue....

 

[Grub54891]

I cut my cartridge filter open once several years ago just to see what was inside....looks for the most part exactly like an automotive oil filter....pleated media....I'm confident the media materials are different but very similar. My motor is a 90HP with a 12 gallon portable tank so water intrusion is not much issue, but an inboard/outboard, built-in tanks water can be a real killer issue....

Not to derail your train, but I've seen plenty of outboards with water intrusion. Mostly from leaving the vent on the cap open.

 

[Bondo]

I have read that the only 'true' water separating filters are the Racor with the bowl, or possibly similar ones made by Sierra and others, they (Racor) are a lot more expensive and the bowls can be tough to get off, but if you have had a water problem in your fuel are probably the best way to go, if you have the room to install one.

Ayuh,.... The Oem steel can filters work exactly the same, ya just can't see the water in the bottom of it,.....

 

[robert graham]

I think the past guard only approves the clear plastic drainable bowls for external transom mounting.....but not for inside/under deck locations.....so if bowl cracks/leaks it won't cause a fire.....

 

[dingbat]

I think the past guard only approves the clear plastic drainable bowls for external transom mounting.....but not for inside/under deck locations.....so if bowl cracks/leaks it won't cause a fire.....

Plastic bowls can be mounted inside/ under deck locations when used with an outboard.

Plastic bowls can not be used below deck on inboard mounted motors

 

[Lou C]

You can get them with metal bowls from both Racor and Sierra..