GM 6.5L Conversion problems!!!!

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GM 6.5L Conversion problems!!!!

Postby VegMeister » Thu Mar 20, 2008 8:48 pm

Hi guys,

I thought I would be driving home on veg oil tonight but instead I got a chilly bike ride.

Preface: I don't think that cutting the heater core supply line is an option in my truck. There is no room, even if I got rid of the A/C unit.

I had originally planned on taking coolant from the fitting where the temperature gauge is screwed in. After taking everything off, draining some coolant and then pulling it off, I realized that it's only 3/8th (and this is after measuring it and figuring for sure it was 1/2"). Since I had bought a T and fittings for 1/2", rather than running into town I decided to try using the spot where the heater core source screws into the front of the engine. That IS 1/2"

I started twisting it TENDERLY with a wrench and it almost immediately sheared right off. After examining the aftermath, it seems like it's VERY fragile aluminum, which has been glued in there with high-temp silicone. There, I'm done with my excuses.

Tomorrow morning I'm going to go back at it, try to use a hacksaw blade to remove what's still left of the fitting in there, without destroying the threads in the aluminum engine piece (the whole thing could be removed... but that would require a LOT more work and I'd have to completely drain my coolant.

Anyone have any great ideas at this point? I think right now I'm basically going to have to use a copper nipple in there (once I get it cleaned out) and at that point I had might as well T in for my supply coolant.
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
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Location: Pembine, WI

Postby SkySkiJason » Fri Mar 21, 2008 8:46 am

Bummer man.

I use 1/2" black iron pipe nipples on 3/4" heater hose (no barbs). Works great!

I also put a valve (I used 1/2" copper 1/4 turn ball valves, sweated copper pipe and a 1/2 a coupling on the end - to make it tight in a heater hose - no barbs :wink: ) on the heater core circuit. I keep this open only about 1/4 way in winter for cab heat (thats plenty, even when its real cold) and close it in the summer for better A/C performance. This forces more coolant flow through the VO loop.

WARNING! off-topic material to follow: :lol:

I chose Evans Coolant as well. This stuff is 'waterless' - as in, water is a contaminant. At 0psi it doesn't boil until 385F. So besides not 'cavitating' and other issues faced by diesel coolant, it can be used at 0psi. I thought this was cool, since pressure is the enemy of my looong VO coolant loop. Oh yeah, it is permanent - it never has to be changed! For this reason, I added a coolant filter as well...

Everyone SHOULD know to change their coolant regularly and make sure you are using THE SPECIFIED coolant for your vehicle. The damage from not doing so can be catastrophic! :shock:
2001 F-350, DRW, 4x4, XLT Crew Cab, flat bed, 7.3, 6 spd, Dipricol Optix gauges, DP tunes - Single-Shot injectors! Vegistroke-style WVO conversion, 55,000 VO miles so far - 190 deg VO before the heads
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Postby VegMeister » Fri Mar 21, 2008 6:30 pm

Thanks for the reply.. the Evan's Coolant wasn't really off topic either.

Anyways I managed to use a modified hacksaw blade and chisel to get the broken fitting out with no damage to the threads... thankfully the same crappy brittle nature of the aluminum in question allowed it to be broken into chunks easily.

I use a close nipple to attache a T to that, and I've got ball valves on each side of the T. On one ball valve I have a 90degree 1/2" barb, (1/2 radiator hose going to the hard line on the exhaust manifold) and on the other I have a straight 3/4" barb (thanks for the tip about using 1/2" close nipple, I'll keep that in mind. For now I had a barb laying around so I'll just use that) which has 3/4" hose going to my FPHE.

Well I just took a break to go to Good Friday service. I'm heading back to the shop. Hopefully by morning I'll have a working veg oil system!
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
VegMeister
 
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Joined: Sat Mar 08, 2008 11:12 am
Location: Pembine, WI

Re: GM 6.5L Conversion problems!!!!

Postby Radrick » Sat Mar 22, 2008 4:51 pm

VegMeister wrote:Hi guys,

Anyone have any great ideas at this point? I think right now I'm basically going to have to use a copper nipple in there (once I get it cleaned out) and at that point I had might as well T in for my supply coolant.


Hey Veg is the the aluminum line with the plastic retainer in it? if so this thing is a source of problems on our trucks. Have you ever been to the Dieselplace forum? you can find the best fix there. It is a chevy diesel forum and the guys in the 6.5 section are awesome. I have read some threads about this fitting but don't remember the best fix now. best of luck.
1995 Chevy K1500 6.5 TD not on WVO yet but soon.
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Postby Welder » Sun Mar 23, 2008 3:36 am

Hi RadRick.

For a second, I was going to correct you that the DieselPlace is for Fords, not Chevys, then I realised that I was thinking of the Dieselstop.
"Is there anybody out there?"

Roger Waters
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Postby VegMeister » Sun Mar 23, 2008 10:21 pm

Radrick: yes, it's that KIND of fitting. But the one I had problems with was right on the front, passenger side of the t-stat housing. It's the fitting that connects the heater core hard (aluminum) line to the engine.

Anyways, that problem is now very fixed (copper nipples and a T and a couple of valves later). I'm completely finished my conversion except for one thing: wiring the pumps. Right now I have a switch wired to the 12V (hot) connection coming from the stock lift pump relay to the stock lift pump. To the switch I've wired the hot leads for each of the lift pumps (stock for diesel, secondary one for veg).

Seems simple right? When I flip the switch, the veg pump gets 12V instead of the diesel pump. Well for some reason in veg mode the veg pump is not always running. Which is a big problem because then the IP will just suck fuel from wherever it can get it (including the diesel tank). I need to have that veg pump running continuous in order to have positive pressure to my veg oil filter.

Is it not possible to have continuous operation pump wired through the stock relay on my GM (1993)? I know I could just wire it straight to a 12V source (there are some handy) but then the problem is I have to install a fuse. And I don't have the safety feature of the relay (I believe it is designed to open the circuit (i.e. stop power to the lift pump) if there is no oil pressure).
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
VegMeister
 
Posts: 86
Joined: Sat Mar 08, 2008 11:12 am
Location: Pembine, WI

Postby Radrick » Tue Mar 25, 2008 2:22 pm

VegMeister wrote:Radrick: yes, it's that KIND of fitting. But the one I had problems with was right on the front, passenger side of the t-stat housing. It's the fitting that connects the heater core hard (aluminum) line to the engine.

Anyways, that problem is now very fixed (copper nipples and a T and a couple of valves later). I'm completely finished my conversion except for one thing: wiring the pumps. Right now I have a switch wired to the 12V (hot) connection coming from the stock lift pump relay to the stock lift pump. To the switch I've wired the hot leads for each of the lift pumps (stock for diesel, secondary one for veg).

Seems simple right? When I flip the switch, the veg pump gets 12V instead of the diesel pump. Well for some reason in veg mode the veg pump is not always running. Which is a big problem because then the IP will just suck fuel from wherever it can get it (including the diesel tank). I need to have that veg pump running continuous in order to have positive pressure to my veg oil filter.

Is it not possible to have continuous operation pump wired through the stock relay on my GM (1993)? I know I could just wire it straight to a 12V source (there are some handy) but then the problem is I have to install a fuse. And I don't have the safety feature of the relay (I believe it is designed to open the circuit (i.e. stop power to the lift pump) if there is no oil pressure).


Sorry about not replying sooner. I haven't been on line for a couple of days. Got invaded by the kidds coming home for easter. The wife and I have definatly adjusted to empty nesting to well. Anyway I'm not always sure how much our trucks have in common since your the machanical ip but yes the pump is controled by the oil pressure switch. I'm also not sure but i don't think the pump will run until the engine is running but that wouldn't be a problem on vo. I am assuming you have the problem solved as i saw on the other thread that you have it running on vo. Congradulations I would love to here all that you are willing to share on how it went and how its working.
1995 Chevy K1500 6.5 TD not on WVO yet but soon.
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Location: Rochester, MN

Postby VegMeister » Wed Mar 26, 2008 8:36 am

I'll add a little post here to kind of reveal what I discovered about the lift pump:

they are continuous operation on my truck. The relay will turn off only if the OPS shows no pressure or the ignition is turned off. I Left the stock pump wired through this relay, but wired the veg pump directly to 12v always on power. They are both grounded to my selector switch, meaning only one can be on at a time (make sure you get the right kind of switch, one guy I know got just a regular on/off switch and that won't work). If the switch is giving ground to the veg pump and you turn of the ignition, get out of the truck and walk away the veg pump will still be running!!!!! It will run until it's dead or the battery is dead. This for me is a good thing. It's a reminder that I shut off on veg, and if I FORGOT to purge, then I turn it back on and purge. If I don't need to purge, then I just flip the switch to either the OFF position or the diesel lift pump circuit (which of course won't work with the ignition turned off).

Perfect system for me, this means I'll NEVER forget to purge my system *knock on wood*
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
VegMeister
 
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Joined: Sat Mar 08, 2008 11:12 am
Location: Pembine, WI

Oil Pressure Switch

Postby sanderlings » Thu Mar 27, 2008 2:25 pm

VegMeister, I would recommend using the safety feature of the OPS. I put a tee under the stock OPS and installed an oil pressure shut-off sender since my stock setup used a mechanical lift pump. I did install a bypass switch so that I can purge for filter changes and prime pumps etc. with the engine turned off. I didn't want to worry about feeding a potential accident scene fire with an always-on WVO pump. It may be unlikely, but stranger things have happened.
todd
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Postby VegMeister » Thu Mar 27, 2008 7:20 pm

Since my veg tank is kept cold, then the oil being pumped would become cold shortly after the water pump stopped pumping. I *think* that would mean that after a few seconds, I'd be pumping cold veg oil onto any fire. Which might make for a slippery mess, but would probably serve to put out any fire it was pumped on. But I could be wrong.
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
VegMeister
 
Posts: 86
Joined: Sat Mar 08, 2008 11:12 am
Location: Pembine, WI

worry wart

Postby sanderlings » Fri Mar 28, 2008 10:29 am

VegMeister, I am not sure about the WVO but my electric diesel pump switch gets its feed from the shut-off switch as well. I am probably paranoid, but I just don't want to be the guy on the six o'clock news with the truck that just flambe'd the Chadwick family.
todd
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Postby VegMeister » Fri Mar 28, 2008 11:19 pm

This we can agree on: the diesel lift pump should have a shut-off mechanism for SURE!!
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
VegMeister
 
Posts: 86
Joined: Sat Mar 08, 2008 11:12 am
Location: Pembine, WI

Shut off

Postby sanderlings » Sat Mar 29, 2008 5:45 am

They also sell shut-off switches that are triggered by impact. They are called inertia switches. They might be an easier option for some applications. Does anybody know how the kit sellers address fuel shut-off in case of an accident?
todd
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Postby coachgeo » Sat Mar 29, 2008 8:46 am

My understanding is the ability to get diesel to ignite in an accident is extremely difficult and quit rare. This is why its not required to have fuel shut off's etc. IMHO... think it would be even harder for VO

Nowwww... would there be less mess and make everyone happeir if you wired in an intertia switch to help prevent spills in accidents. Sure.
Life; It's all in the Balance

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Postby VegMeister » Tue Apr 01, 2008 11:55 am

Hmm I'm on a volunteer fire dept. and firefighters don't mind having cold diesel dumped on the ground at a car fire site. In SOME cases it helps the fire go out.

Now probably it would be better to not have diesel getting spilled, but I think that if there was a clear safety problem, semis would be regulated to be modified to not spew diesel all over the place when they wreck.
centralvalleybiodiesel CF
1993 GMC Sierra K2500 6.5L + homebuilt veg kit, OEM glowplug failure (update: rebuilt with a 6.2 block, working fine)
1988 Ford 6.9L OEM dual tank, 90+% veg oil blend.
1989 Ford 7.3L, 80+% veg oil blend.
VegMeister
 
Posts: 86
Joined: Sat Mar 08, 2008 11:12 am
Location: Pembine, WI


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