Engine lubrication question

[caduceus]

I have done a search but found no results so I have to ask.

When a car engine (specifically speed six(flat plane, dry sump)) turns over BEFORE it fires, is oil being pumped round getting it lubed up? Or does the oil lubrication only happen once the engine is fired/running?

I need the answer to this question before I start another thread on the speed six forum.

TIA
Thanks in advance

[leorest]

If the dry sump oil pumps are electric then listen if they start up before cranking and if they are belt driven then that's your answer. Not much help but I'm sure someone who knows will be along soon.
L

[vyt]

Pressure and scavenge pumps are chain driven from the crank. Oil pumps run as long as the crank is turning, provided nothing is bust!

[Sam_68]

With any engine with an engine driven pump, the pump starts turning and pumping oil as soon as the engine is cranking over, but, since cranking speeds are so low compared to even the idle speed once the engine has fired, oil pressure is very low when cranking and even after that will take a couple of seconds to build up fully as the oil is circulated.

Get any car with a mechanical oil pressure gauge and you can easily see the rate that the oil pressure builds up as the engine cranks and fires.



>> Edited by Sam_68 on Friday 27th January 20:39

[chuntington101]

so what is the best way to "pre oil" before startup? aquasump, electric pump in paralel?

Chris.

[steve_d]

Use an Accusump to pre-oil.
The Accusump holds a quantity of oil at whatever pressure your engine runs at.
When you switch off the ignition a valve closes and traps the oil in the Accusump. When you next switch on the ignition the valve will open and dump the stored oil into the oilways of your engine. So the startup routine is to turn on and pause a moment to let the oil pass through to the bearings then start.

On wet sump engines if you suffer oil surge (track days and attacking tight roundabouts) so that the pump is not producing pressure the Accusump will automatically compensate by releasing oil into the engine.

Steve

[caduceus]

steve_d said:

Use an Accusump to pre-oil. The Accusump holds a quantity of oil at whatever pressure your engine runs at. When you switch off the ignition a valve closes and traps the oil in the Accusump. When you next switch on the ignition the valve will open and dump the stored oil into the oilways of your engine. So the startup routine is to turn on and pause a moment to let the oil pass through to the bearings then start. Steve

Will this application be ok to use on a speed six? You know how funny TVRs are?

Will it be hard to install aswell?

Thanks Steve.

[steve_d]

If you already have remote pipework such as oil cooler or the pipework for the dry sump then you simply tee into the pipe which sends oil to the engine. Add some electrical connections and somewhere to bolt it down and your done.

Steve

[ngr]

If you wire the ignition separate to the starter you can crank the engine to get oil pressure then turn on the ignition to start the engine.

[chuntington101]

also have you thought about pre warmers?????

i know racde teams use them to help get the engines started/reduce wear. also i have read that i can help with fuel econamy!

Chris.

[caduceus]

Thanks for the replies gents

The info was needed purely to put in place a soloution to reduce cold start engine wear and try to make the speed six as reliable as possible.

Trouble is, I keep hearing one bad story after another about the Tuscan speed six and its playing on my mind now to the extent I may well just go for a late 'S' series and muck about with that untill I hear news about the six that inspires confidence.

This is'nt a chance for certain types to say "oh well it sounds like TVR ownership is'nt for you then . . ". I have owned two TVRs and know all about ownership, but they were both R V8s and never missed a beat. Never. Two TVRs, two years, no problems at all. Apart from a rad which I replaced myself.

[vyt]

caduceus said:

Thanks for the replies gents The info was needed purely to put in place a soloution to reduce cold start engine wear and try to make the speed six as reliable as possible. Trouble is, I keep hearing one bad story after another about the Tuscan speed six and its playing on my mind now to the extent I may well just go for a late 'S' series and muck about with that untill I hear news about the six that inspires confidence. This is'nt a chance for certain types to say "oh well it sounds like TVR ownership is'nt for you then . . ". I have owned two TVRs and know all about ownership, but they were both R V8s and never missed a beat. Never. Two TVRs, two years, no problems at all. Apart from a rad which I replaced myself.

I have owned 3 different TVR's over the past 7 years, RV8, AJP8 and S6, all have been used pretty much everyday, all three make visits to the track, none have let me down yet although the S6 is only at 12.5k miles so too early to say it is good.

[dannylt]

I doubt whether many speed 6 engines have suffered from significant cold start wear. And a six can't be flat plane, you're thinking AJP8.