Troopzilla

[Dougal]

Unless they can ultimately prove that the gas is causing the problem, I'd leave it, I've heard so many good reports, my mate just put gas injection on his Brunswick Diesel and he swears by it

Quick question for you: how many diesel companies world wide sell diesel engines with lpg injection?

Second question for you: what is the maximum safe compression ratio for a lpg engine?

 

[dadinabarrel]

1. No idea
2. Also no idea

From a new head (not machined yet) with a 5 notch gasket I've got the lowest possible compression configuration I can get for my 1HZ which is where you need to be on a higher compression N/A motor with aftermarket turbo like mine.

Longevity is directly related to your average pre turbo EGT's

The negative data around LPG vapour systems generally talks about excessive combustion chamber pressures causing cracking.

I can't reconcile the contradiction between the two.

How can the combustion chamber pressure be a problem if you keep the EGT's down?

I also bought a set of brand new head bolts. I tried to source ARP's but couldn't find any here in AUS.

There is plenty of evidence to show that you can run 30psi without blowing head gaskets. I'll be running 20psi.

I'd need more data to agree that it's a bad thing (LPG vapour over diesel)

But I will listen

 

[Dougal]

1. No idea
2. Also no idea

#1 is zero. There are no diesel engine manufacturers who allow diesel and lpg in their engines.
#2 is about 14:1 with no boost or ~11:1 with boost.

Beyond that your engine can/will suffer pre-ignition of the LPG. This pre-ignition causes a rapid pressure rise which is extremely hard on all mechanical components in your engine.

The moral of the story is: Diesel engines should never be fuelled via the intake. If you vapourised diesel fuel (or petrol or methanol etc) into the intake you would also suffer pre-ignition. The only safe way to fuel engines with high compression ratio is by injecting the fuel exactly when it is needed.

From a new head (not machined yet) with a 5 notch gasket I've got the lowest possible compression configuration I can get for my 1HZ which is where you need to be on a higher compression N/A motor with aftermarket turbo like mine.

Longevity is directly related to your average pre turbo EGT's

The negative data around LPG vapour systems generally talks about excessive combustion chamber pressures causing cracking.

I can't reconcile the contradiction between the two.

How can the combustion chamber pressure be a problem if you keep the EGT's down?

I also bought a set of brand new head bolts. I tried to source ARP's but couldn't find any here in AUS.

There is plenty of evidence to show that you can run 30psi without blowing head gaskets. I'll be running 20psi.

I'd need more data to agree that it's a bad thing (LPG vapour over diesel)

But I will listen

Safe EGT is about not melting pistons and not over-heating the head which lowers it's strength. This is very important but is only one factor that needs to be controlled for long engine life.

 

[dadinabarrel]

There are so many companies installing gas vapour over diesel, how could they all be wrong? Or all be disreputable?

 

[Dougal]

There are so many companies installing gas vapour over diesel, how could they all be wrong? Or all be disreputable?

There is money to be made...........

 

[dadinabarrel]

Seems to be the case.

 

[Spudman]

Quick question for you: how many diesel companies world wide sell diesel engines with lpg injection?

Second question for you: what is the maximum safe compression ratio for a lpg engine?

I'm going to answer the 2 questions like this

1. What do you call a deer with no eyes ? No idea
2. What do you call a deer with no eyes or legs ? Still no idea
3. What do you call a deer I with no eyes, no legs having sex? Still no fxxxing idea.

Sorry mate but that's the best I could come up with, I just no it works.

Spudman

 

[dadinabarrel]

Hahahaaaa, that's gold dude

 

[watrob]

My expertise is in short people, and you may ask how much knowledge do I have in this field and I can tell the answer is - very little.

 

[dadinabarrel]

In the interest of lowering EGT and getting maximum breathability, I think we know where this is going.

It's been done by professionals, why not a total amateur?

I'm buggered if I know how I'm going to get this under my bonnet

Just can't leave it alone.....

 

[watrob]

Buy a bigger bonnet? or this will work?

 

[dadinabarrel]

Hahahaha, nope not square enough to fit a pie warmer under. I'm thinking, get it done, cut a hole, find a flat bonnet scoop that covers the hole. My paradigm is: fxxx it let's have a crack, then make it work.

 

[dadinabarrel]

Troopzilla...

 

[Spudman]

Sorry had to do it, it's a pootrol but close enough

 

[dadinabarrel]

I've towed heaps of those fxxxers

 

[dadinabarrel]

Head over here to see my Inlet manifold part of the project:

https://forum.ih8mud.com/threads/1hd-t-intake-manifold-modifications.651365/page-19

 

[dadinabarrel]

Anyway, back to the cracked head... I was able to buy a brand new head, complete for $1200 from Davilaks in Hamilton Hill.

Beautiful isn't it.

I haven't seen one of these for many years:

Inlet runners are very scruffy considering it's brand new

Bought a die grinder for $125, cut a length of rod and slotted the end for 80 grit emory, followed by 120 grit emory with CRC for polishing/lube

Not NASA quality but the soot will find it a bit harder to hang on to it (the 1% ers)

 

[dadinabarrel]

The exhaust gasket was a perfect match to my new manifold, but check this out:

Massive amounts of meat can come out of here to match it to full flow out to the manifold

That's going to take quite a while on a steel head, but it'll definitely make a difference

 

[dadinabarrel]

But if you start with one of these:

It only takes about 4 hours to make it look like this

Then you can bolt this on:

And this little beauty:

Gonna be a busy couple of days coming up...

 

[Dougal]

I think your manifold would be better with trimmed weld elbows used to direct each port towards the turbo, rather that straight into the wall ahead. What is that turbo?