Prins conversion on a 2015 6.0 liter silverado

Propane, Butane, LPG, GPL, C3H8, C4H10
C3H8
Posts: 1003
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

Re: Prins conversion on a 2015 6.0 liter silverado

Post by C3H8 » Mon Mar 20, 2017 1:07 pm

This was an issue when the 6.0L engines first came out. Sequential systems spray petrol/gasoline directly onto the intake valve keeping them cool. Although there is no proof, it was believed that the manufacturers saved a few bucks by using lower graded metal for the valves once these systems came out. Some proof of this can be determined by the fact that you can order a NG prepped engine for the 6L choices. The cost of a prepped engine is quite minor. Back in the early 2000's it cost the dealer $150 to add a prepped engine over the standard 6 litre. In Northern BC where conversion were very popular the local dealer added the NG prep to all his trucks that it was available on. The funny issue is that not everyone has had issues with this. There are 5.3L and 6L engines with 250K out there that have never been opened. On the other hand there are customers that have had this issue as low as 40K. One fact is known and that is that a heavily loaded truck with standard valves will have an issue sooner than a light loaded truck. As an installer I discussed in detail this possibility with every customer. We did not have valve saver systems back then so I don't really have extensive data on their effectiveness, however the logic is sound. Another alternative to the NG prep was to purchase a vehicle with the Flex fuel option. Some manufacturers indicated higher grade of valve materials were used in flex fuel vehicles.

Dan350
Posts: 50
Joined: Fri Dec 05, 2014 8:26 pm

Re: Prins conversion on a 2015 6.0 liter silverado

Post by Dan350 » Mon Mar 27, 2017 8:52 pm

That is interesting. Apperently the NG prepped 6.0 motors are not availlable for pickup trucks but only on the commercial delivery panel trucks. Mine is a flex fuel motor (are they not all?) but i don't think that that automatically qualifies it as an LP or NG prepped motor. I got the truck back last thursday and so far it runs great. They changed the valves, seats and guides. The parts are the same as in the LP prepped motors. The guy that did the job said he did many jobs like this on UPS trucks and that i shouldn't have any problems with my engine anymore. I lost 2 weeks worth of work because of this so i hope he's right.

C3H8
Posts: 1003
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

Re: Prins conversion on a 2015 6.0 liter silverado

Post by C3H8 » Wed Mar 29, 2017 3:17 pm

GM has sols the 2500 HD series for a long time with a NG prep. They partnered with IMPCO for the CGN and LPG kits to be installed at authorized dealers in the US. This setup is still available today on 6.0L HD engine which is SFI only. The thing that the GM dealers in Northern BC discovered was they could order the prepped engine in any 3/4 ton they wanted even if they didn't convert it. By doing this GM warrantied the complete engine for the 5 year/100,000 without any arguments when the converted. The cost may be higher now or it may not be available but just a few years ago it only cost $150 for the prepped engine. They started doing this for all of the inventory because the cost was very cheap for the prepped engine. Is it still available, not sure but it is worth looking into for someone buying a brand new 2500HD that they want to convert..

As for the comment on flex fuel. Not all trucks are flex fuel vehicles any more than cars are. We always wondered if flex fuel vehicles had higher quality valves than the regular engine. After all, Methanol is harder on valves than gasoline, so it was a natural assumption to figure the valves would be made of better material. We could never confirm this though.

C3H8
Posts: 1003
Joined: Fri Sep 09, 2005 11:23 pm
Location: Winnipeg, Canada

Re: Prins conversion on a 2015 6.0 liter silverado

Post by C3H8 » Wed Mar 29, 2017 3:22 pm

In addition I just checked the IMPCO site for instructions of there systems by model and years. They were still offering their kits for the 2016 Silverado 2500HD. Considering that GM warranties these for the full powertrain warranty I would presume the prepped engine is still available. I'm just not sure what the additional cost would be if a customer wanted the engine only.

Dan350
Posts: 50
Joined: Fri Dec 05, 2014 8:26 pm

Re: Prins conversion on a 2015 6.0 liter silverado

Post by Dan350 » Fri Nov 10, 2017 8:33 pm

Update after 115000km: I wanted to share with all of you my experiences with the Prinns system i have on my truck. In earlier posts I mentioned that my heads had to be re-done with new propane compatible valves and seats. I have not had any other proplems related to that since. One major proplem that did occur was not caused by the system itself but by the propane supplier in Sarnia which apparently is where most of the propane in eastern Canada is from. It seems that heavy oil was left in one of their storage tanks which then contaminated the tanker trucks and eventually the storage tank where I fill my truck. As this heavy oil found its way through my system it caused my injectors to stay open longer when the engine was cold. I suspect the oil was was sticking them open. My engine would then run extremely rough and rich until it warmed up. I had to manually switch from gasoline to propane when I new that the motor was hot enough. If I let the system switch over by itself the engine would just die and be hard to re-start. It took over 2 months for my supplier to empty his huge storage tank and apparently the heavy oil exited with the propane because no residue was left inside the tank. Evidence of the heavy oil was in my filters and evaporator and once they were cleaned out and the injectors cleaned the problem went away. The majority of their customers had the same problems as did they with their own trucks. The second problen i had recently is the valve saver pump failed and caused a complete shut down of the system. It has since been replaced and the problem is gone. The third problem is the float inside the sleegers tank I have is leaking causing the level gauge to read empty all the time. A new float has been ordered and should fix the problem. I have gone through 30000 liters or pounds of propane which averages out to 26L/100km pulling a 30 foot gooseneck trailer that weighs 5000lbs empty. Any questions? Fire away

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