Offroad-Express

Bulletproof wrote:

Kiwimidi wrote:since you lot are so knowledgeable . what happened to this piston? was it a result or running lpg? I realise the marks on the top of the piston are from the bits of ring bashing into the head but what about the big hole down the side
quote]

Did you buy that truck from Clyde ?

Were you feeding LPG into it ?

Cheers Richard

the truck has had lpg thru it but not at the time this happened. truck not bought from clyde.

Kiwimidi wrote:

mudzilla wrote:Maybe thats from you lowering the boost and leaving the fuel wound up then towing a dead Nissan a couple hundred Km with your foot on the floor ,,, At a Guess ...

The nissan was definatly part of the problem. I did turn down the smoke quater of a turn. do you think it was over fueling??

Possably,, When you got the truck it was running extra fuel and extra boost and went well .. Maybe buy lowering the boost and not backing off enough fuel or backing off the fuel and continuing to run high boost may have been enough to get the exhaust temp to high and melt the piston.. Running hard (towing a heavy Vehical ) for a long haul and not having an Exhaust temp gauge to keep an eye on may have been the fatal blow for the poor old thing ..

Kiwimidi wrote:

the truck has had lpg thru it but not at the time this happened.

A melt down like that would not be the result of previous LPG use.

A melt down like that would be the result of the pyro temperature too hot on the day . It is something that happens instantly when the temperature gets over a certain point.

I have done it with motor bikes in the past.

Probably caused with over fueling and foot to the floor.

Cheers Richard

so your both saying i should wind more boost into it to avoide this happening again. sounds like fun

Kiwimidi wrote:so your both saying i should wind more boost into it to avoide this happening again. sounds like fun

Actually what you are saying is right. I have a manually turned on supercharger and when I switch it on my pyrometer drops 100 C with the extra air going through the motor.
The other choice is to turn the fuel down.

Cheers richard

burned a hole in a piston on my 351 cleveland as the dissy was jammed at full advance

Guessing here and the guess is based on dead engines running petrol and two stroke racing bikes.

That piston bears all the earmarks of a ring failure. the short bits bounced up and down eroding away at the lands until finally breaking through. As the ring turned around, bits broke off went up on top, making interesting engraving marks and buggering off down the divorce pipe. probably even gave the turbo a smack or two on the way.

The melted bits are created AFTER the ring failure.

Question. Why did the ring fail?
Answer. because it failed. fuknose.

I can tell WHY the sky is blue though.

Moriarty wrote:Guessing here and the guess is based on dead engines running petrol and two stroke racing bikes.

That piston bears all the earmarks of a ring failure. the short bits bounced up and down eroding away at the lands until finally breaking through. As the ring turned around, bits broke off went up on top, making interesting engraving marks and buggering off down the divorce pipe. probably even gave the turbo a smack or two on the way.

The melted bits are created AFTER the ring failure.

Question. Why did the ring fail?
Answer. because it failed. fuknose.

I can tell WHY the sky is blue though.

This is what i assumed happened i just thought i would ask the question if the gas had contributed to the prematuer faliuer fo the ring.

Moriarty wrote:Guessing here and the guess is based on dead engines running petrol and two stroke racing bikes.

That piston bears all the earmarks of a ring failure. the short bits bounced up and down eroding away at the lands until finally breaking through. As the ring turned around, bits broke off went up on top, making interesting engraving marks and buggering off down the divorce pipe. probably even gave the turbo a smack or two on the way.

The melted bits are created AFTER the ring failure.

Question. Why did the ring fail?
Answer. because it failed. fuknose.

I can tell WHY the sky is blue though.

Is that another GUESS Bob

Rings generally fail and break because with the piston getting hot and expanding they jam in the groove.

Excessive carbon build up in the groove can also bring this on.

Other things causing failure is lack of oil in the bore or a faulty cooling system.

All of these things cause heat and a ring generally won't break unless it jams in the groove.

Cheers Richard

mudzilla wrote:

Moriarty wrote:
I can tell WHY the sky is blue though.

Is that another GUESS Bob

Nope, this is proven as to blue sky, not a theory.


(Havent heard back from Ghana yet.)

Bulletproof wrote:Rings generally fail and break because with the piston getting hot and expanding they jam in the groove.

Excessive carbon build up in the groove can also bring this on.

Other things causing failure is lack of oil in the bore or a faulty cooling system.

All of these things cause heat and a ring generally won't break unless it jams in the groove.

Cheers Richard

Generally speaking, you are right, all of those can be, and GENERALLY are, contributing factors. But are not the ONLY reasons.

ohhhh i have something else to add here but cant yet...

i love this thread.

wopass wrote:ohhhh i have something else to add here but cant yet...

Dooooooooooeeeeeeeeeeeeeeeeeeeeeeeeeet!!!!!!!!!!!

Hmmmmmmmm, wow, look at the torque figures!!!!!

Is that over 1000nm i can see??

DieselBoy wrote:Hmmmmmmmm, wow, look at the torque figures!!!!!

Is that over 1000nm i can see??

1390nm fume off
1475nm fume on

ohh and its fuel economy including adding the lpg to total is averaging 8.5km-ltr and thats rolling 35" tyres all the time

nice
should have thrown the missle on there :d
are you still planning the christmas refresh ??
do you want me to price up some bits for you for it ??
we just got on capricorn so a rods etc just halfed in price ...

wopass wrote:ohh and its fuel economy including adding the lpg to total is averaging 8.5km-ltr and thats rolling 35" tyres all the time

For us of more mature years, that translates back to 24 MPG which is VERY respectable, considering the way its driven, as if it was a little old lady doing her shopping. Wonder how it would go driven a litttle more aggressively?


One who spilt milk in it and didn't tell the owner? Cruel, that.

wopass wrote:

DieselBoy wrote:Hmmmmmmmm, wow, look at the torque figures!!!!!

Is that over 1000nm i can see??

1390nm fume off
1475nm fume on

A 6% increase?!?!

KiwiBacon wrote:

smurf182 wrote:

wopass wrote:look at the humble bumble, he shouldnt be able to fly...but he does it with ease

Urban myth

http://www.sciencenews.org/view/generic/id/5400/title/Flight_of_the_Bumblebee

Just like the 1000Nm cruiser engine.

Go the cheerleaders

KiwiBacon wrote:

smurf182 wrote:

wopass wrote:look at the humble bumble, he shouldnt be able to fly...but he does it with ease

Urban myth

http://www.sciencenews.org/view/generic/id/5400/title/Flight_of_the_Bumblebee

Just like the 1000Nm cruiser engine.

Bumblebees cant fly, its a well controlled jump!

probably find if you dynoed it a bumble would have over 1000Nm as well
i do think it would die if you fumed it though

smurf182 wrote:

wopass wrote:

DieselBoy wrote:Hmmmmmmmm, wow, look at the torque figures!!!!!

Is that over 1000nm i can see??

1390nm fume off
1475nm fume on

A 6% increase?!?!

fume made a bigger difference to KW.

Is that NM at the wheels or at the flywheel?

Hard to see what the graph says.

all 4 wheels with 35" tyres on them

Andrew1706 wrote:Is that NM at the wheels or at the flywheel?

Hard to see what the graph says.

the ONLY way you can measure flywheel Nm is ... on a engine dyno
if they try to gove you that off a rolling road or chassis dyno .. its a made up figure

vvega wrote:if they try to gove you that off a rolling road or chassis dyno .. its a made up figure

As long as before and after numbers (right or Wrong) are done on the same dyno you still see your % gain.
Good on ya Wop.. I want to see how it Hauls the Missile on your trailer now