View Full Version : When has blending gone too far?

2nd March 2007, 08:32 AM
Hi All,
We have recently increased the WVO component of the duel to 80%WVO/20%ULP on my son's Navara. The starting was initially harder but cycling the glow plugs 2 or 3 times prior to starting has fixed that.

There is some noise (light knocking) from the engine for the first few minutes though and although I haven't had a chance to look closely, I assume it would be the IP. This wasn't evident at 50WVO/50Dino. If this is so I'd further assume cavitation of the IP until it warms sufficiently to adequately thin the fuel.

Wouldn't this being doing the IP damage? The noise may well be valves etc too. Would reducing the WVO component of the fuel until there is no knocking be an fair indicator of the appropriate mix at the same ambient temperature?

88 Navara 4x4 with about 500km WVO!

2nd March 2007, 10:01 AM
In my experience, ULP does a pretty good job of thinning oil and I would suggest at 20% it would make your oil as thin and perhaps thinner than the 50/50 dino Blend.
You may want to try some viscosity tests on your own oil blends yourself so you can tell just where each blend is at.

To find the source of the knock I would suggest keep playing with the blends. It may be the IP or it may be from the combustion chambers. When I was using 20% ULP my car was starting fine but had a slight knock when warmed up. I assumed this to be the petrol component and reducing it back to 12-16% has eliminated it. Starts are a little slower first one of the day but you only do one really cold start and then run the engine for a much longer time so I erred on the side of what was best for the operation of the engine. I can start the car fine at the end of the day on the lower blends.
Your knock may too be someting to do with combustion even though it seems to be occouring at the opposite end of the scale to mine. If the valves in the engine need doing, I would suggest best to have them serviced to eliminate one possible source of the noise and get the engine where it sould be in the first place.

Reducing the WVO component of your blend up's the petrol component and I would be very hesitant to go more than 20% in my car but yours would be a different system and may tolerate it. I would try dropping back to 15% and see how you go with starting on that and what happens with the noise. If that dosent work I would then go back to 20% ULP and add 10% dino and see how you go with that.

Different engines perform differently on blends and even the same engines have variations from one car to the next depending on wear etc. I have experimented with maybe a Dozen blends in my car to see which ones it likes best and found even with the same blends it appears to behave differently one day to the next on the very same tank of Juice. Occasionaly I find my car takes too long to start, so a teaspoon of methanol down the intake soon has it fireing right up.

There will be an ideal combination for your car somewhere in the scheme of things, just keep playing till you find it.

2nd March 2007, 10:30 AM
just keep playing till you find it.

Yeah just keep playing till you find it or stuff it up :p Just kidding :D

I think this car was running perfectly well on 50D/50V. wasn't it?


When you were running on a kero blend what sort of ratio did you use?



2nd March 2007, 12:39 PM
I was using a 20% Kero blend which worked just fine.
Because Kero is an oil rather than an aromatic like petrol, you can use it in any ratio you like up to 80% KERO/20% WVO.
A 30%-50% kero blend may be very useful as a winter blend and would make the oil very thin and stop gelling down to significantly low temps.

2nd March 2007, 03:16 PM
Thanks guys for your responses,
The differing combustion qualities of a ULP blend with WVO compared with dino blended with WVO are something I've been thinking about for a while and I need to do some net surfing on the topic. Any advice appreciated.

It would certainly help to do some viscosity testing on various samples. I plan to just the use timed fuel flow thru interconnected bottles technique. Wasn't there a posting on the forum where someone was going to do the same with their various samples? I dont recall seeing any results.

3rd March 2007, 08:46 PM
I run an average 15% blend of ULP in my veg for my 3.0 Hiace. 20% is also ok but obviously costs more. Once I experimented with a higher ratio, and while the motor ran quietly, the power loss was dreadful.

The only time the motor has been noisy is when the injector nozzles carboned up. Then I got "diesel knock", quiet at first but steadily increasing as more carbon shrouded the injector port. Once cleaned it was instantly good as new again.
The carbon problem is caused by trying to run an oil/blend too thick.

With the current 15% mix, starting is only slightly more difficult. Cold starts are no problem as I switch to diesel before shutdowns.

It could be worth testing the glow plugs too. A full set of good GP's makes an amazing difference to starting from cold.
In addition I should point out that I heat the fuel, on demand, to 80 -90C. Thats temp at the injector lines.

Let me know if I can be of any more help.

Toyota Vanola, 20,000km, twin tank, Rotary injected 3.0 litre high speed diesel, HIH, 12vGP, 100w injector line heaters

4th March 2007, 12:08 AM
The only time the motor has been noisy is when the injector nozzles carboned up. Then I got "diesel knock", quiet at first but steadily increasing as more carbon shrouded the injector port. Once cleaned it was instantly good as new again.


How did you clean them please?

This an area where I need to get some knowledge. Could you or any one with experience about injectors maintainance give some tips please.

Thanks in advance


4th March 2007, 12:08 PM
Once they are out, I clean with a razorblade.....carefully! The nozzle is flat tipped with only the pintle protruding. I doubt that a razor would damage the pintle but to sure I carefully, carefully remove any carbon and finish up with a brass wire brush. BRASS wire not steel wire brush. Once, I actually dismantled the injector units, each in turn and cleaned the internals but since then, have found that to be unecessary.
More importantly is the port where the nozzle seats in the head. On my Hiace that port carbons up completely, with only a pin-prick of a hole in it to spray through. I use a screw driver of an appropriate size to remove the solid carbon slug, remembering that there's 2 sealing washers. Sometimes these come out with the nozzle, other times they remain in the port.
It got to a point where I was doing this task monthly and I had it down to 45mins. But I got feed up and looked into blending a bit harder.
My conclusion is that rotary injected, high speed Hiace motors run best on blends. Currently 85%/15% ULP approx.
Good luck.

5th March 2007, 01:28 PM
Leaking Injectors
Hi All,
I thought i'd post recent developments with the navara. For several days there has been a leak from the screw caps attaching the injector feed lines to the top of the injectors.

Removing the lines showed that the screw caps were very tight and there was no seal (to my surprise). Sealing is just achieved through the olive on the end of the line squeeezed into the flare on the top of the injector. There was a slight ridge around the olive and retightening hasnt helped.

The local deisel mechanic suggested 1. confirm lines go squarely into injector before tightening. 2. get engine to normal operating temp then back off and retighten screw cap and 3. with nissans sometimes the flare in top of injector can get a ridge or burr requiring it to be replaced, whereas with toyotas its almost always the feedline that needs replacing.

I plan to sand back the ridge on the olive and then carry out 1 and 2 first off. What I was wrestling with is that this leak only coincided with the introduction of ulp into the blend. Only explanation I can come up with is that the imperfect seal has been there a long time but that diesel sludge probably maintained the seal. The ulp has had a solvent action in the blend and washed away the sludge to the point of allowing the leak.

Thought this might be of interest to others.

6th March 2007, 06:41 PM
Removing the lines showed that the screw caps were very tight and there was no seal (to my surprise). Sealing is just achieved through the olive on the end of the line squeeezed into the flare on the top of the injector. There was a slight ridge around the olive and retightening hasnt helped.

In my opinion, I would say over-tightening has been the cause of the problem. Due to the EXTREEEEMELY high pressure from the IP, they will leak if not a perfect seal, no matter what the fuel. They won't be a simple olive either, but a hydraulic quality tapered fitting that is sweated onto the pipe, probably with easiflo braze.

Sanding by hand could be a bit "hit and miss", considering the PSI ......Hope I'm wrong though. A possibility may be to get both parts as true as you can, then "lap them in" with the old valve grind method. It's an extreme measure though. And you'd need to be sure to remove ALL traces of the grinding paste aterward!

A better option, on the cheap, could be to pop out each injector in turn, dismantle and lathe its' sealing surface true. Then get a set of second hand injector lines.

These don't have to be very tight. While there would be a specified torque setting, we used to nip them hand-tight with a SHORT spanner only.

Food for thought?.....hope it helps.

6th March 2007, 08:07 PM
Many thanks 650,
Yep I believe that overtightnening is probably the culprit. Hard to imagine that movement betwen the olive and injector could have caused a wear ridge on the olive when the screw cap had been very tight. Injectors were replaced by a mechanic about 3 year ago and that was the last time they were touched.

Having a go at removing any uneven surface from the injectors is a worth a go becasue as i said previously a local mechanic quoted me $50 each for good second hand ones.

I'm trying to avoid buying replacement lines. What you say about the leak developing irrespective of the type of fuel makes perfect sense yet I'm still struggling with the fact that the leaks (3 out of the 4 injectors) only seemed to appear at the same time as ulp was introduced to the blend. neither the injectors or feed lines or screw caps have been touched for 3 years.

7th March 2007, 05:57 PM
Thank you for the feedback 650,
The inhjector lines are exactly as you have described them. I take your point about the friction fit not letting any fuel leak irrespective of the type of fuel considering the pressure that fuel is under.

It does still have me wondering though why 3 out of 4 injectors all started leaking at the same time and coinciding with the introduction of ulp to the blend less than 2 weeks ago. The injectors, feed lines and screw caps haven'tt been touched in about 3 years since new injectors were fitted.

Given that the caps were still very tight then I agree it is probably due to overtightening back then.

I'll try removing any ridge line from the injector top as per your suggestion and see what happens from there. Hanet had a chance yet to have a good look at the injector mating surface as yet. I'm just trying to avoid having to replace lines/injectors when all are functioning well, except for the dribbling of course.

12th March 2007, 12:38 PM
ULP and algal growth
Hi All,
This post might fit better in another thread...but anyway....

I believe that adding ULP reduces organic activity in WVO. If so then it makes sense to me to add a few percent at least of ULP to the WVO BEFORE leaving it to settle. This would also have the added advantage of reduced viscosity for subsequent filtering.

13th March 2007, 07:08 PM
I always blend before sock filtering, though I do get any solids and fat out of the oil first. The blend helps plenty with the filter speed and any remaining fat or particles will sink quite quickly. So I tap off 30mm above the bottom of that vessel after a brief settling period.

My oil doesn't sit around long enough to get any organic activity. Some of what I picked up yesterday is already in the van's tank. It could be different if there was no shortage.

W123 x 2
14th March 2007, 09:02 AM
Hi tbird650,

Can you correct and add to what I think is your WVO treatment sequence please? Is it something like this?

Collect oil, coarse filter with ?? into holding vessel, add thinning agent (ulp??) and blend (how?), settle briefly, pump through sock filter (5 micron?) and from there to vehicle fuel tank?

Thanks in advance, Michael

20th March 2007, 06:55 PM
Can you correct and add to what I think is your WVO treatment sequence please? Is it something like this?

Collect oil in 20L buckets.......settle (longer times are better).......carefully tip out oil till fat appears while coarse filtering to blending tank.......add desired amount ULP.......agitate with stick ...... settle (longer times are better)....... decant 20mm from bottom of holding tank........ trickle feed through 10micron sock, inside 5 micron filter sock into holding tank (200L drum). Filter through 1micron sock on entry to van vege tank.

The fatty reject oil get stored till I have enough to heat up and add baking soda and salt. Also throw in any ugly oil that's too horrible to filter. This method will settle out the fat quite nicely. Get baking soda and salt from farming supply store.

The 5 & 10 miicron socks mentioned above are fitted to the top of the 200L drum. The 10 fits reasonably well inside the 5 and allows double filtration with a single pass. It also allows for the 10 to be removed and have the accumulated fat removed, by squeezing, from the closed end to the other, with my fingers. Fingers do quite a reasonable job. The 10 micron sock can be recycled over and over with this method.

Hope that's clear.


W123 x 2
20th March 2007, 08:11 PM
Thanks heaps, that was really clear.

Another big ask :D how do you treat (quantities, process etc.) the fatty oil with the baking soda and salts? I am losing approx. 10 -15 % of my collected oils to fat and would like to reclaim some of the oils I can see in there.

Thanks in advance, Michael

20th March 2007, 09:53 PM
When you accidentally splash some vermouth in the gin. Cheers!