Unconfigured Ad Widget

Captain Echidna · 3 October 2006, 10:34 AM

Re: Mercedes 300D conversion

It is amazing how different the cars are from my 78 to your 81. You have put stuff where my car came with stuff (like self leveling suspension resivour) and I put stuff where you have a black box.

Are you goin to put the lift pump after the filters and fuel selector (Bruce style) or before the selector (and use 2 fuel pumps, Tony style)? I have done extra fuel pump and before the selector, but found the new pump would not pump veg oil, so used it for diesel.

And if you use the original tank for veg oil, I found I could get the filters to last longer i I used 2 one on the original fuel feed line, and one on the (original return) line and used that to feed as well, both into a T fitting. By using 2 in paralell they can get a lot more blocked and still feed enough oil to keep the car going at 110.

Fitian · 3 October 2006, 01:58 PM

Re: Mercedes 300D conversion

Hi Chris,

Originally posted by Captain Echidna View Post

It is amazing how different the cars are from my 78 to your 81. You have put stuff where my car came with stuff (like self leveling suspension resivour) and I put stuff where you have a black box.

Yeah I tried to follow what Bruce has done but I had this black electric box in the same location where Bruce installed the heat exchanger. I thought of moving it but the wiring does not allow it. This is why I thought of this bracket.

Originally posted by Captain Echidna View Post

Are you goin to put the lift pump after the filters and fuel selector (Bruce style) or before the selector (and use 2 fuel pumps, Tony style)? I have done extra fuel pump and before the selector, but found the new pump would not pump veg oil, so used it for diesel.
And if you use the original tank for veg oil, I found I could get the filters to last longer i I used 2 one on the original fuel feed line, and one on the (original return) line and used that to feed as well, both into a T fitting. By using 2 in paralell they can get a lot more blocked and still feed enough oil to keep the car going at 110.

I am going to use the car's originsl pump only and it will be after the filter and the fuel selector. I wrote to Bruce asking about what brand pump he used for the second fuel pump and he told me that he is using the original pump and it works fine with the oil.

If you used the original tank for veg oil, did you change the fuel line to a larger diameter to take it to the HE or how did you do it? Have you got a thread with your car conversion to learn from you please.

Cheers

Fitian

Captain Echidna · 3 October 2006, 05:32 PM

Re: Mercedes 300D conversion

I did use the original tank, but used garden hose for the fuel line. which I would not reccomend, andI should have heated it with nylon from the start.
I havent a thread yet, bt will get onto it! It is exceptionaly similar to Tony's on this site, Probably the last thread on this site.
I have wondered about changing the system to pump after, which would allow a blend of startup fuel, as the pump cant even pump veg oil/ diesel mix at 50/50.

Fitian · 7 October 2006, 11:27 PM

Re: Mercedes 300D conversion

I need some advise on how to run the vegy oil hose from the back of the car to the engine. Is there a ready made holes for the hose to run through or do I have to drill a hole? Where is the best place?

Also I am not that good with connecting all the hoses between the Pollak valve and the engine. Any help would be highly appreciated.

Thanks

Fitian

Fitian · 9 October 2006, 04:23 PM

Re: Mercedes 300D conversion

Hi Tony,

These are the questions I told you about. Please help.

Cheers

Fitian

Tony From West Oz · 9 October 2006, 07:44 PM

Re: Mercedes 300D conversion

Originally posted by MB300D81 View Post

I need some advise on how to run the vegy oil hose from the back of the car to the engine. Is there a ready made holes for the hose to run through or do I have to drill a hole? Where is the best place?

Also I am not that good with connecting all the hoses between the Pollak valve and the engine. Any help would be highly appreciated.

Thanks

Fitian

In both of the 300Ds which I have converted, I tied the new fuel line and in one case the coolant lines, bundled with the fule lines and insulated with pipe insulation, to the metal fuel lines under the car, using nylon cable ties. My only concern was where the fuel lines pass between the rear subframe and the suspension. Photos of this part of the conversion:
Under side - rear

Under side - front

In engine bay

Hot coolant line from engine

Coolant retuirn to engine

I believe that it may be possible to run the hoses inside the cabin from the bonnet hinge area, under the carpet and seats to the boot, buit you would need to protect the hoses from abrasion where they pass thru the bulkheads.

Fitian · 10 October 2006, 02:08 AM

Re: Mercedes 300D conversion

Thanks Tony,

When I tried to get the new fuel hose through to the boot of the car, I faced this one problem which is the right place to run it through. Going by your first photo it shows the hose going up but I could not tell to where? Did you have to drill a hole or did you run it through the drain holes under the spare wheel? Also the other end at the engine - Your photos do not show. The reason I asked is because I do not want the hose to be either squeezed at the boot or over heated at the engine.

I have finish connecting the coolant cycle. But I do not know how to connect the hoses to the Pollak valve. There are many hoses going in nd comming out of the diesel fuel filter and I am not sure how to do it. You also advised Bruce to block the banjo bolt - not sure what or where is it. Do you think you can fix me up with this? I'd really like to sort this on the week end. Thanks Tony.

Cheers

Tony From West Oz · 10 October 2006, 03:01 AM

Re: Mercedes 300D conversion

Here is the image for in the engine bay:

At the boot end, I drilled a hole in the wheel well (behind the passenger side rear wheel), so that the fuel hose passed thru this hole, above the muffler heat shield.
Have a look under the car and you will see how I routed the hose from there between the rear subframe and the rear 'swing arm'.

What connection configuration were you considering?
Feeding the individual fuels thru the Pollak valve prior to the fuel pump and the return lines thru the Pollak also, sharing the fuel pump and main diesel fuel filter for diesel and veggie oil? or;
Reconfiguring the diesel filter to before the Pollak so the fuels do not share this filter, but share the fuel pump. In this case, the hoses which connect together on top of the stock fuel filter need to be isolated from the diesel fuel filter. There is a cxircular firring, bolted to the top of the diesel filter housing. undo thisbolt and you will find that it is hollow, allowing fuel to pass thru a small hole in the housing, to the return lines. In the reconfigured location, this will either cause unfiltered oil to be sucked from the diesel tank thru the return line or for the returning vegetable oil to pass to the diesel tank. This is why I recommended that the Banjo Bolt (the circular fitting resembles the sounding box on a Banjo) which is hollow would need to be either replaced with a solid bolt of the same thread pitch, or epoxied up to prevent fuel flow.
If you can draw a diagram of it, you could make it easier to connect the hoses to the correct places.

I have drawn up several versions of conversion diagrams at this thread You may be able to adapt onte of them, using MS Paint or a similar drawing package.

Tony

Fitian · 10 October 2006, 08:45 PM

Re: Mercedes 300D conversion

Thanks Tony for explaining how to run the oil hose. I'll work on it on the week end.

Originally posted by Tony From West Oz View Post

What connection configuration were you considering?

Feeding the individual fuels thru the Pollak valve prior to the fuel pump and the return lines thru the Pollak also, sharing the fuel pump and main diesel fuel filter for diesel and veggie oil?

I seem to understand this configuration better than the other one - Mybe because it is easy for my little brain to take. But what if the return diesel is connected to the Pollak valve then back to the diesel tank and only the oil return is looped back to the heat exchanger rather than going back to the vegy oil tank? This return oil will be hot since it is comming from the engine .. Does this sound correct?

With this config. do you think the original fuelp pump will cope or will I need an extra fuel pump? I know Bruce says it is working for him but what do you recommend?

In regards to sharing the fuel filter ... will that be too much for the filter? The oil will be filter to 5 micron and will me hot comming from the HE. what you think?

Which configuration you think is best for the car Tony?

I look forwards to your reply.

Big thanks

Fitian

Tony From West Oz · 11 October 2006, 12:05 AM

Re: Mercedes 300D conversion

Originally posted by MB300D81 View Post

Thanks Tony for explaining how to run the oil hose. I'll work on it on the week end.

I seem to understand this configuration better than the other one - Mybe because it is easy for my little brain to take. But what if the return diesel is connected to the Pollak valve then back to the diesel tank and only the oil return is looped back to the heat exchanger rather than going back to the vegy oil tank? This return oil will be hot since it is comming from the engine .. Does this sound correct?

With this configuration, the connection from the diesel filter (shared) will also need to be blocked off, as the veggie would return to the diesel tank when veggie is selected.

With this config. do you think the original fuelp pump will cope or will I need an extra fuel pump? I know Bruce says it is working for him but what do you recommend?

The fuel pump will pump veggie as well as it pumps diesel. I am using the fuel pump for 'veggie only' in one car and both fuels in the other car I have here.

In regards to sharing the fuel filter ... will that be too much for the filter? The oil will be filter to 5 micron and will me hot comming from the HE. what you think?

Which configuration you think is best for the car Tony?

I is not so much "which configuration is best for the car?" as "which conversion you are happy with using." I will try to list the advantages and disavantages of each configuration below:
Configuration #1 - Fuel selection valve before the stock fuel pump, both fuels share the diesel filter, air bleed from diesel filter disabled, looped return on veggie, return to tank for diesel.

Easy to install, no added fuel pump needed.
Long purge time due to amount of fuel in the shared filter. This also sends veggie to the diesel tank and may affect cold starting after a while.
Bleeding of fuel system after diesel fuel filter changes is more difficult than unconverted engine.

Configuration #2 - Fuel selection valve before the stock fuel pump, relocate the diesel filter to before the fuel selection valve, air bleed from diesel filter disabled, looped return on veggie, return to tank for diesel.

Requires more modifications to fuel system than #1.
Shorter purge time due to no shared filter. Significant reduction in amount of veggie sent to the diesel tank.
Bleeding of fuel system after diesel fuel filter changes is more difficult than unconverted engine.

Configuration #3 - Separate fuel pumps for diesel (new electric fuel pump) and veggie (stock fuel pump), fuel selection valve between filters and IP inlet, return line returned to appropriate tank for the fuel used, diesel filter air bleed not blocked, air bleed could be provided for veggie filter (to veggie tank return line if fitted).

Requires added fuel pump and some re-arrangement of plumbing to allow fuel pump for veggie use only.
Shorter purge time due to no shared filter. Significant reduction in amount of veggie sent to the diesel tank.
Bleeding of fuel system after diesel fuel filter changes is easier than in unconverted engine (electric pump for priming diesel side).

I look forwards to your reply.

Big thanks

Fitian

I hope that my comments above have helped.
Tony

Fitian · 11 October 2006, 02:32 PM

Re: Mercedes 300D conversion

Tony,

Thanks for taking the time to explain things for me. I think configuration #2 is what I can go by for now. and maybe later I can add an extra pump.

Where to buy that extra pump do you know?

When you said ...

Bleeding of fuel system after diesel fuel filter changes is more difficult than unconverted engine.

Did you mean that it will take longer to bleed, going to be too hard. Could you please explain why?

Thanks Tony

Regards,

Fitian

Tony From West Oz · 12 October 2006, 01:21 AM

Re: Mercedes 300D conversion

Originally posted by MB300D81 View Post

Tony,

Thanks for taking the time to explain things for me. I think configuration #2 is what I can go by for now. and maybe later I can add an extra pump.

Where to buy that extra pump do you know?

I have bought small electric fuel pumps on eBay for around $25 - $40 ea. They need to be able to pump diesel, so in general, the Facet bran or similar should be fine.

When you said ...

Bleeding of fuel system after diesel fuel filter changes is more difficult than unconverted engine.

Did you mean that it will take longer to bleed, going to be too hard. Could you please explain why?

The fuel filter is on the suction side of the fuel pump. The air bleed is blocked. You will need to open the fuel piping somewhere after the fuel pump or loosen the fuel pipe going into the IP, so that the air from the new (empty) filter can be pushed out of the fuel system and be replaced by fuel.

Thanks Tony

Regards,

Fitian

Fitian · 21 October 2006, 07:44 PM

Re: Mercedes 300D conversion

Hello Tony,

In regards to the Banjo Bolt. Do I block it only from the bottom or do I also block the three holes please?

Thanks

Fitian

bruceT · 22 October 2006, 06:09 PM

Re: Mercedes 300D conversion

Fitian, you want the return lines to work and so route the fuel back to the Pollak valve (or to the tank etc), so you have to block the bottom of the bolt only. I used metal epoxy.

If you block all the holes of the banjo bolt you will have a nice mess to clean up when the return lines burst

Unconfigured Ad Widget

Announcement

Mercedes 300D conversion

Mercedes 300D conversion

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment

Comment