Top end clearances.
Posted: Wed Jun 24, 2009 7:26 pm
Just got in from the garden after measuring up the clearances. Went as good as i thought it might, was a pain in the back side trying to get bits out of the way and got a bit confused about trying to measure each value (0.17,0.16,0.15 etc) but realised that im only going to be able to measure in increments of 0.02 because of the blades i have. Once i got that clear in my head the rest was easy.
So far iv measured the gaps and determined what needs shims and what doesnt.
All but one on the exhaust side (and thats on the 0.16 limit) need changing. they are all pretty tight at 0.1mm so are closing and opening sooner than they should. Any particular reason the gap should get smaller? I thought it would get bigger with wear?? Oh, hang on, if there was wear on the valve seat then it would get smaller wouldnt it??
As far as inlets are concerned, none of them except for 1 need doing at 0.18mm; too big.
Managed to get a look at the cam chain tensioner while i was at it and thats looking like its getting near full extension, so no doubt a new chain and tensioner blade is due soon (funny that, with the engine at 18.5K miles
), perhaps just the blade will do?. Will probably get on that next month when ive got a bit more cash.
So, tomorrow im going to re-check my measurements after a good night cooling off. Engine was cold but had been used about 3 hours before hand on a hot day. Then to measure up the shims and see where i am with those. The 10lb magnetic tool i bought has a tip the size of a large fruit pastel so im not going to be able to get shims in or out in with any sort of delicacy, another smaller one is on order, fingers crossed it arrives tomorrow. Also has an inspection mirror with it so for future measuring it'll be a bit easier than the shiny foil from some light bulb packing i've been using to check the cam timing marks
All in all im feeling pretty pleased with myself tonight having got as far as i did, hopefully tomorrow will go just as well.
So far iv measured the gaps and determined what needs shims and what doesnt.
All but one on the exhaust side (and thats on the 0.16 limit) need changing. they are all pretty tight at 0.1mm so are closing and opening sooner than they should. Any particular reason the gap should get smaller? I thought it would get bigger with wear?? Oh, hang on, if there was wear on the valve seat then it would get smaller wouldnt it??
As far as inlets are concerned, none of them except for 1 need doing at 0.18mm; too big.
Managed to get a look at the cam chain tensioner while i was at it and thats looking like its getting near full extension, so no doubt a new chain and tensioner blade is due soon (funny that, with the engine at 18.5K miles

So, tomorrow im going to re-check my measurements after a good night cooling off. Engine was cold but had been used about 3 hours before hand on a hot day. Then to measure up the shims and see where i am with those. The 10lb magnetic tool i bought has a tip the size of a large fruit pastel so im not going to be able to get shims in or out in with any sort of delicacy, another smaller one is on order, fingers crossed it arrives tomorrow. Also has an inspection mirror with it so for future measuring it'll be a bit easier than the shiny foil from some light bulb packing i've been using to check the cam timing marks

All in all im feeling pretty pleased with myself tonight having got as far as i did, hopefully tomorrow will go just as well.