jamesdennison Posted October 20, 2015 Author Report Share Posted October 20, 2015 Ok - will disconnect before the pump - that makes sense. Yes I torqued in the sequence shown in the manual .... and when I took the head off to deal with the nut failure I de-torqued in reverse order. I torqued in stages rather than all at once so 20 / 40 / 60. Garage has vented now but its kids football tomorrow so probably Thursday before I have another go. The fact it is two adjacent cylinders does seem to suggest gasket failure from what I've researched. Gasket was Payen and dry fitted. I'll increase the tappet gap. Feeling like a bit of a saga this. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 20, 2015 Report Share Posted October 20, 2015 if you stick a bolt up the hose make sure its got some shank or the fuel will work down the threads i often use a drill bit ( not the pointy end) an 8mm normally fits . something odd as your now have worse results than before you refurbed the head not looking good ....time for much head scratching .....i doubt pistons would give such low results , more the heads not seated Pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 20, 2015 Author Report Share Posted October 20, 2015 LOL there was me looking for a technical fix to the fuel issue. I had a two litre milk bottle overflowing with petrol at the time and a bolt within grasping distance so I made do. I've read about using compressed air to test for leaks. My neighbour has a compressor - worth a try? If the head need to come off and taken back to the workshop so be it. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 21, 2015 Report Share Posted October 21, 2015 you can make up a adaptor from an old spark plug screw it in and pressurise , see where it comes out needs to be on compression stroke or valves will be open are all the tappet adjuster looking roughly about the same amount of thread on each rocker ??? just thinking outside the box for a while ,, stuck valve etc Pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 21, 2015 Author Report Share Posted October 21, 2015 More petrol fun tonight. Pulled the hose before the tap and it came out of both sides ... which is what I was prepared for, but then the hose split too so I had petrol coming from three places at once. Didn't lose much, but not fun. Luckily the wife was out. Think I'll get an in line fuel on/off tap from e-bay. I see your logic Pete - I'll have a look at the rockers tomorrow night. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 22, 2015 Report Share Posted October 22, 2015 you can get matches from ebay too !!!!!! sorry Pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 22, 2015 Author Report Share Posted October 22, 2015 Tappets gapped to 0.025 No change to test results. I shone a torch into the holes where the manifold fixes to the head and I can see all the valve stems moving up and down so they're not sticking. Air pressure test is a bit inconclusive as I couldn't get a good seal on any of the cylinders. So I've taken the head off again as I seem to be getting nowhere. All the pistons are still nice and clean, I can't see any scoring in the bore and they move fluidly when I turn the engine by hand. The oil I squirted in is still there. I'm going to borrow an engineers ruler from work and see if the block is flat - but looks straight and clean to me. All I can think of now is trying a different gasket from a different supplier. Is there a product I can use to help sealing? .... and the washers are squashed flat so I need to replace those, but I intend to reuse the nuts unless someone can convince me otherwise. I've been told this is ok as they're not stretch nuts. I will win! Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 22, 2015 Report Share Posted October 22, 2015 Deformed washers are the down fall in head clamping , but not untill its been out and about a bit you dont want any sealant its slippy stuff and the head gasket wont get a grip. I doubt a straight rule will divulge much it has to be a payen type gasket with the fire ring recess ( Dont believe a copper based one would work ) try washers from canley classics or a local bolt factors, get a high tensile set, not too hard or they crack. Dont know what to suggest the fact its worse now may point tp the head needs a light skim Which is unusual , these heads are normally fine have you tried a small amount of petrol on the crowns see if it runs straight though into the sump ? but change the oil if it dilutes it Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 22, 2015 Report Share Posted October 22, 2015 Just read all this backwards , you re used most studs, can you run a die nut down to clean the threads and just turning the clock back you had rythmical puffs from the breather, and the valves held a liquid test ok before you had it refurbed, are we heading back to thoughts on a piston but even with no rings I would expect better than 20psi All a bit concerning this is not coming together pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 22, 2015 Author Report Share Posted October 22, 2015 Head was skimmed as part of the refurb Pete. I wondered about putting a bit of petrol down the bore, worth checking .... and I've got loads of the stuff! (now decanted out of the milk carton into a proper petrol container I must add!) I'll change the oil before running anyway. I used to work round the corner from Canley's. I'll give them a call and get another gasket + washers. Away for a few days so will be next week before I get another go. Link to comment Share on other sites More sharing options...
jamesdennison Posted October 22, 2015 Author Report Share Posted October 22, 2015 Just read all this backwards , you re used most studs, can you run a die nut down to clean the threads pete All the studs were new Pete. I'll re-use them. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 22, 2015 Report Share Posted October 22, 2015 Just added some more waffle while you were typing have a good break pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 22, 2015 Author Report Share Posted October 22, 2015 are we heading back to thoughts on a piston but even with no rings I would expect better than 20psi Tonight's test results 1 2 3 4 5 6 160 172 159 68 50 122 I re-ran 4 and 5 a few times and tried turning the engine over for longer - but consistent result. I turned engine over with the rocker cover off too - all seemed to me moving smoothly. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 23, 2015 Report Share Posted October 23, 2015 daft question all 6 do go up and down ??? all rockers operate. ie depress the valves . 4-5 seems a common link to low results then there,s the fume puffing to throw in, not normally due to HG problems , but tends to be ring blow by the problem appeared quite suddenly, after a normal run it time for a holiday Pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 23, 2015 Author Report Share Posted October 23, 2015 Put petrol down the bores. Very slow leak past the pistons, certainly not running straight through. 10mm of petrol took 10 minutes or so to go through. Doesn't seem catastrophic as surely there must be a bit of room for heat expansion and everything is cold? Not quite a normal run Pete - circa. 150 mile round trip to Silverstone Classic in the rain. Was running fine then seemed to go out of tune on the way home. Link to comment Share on other sites More sharing options...
dougbgt6 Posted October 23, 2015 Report Share Posted October 23, 2015 Like Pete I just re-read it all again, number 4 doesn't seem to have improved much and number 5 has gone from not very good to disastrous. I would be suspicious of the work that's been done to the head and do the valve leak test again. Also peering closely at the last pictures there does seem to be some debris in the bore recesses which could cause a problem. After that I'm running out of ideas. Andy Cook had a timing chain gear lose some teeth and it went from running OK, to not so good but carried on and got him to the Isle of Wight. Just a thought? 1 Link to comment Share on other sites More sharing options...
68vitesse Posted October 23, 2015 Report Share Posted October 23, 2015 If you put a spark plug in five does the compression on four improve? and the other way round. Could indicate a leak between four and five. Regards Paul Link to comment Share on other sites More sharing options...
jamesdennison Posted October 25, 2015 Author Report Share Posted October 25, 2015 I had a leak from the timing chain cover a couple of years ago so changed the chain at the same time. Possible that a problem has developed. Can somebody explain how that could affect the compression results so I can get my head around it? I'll pour petrol in the upturned head again and check there is a good seal. Head is already off so I can't rerun the test with a plug in 5 - but I see where you're going with that. It does make sense that there is a problem between 4 and 5. Did my results with petrol in the bores sound ok? i.e. a slow drain through over 10 mins? I'd like to eliminate issues with the pistons if I can as I don't have space or tackle to take the engine out - that would be game over for me and I'd have to take elsewhere. Thanks for the help so far - I'm learning a lot, but will be nice to crack this. Link to comment Share on other sites More sharing options...
dougbgt6 Posted October 25, 2015 Report Share Posted October 25, 2015 Sorry, I don't know how the timing chain would affect the compression results, just some inane ramblings! I would however, clear out the recessed bit of the bores, if the gasket is not seating properly you could get blow by. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 25, 2015 Report Share Posted October 25, 2015 If the chain had jumped some teeth then efficiency is down as opening and closing the valves will be out of sync with where the piston is , so i would expect a drop in pressure as the breathing is compromised the petrol on the crown sounds reasonable to me , thers no set expectaion around for this but 10mins I would think is pretty fair., and as all were the same , it dispels 4 and 5 as duff pete 1 Link to comment Share on other sites More sharing options...
jamesdennison Posted October 25, 2015 Author Report Share Posted October 25, 2015 I checked the timing with a strobe light as part of my tuning efforts when the problem first happened, but I guess if the chain has slipped then the datum I'm checking to would be wrong. .... that said the timing wasn't out. I like the lateral thinking. Is there an easy way to check? I can see the pistons! Link to comment Share on other sites More sharing options...
jamesdennison Posted October 25, 2015 Author Report Share Posted October 25, 2015 Just read how to do this - I'll check No1 piston is at the top of its stroke at the TDC mark on the pulley. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 25, 2015 Report Share Posted October 25, 2015 Its not unkown for the damper ring withnthe marks on looses its bond and moves around the base pulley so ign can be incorrect but it wont affect compression just performance doing a valve timing check with the rockers off is a bit involved with dial indicators on the cam followers to measure the cam lobe lift points pete Link to comment Share on other sites More sharing options...
jamesdennison Posted October 27, 2015 Author Report Share Posted October 27, 2015 Making progress. I leak tested the head with petrol and it p'eed straight through the suspect valves. Just taken it back to the head shop and the gaffer has vacuum tested it. No vacuum at all on 5 and poor readings on the others. He didn't do the work the first time round but will do it himself this time. He's told me they always lapp the valves but don't necessarily test them afterwards, but he will this time. Fingers crossed this is the cause. ..... and the TDC mark on the pulley lined up with TDC for 1 and 6, which makes sense as I guess they're opposites for compression / exhaust. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 27, 2015 Report Share Posted October 27, 2015 now youre into the frustration of relying on those who take your money, and give you a bum job, thats a pretty basic cock up and totally inexcusable do a leak test when it returns pete Link to comment Share on other sites More sharing options...
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