Club 80-90 Forums

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

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

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

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

Think I'd do both Kev.

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.

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


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

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

If it ain't broke .....

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

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

kevtherev wrote: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.

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

itchyfeet wrote:

kevtherev wrote: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

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.