Compression test results

[kevtherev]

OK
DJ engine
Home tested compression
8 turns of the engine. (working temp)
#1... 9.5 bar (127 psi)
#2... 10.5 bar (150psi)
#3... 9.0 bar (126psi)
#4... 10.5 bar (150psi)

Not sure of the sealing ability of the tester
All within spec compression but not as even as I would have liked.
The front two are the lowest.
I think the valves might benefit from some lapping
Any thoughts welcome

[silverbullet]

Compared to the DJ that Elvis has just pulled it does look a bit limp.

Sent from my Atari 7800

[itchyfeet]

my DG is higher than that, don't have the figures on me but can post later.

[kevtherev]

So what would be the way to go
Just valves or rings too

[CovKid]

Think I'd do both Kev.

[itchyfeet]

What brand is the test guage?
my tester is Gunson, might be worth trying another just to be sure it's not a duff guage before pulling the engine appart.

[printmonkey]

I'm quite envious of those numbers, I'm getting 80psi (lowest) and 105psi (highest) on my MV.


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[itchyfeet]

I wonder if the preload on tappets could make any difference to cranking pressures?

[Ian Hulley]

So what would be the way to go
Just valves or rings too

If it ain't broke .....

[kevtherev]

Yes Ian you're quite right, but as this was part of the preventative maintenance program, I have to react to these results.
While there is no danger of imminent engine death, no action will be taken.
However, It's quite clear that I have to start saving up to address as soon as I can.

The readings were triple checked but as the gauge connector used an O ring to seal I could not get it any more than finger tight due to its poor design.
This will have to be addressed too

[kevtherev]

Asa side note
This engine is a VW replacement engine, it has done a documented 32,000 miles when bought it.
Now at 67,000 miles, I have been running it on lpg, and having that on miser rate.
I am thinking my lean mixture might have compromised a valve seat

A mixture test is next....after bustypes

[itchyfeet]

Asa side note
This engine is a VW replacement engine, it has done a documented 32,000 miles when bought it.
Now at 67,000 miles, I have been running it on lpg, and having that on miser rate.
I am thinking my lean mixture might have compromised a valve seat

A mixture test is next....after bustypes

I suspect most LPG setups are lean, people talk of great mpg figures, my closed loop doesn't do more than 19mpg on a run but at least I know is's running stoich becase my air fuel guage tells me so.

[what2do]

But has the gauge been calibrated? I bet that hadn't crossed your mind, what's the life span of a lambda sensor?

[Ian Hulley]

Asa side note
This engine is a VW replacement engine, it has done a documented 32,000 miles when bought it.
Now at 67,000 miles, I have been running it on lpg, and having that on miser rate.
I am thinking my lean mixture might have compromised a valve seat

A mixture test is next....after bustypes

I suspect most LPG setups are lean, people talk of great mpg figures, my closed loop doesn't do more than 19mpg on a run but at least I know is's running stoich becase my air fuel guage tells me so.

Having had a new vapouriser fitted a couple of weeks ago I know where mine is and wasn't too lean. I get about 18mpg round here.

Ian

[ghost123uk]

I get around 18 mpg average on gas too.
Good condition dg with open loop blos, mixture checked not long ago, but maybe worth noting that mine is a fairly lightly loaded tin-top camper, but on the other hand, whilst I don't thrash it, I don't pussy foot around either.