HZJ75 - I want to be SVO enabled...

[Aesk_HZJ75 Junior Member Find all posts View Profile Close Aesk_HZJ75]

Hi all, mechanical novice and first post here.
As i'm looking in to WVO/SVO stuff and this site keeps being a main source of info, I thought i'd better get involved.

I've just purchased a 1996 HZJ75 Troopy a couple of weeks ago, and intend to be travelling around Oz in two months time.
The vehicle is a blank canvas – and pretty stock aside from 33's and 2 inch lift, it has what I believe to be two 90l stock tanks.

So from what i've learnt in the last couple of weeks the current plan is this;

• Enable/convert front tank for SVO, rear for diesel (as per ironfarmer).
• Run transparent 11mm ID fuel line for send and 8mm ID for return
• SVO tank » 30 plate heat exchanger » heated CAV filter » relocated solenoids » Inline filter » IP

Main & Aux tanks swap
Originally I thought i'd use the aux tank for SVO, but then I read ironfarmer's logic on using the front, which made sense to me. I thought i'd stick to the stock solenoid's initially and if it fails step up to a 6 valve pollak. I like the idea (TroopyHZJ75 and others are using) of capacitors for delay on the return line. I figured in case the main fuel selector solenoid failing, it is likely to remain open to the primary rather than auxillary tank (can anyone confirm this?). Given I am having SVO in the main tank, i'd want to swap over the lines into the solenoid so that it defaults to the dino tank in a failure. So now the little green light on AUX tank means SVO, though the gauges are swapped, so i'd have to flip those wires over as well. I think this is all ok.

Layout
I'd rerun the main tank lines with transparent 11mm hosing and return with 8mm hosing. From the tank through 11mm pipes to the FPHE, to a CAV filter (possibly heated?), then to the solenoid, then just before the IP, a little inline filter. I'd try to mount the CAV as the highest point in the line to trap air, and have the FPHE, CAV and solenoid as close to the IP as practical.
I would like to keep the return line functioning as it is (rather than a return loop), to give a bit of heat to the tank and constantly cycle the oil through the filters.

The questions

1. When people refer to fuel line sizes, is the standard reference internal diameter?
2. Do I need a booster pump? if so how do I choose one? I have seen references to too much/too little pressure being bad...
3. Are CAV filters the filter of choice for this SVO application, any other suggestions?
4. Would the heated filter be helpful, or just unnecessary?
5. Anything else?

I'm not too concerned with having to run SVO at colder temps for now, if it runs when it's 10ºc outside, that's great.

I haven't actually bought anything for it yet, as I wanted to get some feedback to make sure i'm on the right track, particularly as there seem to be several people who have been running troopy's and 1hz's on SVO for years on this forum. I'd prefer use the experiences gained on this forum and do it right the first if possible!

Any recommendations and feedback greatly appreciated.

Cheers,
Kit

[Tim-HJ61 Donating Member Find all posts View Profile Close Tim-HJ61]

Re: HZJ75 - I want to be SVO enabled...

Welcome aboard Kit,

Well done for doing all your research.

Just a few initial thoughts.

>>>>Pollack valve.
You cannot delay the return switching with the Pollack. They have one motor that drives two plungers that change both sets of 3 lines at the same time. There is no way of changing this unless you buy 2 x 3 port Pollacks, or 2 x 6 ports and not use all the ports. Best to invest in some good three way solenoids from the start with a 12mm orifice to ensure no restriction.


>>>>Fuel line.
Yes, the standard measurement for rubber fuel line is internal. Unless you buy air line, in which case it is an external measurement. Air line wall is a bit over 1mm I think, so 10mm OD is really less than 8mm ID. For a 6 cyl diesel using up to 16l/100km, larger diameter is a good thing to cater for the increased viscosity of WVO.

>>>Do I need a booster pump? if so how do I choose one? I have seen references to too much/too little pressure being bad...

Not unless your fuel lines are too small. IMHO, it is much more reliable to have large bore - 12mm ID - fuel lines, than have to install a fuel pump


>>>>Are CAV filters the filter of choice for this SVO application, any other suggestions?
They are popular. Elements are cheap. If you mount them in the opposite flow to the arrows, the crud and bits settle into glass bowl first and you can see what you have in the filter.

On the other side, they are really messy to change. There are three large and one small O rings that must be placed in their correct position when doing them up again. You'll need space under them to put an ice-cream container or something to catch the mess and the O rings when you change the filter. I prefer a spin on.

>>>Would the heated filter be helpful, or just unnecessary?
Always helpful, but not necessary. They are useful if you end up with high melting point fats in your oil, and in cold climates to aid a quicker changeover.

>>>Anything else?

Others will have more comment on your setup of WVO with a 1Hz.


Tim

[Aesk_HZJ75 Junior Member Find all posts View Profile Close Aesk_HZJ75]

Re: HZJ75 - I want to be SVO enabled...

Thanks for the feedback Tim.

I'd hoped to keep the existing solenoid, and only change to a new solenoid or pollack in case of a failure (still not sure on Pollak vs Solenoid) – though your post made me realise the stock solenoid probably only has 8mm connections. So I guess i'll check that on Monday when i'm back home and if it's not big enough buy a new pair of solenoids or pollaks to suit. What sort of valves are you using Tim, can you recommend some good 3 way 12mm solenoids?

The place i've sourced the fuel lines from doesn't have 12mm, only 11mm so i'm hoping that will be sufficient, unless someone can point me in the direction of 12mm transparent fuel hose..
Otherwise I might go ahead and purchase the fuel lines as i'm looking at a 3 week delivery time.

On fuel line / coolant line sizes
- If i'm running 11mm hosing, would I want to make sure all connections – the filter, solenoid and FPHE all accept 1/2" connections?
- I'm guessing it's ok to reduce down to stock 8mm line after the solenoid, just before the IP as the oil would be heated by then?
- On the FPHE's I can find are 1/2" connectors, though my coolant lines are larger is this likely to put extra pressure on the coolant system?

I found it hard to find a heated CAV with 1/2" connectors so i'll leave that idea for the time being and just insulate whichever filter I opt for along with the FPHE.
I'm still not quite sure if CAV or spin on is the way to go.

Cheers.

[craigcurtin Senior Member Find all posts View Profile Close craigcurtin]

Re: HZJ75 - I want to be SVO enabled...

Thanks for the feedback Tim.

I'd hoped to keep the existing solenoid, and only change to a new solenoid or pollack in case of a failure (still not sure on Pollak vs Solenoid) – though your post made me realise the stock solenoid probably only has 8mm connections. So I guess i'll check that on Monday when i'm back home and if it's not big enough buy a new pair of solenoids or pollaks to suit. What sort of valves are you using Tim, can you recommend some good 3 way 12mm solenoids?

The place i've sourced the fuel lines from doesn't have 12mm, only 11mm so i'm hoping that will be sufficient, unless someone can point me in the direction of 12mm transparent fuel hose..
Otherwise I might go ahead and purchase the fuel lines as i'm looking at a 3 week delivery time.

On fuel line / coolant line sizes
- If i'm running 11mm hosing, would I want to make sure all connections – the filter, solenoid and FPHE all accept 1/2" connections?
- I'm guessing it's ok to reduce down to stock 8mm line after the solenoid, just before the IP as the oil would be heated by then?
- On the FPHE's I can find are 1/2" connectors, though my coolant lines are larger is this likely to put extra pressure on the coolant system?

I found it hard to find a heated CAV with 1/2" connectors so i'll leave that idea for the time being and just insulate whichever filter I opt for along with the FPHE.
I'm still not quite sure if CAV or spin on is the way to go.

Cheers.

As Tim has said - CAVs are easy but messy - in my first car it was under the bonnet and made a hell of a mess every time it needed changing - on my suburban i have placed them on the side frame rails and it is much better now as the mess just goes straight into an oil catch container - but you still will get yourself covered in oil etc.

A CAV will cost you somewhere around $50-$60 - have a look at the write up recently by JonnoJack (i think) about a better filter - he manufactured one himself - but in the thread was a link to a stainless steel filter that used the standard water filter elements for aonly around $140 - when time and money permit i intend to redo my setup with these and modify the housings with a drain valve to further reduce mess

You are far better looping your return - you do not want hot oil going back to your tank as this will just promote growth and oxidisation. Keep the heat under the bonnet. It is your friend there.

Have seperate filters for both fuels - this will take more room but will mean you are not forced to stop when your vegoil filter clogs up - but can rather switch to your BIO/DINO fuel tank and continue on until it is convenient to change. I can not tell you how many times i had to change a clogged filter either on the side of a busy road or in the rain (murphy!!) in the Toyota Surf when i had a single filter for both fuels.

Make sure you install a pressure gauge on the fuel line so you have an idea of what your normal pressures look like and can then anticipate when a filter change will be needed.

Craig

[Grampiansmerc Member Find all posts View Profile Close Grampiansmerc]

Re: HZJ75 - I want to be SVO enabled...

I would use large diameter fuel line between tank and heat exchanger/fuel heater then 10 or 8mm after that. It is often easy to change diameters of fuel lines on the components - ie I change from 1/2 inch (12 or 13 mm) to 3/8 (10mm) at the heat exchanger then down to 5/16 (8mm) at the valve to match the vehicles plumbing.

On my crusier my 2H motor does not have a diesel return line (it is factory looped) so only one valve is necessary. I assume the 1HZ motor has return lines...?

If you can, use multifuel line (pink colour), which is used in heavy industrial applications This is air, water, diesel proof lines that do not collapse when heated and under vaccum!

I have used CAV filters - I can disconnect mine and remove from the vehicle without spillage (a drop or two can be caught with a rag) and refit new filter element over a catch tray - then return to vehicle with a new to reconnect.

[Aesk_HZJ75 Junior Member Find all posts View Profile Close Aesk_HZJ75]

Re: HZJ75 - I want to be SVO enabled...

Cheers Grampiansmerc, i've now ordered the fuel lines, 11mm bore for supply and 8mm bore in case I need it – it's listed as being compatible with biodiesels, SVO etc.

I've bought a couple of 1/2" solenoid valves, though in retrospect I only needed one for the supply, as I could have used one of the existing smaller bore solenoids for the return (if it's kept). The 1HZ has return lines to both tanks, two solenoid valves controlling supply and return lines respectively. Maybe i'll use the spare for the water system, and then i've also got it as a backup.

I'll probably just use the full 11mm bore right up to the supply solenoid, which I hope to be within 300mm of the injector pump.

I've also ordered a dual display gauge with an oil temperature and vacuum sensor, installing one of these seems like common sense to be able to know what's going on under the hood.

Thanks Craig, I hadn't realised the heat of the return could promote growth & oxidisation in-tank.
l'll definitely be running separate filters for the diesel and SVO, except a small inline one before the IP, i'm also now looking at adding a 10 plate heat exchanger after the supply solenoid.

I've found some heat exchangers with 3/4" fittings, which appears to be the what my coolant lines are, so I'm thinking about getting three of these.
- 30 plate for main SVO heating
- 30 plate for hot water
- 10 plate before the IP that heats both SVO and diesel.

I'm not sure how necessary the 10 Plate is, but figure even if it only adds 20ºC to the diesel, that's 20ºC less thermal shock the pump will receive when switching to (what will hopefully be) 80ºC SVO. It also gives the SVO another boost to compensate for heat loss from the line.
One thing i'm still trying to work out is if three heat exchangers is likely to put any flow restriction/pressure on the water pump, especially the 10 plate which I believe would have less flow.

Haven't thought more about filters yet, CAVS vs spin etc, though i am thinking about collecting & filtering oil on the road, which might make a visible water trap a good visual indicator of the WVO processing.

I'll probably loop the SVO, but still not sure on the diesel, I might leave that as a returning line. My logic here is one of air trapping, if I suspect an air leak, I can switch to a returning line (diesel) and see if symptoms clear. I also saw reference to a limited return line, which i'll look into as well.

Cheers.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: HZJ75 - I want to be SVO enabled...

You wrote

One thing i'm still trying to work out is if three heat exchangers is likely to put any flow restriction/pressure on the water pump, especially the 10 plate which I believe would have less flow.

If the heat exchangers are connected in parallel, across the heater circuit of the engine, then all heart exchangers will receive the same temperature coolant, providing maximum heating in each.
The only downside to this connection is that it is possible that the cabin heater will have less coolant flow available to it.

Winter is on its way, so you will soon be able to verify the cabin heater operation in cold conditions for your location.
Unless you have problems keeping the cabin of the vehicle warm enough, I would not change from the parallel connection.
If you are not using the hot water from your second 30 plate (eg while driving) then you could connect it in series with the other 30 plate heat exchanger (oil heating). This will reduce the coolant flow bypassing the cabin heater.

I hope this helps,
Tony

[Aesk_HZJ75 Junior Member Find all posts View Profile Close Aesk_HZJ75]

Re: HZJ75 - I want to be SVO enabled...

Ah, that does help a lot thanks Tony – timely too, I was just looking in to this further.

Putting them in parallel hadn't occurred to me, I was going to connect them up in series (parallel to heater, when open).
I was trying to find the coolant flow of my water pump (without luck) with which to do the calculations on flow.

I will try with both 30's in series and put the 10 in parallel to begin with.

Thanks.

[craigcurtin Senior Member Find all posts View Profile Close craigcurtin]

Re: HZJ75 - I want to be SVO enabled...

Can i suggest to you that you might look at a helton dual cool for your first stage WVO heating and the hot water side ? This is what i have done with my suburban

So down the back of the car is my Oil tank and the helton dual coil - one coil is used to heat the oil before it goes to the WVO pump and the filters (i have my CAV filters at the rear of the car), the 2nd coil is to provide a hot water loop when we go camping etc. I find this can deliver a couple of litres of water per minute at 45c or so. (I had to add a Bosch Water pump to this circuit to push my coolant from front to back)

Then under the bonnet put your 30 plate FPHE - have both fuels run through it (add a little bit of SVO to your Diesel tank to remove issues with lubrication of DINO at higher temps)

This means you will have both fuels at the same temp when they hit the IP so no issue of thermal shock (not sure i believe that is even really a concern or not). The only downside is that it takes longer to purge this way as you have a FPHE full of fuel to go through to purge properly.

MY 30 FPHE hoolds 400mls of fuel so it only adds about 20 seconds to my purge time

I do what you have suggested - i have a return line on my BIO startup tank to help with purging air and a looped return on my WVO tank

Craig

[RODEONICK Too Busy To Bio. Find all posts View Profile Close RODEONICK]

Re: HZJ75 - I want to be SVO enabled...

Are the 30 FPHE good enough for your water heating requirements? (tony can you help?) On my truck i use the TWINE HX for showers etc on my old truck i had a helton dual coil HX for heating fuel.

The Heltons are great and they customise too for quite reasonable rates i thought.

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: HZJ75 - I want to be SVO enabled...

I did tests using a 4 channel data logging thermometer on a 10 plate FPHe and later, on a dual coil Helton, both on my Mercedes 300D.

With the 10 plate FPHE, the fuel temperature at the FPHE outlet was with in 5 degrees C of the coolant temperature under all driving conditions, including warm up.
The Helton was unable to achieve anything like this. I provided the test results to Helton at the time.

Tim-HJ61 uses a 30 plate on his Tojo because of the high flow of fuel in the Toyota return line on that model.

We are currently using a blend of Used Cooking Oil and stale petrol (some 2 stroke in it as well) from a local bike shop. I have no conversion on my W123 '85 300CD and my wife's W124 300D has had the fuel thermostat removed, allowing the stock fuel heater to operate all of the time. Not particularly effective but does overcome most issues with a little HMP in the fuel during winter.
Regards,
Tony

[RODEONICK Too Busy To Bio. Find all posts View Profile Close RODEONICK]

Re: HZJ75 - I want to be SVO enabled...

Tim-HJ61 uses a 30 plate on his Tojo because of the high flow of fuel in the Toyota return line on that model.

Tony thanks for your response.
the reason i asked was for the HWS he is planning to install. would a 30 plate heat enough for say a fresh water flow of say 6LPM to 45C? i just wouldnt like for him to buy one and install it for the purpose of a hot water camp shower and it not be adequite that was all.
Cheers

[RODEONICK Too Busy To Bio. Find all posts View Profile Close RODEONICK]

Re: HZJ75 - I want to be SVO enabled...

Oh and do the 12ht's have a return line? i know the 2H doesnt which seems strange when the engines are quite similar. I wonder why they did that?

[Tim-HJ61 Donating Member Find all posts View Profile Close Tim-HJ61]

Re: HZJ75 - I want to be SVO enabled...

Oh and do the 12ht's have a return line? i know the 2H doesnt which seems strange when the engines are quite similar. I wonder why they did that?

Hi Nick,

Yes, the 12h-t has a return line, and the 2H doesn't. I loop mine when on veggie.

Why the difference?? Don't know.

It 'might' have something to do with the extra fuelling management required for a DI and factory turbo. What I'm thinking is that inside the outlet that turns into the return pipe on the 12h-t is a pressure release ball valve, which in part regulates the internal pressure inside the IP. There is a similar hole in the 2H IP, perhaps the engineers figured they could use it for something useful. On the 2H it is referred to as an air bleed for the IP. I've often wondered if a 12h-t ball valve could be installed in that hole and for it to be combined with a valve in order to speed up the purge on the 2H. Not a necessary conversion and probably with minimal gain, but something that I have wondered about.

It also might be something to do with cooling the fuel, and a reflection on the generally higher heat load of a turbo motor.

Remember these were Toyota's first factory turbos. They came in before the Nissans. To some extent they had an experimental or developmental role in a period of growth in interest in 4wd passenger diesel. They soon moved to the 1Hz and 1HD-T and the 12h-t was only produced for a few years - 1985 - 1989 I believe, consigning them to legendary status.

Tim

[Tony From West Oz Vice Chairperson of WARFA Find all posts View Profile Close Tony From West Oz]

Re: HZJ75 - I want to be SVO enabled...

Tony thanks for your response.
the reason i asked was for the HWS he is planning to install. would a 30 plate heat enough for say a fresh water flow of say 6LPM to 45C? i just wouldnt like for him to buy one and install it for the purpose of a hot water camp shower and it not be adequite that was all.
Cheers

Nick, If you have used a Helton dual HE in the past, then you know its performance. A 30 plate FPHE will transfer a LOT more heat to the water than a Helton would. In fact, you would need to add cold water if the engine is at operating temperature, unless you have plenty of flow.

Heltons are good for what they were designed for - heating a small amount of water so you don't have a COLD shower.

FPHE are designed for maximum heat transfer from one fluid to the other. The bigger they are, the greater the heat transfer.

Regards,
Tony