s130 said:

A little secret I use when doing valve clearances with shims is to:

1) measure the gaps
2) even if gap is ok remove shim and check size and record shim size for future reference.

Makes future adjustments a breeze and can reduce the number of shims you have to buy.

Click to expand...

So are the shims fully hardened throughout & not just the top & bottom faces? Just thinking that if a shim has worn beyond measured tolerance, you might fit a worn shim that has no hardened surface... leading to rapid further wear...well it makes sense to me...
If shims are hardened through rather than surface hardened no problemo...

The shims are only case hardened which is why they should never be ground. Shims can be safely shuffled with the following provisos:

1) they are in good condition - has to explain but when you see a new shim, a good old shim and a bad shim then it all becomes very obvious

2) confirm visual condition with a micrometer - 5 measurements - center and at the edges at 12 : 3 : 6 & 9 o'clock

3) when the shim is out check the follower mating surface and the condition of the cam lobe

4) know their history & usage - this is a little tedious to do but I keep logs of shims, sizes, which are in us and in which car and on which valve and also is a new or used shim. When I had 4 cars that all requiried shimming then it did get a little complicated keeping the records.

Unless you do the above or similar then shim shuffling is not advised and you should just buy a new shim everytime.

Any tips on removing the shims? Do you need any special tools?

Awesome thread this!

I bow down to your superior spannering skills!

hi again all,
wow! lots of very encouraging comments, thanks gentlemen!

right, a quick update on the Doblo.
just passed the MOT, the examiner commented " that's got very low emissions for the mileage, as good as a new one..."
MPG has gone up from 520miles per 60lt (fill to neck of tank, refill to neck of tank)
to 630miles.
i also replaced the rear 'spring assisters' or 'bumpstops' as some call them. (ps, this is not where they should go...)



got them from EBAY, £22 each plus £4 post, i ordered 4 of them (my mate needed some too) the chap did them for £88 inc delivery. brilliant!

i think they have gone up to about £23 + 5 delivery now, and mine are yellow, but the ones sold now look black -FIAT DUCATO MAXI 18 94-02 REAR BUMP STOP - http://stores.ebay.co.uk/Red-Line-Car-Parts-UK?_trksid=p4340.l2563

the genuine ones are about £45 i think?

anyway, very easy to fit. i've got pics if you want to see.

oh, and punto60_s, i did not use any 'special' tools as such - if the cam is off you just need a thin bladed jewelers screwdriver or a pair of circlip pliers. let me know if you want more info or pics

thanks again chaps !

austin

Hi all
this topic is bang on what Ia mtryinhg to discover, I need to do a compression test on my 1.9JTD Stilo and need to know the sort of psi figures to aim for please can someone advise me.
many thanks
foxy

hi foxy,

i believe that the stilo 1.9JTD engine is similar to the doblo unit?
however, there are a number of factors to take into consideration when making comparisons.
for example - what year is your engine? mine is a 2002.
why are you wanting to test the compression?
what fault is present?

a pressure reading of 350 to 400 psi would seem to be good for my engine.
this is measured cold [ie engine has not been run for 4 hours, ambient(air) temperature is between 10 and 20'C]
if the engine is hot, higher readings will be present etc.

low compression (as discussed in the thread previously) can be caused by a number of factors. as i do not know your level of understanding i do not wish to be patronising or complicated here

a good test of an engine that is just old/worn generally or which has a problem with one/two cylinders, is the comparison of cylinder pressures.
however, because of the awkward location of the glowplugs, other factors such as a poor seal/damaged thread/seat could give false readings on the compression guage.

so compression testing can only be used as a guide along with other tests and observations...

hope that this is of some help, ask/clarify more if you have more questions

austin

ps came across the article below (american) when finding out stuff for myself, it sort of explains why 'just' a compression reading is not necessarily indicative of compression ratio/condition etc.

compression ratio
first find the volumn of your cylinder, this is the bore radius squared x the stroke. Add to it the unswept area of the cylinder, and subtract or the ammount of area either filled by piston domes or increased by dish in the piston, compute the area inside your head gasket and add that and the combustion chamber area to it. This will give you the total volumn. divide this by the added figures of the combustion chamber, head gasket relief, and the total unswept area.
Example: You have a 350 cubic inch engine= 4inch bore and 3.48 inch stroke. convert this to CC's by multiplying by 16.39. = 716.39 CC's.
Combustion chamber size maybe around 68CC's.
gasket area 4.1 inch diameter and .040 inches thick.= .168 cu inches or 2.76 CC's.
Unswept area, distance from piston top to deck of block, say around .020 inches. = .25 cu inches or 4.18 CC's.
if you have flat top pistons, then there is no dome or dish to compensate for. To get the cc's of the dome or dish, refer to the manufacturer of the piston.
Your total unswept area is 68cc's + 2.76 cc's + 4.18 cc's = 74.94 cc's. Add this to the displacement of 716.39 = 791.33 cc's. now divide by the uswept area of 74.94 cc's = 10.56:1 compression ratio. This is the mathmatical figure, and compression ratio in no way is related to cylinder pressure.