I recently tore down a 6V92T and when I started to order the parts I discovered that this engine does not have the right fuel injectors for its serial number. No big deal I thought...….until now since I have been unable to locate my 92 service manual. The engine had 9A90's in it, but it calls for 9B90's . What I am looking for is the old printed injector chart that gave all the types of injectors, and the timing heights for each build. Does anyone have that by chance?
I have a 92 service manual sitting here but it might be too old as it only shows engine tune up spec's up to 1980. But on the outside chance it will help here is the 1980 info:
I’ll look when I get home. Idk how new my 92 series books are. One of my little cheater books is fairly new so maybe it’ll have what you need.
I'll look at my manual in the morning.
Great job Ken! I believe this is an 87 model engine so if one of you other guys could confirm this that would be fantastic. I will say out of all the 6V92t's I have done over the years in Bomag recyclers, this one is different. Base engine is the same except this engine has a throttle delay set-up and the oddest thermostat housing make-up. If I didn't know any better it almost looks like a marine engine build in some ways. I cant tell at this time whether this is even the original engine, although the paint matches the machine in color .
I usta have that chart in a wallet side laminated card had about 10 of'm.. key word here is> "usta".. sorry.
My 1987 Detroit 92 series manual don't show either 9A90 or 9B90 used for that year . I had to turn back to the 1984 chart to see both used in the 92's . 9A90's were used in 8V-92 TA/TTA automotive engines . Timing 1.470 9B90's in 6V-92 TA/TTA automotive engines .Timing 1.475 If I remember correct your Detroit project is in a truck ?
My book shows 74 to 87 years. Let me know if you want a particular page. It only shows 9a90's in 6v92 in california spec, 1976, 1977, 1978 after that they only appear in the 8v92
No, this is in a Bomag recycler which is why it’s a strange set up.
I’m still not sure on this. What should I time 9b90’s to? The 9a90’s are double the price
All the charts so far are for automotive engines, yours is an industrial engine. I'll see if I have a manual that covers industrial engines. Otherwise, 1.480" is safer than 1.470" to start with. It may smoke a bit more cold, but wont burn piston rings if the cams are advanced.
Picking up my overhaul kit today and will build the piston kits for installation tomorrow. Machine shop still doesn't have the heads ready yet
Can any of you guys get me instructions on the throttle cylinder adjust procedures? I am in dire need.
Do you mean the throttle delay?
Would this be what Detroit calls the throttle Delay Mechanism to cut back on the smoke while turbo gets up to speed? I'll scan in the three pages on that just in case.
fwiw detroit advertised a 565 hp marine 6v92 in the middle 80s .you may have stumbled on to one of those in an ind. app
Thank You Ken! That is exactly what I need. Could very well be so. I have done numerous of these in industrial applications, but this is either a marine or coach/on-highway application. I have NEVER seen this type in an industrial application ever which is why I have no experience with the throttle delay. I should have this engine finished this week and will take a pic of it when I finish. For those of you with any Detroit access, the serial # on this engine is 06VF-70741
Glad to be of a little help! And if possible when it's done and running how about a short video with sound?
Ok guys, a new issue for me. After going through Ken's info on setting this throttle delay up, it is requiring a few tools I do not have. I will be trying to locate those this morning but just in case it proves to be impossible I am wondering what ramifications I could have by removing the throttle delay all together? I have no idea if the cam timing is different or not on this engine. It is my understanding that the throttle delay cylinder helps slow the quick wind up of the engine for the on highway apps, turbo wind-up.....etc. Is it even necessary in this industrial machine?
I may have missed it somewhere but what exactly is the application for this engine..?
It's in a bomag mph100r
I don't know why you need it other than for regulatory people. It just prevents smoke on sudden acceleration. Does your machine have an electrically controlled throttle that goes from low idle to high idle? The tool that I used to have looked like a small piece of gutter of a specified length. Detroit dealers should still carry it. I sold my Detroit tools about a year ago but I got them originally from a tool truck. The kit was put together by Kent Moore.
What is controlling the RPM now? In a highway engine I would normally expect to see a min-max governor which if put on a piece of machinery would be no fun to operate. Since the driver's foot controls the rack directly except for max RPM and idle speed. Just thinking out loud here, unless the machine is always operated by running the engine right to max RPM and just plowing into the work. So is there some other governor provided by the machine that is operating the Detroit throttle linkage, or did somebody change parts of the engine governor to a variable speed configuration, or what?
If you disconnect the dash pot, it will allow it to go to full fuel without delay. What that means is you’ll get a nice storm cloud until the turbo has a chance to catch up with the air. The throttle response will be quick and the Dodge Cummins boys will be impressed.
I forgot to add my story, back in the 90s we ran an early 80s fire truck for a time that had exactly this, a 6v92 with the delay apparently disconnected. When you would thwack the throttle open on that thing it was awe inspiring to the point of being a menace to traffic. It did not really improve the acceleration all that much, though. Too much fuel with no air (turbo spoolup) to burn it just makes a lot of filthy smoke with nothing to show for it. In some cases it seems counterproductive to me but I don't have data to back it up.
I see I had an error in my post above #27, but caught it too late to edit. If you click on it you can see the chart showing which tool is needed depending on the application and injectors installed.
Looks like I'm going to eliminate the throttle delay. I don't know if the spring assisted yield link will need to be replaced or not. The engine is equipped with the swvs governor. The machine engine is usually set to high rpm and run at that speed full time driving a big hydrostatic pump.
Well might work okay but I'd hang on to any parts removed just on the chance it smokes too much and someone freaks out! I'm thinking it all depends on constant a load is on the engine. If load fluctuated a lot every time the governor call for more fuel it could blow serious smoke. Just cause the rpms of the crank might be steady the turbo speeds are controlled by the load on the engine and the percentage of fuel output the injectors are called on to supply. Maybe someone else can opinion on this?
An easy way to disable the throttle delay without change out the rocker shaft stand is to remove the ball and spring from the check valve. Its been years, but I think it takes a 7/16 or 3/8 in wrench to loosen the brass fitting to get to the spring and ball. That create a dump for the oil and the plunger is along for a free ride. No resistance=no delay.
If you remove the throttle delay, don't worry about the yield link. It will run just fine.
I haven't seen if the machine has an electric throttle control or not but if so you would only get the smoke when you go from low idle to suddenly going to high idle. Probably puff some to start with but be ok when you are running the machine pulling a hydraulic pump. Those kinds of loads are similar to a generator set, set wide open and the load will adjust the engine speed.
Now I just remembered I needed to update this. The engine is built and running. I eliminated the throttle delay with no issues. Now I have to wait 3 weeks for the rotor motor mechanical seal and the face plate to be made and shipped from England before I can get the machine outside and work it a bit. More to come...….