Sideways Tim Posted May 10, 2012 Share Posted May 10, 2012 Learned fellows...Following Tuesday nights exciting trip on the back of a recovery wagon after this happened I've been dealing with the matter. Unblocked the oil way in the head, which was a little gunked up but can anyone tell me, with the head off, tuning the engine on the starter, should oil be coming out of the hole that feeds the head/rocker assembly.If it should and isn't, what is the likely culprit?Many thanks in advance.Tim. Link to comment Share on other sites More sharing options...
Steve AKA vitessesteve Posted May 10, 2012 Share Posted May 10, 2012 What happened? I can see a push rod not pushing its rocker.If oil gallery was blocked in head - the oil holes in the valve gear are also likely to blocked or partly blocked. Oil should be passing through the rocker shaft to each rocker. How much movement is there on the rockers - they should turn on the shaft but not twist. If the shaft has been running dry there will wear where the rocker have rubbed on the metal of the shaft rather than on a film of oil.. Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 10, 2012 Author Share Posted May 10, 2012 Oh number three rocker was well and truly seized. The rest are scored, I've got a replacement rocker assembly and new push rods and followers to go back in place, but the the head gallery is now squeaky clean.In answer to my own question, yes oil should exit the hole without the head in place as it's just started doing. Sump coming off and oil pump to be re-furbed tonight :) Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 10, 2012 Author Share Posted May 10, 2012 Hmmm. Sump off, all seems well (no great big chunks of anything rattling about anyway). Oil pimp apart and it's definitely outside the tolerances in the Haynes manual, but only by 0.001". I've bought a refurb kit anyway, just in case, however...That's the old one.This is the the old and new side by side...As the kids on the street say, wha gwan?Have I got an odd pump in place, or have I been given the wrong one (can't find any variations listed relating to rotor depth :(It's a '72 MK IV if that helps.Thanks :) Link to comment Share on other sites More sharing options...
That Man Posted May 10, 2012 Share Posted May 10, 2012 Cast iron pumps are 1" deep, the later aluminium pumps are 1.25" deep, you have the kit for the later pump.Gordon Link to comment Share on other sites More sharing options...
Pete TR7 Posted May 10, 2012 Share Posted May 10, 2012 I had a similar problem a few years ago. Lack of oil to the head resulted in a stuck valve.I couldn't find any blockages, fitted the dreaded external oil feed instead and stuck head in sand.Result was that the car ran ok but with excessive oil consumption - we all know why these days.I suspect the problem is with the camshaft, next winter I will finally motivate my self to take the engine apart. Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 10, 2012 Author Share Posted May 10, 2012 That_Man wrote:Cast iron pumps are 1" deep, the later aluminium pumps are 1.25" deep, you have the kit for the later pump.GordonI thank you. Worth getting the right kit, or replacing the pump as a whole? Link to comment Share on other sites More sharing options...
Paudman Posted May 10, 2012 Share Posted May 10, 2012 2356 wrote: Oil pimp apart I know the price has gone up, but surely there's no need to sell yourself for a few pints of the stuff? Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 10, 2012 Author Share Posted May 10, 2012 You need an oil pimp to keep the cooler ho's from chafing. Link to comment Share on other sites More sharing options...
Nick Jones Posted May 10, 2012 Share Posted May 10, 2012 In what respect is your old pump out of tolerance? If it's end float there are ways of dealing with that involving a sheet of glass, some fine wet/dry paper and elbow grease...... Do you have an oil pressure gauge? If it can manage more than 10 - 15 psi at hot (properly hot) idle then there's not alot wrong with pump or bearings.There isn't meant to be loads of oil to the top end. It's actually metered by a flat on the rear cam journal. Might be worth checking the oil-way that goes down from the block face to said journal is clear (it's a straight drilling) but I expect it is.Problem with the metered flow is that when the rocker shaft and/or rockers wear the oil all escapes through the excessive gaps nearest to the supply point and the furthest ones get starved. The external feed kit will happily mask this problem but you will be dumping a fair bit of oil up top through the enlarged gaps leading to oil burning and possibly robbing oil from below. Correct cure is good shaft and rockers.I notice your tappet adjusters are wound all the way up...... suggests heavily skimmed head or wrong pushrods?Nick Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 10, 2012 Author Share Posted May 10, 2012 The rockers you see there were new about eight months ago as was the shaft. The old ones had worn due to the shaft having no bungs in it's ends, so very little oil was getting to the rockers at all. I thought the problem had gone away with the new shaft, but obviously not. All stripped now and I've cleared the oil gallery in the head to the rocker assembly and through the block. Fingers crossed :)I thought I,d check the pump as although hot pressure at anything over 2000 rpm is about 40psi, at idle it's showing less than 5psi and sometimes zero when very hot.The pump end float is fine, less than the Haynes figure, but the lobes are at .011 and the body is .090.The tappet adjusters are just quite long, head hasn't been skimmed. Link to comment Share on other sites More sharing options...
aar0sc Posted May 10, 2012 Share Posted May 10, 2012 2356 wrote:Oil pimpEh?!?! ;D Link to comment Share on other sites More sharing options...
Jaydub Posted May 11, 2012 Share Posted May 11, 2012 Just a quick comment - last time I bought a replacement pump fom a well known supplier it was further outside the tolerances than my worn one. Worth checking before you fit it. Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 11, 2012 Author Share Posted May 11, 2012 My thoughts exactly. Since the body of my cast iron pump seems to be in very good order, I think I'll just get the correct innards and take a set of feelers with me, just to be on the safe side. Link to comment Share on other sites More sharing options...
uksnatcher Posted May 11, 2012 Share Posted May 11, 2012 I have been reading this thread with interest as i have just bought and replaced my old rocker assem with a new re-con one, not knowing about the end caps.The old one had no end caps on the shaft , the new has allen head grub screws in both ends, logic says the oil wont lube the rockers on the old one as the oil would just run out of one end of the hollow rocker shaft ...but they did, oil seeped through the rockers holes on all rockers, i checked it after every routine tappet adjustment, the only reason i changed it was it was another new bit to add and didnt have any issues with the old one, many k's miles with usual wear on the rocker profiles for the mileage.Was i just lucky and have i escaped the seized rocker prob?? Am i likely to find two caps in the sump if i drop it :D Link to comment Share on other sites More sharing options...
JensH Posted May 11, 2012 Share Posted May 11, 2012 Gaz,take a look at your old rocker shaft - you might find 2x small end caps sitting 1/2 a inch inside both ends. Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 11, 2012 Author Share Posted May 11, 2012 I think the key thing, is to clean out the oil gallery in the head. All you need is a couple of drill bits (I think 1/4", and 3/16" were what I used). it's only a narrow gallery and the accumulated crap of 40 years makes it even narrower. That's what I didn't do last time.The previous rocker assembly had no end caps in the shaft and the result was a lot of wear to everything. Only picked up on it due to a missfire, which was down to a worn valve and seat resulting from the rocker being so worn it wasn't opening/shutting the valve fully. Link to comment Share on other sites More sharing options...
uksnatcher Posted May 11, 2012 Share Posted May 11, 2012 Hi Jens.No the old shaft you can see right through it, the only thing is the split pin on the end... :-/Thanks Tim, i will pop it off and check the oil gallery, guess i changed it at the right time ;) Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 11, 2012 Author Share Posted May 11, 2012 Got new pump internals this morning - lapped the end faces of the pump and everything is well within tolerances. Just a case of putting it all back together and marvelling at my incredible oil pressure now :) Link to comment Share on other sites More sharing options...
Nick Jones Posted May 11, 2012 Share Posted May 11, 2012 While you have the sump off you should take a look at the bearings. They can have a greater effect on oil pressure than knackered oil pump. It is possible to change all the shells and thrust washers with the engine in, though it is a pain to do the front main. I'd suggest dropping the centre main cap for sure - it will almost certainly be tired - it's always the most worn as it takes the most thump. If the rear main is only a bit worn I'd be tempted to leave the front one alone as you have to remove the alloy bridge piece to get at it and this usually busts the front plate gasket (even if you are really careful) making it hard to get a decent seal on reassembly. Big ends usually need doing..... as do the thrusts. Be very careful to put the thrusts in the right way round!Nick Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 11, 2012 Author Share Posted May 11, 2012 Checking those tomorrow hopefully :) Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 12, 2012 Author Share Posted May 12, 2012 Bearings all OK. Sump back on, head back on, problem setting valve clearance. As mentioned earlier, my adjusters are all the way out. With this new rocker assembly I cannot get more than 002 clearance on valves two and seven. This points to either push rods being too long (they all seam to be standard length though) or head being skimmed. Now the head is in very nice order and the compession test I did a while back didn't scream of the ratio being overly huge - any ideas what could have happened?I think I'll just fit some pedestal shims and check it all fits under the rocker cover, but is there a way I can tell if the head has been over-skimmed?Cheers! Link to comment Share on other sites More sharing options...
junkuser Posted May 12, 2012 Share Posted May 12, 2012 You could measure the head depth in situ with a vernier caliper.Is there any valve seat recession?Are the push rods the correct ones for that engine?If the head has been modified at any stage there is a chance that valves of incorrect stem length have been used.Just a case of measuring things. Link to comment Share on other sites More sharing options...
Sideways Tim Posted May 12, 2012 Author Share Posted May 12, 2012 I'll measure the head depth, good idea! Valve seats are all fine, valves are standard, looks like it might be a very early version of the MKIV as a few things recently have been odd fits.I've just found that Moss offer long or short push rods. Any idea what the length of a standard ( I guess long) push rod should be?I'm going to make some pedestal shims and see what how that improves things. What's the worst that can happen? Link to comment Share on other sites More sharing options...
junkuser Posted May 13, 2012 Share Posted May 13, 2012 Raising the pedestals does change the geometry but I'm not sure of the significance of this.There was a thread about this on Sideways Technologies years back which you may be able to find if interested. I stopped visiting that site when Dave stopped allowing "guests" so don't know how easy the thread would be to find.Don't know if he has reversed that decision.Push rod lengths were mentioned in a thread on here recently so maybe you could find it or someone with the knowledge may get involved. Link to comment Share on other sites More sharing options...
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