One tooth out

[moeee]

I've driven a recently purchased vehicle same as mine and it seems like it has much less acceleration than my vehicle.
Although it does run and idles particularly well.
This motor has dual/fuel LPG connected to it.

I've pulled the motor out and am cleaning it and checking things like clutch plate and oil leaks and stuff before I install it in my vehicle to replace my stuffed engine.
The valve timing appears to be not reaching its mark when the crankshaft has reached TDC.
It looks one tooth out.
Would the valve timing be purposely one tooth out to accomodate the LPG situation.
If it was one tooth out would it still run without backfiring and stuff?
I checked the TDC marks on my stuffed engine and the valve timing dimple aligns with the mark on the cover exactly at TDC.
I have a gregorys manual and have played with engines on many occasions.
It is an old Mitsubishi L300 Van.
1.6 litre I believe.

[hillbilly]

I don't think you should have to change the timing to suit LPG, if anything you should be able to advance the timing as LPG is a high RON fuel, thus making it go better!

check you timing belt/chain, it may have stretched or broken a tooth.

[moeee]

I done a bit of a Google and it seems if you are one tooth out the engine does run sluggish and lacks power.
And many engines woudn't smack the piston onto the valve if only one tooth out.
It uses a timing belt and all teeth are fine.
I'm starting to think that the previous owner may have replaced the timing belt wrong and thought the motor was a bit stuffed because it wouldn't run too good and that is why he got rid of the vehicle.

[LeroyPatrol]

hillbilly, Cam timing and ignition timing are 2 different animals. You are taling about ignition timing.

moeee, set the cam timing to what it should be acording to the marks. You will get the sort of performance you describe with retarded cam timing.

Leroy

[moeee]

Thanks Leroy.
Just lacking in self belief.
Cheers.
By the way, only noticed the error when I was looking where the oil leak might be coming from.
Thought I might check seeing as how I had the timing covers off.

[z80]

is it the correct belt?

[moeee]

is it the correct belt?

Yes it is.
And if it wasn't???

Another question.
The rocker cover uses just 2 bolts to hold it down.
Sealing is with a rubber type gasket that sits in a groove right around the cover.
If the cover is slightly warped, I'l imagine that there will be less pressure holding it down evenly all over.
Anyone recommend some sort of sealant I could use between the gasket and the head?
I really don't wanna wash the engine , fitting it in the vehicle ,to then find oil leaking all over it the next few days.
Bit of mucking around once the engine is installed.

[gdmck]

Just a smear of silastic along the rubber seal that goes into the groove of the rocker cover make sure all oil is cleaned off the head and rocker cover first and it wont leak then...and they do not alter valve timing to suite lpg engines only ignition timing...

[moeee]

Thanks gdmick.
How come no silastic on the head as well?
And would I get the silastic from Super Cheap auto?

[myf360f1]

Hi Moeee,

can get silastic just about anywhere including repco etc.... failing that you could use grease on the seal coat it completely fairly thick then bolt down and wipe of excess, thats how it was done before silastic turned up

[SystemRat]

If it has a timing belt and you do not know how old it is I would replace it as it may save you grief latter on.

At the same time setup the new belt to the correct setting. Sluggish performance can also be due to a faulty advance mechanism in the distributor.

They may have fiddled with the default setting and timing position for the LPG. That I don’t know about.

[Godzilla]

The belt should not be set one tooth out regardless of the fuel being used.

A mark should be available on the harmonic balancer, a corresponding mark should be available and the cam sprocket.

If the marks don't line up, rotate the crank another 360 degrees and check again.

2 turns of the crank= 1 turn of the camshaft.

Check before dismantling to prove to yourself if this is your problem.

When dealing with an unknown engine always replace rubber timing belts as soon as possible, if your engine is an interference type design and the belt breaks its goodbye valves and pistons.

Id agree that your problem may be an ignition advance or setting problem.

Use some silastic engine sealant on the cover if the gasket is old. If the gasket is rubber and new and it doesn't have to go around cam cut outs in the head you shouldnt need anything, the 2 bolts will compress it nicely.
If you have cam cut outs you need to apply silicon sealant in these areas regardless if its old or new.

Do a search here for "Headgasket replacement", i have picks of the correct method to apply silicon in the cam cutouts.

Cam timing position characteristics (if you decided to move your cam position from standard)-
Advancing the camshaft position in relation to the crankshaft induces low end torque, retarding the camshaft induces high rpm horsepower.

We are talking 10 degrees max, with 5 being the norm.

Ive spent enough time dialing in camshafts with a degree wheel. The results really show on a drag strip

[dogsbreath]

I was looking at one of those L300 motors a couple of months ago. It would be very easy to get the belt timing out as the mark is very small and obscure for the cam and not where you would expect it to be. The one we looked at was on gas also and the valve ends had completely mushroomed down almost down to the spring retainers. A new head and stellite valves was obtained from a place in/near Buchan. I think the overall cost of the head and valves was around $500 which I felt was pretty reasonable. Last head I bought was over $2500 for a diesel Jackaroo.

[SystemRat]

Ok this comes from a Russian friend who was a mechanic until he had had enough of working on cars and now delivers pizzas for a living therefore it must be right.

Seems the good conversion places will dyno the car to get the best out of the gas conversion, which generally means the ignition timing will be advanced a tad. I asked what about petrol. He said well they optimize for gas as 99% of the time it will be on gas because it is cheaper to run and petrol would only be used if you were out of gas.

Thus if your now only running petrol you will need to stick a timing light on it and set it to the normal advance setting and if the cam timing is out it is wrong and must be corrected too.

There was also talk of ECU mapping but I do not think that is an issue here.

[Godzilla]

Tunning for LPG?

See post 71 here

Its just an overview but you will get the idea. Take note of the very last paragraph.

Edit; i think we went over it here too.LOL

[gdmck]

L300,s have a plastic timing cover and you realy have to remove it to check the timing properly and im pretty sure they have a balance shaft that has to be in time as well....all dots have to be in line together... running on lpg you lose approx %10power and use %10 more fuel and the gas is slower burning hence the advencement in the ignition timing to recover performance..