Detroit Diesels Max RPM

[syd]

I took the old girl out for a spin yesterday and decided to blow out the cobwebs by giving her a short blast of WOT. Both engines maxed at 2000rpm, which I thought was a bit low.
Put both engines in nuetral and did the same WOT, both engines maxed 2000rpm...

Is this normal ?

Syd

 

[epervier]

You know that Alf's your man for this, but He posted he was moving round to Inverness from Peterhead,so he may not be online, I can't remember when he said he was doing it.

 

[Divemaster1]

Syd,

Get those engine Serial Nos to Detroit ... they will give you the spec.

Suspect you should not be limited to 2000 RPM (are rev counters at helm mechanical or not ... wire to back if they are), and if so are they synchronised with the mechanical ones in engine bay ? .. presume you have a set down there that is ??

some of these engines was rated at 1900 RPM, but that was usually for continous load 24/7...

Suspect you should as a minimum (like mine) which are true Detroits, have WOT at 2300. The later Johnson Towers Marinised ones ran the fuel pump up to WOT at 2600 and took out 485 HP of the iron lumps.

You cannot check the mechanical gauges in engine room with the helm ones at idle only, but you need to spin her up a bit. ... Last week-end my port engine at helm was 150 rpm higher than the mechanical one at 1400 RPM... noticed that as we were moving slower than what I expected at 17 knots when at a perceived 1800 RPM ... once adjusted for that (and once again synchroinised) we did our usual 18 - 19 knots at 1800 RPM... and nearing 20 at 1850.. Me a happy man again ..

Anyway... checks are simple... WOT in neutral (may by the way be stamped on valve rocker cover as well...). should equal WOT at Load.

took up in the tune up section of the 800 page manual I gave you and that gives you the full procedure for setting up the engine properly !!

By the way ... do the KIS check first !!!... do your throttle leavers pull governors leaver to WOT ? .. if not correct his first and you may be surprised...

Tuning includes;

Back off governor Buffer screw (prevents hunting)
Back off Idle screw (takes pre-load off fuel rack)
Back off fuel rack from injectors
check governor clearances (this determines WOT) and when correectly adjusted you should have the determined WOT
Set exhaust valve clearance
Set injector timing (tool to measure this for your adjustments will set you back about £12)
Set fuel rack as if on WOT (without engine running of course !!!)
Re-set Idle
Start engine and verify idle ... adust as appropriate..
Set buffer screw if required (careful here!!)

...now you should be back to an engine which is in tune and should give you correct no load WOT.... simples ..

Anything else, please ask...

 

[syd]

Thank you Alf. Something to be getting on with over the winter months

 

[Divemaster1]

You need to get the spec for the engines !! ... this determines the injector timing setup and the injector timing tool is made for that specific timing.

http://www.dieselpro.com/dp-j1853kentmooretimingtoolfordetroitdieselinjector.aspx

Plenty of UK sources, but this was the first piture I could find...