But my XJS has been laid up for the past 18 Months and now I want to Start her up and get her ready for Summer

So should I disconnect the Fuel Pump Relay (so that She won't Start) and Spin her on the Key Before I do so, because this Car most usually fires up on the very first turn of the Key

Thoughts please Guys

Alex

 

No. If you're going to start it, start it.

You want it running quickly to get the oil up into the engine. Slow speed on the starter doesn't get much oil circulating, it just causes bearing wear.

 

Cheers! Jagboi
something else I didn't know!
Also 'Greg'

 

Jagboi64,

I'm really interested in your recommendation to just start up the car. I was brought up on the principle of spinning the engine over after a layup, so that the oil could circulate up to the cams etc without the excessive speed of the engine running. Ideally, I would also do that with the plugs out to lower the strain on pistons, crank etc. It's a technique I still employ. But maybe I've been getting it wrong all this time?

You seem to be saying that it's better for the components of the engine to get it turning over faster at, say 1000 rpm, than to turn it at, say, 200rpm on the starter? Do you consider that would still be better than turning it over very slowly by turning the crank by hand to move the components and get the oil starting to move?

Thanks

Paul

 

Paul , if you understand how an oil pump works you’ll realize that turning it over by hand won’t do what you want it to do.
You could do like formula 1 teams do which is put in pre-heated coolant, preheated oil and then start it.

 

Just don’t rev up the engine when it’s cold.

 

Cheers Guys! Jagboi@Mguar@Paul(ptjs)@Greg@anyone else I may have missed

As said, I seemed to remember that this was Controversial (so its always worth asking to Check)

My Engine used to Start off at 1500 Rpm but after taking Jagboi's advice, She now Starts at 800 Rpm and stays there, though I may have to 'Feather' the Throttle in this Cold Weather to prevent her from Stalling until She is warm enough to run on her own

I haven't tried to Start her yet, as I've got to put on a New Battery 640 CCA and so I will Start Her to Run and not on the Key but keep the Revs down

Maybe Tomorrow Weather Permitting!

 

My experience comes from packaging large industrial engines and the recommendations from the OEM's was to either prelube, or start the engine. The bigger engines were designed to have a separate auxiliary external oil pump for prelubing. The starting procedure built into the control panel was to have the external pump circulate the oil to build pressure while the engine was stationary, and the starter wouldn't engage until there was at least 5 psi oil gallery pressure. This was typically for engines larger than 1500hp.

For the smaller engines (typically 400-1300hp) there was specs for minimum starter speed to ensure a fast crank, fast start, and to get the oil circulating. It was forbidden to have either an extended crank in an attempt it build oil pressure, or a slow cranking speed. Sometimes we used 2 starters to ensure the crank speed was sufficient. The starters were air powered, so some packages required a fairly large starting air supply and reservoir to ensure sufficient crank speed. However, with a good pressure those starters really spun the engines over, they were running in under a second.

The oil pump output isn't linear at low speeds, so the volume of oil moved at cranking speed is very low. That is the reason for wanting a fast start, as it ensures sufficient pump speed to generate flow and to build pressure.

For the engine packages I built, it was considered best to have a prelube system, if that wasn't possible then a fast start, and worst was extended and/or slow cranking. I was on a course at the Caterpillar factory for Design Engineers who incorporate these engines into their machinery and someone asked if the prelube was really necessary for the big engines. The answer that came back was: "You can do whatever you want, we sell parts!"

 

18 months, that's really not very long, I'd just fire up. Maybe if it was 18 years I'd be think of squirting some oil down the bore.. good luck

 

Hi Cycloid@Jagboi

Cheers Guys!

My other V12 Cherry Blossom was laid up for 14 Years!

Where apart from Stuck Injectors, She Started up Straight away without any probs on the Battery

So Tomorrow I'll do the Same with '50 Shades' my Grey XJS and then I can take her for an MOT

 

I like to pre-lube any of the V12s I have rebuilt and put in my XJSs.
I take out the oil pressure sender and use an adaptor tube with a 1 litre plastic container glued to it.
Fill the container with oil and let it percolate down into the engine for a day or so.
That is on the outlet side of the oil filter and will fill the cams and bearing oil gallery.
Then refit the sender and fire it up.

I do not drive my XJSs much, but rarely fail to drive them at least every 2 months.
If an interval was more than 12 months I would do the pre-lube.

 

Hi RichardsJags

I'll have a look Tomorrow and see what's involved

Though I'll probably go with Jagboi's idea and just see if she will start