Tappet shim removal and measuring.....

[hongkongphooey]

This is probably a well worn topic for you guys,but i can't seem to find any info in the search....

Now,in the haynes manual It says to remove the shims by levering down the buckets with a bent screwdriver if you don't have the correct tool. Well,i don't seem to be able even get the edge of a screw driver in there! Is there a special technique that i'm missing?

Also,if you have no valve clearance to start with,how do you work out what shim size you need?

Thanks

[Thotos]

You can't use the bent screwdriver or the tool to compress the valve and take the shim out. The idea is that you push the valve in by turning the engine so the camshaft does the work for you. Once the cam lobe has pressed the valve all the way, you insert the bent screwdriver or the tool to hold the valve down and turn the camshaft so it's off the valve before getting the shim out. Having said that, I tried the Haynes bent screwdriver tool suggestion many years ago and gave up as it wouldn't work and I bought the tool. I suggest you do the same and get the correct tool for the job. If you have no gap at all at the moment there must be something seriously wrong (valve seat recession?). Otherwise you'll have to change the shim to one of a known value that gives you a measurable gap and work from there.

[hongkongphooey]

Thanks for the quick reply!

When turning the cam off the tappet while it's compressed,is there a danger of piston/valve contact?

Also,do you know of a good source for selling the correct tool?

I think the cam carrier gasket is too thin on mine......the valve seats didn't seem recessed when i lapped them in.

[HFStuart]

When turning the cam off the tappet while it's compressed,is there a danger of piston/valve contact?

Yes ! Go easy turning the crank and make sure the plugs are out !

The shim tool is available on occasion in the UK but the best bet is the US Fiat specialists. International Autos have them at the moment. http://www.international-auto.com/index.cfm?fa=p&pid=5081

Stuart

[hongkongphooey]

OK Cheers.....i think my best bet is to order that and one of their smallest shims,and then take all my measurements from that one shim. That'll be a pain!

I'll take the plugs out and stick a thin piece of dowel or something down the plug hole so i know exactly what that piston is doing.

[75coupe]

I used the square 90 degree key that came with my sykes pickavant piston ring compressor and find it works ok. the bent screwdriver as suggested by Haynes needs to be a square section so it can just  rest on the side of the bucket, most scewdrivers are round shaft and completely useless!

I have tried the special tools and found the one I bought from Vickauto in the US whilst looking the part, turned out to be pretty useless!!!

Don't be too worried about turning the cam whilst the valve is fully open, I have 304 degree cams with big overlap and did not have a problem so long as you do not turn it more than 90 degrees. You only need to turn it far enough to get the shim out with a a sharp pointed pick. Make sure the cut out in the bucket is in a place you can get to before rotating the cam.

As for shim thickness, the range is from 3.2 to 4.7 mm I think???  You need a digital caliper or similar to measure the thickness of the shims.

I would take out a few shims and measure them with the caliper to see where you are at. If you are already at 3.2mm you need to add another gasket under the cam box, or grind the top of the valve stems. You can also measure the valve stem height relative to the cam box base flange on the head to see how much the valve sticks up out of the head. I have a measurement somewhere (I'll try to find it).

Do you have no clearance on all valves or just some? The standard setting is around 0.4mm inlet, but you can go as tight as 0.2mm (gives a little more duration and lift....)

[hongkongphooey]

Thanks for the info....

I can't get the thinnest feeler of my gauges in between any of the shims....in fact no1 inlet is staying slightly open and i think no4 exhaust is too.So i'd say no,no vlearance at all.

I was actually thinking of buying another set of gaskets and using those too,i just wasn't sure it was a good idea.

[thecolonel]

If the shims have been inserted the right way round the size should be written on the hidden side.

this chaps has been ok in the past

http://cgi.ebay.co.uk/TAPPET-SHIM-3-30-4-90-LANCIA-BETA-216825-/130420613268?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1e5daca094

[hongkongphooey]

If the shims have been inserted the right way round the size should be written on the hidden side.

this chaps has been ok in the past

http://cgi.ebay.co.uk/TAPPET-SHIM-3-30-4-90-LANCIA-BETA-216825-/130420613268?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1e5daca094

Thanks

[75coupe]

I have used 2 base gaskets before after having my valve seats re cut - the valves sat deeper in the head. It worked fine, just make sure you re torque the bolts after leaving overnight as the gaskets settle. The only down side is it will affect your cam timing very slightly, but not enough to cause a drama with std cams.

I stand corrected with the shim range - it is 3.3 to 4.9mm, memory is fading fast these days......

[hongkongphooey]

Auto international seem to be offering 2.55 as their smallest size,so i think i'll use one of those as a datum point.

Thanks for your help and advice folks

[HFStuart]

Just don't use thiner than 3.3 in the build - if you do there's a good chance of the cam hitting the bucket instead of the shim.

Stuart

[hongkongphooey]

Just don't use thiner than 3.3 in the build - if you do there's a good chance of the cam hitting the bucket instead of the shim.

Stuart

Ah,that's not so good..... I wonder why are they selling sizes smaller than that then?

[rossocorsa]

that size shim doesn't just fit Fiat engines it fits a few other makes as well

[hongkongphooey]

that size shim doesn't just fit Fiat engines it fits a few other makes as well

Yeah,33mms are in all sorts....just seems strange they offer them for Fiats. Makes me wonder what sort of outfit they are,if you know what i mean.

[WestonE]

Hong Kong

With clearance that tight slacken the other cam box off to avoid clashing the valves. Or remove the cam box concerned and fit 4 x 3.5mm shims with 2 stacked cam box gaskets so you can measure the gap verses known thickness shims. If it is vast try I cam base gasket only and measure again expect the cambox gaskets to settle over night closing the clearances by approx 0.05mm. 0.40mm inlet 0.45mm exhaust.

I suggest a magnet on a stick and a fine flatblade screwdriver to lever the shims out are added to to buying the tappet hold down tool.

The factory normally fitted 4.25 - 4.05 shims. Do not go smaller than 3.30mm or you will scuff the cams.

Enjoy

Eric 

[hongkongphooey]

Thanks for the info Eric!

[mangocrazy]

I have tried the special tools and found the one I bought from Vickauto in the US whilst looking the part, turned out to be pretty useless!!!

Bugger - I've just bought one of those - are they cr@p, and have I wasted my money? To be honest they look exactly the same as the one that intenational-auto.com are selling:

http://www.international-auto.com/index.cfm?fa=p&pid=5081

[Thotos]

Bugger - I've just bought one of those - are they cr@p

Tool looks cheap(ish) but should be OK    You are not trying to compress the valve using the tool, are you? See http://www.betaboyz.myzen.co.uk/forum/index.php?topic=908.msg4147#msg4147

[mangocrazy]

Hi Thotos,

I'm not actually trying to adjust the clearances at present; I just bought the tool in preparation for doing it. My concern was that the tool I'd bought wouldn't do the job, and was hoping for some feedback on its suitability.