So, I contacted SS diesel supply b/c thats where my FSD heat sink is from and wanted to confirm that the intake manifold was the best place for the relocation.....I casually mentioned that I just converted to run on WVO and they owner told me that my IP WILL fail running anything higher than 5% biofuels......and hes never seen one go longer than a month.

How many miles do you guys have on your 6.5 conversions? And those that have had failures.....WHY? What have you done to correct the situation?

I just finished my conversion friday and took it on a 3 hr round trip on veg. THe thing runs AWESOME! 180* oil temps the whole trip.....not even a hiccup out of the engine! I get nervous when I hear the horror stories though. Ive got about 1500 into the conversion and bought this truck JUST for this reason.

I have a year and 12K miles on my 6.5 running 2 tanks WVO. It's running very well, no problems. Maybe all those of us running the 6.5 on WVO should call and tell him?

Soyburban has had good success with his conversions.

He's also had IP drive shafts break and the current theory is that a cold/lukewarm IP has enough thermal mass/heat-sink ability to rob enough heat from incoming hot veggie to thicken its' visc enough to snap the IP driveshaft.

Hot, dry, clean WVO fed into a hot IP and hot engine should do the trick.

I haven't done my conversion yet, but I've read a lot of stuff from people who have succeeded with 6.5s and 7.3s to know that it can be done right. I mentioned the 7.3s because the older pre-powerstroke IDIs use a similar variant of the Stanadyne DB2 rotary IP that's used on a 6.5.

Nice guys......B.K......nice going.....12k is definately more than 1 month on veg! HA! There are others that chimed in on greasecar that have over 20-30k on veg....or several yrs. Im not too worried.....im pretty sure my set up is built very well and the oil is real hot and clean going in. My IP has some miles on it, so I will probably replace it soon for that reason.

I would wait. From all documentation on my truck, I dont' think mine has been replaced, and I have 275K on it.

Yea....im up in the air about it. If I replace it now, in theory, I wont have to worry about it.....but on the other hand, it could go another 50k or whatever. I just fear that im on the road with my camper on the back, 500 miles from home and the thing takes a crap....then im at the mercy of some repair shop because I cant really do that job on the side of the road. Tough call.

quote:

im pretty sure my set up is built very well and the oil is real hot and clean going in. My IP has some miles on it, so I will probably replace it soon for that reason.

Actually, I've heard that you'll know when to replace your IP because it will eventually wear out to the point where it will still function normally on veggie, but won't handle ULSD properly any more.

THAT'S what I was thinking, Welder. Mine at 200K+ is "worn", so the tolerances and clearances are loose. Perfect for a thicker fuel. Imagine replacing the IP, and due to the brand new, tight clearances, it shears the IP driveshaft in 6 months due to a slug of thick VO...heck no.

quote:

Imagine replacing the IP, and due to the brand new, tight clearances, it shears the IP driveshaft in 6 months due to a slug of thick VO...heck no.

That's why I keep recomending sharing a FPHE with BOTH the stop/start fuel AND the WVO/SVO, because after a guy shells out the money for a new IP, he doesn't need the frustration of killing his replacement by rethickening his hot veggie with a cool IP heatsinking the viscosity back up again. I admit that I haven't converted yet, but I've read enough stories from people to see the cheap insurance offered by the shared HE for ALL fuels in a converted diesel.

Blending in 5 or 10% veggie or maybe 20% B100 should help guarantee high temp lubricity of ULSD. They say that ULSD should be safe at SVO temps, but every now and then you hear about occassional refinery errors where a load of ULSD leaves the refinery without recieving the lubricity addives. If a FPHE is cheap insurance against a snapped shaft, then blending some veggie or B100 into the start/stop fuel should also be cheap insurance against refinery error.

Anywhere there are humans, there will be human error. To err is human... (Now I know why my wife thinks I'm super-human!)

INteresting stuff.....so the IP doesnt just GO? It gives plenty of warning? If thats the case, I will just run the thing as is and worry about it if/when it breaks.

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INteresting stuff.....so the IP doesnt just GO? It gives plenty of warning?

It dies suddenly if it's inadequately pre-heated, then fed hot veggie. The drive shaft snaps.

If your veggie isn't dewatered thoroughly enough, slow cumulative cavitation will erode the tolerances of your IP until it only works right on veggie, not diesel. Once it gets to the point that you can't start on diesel, it's game over because then your IP still can't push cold veggie.

I just talked to a diesel mechanic, who said that the IPs with electrical fuel systems (>1993) have an optical component. He said there's a rotating disk and light has to shine through certain points on it. He said that water in the oil or the oil itself can build up on the disk and wreck the pump. Has anyone heard of this or know more about it?

He strongly recommended not to go wvo with the truck but since I'll be using very clean wvo and biodiesel, I hope it'll be ok.

1993 and older 6.5's are mechanically injected.
1994 and newer are electronic.

The older ones you mostly have to worry about busting the shaft, the newer ones seem mostly prone to electronic issues... yes, including optical sensor problems.

IMO, the 6.5's are delicate. I'm not saying don't grease it but you have to do it by the book. Switch over temps, purge times and lift pump pressure are all important for longevity. Not like a Mercedes which will continue to run with candle wax in the tank.

I have over 10K with SVO on my 1993 6.5. 2 tanks, of course. I blew the IP once by running too much pressure to the IP (busted shaft), I've read too little will do the same. Cold veg will also do it. Now I have gauges on everything, just to make sure.

I just put another 500 miles on my 6.2 this weekend running a WVO blend, about 5,000 miles now in 4 months.
As has been mentioned countless times, the problem is people not using clean, dry WVO.
I also make sure my blend is close to the viscosity of diesel so I am not running anything too thick through the IP.
Rusty

I put 35k on my '95 2500 4x4 burb over the last year running a lot of 50/50 diesel/stocking filtered wvo (75/25 in the winter here in the NE). No grease kit. So far so good, except for the usual post wvo switch filter changes. Truck now has 182k. 17-18 mpg hwy (towing gears).

I know there are a lot of theorists out there, but this is real.

ADDED: Whenever I run the wvo mix I treat the fuel with Diesel Kleen, if I remember or have it.

Mods: HeathDiesel PMD relo & 4" turbo back exhaust & trans chip & fixed wastegate

burbzilla, how often do you have to change filters? I have about 4-5,000 miles on blends and think my oil is really clean but seems like I have to change the filter every 5-700 miles.
Rusty

Funny you should mention that, Rusty.

After reading a few of the posts here, I decided to check and change my top fuel hoses today. Since you cannot rip them out w/o getting the filter canister out first, I pulled it completely out and checked the filter. I was amazed to find the bottom full of gritty mud - much worse than ever before.

This is after cca. 2700 mi - I usually go about 4000-5000. It was so bad that my canister bleed hose that goes to the bleed valve by the front was plugged for about four inches where it dips to the lowest point in the valley under the intake.

Glad I checked it - could not poke through it with a sturdy wire once I had it out. 2700 miles ago it worked just fine. Would have been a surprise at the next filter change.

I doubt it is sabotage as I have a locking cap. Likely crappy diesel fuel.

Good news is that the IP feed line, though hard and brittle, was clean as a whistle.

I should add that if the truck ever even coughs on wvo mix, I hit the next station and dump in a few gals of diesel. I've had it happen twice since I've owned it.

I also carry a bottle of Diesel 911 in case of water problems. That stuff is amazing. Worked in five minutes on my wvo fueled Kubota which had a bit of fuel gelling going in the translucent fuel filter.

I changed my filter and no change, still bucking and lurching on deceleration and even a erratic idle. I seems to get worse as it warms up, kinda strange. I am thinking it might be the fuel return check valve not letting enough (or any) fuel return.
I have been trying to run a 70wvo/30 diesel blend and it may be too much, I am going to drain some of it and start over with less wvo.
Rusty

What's the lowest temp?

It's been a bit cold at night up here in the NE (50s). I noticed that burbzilla started a little rough in the morning on 50/50. I should get the injectors checked one of these days... I think at least one of them is not atomizing properly until it warms up.

My son's F-350 and F-250 are easier - start and shudown on diesel, switch to blend in between.