Engine Exhaust Wraps?

[Ray Davis]

Not sure if that's the correct term or not, but the Prevost mechanic suggested to me that it's a good idea to get the covers (wraps) that go on the exhaust/turbo/etc pipes, which help contain the heat generated there.

Has anyone had any experience there? Are they worth it? Where would you get them?

Thanks in advance.

Ray

[dalej]

I'll go out and look and see if I can find the info on the "wraps". I like them for what it's worth.

[lewpopp]

Your technical reply on the wraps will be on the way as soon as Anal Jon returns from Oshkosh.

[Jerry Winchester]

Lew,

Let me save you the trouble. Anal Jon will say, "If it wasn't standard equipment on a Liberty, then it doesn't belong."

And you need to know he put on a pitiful bling exhibition tonight. Mike and I had run to town to get some grub for the masses and when we returned to Camp Prevost, Jon had all the Liberty bling fired up and was busy impressing the prolateriate.

The cooker is safe. Factory bling doesn't count.

[truk4u]

Ray,
Mine is coverted all the way to the muffler, thought that was a standard Prevost item!:confused:

[Jon Wehrenberg]

I notice a trend here. While I was away from my computer Jerry was laying in his tent with the generator screaming in his ear so he could make these posts. From now on his "handle" needs to be Shadow Boxer because he takes jabs when nobody is there.

Like Tom I have the "wraps". I endorse their use because a 40 foot coach especially can get pretty hot in the bedroom and they do help prevent heat from ending up there. When these were first touted in the early 90's it was for that purpose. The only caution is to insure the exhaust system is sound because these will cover any CO leaks that may occur after covering and you would never see the hole in the exhaust. Anybody running their coach engine all night when in sub zero conditions is exposed to CO. I doubt if it is an issue otherwise.

[Ray Davis]

Any suggested sources for said wraps? Approximate cost? I might have to forego adding bling, if they cost too much! :D

[BrianE]

Ray,

Check the thread "8V Heat Muffs" 12/15/05 on the other site. I have since purchased and installed the muffs from Firwin (firwin.com) and while there is no discernable improvement in the guages, I can't help but think that ambient temp around the DDEC and upper engine compartment must be significantly cooler. They are made with high quality materials, are easy to install and improve the appearance, ie: add "bling" to the engine compartment. The cost of the full set was less than $600.00. The next step is to polish the copper pipes.:cool:

BrianE
94 Liberty XL

[Jon Wehrenberg]

I love it. With all the Liberty guys with polished copper and heat wraps I expect Winchester will be screaming that it ain't bling if it came on the coach.

I believe maybe the Amish grille that JPJ showed in one of his posts should be the prize for whiners. JW will take that prize without breaking a sweat. I just hope Brian doesn't fly a V tail.

[win42]

Will someone please post a picture of these wraps in place. Enclosing the inlet side of the turbo and any inlet duct with the hot exhaust side is not smart. Mr. Banks offers the following for use on smaller diesel engine, but the same holds true for ours. http://www.banksdiesel.com/newproducts-6-05.cfm
It would be good for us to add intercoolers to the turbo inlet air and even better to the blower. With our 8V92's this would be difficult. However there is another method of inlet cooling avaible. Propane injection has been perfected for the smaller Diesels and will soon be available for ours at a store near you. It raises the H.P. and torque a bunch. This would be real bling.
Covering the exhaust system raises the temperature of the metal the system is made of. As Jon says any failure undetected here could be fatal. If you change any of your exhaust sytem components, you would do well to use 430 SS or at least 300 series SS. for a fully seal welded system.
I open the side and back engine compartment doors after a run. It makes for better sleeping temperature above.
High temp. insulation (2000F) Calcium silicate blankets and Calsil woven fabric is readily available at Industrial Insulation suppliers for us do it your selfers.

[Joe Cannarozzi]

I have been eagerly awaiting this topic of propain injection to come up. I once saw a build up of a deisel and all the other components combined did not equal the increases from propain alone. We need to elaborate here. Who has more info, Jon, Jeff?

[win42]

www.dieselperformanceproducts.com These are the guys to talk to about propane Diesel injection. When they develop the first system for an 8V92 Detroit I will be a buyer.

[win42]

From: www.dieselperformanceproducts.com

To install the Powershot Propane System to any (? ) vehicle:
Attach the lockoff valve to the tank. Mount the Powershot unit, either on the tank, or where ever is convenient using the attached bracket.

Next, take the out the 40 ft of hose. Do not cut the spool of hose. You will be running two hoses from the engine to the tank, they will not be equal lengths, one will be longer than the other. Make one run, cut then you will have more than enough for the other run.

From where the tank will be mounted, make a run with the hose from the tank, to the engine.


Determine where you will introduce the propane into the engine. If the vehicle has an air box with a filter indicator, which is a gauge that tells whether the filter is clean or dirty, you can just remove the filter minder and insert the hose about a foot down into the air box so that it is beyond the filter. If not, simply drill a small hole into the air tube AFTER the filter and BEFORE the turbo. It can be about 6-8 inches away from the turbo INLET. It must be introduced BEFORE the turbo. Attach the label LP HOSE to this hose. Run it to the tank. You will cut and attach this hose to the Powershot unit. This hose will be attached to the fitting coming out the side of the Powershot unit. Or in line from the tank. This is the propane out to the engine fitting. Secure with hose clamp to the Powershot unit.


You will need to find a source to pick up boost pressure. Boost pressure from the turbo charger is what operates the Powershot regulator. If the vehicle has a boost gauge/meter installed, you can tee off of that area. If not, you will have to drill and tap a 1/8 pt
(fitting included) at the manifold to pick up boost pressure.

Next take the remaining hose and install the hose to this fitting. Secure with hose clamp. Attach the enclosed BOOST PSI label to the hose. Take the full spool of hose and run it the Powershot unit. This hose will attach to the BOTTOM of the Powershot unit. The BOOST IN on the photo or the fitting directly under the large brass nut on the top. This is what operates the regulator and controls the flow of propane. Attach and secure with hose clamp.


Attach the wiring harness to the lock off valve solenoid, which is screwed into the tank. From this harness, attach to the switch assembly and run into the drivers compartment/cab to mount . These are the on/off and reactivate/system re arm switches. These should be wired to the vehicle’s ignition, so that the Powershot system will can be activated or turned on only when the ignition is on. So power with ignition on, no power with ignition off.

Sounds simple enough for even a POG trained "Enganeer" to master
I'm waiting to hear from them on the 8V92 version. You series 60 guys may be in better shape if you have higher turbo pressures.

[BrianE]

I just hope Brian doesn't fly a V tail.[/QUOTE]

Jon, May you boil me in diesel if I even get near one of those things. Wings on top for me!:rolleyes: Besides they make me airsick. I know Jerry's a nice guy but REALLY.:D

Seems to me that propane injection is a good idea for cooling turbine inlet temps but using the cooler (more dense) air to make more power will put more load on the coolant system which is the achilles heel of the 8V. You can't have it both ways. (I don't think).

[Jon Wehrenberg]

Sounds like I have company when debating the merits of real planes with real tail feathers compared to Vee tails in which one of the three components is missing, or the goofy planes with their tails on backwards. Stick with me Brian.

WIN42, Just so there is no misunderstanding, all of the installed exhaust wraps I have seen are of the exhaust downstream from the turbo. There is no means of air to air intercooling an 8V92 that I am aware of due to the turbo pumping directly into the blower, but in the airbox on the 8V92 is a coolant to air intercooler.

The Series 60 engines that I have seen have the wraps so that may be a Prevost installed item, and the turbocharged air on those have an air to air intercooler stacked along with the radiator.

[win42]

Jon I was refering to adding an air to air cooler per Mr. Banks. I'm aware of the hot water to air so called cooler under the blower. I never understood why they have tried to cool items such as the above and transmissions using 185 degree hot water. In liew of ambient air. I guess they figure Artic engineering works everywhere. Glad to hear the wraps on the 8V92's only cover the exhaust portion. I guess I won't need that picture after all.

Boy those guys are right, You don't let us get away with s--t. Keep up the good work, those whippersnappers need some looking after.

Jon; What's your take on Propane injection?

[Just Plain Jeff]

A 2 cents worth here is the wisdom from the above post stating that when DD has a kit available for an 8V92, then it would be time to get one.

Pretty long conversation about the propane injection system, but basically it burns diesel much hotter and faster (creating more heat). If you note carefully on some of the internet sites, they never mention using such a modification on a two-stroke injection. That's likely because the 8V92 is a very finely balanced engine, much more so than the Series 60. My take on it is that playing with Mother Nature with propane on the 8V92 is likely to be very exciting at first, until the engine blows.

I've had 3 8V92 machines and think they are terrific engines! They are the culmination of 50 years of engineering and tweaking by DD. They have gotten a bad rap by RV salespeople trying to sell the newer and bigger $eries 60 (which I have), giving you more low end torque and a few MPG better.

But if anyone is simply interested in MPG, here are some other tips:

Here are a few additional tips that can help increase your fuel mileage:


Have your front end alignment checked and set regularly.

Have your brakes checked occasionally to make sure they aren't dragging.

Check your tire pressure. Low tire pressure requires more power from the engine when driving.

Use your air conditioner only when necessary.

In cold weather, keep warm-up time as short as possible.

Turn your engine off instead of idling it when you have to wait for long periods of time.

Avoid quick takeoffs and stops. Smooth, easy accelerating and decelerating is the most economical.

Keep your Rpm's as low as possible without lugging the engine and your driving speed steady.

Driving at speeds of approximately 55 mph or less is generally the most efficient.

Use the cruise control on long stretches when possible.

[win42]

Jeff: Thanks
Very wise input for us arm chair engineers. Until the propane tests are run on a 8V92 2 stroke test engine, we better cool it.
I do think the four stroke guys stand a chance with it. We blew a lot of engines in our Hot Rods using Nitro before they learned how to handle it.

I asked a veteran service manager at DD in Billings how the 8V92 compared with the newer series 60. He said they were both good relable engines. The difference = 2 8V92 to one transmission and 1 series 60 to four transmissions.
He attributed it to greater HP/Torque of the 60. Which says be carefull using the torque on the transmission and hopefully Allison will build a heaver transmission in the future. He was talking in terms of trucks putting on more miles a month then our coaches see in five years.

"For every action in one direction there is an equal reaction in the opposite direction"

[Jon Wehrenberg]

Win,

I never gave any consideration to giving an 8V92 a propane boost, and like Jeff says I think there are some concerns.

What I can't embrace is the fact that a potentially explosive charge of air and propane will be in the airbox on the 8V92. I know an air and propane mixture needs to be in the right proportions to explode, or even ignite, but other than direct injection of propane into the cylinder at the precise moment to add boost I think anything else could have some exciting consequences.

Maybe someone on the forum wants to donate their bus and engine for testing purely in the interests of science.:D