42 replies to this topic

[Fast Ivan]

Going to do the valve clearances tomorrow I think, is it urgent that I change the rocker gasket when I take the cover off? I don't have another one handy :-S

depends on the condition of it, if it comes off in one piece and looks ok then reuse it for the time being, keeping an eye out for leaks.
to help with the compression test - pressure should build up quickly, low pressure on the first crank that slowly builds on further cranks indicates worn bore/rings. if the pressure doesn't build on further cranks this would indicate leaking valves. If, like you, there is one cylinder reading lower then add a small amount of oil through the spark plug hole and repeat the test, if it improves then it would indicate bore/ring wear, if it doesn't then it would also point towards leaking valves.

[josh austin mini city e 82]

Ok thanks, I only changed the rocker gasket 4-5 months ago so I can't see it being too bad. Ill check the clearances later and adjust where needed, then do another compression test with some oil. I think it will be the valves, with it being a leaded head. From what I can remember if you keep using unleaded over time it burns the valve seats away which would cause valves to leak quite a lot wouldn't it? Please correct me if I'm wrong :)
So if it turns out it is the valves what's my best option? Buy an new unleaded head off mini spares for about 230, send my head off to be machined and have hardened valve seats? Or just buy I new engine?
As my pressure test readings were ridiculously low, I'm sure you can understand just how down on power my mini is :-/

[josh austin mini city e 82]

Bump

[leroy26]

hopefully its jusr the head in which case get yours reconditioned/skimmed you could probs do your valves yourself with a valve puller

[josh austin mini city e 82]

I don't know what to do at the moment... One of my friends has offered me a 1275 for 200quid, which is becoming quite tempting. Iv been assured it has good compression and that it runs sound.

[leroy26]

you can always buy it and rebuild that unit..

[Fast Ivan]

Just take it a step at a time, try and establish what the problem is then look at your options. Hopefully its a head issue as this will be easy and fairly cheap to fix. Complete the compression test as described and go from there. With regards to the other engine - its second hand so even though your friend has made assurances it can't be guaranteed to be ok. But if it turns out that the problem is more severe than head work then that engine could be one of your options.

[josh austin mini city e 82]

Struggling at the moment as its snowing -.- and I have no garage. As soon as I get the chance ill get it done and see what's what. How much would I be able to sell my 998 for, as it is and if I fixed the problem? Or should I keep it just encase? Ill probably buy this 1275 off my friend anyway

[leroy26]

personally id say keep it and rebuild it yourself as and when you can afford the parts, that way yoill learn everything about an old school engine and nothing will be a problem again

[ACDodd]

The main point is if you do a rebuild it yourself you need critical measurements taken, by a competent engineer. So long as clearances are checked you should have little worries. Only by measuring can you identify what work needs to be done, which will then lead to a plan then a cost can be derived.

Did I mention, I am happy to perform free engine measuring for TMF members?

Ac

Edited by ACDodd, 10 February 2013 - 02:41 PM.

[josh austin mini city e 82]

I have alright knowledge on rebuilding engines, not so much old ones tho, iv stripped and rebuild a fiesta zetec engine before, iv got my Lvl 3 in motor vehicle maintenance and repair so I have a good idea of everything, and am currently training as an engineer so it would be very good practice for me :) as there is a lot more for me to learn !
I think I will rebuild that 998 of mine, that way should I need it again it will be there and if not I will be able to sell it for considerably more

[1984mini25]

Mini engines are pretty simple to work on, but then I only did a level 2 motor vehicle course quite a number of years ago. Although you'll learn a lot more by getting suck in and getting your hands dirty than you ever will from a text book.
A few things that do help a compression test though is a warm engine, a good battery/starter and the throttle fully open.

[Dec1]

Manx Engines, your side of Derby provide a good service. They will do what ever is required. From experience I think they are keen on price. My mate in the trade won't deal with anyone else