Re Shimming The Head

[Dan Ingram 1]

My engine is really tappety and im guessing It needs re shimming. Has anyone attempted this?? if so it an easy task or is it a case of trial and error???

 

From what i've read so far I have to measure the gaps then buy the correct shims to get it to what its meant to be. How accurate does it need to be???

 

Also if im going to have to take the head off ill do the valve stem seals, from what i've read Its a peugeot dealers for the job, is that right or can I do it myself??

 

thanks in advance

 

Dan

[jimbean 0]

to be honest fella i would recomend you send the head to a engineer

even somone that like miself that has done a few shimming jobs on my own engines over the years and found they are utterly horrible....

unless u do them often... and have a good calculator and micromiter they are a pain, and need to be really accurate to stop tappy tappets or no compression when hot

for what it costs send it out

[boombang 2]

Accuracy is to within 0.05mm so yeah its pretty accurate. If you search I posted about this very recently.

 

Yes you can easily do stem seals at home with the head off - valve spring compressor, remove collects, remove valves, remove old stem seals, get 11mm socket and tap new ones on. Ensure no burrs or sharp edges on valves and refit.

 

Depending on condition of valve seats may be worth grinding back in with a little paste or re-cut if damaged.

 

You don't have to take the head off to do the shims btw.

[matt1900 0]

it is a bit of a pain to do this job but not impossibe if you know your way round the engine.

 

it's easy to check the current clearences, just take off the cam cover and slide a feeler guage under each cam lobe when it is pointing upwards.

 

to actually adjust the clearance you'll need to remove the cambelt, the cam pully, then the cam caps then then the shaft.

 

then say one of your inlet valves for example has a clearance of .27 and you want it to be .20 you'll need to replace the shim under the corresponding bucket with one .7 bigger than the one currently there to take up the gap. (use a micrometer)

 

all the spec's for the clearances are in the the haynes manual with full instructions for doing the job.

 

you'll need to measure the clearances first, then measure your shims - work out how much bigger your new shims need to be, then get down to your pug main dealer and order exactly the sizes you need.

 

bet thats put you right off lol!

[24seven 104]

how much do shims usually cost? I'm just doing the same on my head now (all the buckets fell out and I've no idea which came from where, so I'm working on the principle that it needs reshimming.

[boombang 2]

£2.41 each for most of them - a couple are over £6 though (no idea why!).

[Dan Ingram 1]

Cheers for that, its exactly what I needed to know. Ill have a go at it over the next couple of weeks.

[boombang 2]

On second thoughts I would just pay someone else to do it - having real issues with shimming mine now.

 

7 of 8 were spot on first time but one is absolutely doing my head in!

 

2.7mm shim goes in, clearance is over 0.25 but less than 0.26, total clearance without shim is therefore 2.95

After a clearance of 0.15 to 0.20 so therefore need a shim somewhere between 2.8 and 2.75

 

Get a 2.775 shim, thinking clearance will then be 0.175 give or take very little. Clearance measured up as nothing!

 

So took it out, all is clean - tried 2.7 again and exactly same results.

 

Cleaned everything, put in 2.775 AGAIN and no clearance!

 

Everything measures up as it should with the calipers (which did everything else perfectly) so wondering if its the feeler gauges - one of the blades perhaps isn't the right size. Will be checking tomorrow but may order a 2.75 shim and try that

[24seven 104]

Reshimmed mine today. I'd reground all the valves in and mixed up all the buckets and shims from before, so I started fresh. Numbered all the buckets and shims 1-8, measured the shims with a vernier and put them in the head. Bought some new feeler guages to do this and using them measured all the gaps. Recorded all this down so I knew which size shim was where, and how big it made the gap.

 

Went inside for some lunch and a bit of number crunching and worked out that I could reorganise the shims so that 5 of them would be within 0.02mm of perfect clearance (Working to a Haynes specified tolerance of +/- 0.05). The other 3 were just too big. Time to break out the oil stone and shrink them down a bit.

 

Several hours of finger and shim grinding later I had 3 perfectly sized shims left that needed to go back in, so they did. Rebuilt the head and checked the tolerances, the 3 I ground were perfect and none of the other 5 were more than 0.01 out. Happy chappy, and it didn't cost me a single overpriced penny for new shims.

[Guest rick03054]

That's always reassuring to hear, love the ingenuity too!

 

Was it easy enough to get the shims square with an oil stone? did none of them end up a bit wedge shaped?

[24seven 104]

As long as you hold them flat it's ok. Don't try and use any tools to get a grip on them, because it doesn't work and can cause them to be wedge shaped like you said. Ground them down using the rough side and smoothed them off using the fine side, and checked them for consistency/flatness using the vernier. bit of WD40 helps too, but it does take a while. Alos they may end up with sharp edges depending how much you're taking off, so I used a bit of 800 wet/dry just to round the edges a teeny bit.

[boombang 2]

btw I was being a bellend - they were all absolutely bang on (bar one which was inbetween shim sizes - its still well within tollerance though, just not as tight as I was going for).

 

Its all timed up and should be ready to go, just the battery died as it kicked into life

[PumaRacing 1]

£2.41 each for most of them - a couple are over £6 though (no idea why!).

 

Struth. I guess that's the Peugeot dealer price. I can supply shims for £1.50 each any size if anyone gets stuck. I keep all usual sizes between 2.50mm and 3.30mm in 0.05mm increments. Standard engines usually require shims in the range 3.00 to 3.20mm and after the valves and seats have been cut it's usually 2.70 to 2.90mm

[PumaRacing 1]

PS. Just to repeat what my website says I don't agree with the Peugeot valve clearance specs on exhaust valves. I use 0.20 to 0.25mm on inlet valves (the same) but 0.30 to 0.35mm on exhausts. The official 0.35 to 0.45mm is too big IMO. Similarly the Piper and Catcams recommendation of 0.25mm on exhausts is too small. Engines run very smoothly and quietly on my specs.

[24seven 104]

Interesting to know that PR. I used the haynes values which were .40 +/- .05, none of the shims were too small but a couple were .01/.02 big (I assume it shouldn't make a difference as it's such a small amount). I'll have to have another read of your site and try to remember it in future.

Edited October 22, 2006 by 24Seven

[pee vee 1]

Glad you posted that Pumaracing! i gotta do mine soon, so i will almost certainly be after some shims from you

[boombang 2]

I've now got a nice little stock (3 engines worth plus a few randoms).

 

If anyone needs shims at anytime, I'm happy "swapping" - that way people won't have to pay out all the time.

 

I didn't object at all to paying £2.41 for a couple as they were in stock and it meant I could get it back together.

 

I did get hold of 2 in a 2.6 size and 2 in 2.7 so if anyone has had a lot cut from the valve seats I also wouldn't mind lending them as referance shims.

 

We build/refurb so many engines these days its very handy to have a load around! (We being us lot who go rallying together - plus we do some other peoples engines if we have time).