Diesel fuel filter for petrol?

[Gazzar]

I'm building a lightweight, and intend to use a petrol engine, on megasquirt.

For  aesthetic reasons I don't like in-line filters, so was wondering would a series, or tdi200 diesel filter work instead?  I can't see why not, I'd have thought diesel filtration would be better than petrol, but...........

This would be between the tank and the low pressure  electric fuel pump.

G.

[RedLineMike]

Currently using a td5 filter & filter head on my Ls V8 without any issues 

[Bowie69]

Either diesel or petrol filter (from a EFI vehicle) will be fine enough.

[Gazzar]

Thanks, all, I can think about the best location now. Probably where the pre filter goes on export models, between the tank rigger and the bulkhead rider.

[smallfry]

Only possible problem I can think of is that petrol ,might degrade the rubber seals ?????

Wouldn't have thought so, but keep an eye on it ?

[Landrovernuts]

I used a series 3 diesel filter on my V8 ninety for 10 years and a similar filter on my petrol series 1 since 1987 with no problem. 

Toby

[Gazzar]

Thanks. I think if I go for a good brand of filter I should be okay.

[Snagger]

Diesel filters tend to be much more effective than petrol in-line filters - they are much finer and trap more, which is why they have to be so much bigger to allow the fuel flow rate.  I don't think an in-line filter would be a good idea with fuel injection, only carbs.

Because of how effective they are, diesel filters need positive pressure, not suction, so you'll need to fit the filter after the lift pump, not before it (just like LR diesels).

[ballcock]

3 minutes ago, Snagger said:

Diesel filters tend to be much more effective than petrol in-line filters - they are much finer and trap more, which is why they have to be so much bigger to allow the fuel flow rate.  I don't think an in-line filter would be a good idea with fuel injection, only carbs.

Modern petrol vehicles use inline filter canisters which are more than adequate for large volume injected engines. If fitted on the chassis rail with a "P" clip you wouldn't know it was there. (until it blocks up).

[Snagger]

Ok.  I thought from the context and the comment about aesthetics that the type in mind was like those small types fitted to carb fed engines, not a bigger modern type.  I thought the filters on RV8 EFIs must have been quite a lot bulkier than the carb fed engines had.

[Escape]

The inline filter on the GEMS 4.0/4.6 isn't bigger than that on an old 4-pot petrol on carbs. The Bosch 4.0/4.6 doens't even have a replaceable filter, just one built into the fuel pump in the tank. More recent V8s are described as having a lifetime filter, I think also in the tank.

Diesel being more viscous than petrol needs better filters, so you should be OK using those. I checked the Mann filter catalogue, but couldn't find any different specs for petrol or diesel.

Filip

[Bowie69]

RRC filter is about 4" long and about 1.5" round, from memory, but has awkward inline fittings.

[Gazzar]

The filter should be before the pump, though. And is in export spec series models, as part of the sediment filter.

I think sediment filter first, pump, then diesel filter on bulkhead. That should blend aesthetic requirements and petrol injection requirements.

Thanks!

[Snagger]

1 hour ago, Gazzar said:

The filter should be before the pump, though. And is in export spec series models, as part of the sediment filter.

I think sediment filter first, pump, then diesel filter on bulkhead. That should blend aesthetic requirements and petrol injection requirements.

Thanks!

That'll work.  But you won't get good fuel delivery if the main filter is before the lift pump.

[Gazzar]

It's for mega squirt.

So sediment, low pressure electric pump, electric, standard diesel filter, high pressure electric fuel pump.

Oh, and times two to the standard diesel filter, as I'm running twin tanks.

Don't forget the sediment filter is on the chassis rail so is low down at the same level as the track.

[Snagger]

That seems unduly complex and expensive.  The more parts you fit, the more there are to leak.  I'd recommend running the fuel through the tank selector valve to the sedimenter, then the low pressure pump and onto the filter.  There is no advantage in having extra sedimenters or filters.  That's how LR did it, and how I did it on my 3 tank 109 (Tdi, with heated filter and a coolant/fuel heat exchanger for running veggoil)

[Troll Hunter]

On 12/23/2018 at 4:23 AM, Escape said:

 More recent V8s are described as having a lifetime filter, I think also in the tank.

 

Anything claimed to be "lifetime" is the subject of a con trick, particularly a fuel filter.  How does the claimant know what sort of sediment is going to be generated by, or fed into, a vehicle's fuel tank?  Please, don't rely on anything claimed to be "lifetime", and fit a proper renewable fuel filter.

Mike

[Escape]

Mike, I totally agree with you! It's the same with gearboxes sealed for life, they still benefit from regular oil (and filter) changes.

My point was that the filters are placed in the tank, as they're not supposed to need replacement before the fuel pump fails, and it's difficult to find any sort of spec for the filters.

Filip

[qwakers]

this^^

 

the renault laguna mk2 (and renault traffic van) got a terrible reputation for exploading gearboxes. the reason? sealed for life.

 

i change the oil in (all of) my family's pk series gearboxes every 50k. guess what? my laguna is now on 212k miles, on its original box, my old laguna was on 180k, my dads old trafic was on 98k and his current vivaro on 62k, the lagunas and trafics milages are totally unheard of, and people wont believe me when ive told them they're on their original boxes (but not clutches in the lagunas case lol)

Edited December 24, 2018 by qwakers

[Gazzar]

3 hours ago, Snagger said:

That seems unduly complex and expensive.  The more parts you fit, the more there are to leak.  I'd recommend running the fuel through the tank selector valve to the sedimenter, then the low pressure pump and onto the filter.  There is no advantage in having extra sedimenters or filters.  That's how LR did it, and how I did it on my 3 tank 109 (Tdi, with heated filter and a coolant/fuel heat exchanger for running veggoil)

That's good thinking, except getting the fuel return back to the active tank then becomes complex. That's where the two pumps come in. The selector electrics choose the pump, and the return is via the mechanical valve.

I'm now thinking of an in tank pump, like the RRC per tank, but one per tank.

Then I could feed to a single sediment filter and on. 

 

[Bowie69]

Much better, but why the sedimenter? Not seen any petrol powered vehicles fitted with one...

[Gazzar]

Lack of trust of fuel sources?  I grew up on a farm, we used to drag drums of fuel everywhere, goodness knows what carp they had in them.

My first LR had a sedimenter, when I did its first service it was half full of silt.  Export spec 2286 diesel.

Diesel, mind, but I can't imagine petrol injection is any less tolerant of dirt in the fuel.

I know, I know, it probably won't see nothing but the finest BP Ultimate, but I'd rather build in resilience and not need it, rather than the other way around!  Afterall I do intent to travel widely with this vehicle.

Now, does anyone know how deep a RRC efi fuel tank is?  Compared to a SWB Series?  

 

[Bowie69]

Fair enough A

 90 tank is similar in height, I think I add about 6" into the fuel pump normally.

[Gazzar]

So, they can be extended?  They look as if they can be.

 

G.

[Bowie69]

Yup,  use a strip of aluminium normally, then extend the hose, well, with fuel hose

Wires are often long enough.