I've searched and found someone on Ausmini reporting new engines have 150psi.

Cant Remember A F.... Thing

I did a compression test on an engine i recently procured and its got 125 in three pots and 135 in another. Worn valves perhaps from unleaded? I thoguht from many years ago that 140psi was good but I can no longer remember the numbers.

Calling for help please?

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..still waiting for the Italian Job sequel to see if the bus went down

i like to see 160 on road cars

230-ish & upwards is quite common on race cars

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

Gee Matt, then this engine is pretty far down.

I seem to recall 110 as the lower limit for a road car indicating time to lift the cyl head - would that be correct? I mean to prolong usable life - not based on performance...

Thanks Wayne (over 50s club )

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..still waiting for the Italian Job sequel to see if the bus went down

well,,, 160 would be new-ish & run-in & all sweet & etc

140 is still fine really, for a 2nd hand engine you couldn`t complain if they were all even & around 140

120 is getting lowing but in saying that if it`s a really old donk, some were made as Low-Comp motors (way back) & if it`s ancient & years of wear then it could be looking at being around 110-120-ish & can still be a fair donk if it don`t smoke

providing they`re all the same-ish,,, like-> 110 ,,,115,,,110... 115

or there abouts,,, then they`re all "pretty-even" hey? so i`d strill go with it if it doesn`t smoke

But ,,,!!!!!,,,, in saying all that--> i`m not a fan of running (or attempting to run) a mini engine at or around 110 mark,,, to me that`s just a pig

Over 50s club ya bugga!!!
I actually havn`t had a shave since i turned 50 im looking a bit like grizzly Adams at the moment

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

U de man Matty

& Thanks (you old b%#tard and lucky to be here at that!)

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..still waiting for the Italian Job sequel to see if the bus went down

Sometimes the quality of the gauge has a lot to do with high readings! The balance across cylinders tells you more. 150 to 170 is about the number to look for, 120 is getting tired, this is all based on a reasonable gauge in my view.

When I first got mine the pressures were uneven and varied from 110 to 140. The local mechanic here said the motor was stuffed and it needed a rebuild.

I did a rocker adjustment after that and got 140 across the board so maybe give that a go before you get too worried. What do you reckon Matt?

Just a $35 (?) supercrap gauge so nothing special.

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Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

yeah definitely check rockers first before assuming an engine is rooted

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

[quote=
I did a rocker adjustment after that and got 140 across the board so maybe give that a go before you get too worried. What do you reckon Matt?

Just a $35 (?) supercrap gauge so nothing special.[/quote] oops...


Thanks guys, it makes some sense now that its pointed out but i thought I would have noisy tappets if the gaps were too big. On the other hand if they are down too hard they are no letting a proper seal then gas is escaping. i shall reset the tappets.

And before that I'll try a pot in my good car I did the head up on within the year to see how the Supercrap gauge is performing. It sure looks to be the goods but you never know.

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..still waiting for the Italian Job sequel to see if the bus went down

Even if the gauge is calibrated a bit out if the pressures are uniform that is a better sign than them being all over the place.

And dont rely on one test per cylinder - do a couple on each to confirm the values.

Matt (and others) are the experts by the way.

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Cheers
Alec
1275LS - July 78 - XNFAD18Y/102918

Noted. Thanks Alec.

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..still waiting for the Italian Job sequel to see if the bus went down