Curious but not serious!

damage to fuel pump, ring lands, possible burning piston depending on type, also injector tip, again depending type, run like the proverble back house,

<hr width=100% size=1>
 
My understanding is that it's nothing like the same ! I'm sure others will have a better idea than myself.

In a diesel engine, the fuel is injected on the POWER stroke into a cylinder with high compression. Hence the need for high-pressure, close tollerance fuel pump.

GDI engines inject the fuel into the INDUCTION stroke at a consequently much lower pressure.

That's how I believe it works. Am I correct??

Jim

<hr width=100% size=1>
 
Re: Real Anorak questions

Good God, man! Do you spend all your spare time making up question for pub quiz nights??

<hr width=100% size=1>
 
Having had a petrol spill in the cockpit while filling the outboard with the inboard diesel running I can only say that to see and hear your engine rev up so high that it breaks the rev counter and will not switch off whatever you do is most frightening. That was just fumes into the air intake some 10ft. away from the spill.


Phil

<hr width=100% size=1>
 
Great so there is a way to get gunnarsilins' Moody to do 40 knots with a 700 horsepower engine - he just needs to arrange for petrol vapour to go in via the air intake rather than through the fuel pump/injectors! Perhaps a bit of nitrous oxide could help as well?

Seriously, sounds scary and something I'd never have thought about. Did the engine suffer any permanant damage from the overreving?

Chris

<hr width=100% size=1>
 
Did rattle for a while, but that ceased after an oil change using SAE30 mineral oil.

The scary thing was that it just wouldn't shut down and kept running at something like 6000 rpm with fuel shut off, morse controls to stop and ignition off. The old lump was only designed to do half that.

Phil

<hr width=100% size=1>
 
Bermuda Triangle

One of the theories for lost ships and aircraft in the Bermuda Triangle is the sublimation of solid methane in the earth's crust, bubbling up through the water into the air and causing engines to over-rev and blow up. Apparently bubbling water surfaces have been seen by sailing cruisers.
Remember the days when the only way to get the old single cylinder diesel to start was to spray some ether into the air intake? I blew the head gasket on my Yanmar 1GM once this way in a fit of excitement! Still have the aeresol can in the garage. Maybe next time a stinkpot comes too close I should give him a spray (just kidding).

<hr width=100% size=1>
 
I was senile long before age came into it and managed to put neat petrol into a 2 stroke petrol engine many years ago. A Stuart Turner if I remember correctly and that never worked again so as the boat was a small Hurley went to an outboard instead.

Phil

<hr width=100% size=1>
 
Diesel engines can do the same thing all on their own, without the aid of petrol vapour, by breathing in their own crankcase fumes when they get old and knackered. Just stand well back and wait 4 them 2 go BANG !

<hr width=100% size=1>
 
I cannot see how a GDI could work with fuel injection in the induction stroke, the fuel would pre-ignite (pink?) long before TDC. This is because the compression ratio is higher, so generating higher temperatures as the fuel/air mixture is compressed. So, like a traditional diesel engine, I believe that the fuel is injected at some small angle before TDC. As I understand it the advantages of burning petrol this way is a high revving engine (in the style of a traditional petrol engine), but with the improved thermal efficiency of a diesel engine - giving better MPG.

Somebody out there will confirm/deny this.

Jeff.

<hr width=100% size=1>
 
The petrol mix is still ignited by a spark in a GDI engine, the only difference is that the petrol is injected directly into the combustion chamber on the intake/compression stroke.

<hr width=100% size=1>
 
Re: Yeah!!! Now we talk...

hi i think you have got the most posts for a question ever,(no doubt some anorak will tell me different) chris

<hr width=100% size=1>
 
Rocket Fuel

Petrol IS rocket fuel - Space Shuttle main disposable tank on lift off, about one third is petrol, the rest is liquid oxygen. The Space Shuttle booster rockets use [amongst other ingredients] rust and aluminium powder to set off a thermite reaction. And there are some thinking I'm nuts to consider a petrol inboard...

Astronaut to petrol station owner:- Fill 'er up wi' 400000 gallons of unleaded, Jack. VISA OK?

Regards

Richard


<hr width=100% size=1>
 
Once after buying a diesel shogun the gally captain half filled it with petrol.

Instead of letting me know it was driven 10 miles so that I could be told !!!!!

After having booked her in for a brain bypass, I phoned the RAC.

They told me to drive to the nearest filling station and fill with diesel.

Thing is the car never drove better. More power,smoother,quieter!!

Couldnt bring myself to tell her though.

<hr width=100% size=1>
 
You must log in or register to reply here.

Share this page

Top