Iain T Posted October 20, 2020 Report Share Posted October 20, 2020 The answer is I don't know, but I'll be writing down the questions for tomorrow just in case I have a senior moment! Link to comment Share on other sites More sharing options...
KevinR Posted October 20, 2020 Report Share Posted October 20, 2020 The problem with the 6 cylinder engine is that oilway in the block from the oil pressure tapping to the rear bearings on the crankshaft impedes oil flow, so that even if one sees good pressure at the oil pressure switch it is not necessarily good at the back end of the block. To get around this problem in racing engines, Kas Kastner developed a device that bypassed the oilways in the block and took oil direct to the relevant areas of the block - this was nicknamed the "Octopus". Read more about the problem here - http://sideways-technologies.co.uk/forums/index.php?/topic/5712-competition-oiling-draft/page/2/ Link to comment Share on other sites More sharing options...
Iain T Posted October 20, 2020 Report Share Posted October 20, 2020 Kevin, I've seen this before in my many many searches for enlightenment! I understand the potential lack of oil to the front of the engine but you are saying it is also restricted to the rear? Reading the Sideways posts drilling out the main oil gallery is a must. Iain Link to comment Share on other sites More sharing options...
NonMember Posted October 20, 2020 Report Share Posted October 20, 2020 Kastner pushed his engines beyond their limits. The standard oil gallery is sufficient for "pootling" as Marcus would call it. Link to comment Share on other sites More sharing options...
Nick Jones Posted October 20, 2020 Report Share Posted October 20, 2020 So I plagiarised my own post from Sideways. This is relevant because it illustrates that path from the main filter outlet gallery (which is HUGE) to the rear main and rear cam journal, is short and not shared by anything else, apart from the rocker gear, which is fed from the rear cam bearing. These areas have the best oil supply in the house..... Quote The pic shows the block side on. I believe the critical area to be the longitudinal oil gallery shown by the green line. It's 11mm diameter all the way along, except where the shaft bushing passes through, where it's actually bigger due to being able to go both ways round the bush. More specifically it is the shorter section of this, indicated by the white line, between the point where it is fed from the oil filter (other green line joining) and the shaft bushing which has to feed 3 main bearings, 5 big ends and 4 cam bearings through one 11mm gallery. While it's adequate for road service with decent bearing clearances, at high rpm and/or when bearing clearances are bigger I reckon this is the real bottleneck. What the octopus does is bypass this. In fact, I suspect that the octopus is probably overkill. I reckon that connecting a single external line (purple dotted line) from the feed gallery just above the oil filter to the front main feed giving a ring-main effect would be enough - if only you could get a big enough connection into the block at that point. The octopus still scores in that by taking oil to each main feed point, you don't need to worry about individual flows so much. Another approach, and I seem to remember Steve that you did do quite a bit of work on this a while back, was to enlarge the longitudinal oil gallery by drilling it out a bit. Challenging due to the length. However, I'd say that you'd win a large part of the benefit simply by drilling the rear section up to the bush. If you could push that a bit further, just up to the next cam feed or even just chamfer the entrance to the next section, then you'd gain a little more. The front section doesn't matter nearly so much as it's feeding much less. Now I'm basing this on 30 minutes poking around the oilways, vs. years of hard, real-world trial by racing, so feel free to shoot my theory full of holes..... What I'm wondering now is whether I can be bothered (and be brave enough to risk hurting what is a pretty much fully prepared block) to drill that first section bigger. This is only a road engine and while it'll doubtless get a good ragging, the old one has withstood the same treatment for years....." What I actually did, rather than than drill any oil galleries was to take turn my suggested purple dotted line above into an actual pipe..... Octopus lite..... if you like. almost 20k miles in and it hasn't blown yet. There are some tough miles among them, including over 200 on track. That has led to some low oil pressures, but now I have an oil temperature gauge I know why...... Nick 1 2 Link to comment Share on other sites More sharing options...
Iain T Posted October 20, 2020 Report Share Posted October 20, 2020 Nick, where did you locate your oil pressure gauge? Iain Link to comment Share on other sites More sharing options...
Nick Jones Posted October 20, 2020 Report Share Posted October 20, 2020 Oil pressure gauge take off is T’d off from the factory switch position. It’s still blanked off in the pic above which is no doubt why you are puzzled. The gauge itself is in the dash..... combined in the temp gauge. The ring main feed is taken from the large (3/4” UNF IIRC) blanking plug in the main filter outlet gallery to make sure it’s not robbing anything else. Nick 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 21, 2020 Report Share Posted October 21, 2020 I still wonder if the bearing failures and the lack of rocker feed is all down to a blocked or gallery full of debris , if the rear cam journal is not being fed then no rocker feed is the result and wrong end of the problem Pete Link to comment Share on other sites More sharing options...
Iain T Posted October 21, 2020 Report Share Posted October 21, 2020 Pete, You and me both! Link to comment Share on other sites More sharing options...
Nick Jones Posted October 21, 2020 Report Share Posted October 21, 2020 It’s not hard to clean the oil galleries on these. Just means removing some threaded plugs and the oil pump/distributor drive bush. Also very easy and direct access to the rear cam bearing if the core plug is removed. I would do this whenever an engine is dismantled for refurb and with especial care when there has been an oiling related mishap. I’d be amazed if your engine guy has not already done this. I can see problems occurring with the front bearings if the oil pump/relief valve are compromised as low oil pressure would lead to reduced flow at the end of the line. However I’d reckon that would involve pressures of less that 20psi (as measured in the usual spot) at higher revs. Nick Link to comment Share on other sites More sharing options...
Iain T Posted October 21, 2020 Report Share Posted October 21, 2020 Nick, although a partially blocked oilway could be the problem the engine company has done many Triumph engines before and as I said current race engines. They also have a dedicated engine builder who has been with them for decades so I have to believe them when they say all the oilways are clear. I think the front shells wear (they were down to the copper? base in places) was down to low oil pressure on a longish high speed run due to a very soft prv spring and possibly compromised pump. That is now fixed. As to the rocker feed, with the aid of the ext feeder that should be fixed. However what caused the lack of oil flow is puzzling. Oil does dribble out of the head at the pillar hole so there is oil at the cam journal. My bet is worn block journal although they say there isn't I would have to be convinced as to ovality and roundness. Looking at the oil diagram Gully sent the rocker feed comes off vertically and I assume most of the journal wear would be at the bottom as the pressure on the cam is always from the top. What I don't know is how much wear would result in oil being squeezed out the side in preference to up to the rockers. Probably very little wear would have a large effect. Iain Link to comment Share on other sites More sharing options...
JohnD Posted October 21, 2020 Report Share Posted October 21, 2020 35 minutes ago, Iain T said: As to the rocker feed, with the aid of the ext feeder that should be fixed. Iain Is there a restrictor in your external feed? Without that, all your shiney new oil pumps output goes up into the head, starving the mains. See many, many references to Ye Spawnne of Ye Deville. Link to comment Share on other sites More sharing options...
Iain T Posted October 21, 2020 Report Share Posted October 21, 2020 John, yes there is a restrictor or on your favourite 'must have' Just waiting for the call back and I'll be off to see where we are........ Link to comment Share on other sites More sharing options...
thescrapman Posted October 21, 2020 Report Share Posted October 21, 2020 I am wondering If someone has been there before with the external feed and blocked the internal route as recommended. Link to comment Share on other sites More sharing options...
SpitFire6 Posted October 21, 2020 Report Share Posted October 21, 2020 Too long a screw. I assume something has already been pushed thru the head & its clear? Link to comment Share on other sites More sharing options...
Iain T Posted October 22, 2020 Report Share Posted October 22, 2020 14 hours ago, SpitFire6 said: I assume something has already been pushed thru the head & its clear? Yes the head is clear and checked twice and the oil way from the cam up is clear. As I said the lack of oil is from worn journals or restricted oil way to the journal, however this has also been checked and rechecked. I assume the company has many widgets and gadgets to clear and clean oilways. They have also used their cctv camera to inspect. Unfortunately no work was done on the car yesterday but I will know today! Link to comment Share on other sites More sharing options...
Iain T Posted October 22, 2020 Report Share Posted October 22, 2020 14 hours ago, thescrapman said: I am wondering If someone has been there before with the external feed and blocked the internal route as recommended. So the internal oilway is recommended to be blocked? I haven't physically seen the kit I assumed the banjo end is at the head end. Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 22, 2020 Report Share Posted October 22, 2020 yes the banjo bolt just replaces the setscrew that plugs the drilling its not long enough to obstruct anything unless some gremlins been at work on a previous life no idea if anything screwed in this threaded hole could actually block it most would cork the hole on the block face , that would hopefully be obvious to the rebuilder when the head was off. I still have this nagging that there is no flow to the rear cam journal hence no flow up the head to the pedestal ......i hope the rear pedestal has the hole up it ???? Pete Link to comment Share on other sites More sharing options...
Iain T Posted October 22, 2020 Report Share Posted October 22, 2020 56 minutes ago, Pete Lewis said: I still have this nagging that there is no flow to the rear cam journal hence no flow up the head to the pedestal ......i hope the rear pedestal has the hole up it ???? This is my main concern but I am assured the oilways are clear. There certainly is oil there, how much I don't know, as some does get pushed up to the head. Yes the pedestal does have the hole! I checked the flow with the rocker assembly off so I could see what came out of the head. Looking at the cam the flat is just in the centre of the bearing surface so it would seem the easier route for the oil to go up to the rockers than squeeze out the small gap in the journal. I wonder if the rocker feed hole in the journal is off centre and not fully in line with the cam flat? All supposition as I won't know unless I take the engine out! Iain Link to comment Share on other sites More sharing options...
Nick Jones Posted October 22, 2020 Report Share Posted October 22, 2020 The oil way that feeds the rear cam journal reduces to around 3mm where it enters the cam way. The path on up to the head is further “obstructed” (metered even) by the flat on the cam and spiral groove in the cam journal. This by design...... so suggesting that the flow to the head is restricted....... by intent? My mileage on Triumph engines using this rocker feed arrangement is well into 6 figures and virtually all with only the standard feed. A short interlude with an external feed on a 1500 (in a Herald) was notable for its smokiness. Turned out the reason the front few rockers were getting no oil was that the back ones were so worn the whole of the metered volume was escaping within the first four. Fitting the external feed practically filled the rocker box with oil........ The penny dropped and I fitted a less knackered rocker assembly. The flooding stopped. But then I didn’t need the external feed either...... Nick Link to comment Share on other sites More sharing options...
Iain T Posted October 23, 2020 Report Share Posted October 23, 2020 All going well! A question for all you Triumph knowledgistas, has anyone ever seen a misaligned rocker feeder hole in the block journal? If this hole is not in line with the cam slot it would account for the lack of oil flow. This hole is part of the block casting so not accurately machined and if partially obscured could be the answer to my woes. I ask because given the oil ways are clear, the cam journals are not excessively worn (both checked twice) and the oil pressure is now 70psi when warm something must be causing the restricted oil flow. If the cam journal was very worn and oil was pi****g out surely this would cause a huge drop in oil pressure which is not evident with the new oil pump and external feeder fitted. Clutching at straws but I'm running out of ideas! The lack of oil was the same using my original Bastuck and the new Newmans cam so it doesn't point to any new parts that have been fitted. I almost want to strip the engine down to check....but not this year!!!! Iain Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 23, 2020 Report Share Posted October 23, 2020 well its a possibility, i guess the solution would be to elongate the cam flat/slot to accomodate the missaliged holes to give a longer radial squirt availability all a bit of a long shot Pete Link to comment Share on other sites More sharing options...
Iain T Posted October 23, 2020 Report Share Posted October 23, 2020 15 minutes ago, Pete Lewis said: all a bit of a long shot I have to reduce my blood pressure and increase my enthusiasm before I do anymore work! However if it is the cause it could explain a long term issue with the rocker oil feed, and not just on my engine. Iain Link to comment Share on other sites More sharing options...
thescrapman Posted October 23, 2020 Report Share Posted October 23, 2020 How many miles did the engine do in the past, before this problem occurred? just wondering if it really isn't a problem, and the oil flow is normal. Link to comment Share on other sites More sharing options...
Iain T Posted October 23, 2020 Report Share Posted October 23, 2020 I've done about 3k in 3 years. The PO not sure but the car was totally restored with allegedly refurbished engine from around 2007 to 2012. A long and horrendously expensive restoration. If anyone would care to take their rocker assembly off and take a video of how much oil spurts out of the head hole it would be helpful! Or even a video of how much oil drips out of the rockers from a known good engine? This was mine (finally uploaded) before the new oil pump and prv spring. Iain VID_20201005_104858.mp4 Link to comment Share on other sites More sharing options...
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