wq93
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Re: Evans Dash Air Nightmare
Many diesel engines were equipped with a small vacuum pump driven off the belt to provide vacuum for accessories. I suspect that some manufacturers may have also used electrically operated vacuum pumps and if you are trying to retrofit a vacuum pump to a system that didn't come with one that is probably the simplest approach. Diesel engines won't provide a reliable vacuum source whether turbocharged or naturally aspirated because they don't have a throttle plate so there is very little air restriction on the intake side and thus no significant manifold vacuum. This is the same reason that diesel engines not equipped with some sort of exhaust brake provide very little engine braking compared to a gas engine which develops its engine braking by forcing the engine to pull air through a nearly closed throttle plate. With large diesels, a "Jake brake" discharges the compressed air at the top of the compression stroke to provide excellent braking while lighter duty/small diesels use some sort of exhaust restrictor to provide engine braking often in the form of variable exhaust vanes in newer turbo diesel engines. Some of the newer DPF equipped diesels have a throttle plate to help heat the system during regen but this isn't intended to provide a reliable source of vacuum or engine braking.1.3KViews0likes0CommentsRe: GM Yukon XL Denali Transmission Temps
Are you sure that the cooling stack is really clean? Often you get a lot of debris buildup between the condenser and radiator. The HD trucks are well known for this issue after a few years and although you don't have the additional intercooler of the diesel pickups there is still a lot of area between the condenser and the radiator for stuff to get caught greatly reducing airflow. It won't make a huge difference, but the engine heat increase may be a little less if the added transmission cooler is plumbed in ahead of the cooler in the radiator tank because it will dump more of the transmission heat before adding it to the engine coolant.2.1KViews0likes0CommentsRe: Tesla Semi truck unveil & test ride set for Oct 26th !
Caterpillar released a performance guide in 2006 that does a good job of explaining horsepower requirements for different motor coach operating conditions. Do the HP to KWH conversion from their data and it shows that this hoped for motor home is going to need a really large battery pack. https://prevostcommunity.com/PDF/Motor%20Home%20Fuel%20economy.pdf315Views0likes0CommentsRe: OH Happy Day... for now..... only 2 cents apart
And keep in mind that a lot of current gas powered engines need 89 or 91 to provide rated power and economy even though they can operate on 87 via audible knock sensors which alert the ECM to use the low octane map. My Corvette Z06 wants 93 octane which is anything but cheap although I do run a couple of tanks of 91 octane through it just before winter because that is the highest octane available ethanol free in this area. I use red dye diesel fuel for my tractor and to keep the tank filled in my standby generator since it is significantly cheaper because there is no road tax. In many areas, the greater spread between diesel and gas is from long years of taxing diesel at a higher rate to further tax the road damaging heavy truck industry coupled with the view that it was a "hidden" pass along tax so average citizens wouldn't scream as loudly about it since they don't realize that they are paying it indirectly in the cost of goods. But there is no way I would risk that fuel and the associated fines in my GMC 2500HD. Several years ago there was a brief period when red dye was allowed in this area on the road because of a shortage of road taxed diesel but that was a brief and unusual experience.587Views0likes0CommentsRe: 2015 GMC Sierra Denali-catastrophic fuel pump failure
With it in the miles/time warranty it is either warranty parts failure or a fuel issue. If GM is refusing the warranty repair based upon water in fuel/contaminated fuel then check with your insurance company to see if this is covered under the comprehensive portion of your coverage. If so then the insurance company will cover the repair (less your deductible) and their subrogation department will attempt to collect from the fuel provider.353Views0likes0CommentsRe: Allison 1000 spin-on filter and fluid change
Just pre-fill the new filter and put a pan to catch the very small drip that will occur when you change the filter. You won't need to add any to the transmission but if you haven't done the proper level check procedure in some time you should do so anyway because it may have been too high or too low when you bought the vehicle. The Allison 1000 requires the fluid be warmed to the proper temperature for an accurate check AND too much fluid will make the transmission run hotter. There is a circular magnet that sits in the filter housing and this magnet sometimes comes off with the filter. It should always be wiped clean and put back in place and doing this makes sure that you don't accidentally throw the filter magnet away with the old filter. If this is a GM pickup, the Allison filters are MUCH cheaper at a truck dealership than at your GM dealer. Filters are cheap and I would replace once a year or at every other oil change, whichever comes first.1.2KViews0likes0CommentsRe: Bio-diesel / Is it a good or bad thing for the engine ?
Bio helps provide some of the lubricity lost with the switch to ULSD years ago. I have been using it in my diesel pickups for years without trouble and my circa 1995 Deere utility tractor uses it also with no problem. My soon to be delivered 40KW standby generator will also be running a bio blend. Your biggest issue will be it has higher cloud and gel points than non-bio and vehicles designed for higher concentrations will generally have a larger capacity fuel heater at the filter. Bio diesel is a little better solvent than straight diesel and an older fuel system first introduced to bio will likely need a filter change fairly soon for the first cycle. You have probably run bio before without knowing it because it has been prevalent in most of the market for over a decade. I hate "farmer gas" ethanol fuel but I am fine with bio diesel (which also makes far more sense economically and environmentally than the ethanol laced garbage fuel).215Views0likes0CommentsRe: 2020 GMC/Chevrolet Diesel Engine
Huntindog, What you noticed is part of a trend that started several years ago. I looked at a 1/2 ton version of a GMC Denali maybe 8 years ago and it was being built with a full time 4WD system that was related to the system being used on a lot of the "crossover" type vehicles. It was primarily a RWD system that was aimed more at performance than snow/off road traction and there were a lot of complaints from snow country owners because the system didn't react immediately when transitioning into snow and was particularly troublesome when turning from a clear road onto a snow covered surface. It was aimed more at stoplight racing than off road traction. A lot of these systems also use individual wheel brakes activated via the stability and traction control systems as a substitute for a locking or limited slip differential-another software dodge to save hardware dollars that is fine for some but not all uses. I suspect the wide ratio range which is the norm with current 8 and 10 speed transmissions is also helping to drive move from low range in some of the light duty 4WD systems where an extremely low first gear is seen as something of a substitute for the low side of the transfer case-of course it isn't as useful for many situations but the majority of owners never take their vehicles off road and few understand the proper procedure for shifting into/out of low range with transfer cases that aren't designed for making this shift at speed and under load.437Views0likes0CommentsRe: 2020 GMC/Chevrolet Diesel Engine
Cummins12V98 wrote: " Allison 1000 series that was developed within Allison and is sold by Allison. " Is this a FACTUAL statement? "sold by "Allison" ??? The 1000 series is an actual Allison transmission and is part of their basic 1000-4000 highway series that includes related models with and without parking pawls at various power ratings. See: https://www.allisontransmission.com/transmissions/models/highway-series for their motorhome brochure using these models. The 1000 and related series are also found in other Allison vocational series brochures. And versions of the 1000 and 2000 series will continue to be used in the new GM/Navi MD siblings instead of the 10 speed: http://gmauthority.com/blog/2018/10/allison-transmission-begins-production-ahead-of-chevy-medium-duty-truck-launch/ I don't expect you will see anything like this new 10 speed being sold through Allison unlike the current 1000 series which was developed by Allison and is supplied by them to numerous users.437Views0likes0Comments
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