thinking about Jakes

David Anderson · February 01, 2016, 04:54:29 PM

Are jakes available form my 1985 6v92? If so, where would I look, how much, and who could install them? San Antonio area.

David

TomC · February 01, 2016, 05:25:37 PM

If you want to come west of I-25 then Jakes are a good idea. Jakes are so good now that most all the big Diesel engines in trucks come with Jakes as standard equipment. Jake brake was the first thing I had installed on my bus before I even drove it home from Portland, Or. Good Luck, TomC

luvrbus · February 02, 2016, 01:24:39 AM

David,if I remember you have a front mounted turbo is that correct ? if so it is a major job you need to reroute the air intake on the passengers side it's not worth the time and effort on a 6v92 JMO

David Anderson · February 02, 2016, 11:29:42 AM

Quote from: luvrbus on February 02, 2016, 01:24:39 AM
David,if I remember you have a front mounted turbo is that correct ? if so it is a major job you need to reroute the air intake on the passengers side it's not worth the time and effort on a 6v92 JMO

Yikes I didn't want to hear that. Let me take a picture so you can tell me for sure, but I think you are correct.

David

LowTide · February 02, 2016, 11:38:18 AM

Quote from: TomC on February 01, 2016, 05:25:37 PM
If you want to come west of I-25 then Jakes are a good idea. Jakes are so good now that most all the big Diesel engines in trucks come with Jakes as standard equipment. Jake brake was the first thing I had installed on my bus before I even drove it home from Portland, Or. Good Luck, TomC

I want to take the DW to Washington State and Oregon one day. I will never forget some of the steep grades I encountered when I moved to washington many years ago.

The first thing I said to her was I think we may need to ad some jake brakes, but then again, these buses ran all over the US and I could probably get there using the gears and I would think that having the jakes might remove allot of the worry away?

David Anderson · February 02, 2016, 12:11:11 PM

Here are some pics

David

luvrbus · February 02, 2016, 01:46:44 PM

You are good to go David they will work on your setup

David Anderson · February 02, 2016, 04:27:33 PM

Quote from: luvrbus on February 02, 2016, 01:46:44 PM
You are good to go David they will work on your setup

What would I expect to pay? I'd have to have it done. It's beyond my skill level.

David

luvrbus · February 03, 2016, 01:54:36 AM

Expect to pay around 6 to 8 hrs labor plus the parts by chance do you have the tall valve covers ? somewhere on this board I posted the parts list lol I wouldn't waste the wire for doing a 2 stage Jake

muldoonman · February 03, 2016, 03:05:02 AM

Hey David, what part of the country are you in the Eagle Ford area (south texas) . I found out if you check with the well service companies they seemed to have a 2 stroke cat around as they used those engines for years on the rigs or at least they did out in the west Texas (Odessa) area years ago. Don't have or haven't found anybody up la grange tx. way.

TomC · February 03, 2016, 03:56:01 AM

Easiest way to wire is to have an on/off switch with a foot operated switch. Then you don't have to deal with the governor switch. Good Luck, TomC

Geom · February 03, 2016, 05:40:17 AM

This is probably how religious battle-lines are drawn, but I am genuinely curious,
Just how useful are jakes, on a 6v92 in particular?

I too had tossed around the idea of having them installed based on some previous posts. But we have that engine and I had a assumed the compression was high enough in the engine, to simply back off of the throttle, drop to a lower gear, and use that natural back-pressure to hold a grade.
Please keep in mind, I haven't driven it in CO type grades (yet), but we did bring it back from CA to MO (along the southern route) and we came across some fairly decent grades. But the real test was in her original stomping grounds of the PO. They lived on a fairly steep and long hill (~10 miles), that reminded me of CO driving; and we had no problem creeping down that hill (several times), in first, and holding the grade well.

We do intend on doing quite some driving around CO, as we spend time exploring that state; among others with similar topography.
I'd like to get thoughts, opinions, and direct experience with and without jakes on that engine and the preception of their usefulness.
Do jakes make it easier? More fuel efficient? Safer? Less strain on the engine?
Or is creeping in first (we actually ended up needing 2nd because first was toooo slow, in our experience) usually sufficient with this engine?

Thanks,
George

buswarrior · February 03, 2016, 06:34:43 AM

Here's another way to think of Jakes:

They let you go faster down the hill than you otherwise could do safely without them.

By safely, I mean without having to use the brakes to control the downhill acceleration so much as to overheat them.

How much faster, depends on the strength you can get out of a given set-up.

How fast do you want to go?

happy coaching!
buswarrior

bevans6 · February 03, 2016, 07:29:32 AM

Diesel engines naturally don't have back pressure. As they are motored over on no-fuel coasting down a hill they fully compress whatever air they take in ( always positive air pressure in a two stroke from the blower so the cylinders always get about fully charged with air) and then they get all the energy that it took to compress the gas back on the down-stroke. Virtually a zero-sum game, energy in is energy out less friction losses. Exhaust brakes, variable geometry turbos, et al all add a restriction that traps the exhausting gas and creates a back pressure, but two strokes don't use those tricks.

Jake brakes work fine on a two stroke as long as you don't expect too much. It's a gentle retardation at low speeds and rpm, and works best at high rpm. Mine will slow me down too much on a typical Interstate grade of 4%, keep up just fine on a 6% grade, and I need to tap the brakes a bit on a 10% grade. Anyone from the east coast that knows the grade down I77 from Fancy Gap, I have to cycle the Jake brake on and off to maintain speed. Now, add 15K lbs of coach to my 30K lbs and the story might be very different.

Brian

RJ · February 03, 2016, 07:35:40 AM

IMHO, Jakes are well worth the investment.

One-time installation cost, very little maintenance.

Less expensive than two complete brake overhauls, which you WILL be doing if you spend anytime going up and down RockyTop out west.

Coming down the hill, the cooler your brakes, the better.

WB from Reno, NV to Sacramento, CA on I-80, you've got 70 MILES of 4%, 5%, and 6% grades. That's 3rd gear @ 45 mph and on/off the brakes constantly, with them stinking at the rest stop without Jakes. With Jakes, it's 60 mph in 4th and never having to touch the brakes unless traffic requires you to do so. BTDT - fully loaded MC-9s, both with 8V71s and 6V92s (there's only 16 cu.in. difference between the two, really insignificant.)

Additionally, when wired thru the throttle, they come on instantly as soon as you back off, which means they'll actually start slowing the coach before you've got your foot on the service brake and applying it. Could be the difference between a hit and a miss. . .

For me, I consider them a SAFETY item on my coach.

FWIW & HTH. . .