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Re: TS24 8V-71 Help required

Posted: Sun May 07, 2017 10:33 pm
by FOWLER MAN
Jeremy Rowland wrote:Thanks Fred :wave: yes the engine was running fine until this issue; I will pass on what has been said by others here to Tim and see if he can locate the faulty pipes/injector?
Fred if it was say for example caused by a cracked injector then I trust that all of the injectors on that bank of the engine would need setting up? I have never setup a Detroit, if it was a Cummins then yes no problem I have the tools to set those up but not the Detroit.

Jeremy


Hi Jeremy,
It would only be necessary to set the injector you changed.

In my last post I was not saying that you could not do the job without the GM tool kit. As Paul says it's easy enough setting up the timing using the tail of a Vernier instead of the GM depth gauge.

Unlike the Cummins "Pressure/Time" system each GM injector unit is in effect an injector and pump in one, each having its own rack.
These are connected by a link to a shaft running the length of the head which is in turn connected to the governor.
Each of these links has a pair of adjusting screws which allow the rack in each injector unit to be individually adjusted.

That procedure is time consuming and a bit of a pain in the a##e but I will try to explain if you need to know.
Fred

Re: TS24 8V-71 Help required

Posted: Sun May 07, 2017 10:44 pm
by Jeremy Rowland
Thanks Fred :thumbup: I doubt that I will be having a go at it myself as I am busy on the 580BT which I have now managed to connect the pipes to the right hand spool valve so that the slew control is the right way round; then it blew the long flexi hydraulic hose to the right hand brake and proved to be a pig of a job as the tube through which the hose passes through the back of the machines main tub had taken a knock putting a dent in it, I managed to used a slitting disc to grind two slots that I joined and peeled the dented part of the tube open allowing me to removed the hose, still learning :lol:

Jeremy

Re: TS24 8V-71 Help required

Posted: Mon May 08, 2017 5:45 am
by Mark Williams
Hello Jeremy,
I haven't set one of these up for a long time.You can find a link on videos on Youtube on this engine & how to do a complete top set.There is a bus fitter on there from the US changing out an injector,not much room for him to work in, as most of the buses out here are rear, or mid engined .All the DDs from an inline 2 to a V16 are virtually the same to set,except for the injectors, which have a different depth (N73) injector rings a bell for instance.
The easiest way to find a fuel leak on these, is to get some infra red fuel dye, which is easily obtained & put some in the fuel tank. I,m sure that plenty of people know where you can borrow an infra red test light which will show the leaking fuel area up as a bright purple. These engines are so common for fuel dilution, you would not believe,especially after a rebuild, or injector pipe loosen. There is actually a torque setting for the fuel lines. The bell flange of the pipes split if over tightened.
Get the engine up to operating temperature with the rocker covers off & shine the infra red light all around the pipes & injectors. The leaking engine oil in the area that is leaking will show up purple from the diesel. To do this test, you might have to put new engine oil in first,depending on how diluted the oil is. The cold weather & the scraper standing might have been the cause of the problem, due to expanding & contracting of the faulty component.
Extremely important after the fault is remedied,change the engine oil & filter, as bearing failure is for certain.
Carry out repeat with infra red light after fix to make sure no more dilution is evident.
As Fred says, there is only need to set valves, injector & synchronization on the troubled cylinder. Use a vernier to set injector to correct spec.
I cant remember the sequence, a top set is as follows, set valves,set governor, set injector & set synchronization.
hope this helps,
let us know what you find,
regards,
Mark Williams.

Re: TS24 8V-71 Help required

Posted: Mon May 08, 2017 7:32 am
by Jeremy Rowland
Thank you Mark I will pass this information on to Tim. :thumbup:

Jeremy

Re: TS24 8V-71 Help required

Posted: Tue May 09, 2017 12:13 am
by FOWLER MAN
Hello Mark.
Thank you for your post.
I have never used infra-red dye to trace a fuel leak but I guess your never too old to learn.
Forty-five years since I did much with these, but I remember that there was a torque setting for tightening the fuel pipe unions but I have no record of it in my notes. GM had a special spanner for the job.
According to my figures the depth gauge setting for the injector timing on the 71 engines was 1.484"
Fred

Re: TS24 8V-71 Help required

Posted: Thu May 11, 2017 9:56 pm
by Jeremy Rowland
A quick update for you here; I went to work on my 580BT today and Tim Brown had another go at trying to find the internal fuel leak on this engine, he pressurised the fuel line with compressed air and tried using soapy water sprayed onto the injector pipes to see if there was any bubbles of air escaping but there was no look with that, neither of us could see any leakage of air indicating a cracked pipe.
For the moment I think that they are going to monitor the situation; would it be possible for fuel to leak through an injector and down one of the cylinder bores? This engine does a lot of standing and no work most of the time when it is run?
Tim forgot to turn off the fuel last week and he thought there may just be a sump full of fuel but when he checked it out there had been no additional leakage. I believe he dropped the test oil that he had put in it to try and find the fault, this was done after he had drained the sump of oil that was contaminated with diesel and has now put some good oil back in the engine.

Jeremy

Re: TS24 8V-71 Help required

Posted: Fri May 12, 2017 12:44 am
by essexpete
I am way out of my limited knowledge here Jeremy but could there be a weak injector shut off spring coupled with some kind of reservoir higher up for say a cold start device?

Re: TS24 8V-71 Help required

Posted: Fri May 12, 2017 7:37 am
by Jeremy Rowland
essexpete wrote:I am way out of my limited knowledge here Jeremy but could there be a weak injector shut off spring coupled with some kind of reservoir higher up for say a cold start device?


Pete the fuel tank in this instance is higher than the engine which is why Tim wondered if he would find that the sump had filled with fuel again as he left the fuel tap turned on; I am not sure if there is a cold start device on these engines? We had wondered if perhaps one of the injectors had briefly stuck allowing fuel to leak down the engine bore and into the sump? Guess they will find out when they monitor the situation.

Jeremy

Re: TS24 8V-71 Help required

Posted: Fri May 12, 2017 10:09 am
by Mrsmackpaul
Dunno if the fuel could leak down a injector and if so it would only leak thru the pistons on bottom dead center as any others would just go out the air box drains
How ever if this has only happened after working on it I would think this is hint of were to look

Paul

Re: TS24 8V-71 Help required

Posted: Mon May 22, 2017 6:06 am
by Mark Williams
Hello Jeremy,
A good friend of mine who has a great deal of experience on DDs suggested, if the TS 24 is only used as a show piece, is to drop the oil pan on a dry place of repair & lay a clean piece of cardboard under the engine for a few hours & see if there is any sign of diesel leaking down a particular cylinder. It will lead you in a more direct position, maybe a dribbling injector & so forth. Just a suggestion.
Regards,
Mark Williams.