Guppy916 Posted April 30, 2018 Author Report Share Posted April 30, 2018 I will check the rockers and springs today , there are no cam bearing fitted , Link to comment Share on other sites More sharing options...
JohnD Posted April 30, 2018 Report Share Posted April 30, 2018 If it had been due to excessively strong valve springs, I think you would have noticed changing valve gaps. When I bought SofS, the engine it had in it looked newly built. The oil was golden. Lots of other work needed, the car had been in the back of a barn for twelve years, so I just ran the engine. Road testing, it threw a push rod, which I attributed to happenstance, but on track testing the gaps had to be adjusted after every session, and we stopped testing, as something was clearly wrong. Can't recall about oil pressure. Stripping revealed clearly ovalised cam bores. There had been no bearings, the wear was so great that it couldn't be bored for them and the block was a boat anchor. Measurement, by comparison with known original valve springs showed that the DPO had fitted springs almost half as stiff again. John Link to comment Share on other sites More sharing options...
hugh Posted April 30, 2018 Report Share Posted April 30, 2018 Have to agree with john most of your oil pressure has gone out the knackered cam journals , the block will be oval and cannot be line bored seen this loads of times, on both 4&6 cyl engines its also very easy to miss on a home rebuild, I've done it myself, a lumpy can with strong valve springs only makes it worse, strongly suspect the block is only fit for the recycle bin, been warning people about cams running directly in the block for years, and as they are getting older the problem is getting worse, beware Link to comment Share on other sites More sharing options...
hugh Posted April 30, 2018 Report Share Posted April 30, 2018 Just for interest sake 80 miles will probably be about 3 hours running, assuming average engine rpm of 2500 that = 450000 rpm, cam devide engine rotation by 2 = 225000 rpm its very possible if cam bearing faces in the block were rough, that every thing will be destroyed in that time , even at 600 rpm that's 10 crank rotations a second, 5 for the cam !! Link to comment Share on other sites More sharing options...
Guppy916 Posted April 30, 2018 Author Report Share Posted April 30, 2018 The valve springs are Rimmer's 'Uprated Fast Road " I don't know the lbs rating Part number RR1554 Link to comment Share on other sites More sharing options...
hugh Posted May 1, 2018 Report Share Posted May 1, 2018 Uprated are usually around the 200lb mark, the the high lift cam with the springs may have become coil bound on the springs, was it checked?, should have been about 25 thou between the coils on the springs, any less and with the bonce in the valve train it become solid at higher rpm , strangely it tends to destroy cam bearings rather than lobes Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 1, 2018 Report Share Posted May 1, 2018 to compare std springs to the 'uprated' you have fitter inner free 1.56" 1.14" @ 11-14lbs outer free 1.61" 1.36" @ 27-30 lbs the rimmers uprated dont give any specifications but do state leave the lower location caps off pete Link to comment Share on other sites More sharing options...
JohnD Posted May 1, 2018 Report Share Posted May 1, 2018 Comparing springs, if you have them available, is merely putting both in a vice, in series. Winding the vice then allows direct comparison of relative compression, and you can easily see which becomes coil bound first. John Link to comment Share on other sites More sharing options...
Guppy916 Posted May 1, 2018 Author Report Share Posted May 1, 2018 yes Pete the caps were left off, Good point with the vice John I still have the old springs but I have no idea as to what they are, I will look at the old cam to see if there are any markings on it that might be an in sight for the old springs Link to comment Share on other sites More sharing options...
Guppy916 Posted May 1, 2018 Author Report Share Posted May 1, 2018 Guys can any body tell me if TR6 and 2.5 blocks are the same thanks Link to comment Share on other sites More sharing options...
Nick Jones Posted May 1, 2018 Report Share Posted May 1, 2018 Yes. In fact pretty much all of the Mk2 2L and 2.5 blocks are the same insofar as they are interchangeable. There are detail differences but these vary more by year than 2L vs 2.5. It is even possible to use the later (large bearing) 2L Mk1 blocks if you drill and tap for larger head studs. Nick Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 2, 2018 Report Share Posted May 2, 2018 I agree with Nick Link to comment Share on other sites More sharing options...
JohnD Posted May 2, 2018 Report Share Posted May 2, 2018 The only difference was in the layout, as the saloon engines were canted, tilted to the right, for a lower bonnet line, so front mounts and rear engine plate cannot be reused in a 'small chassis' Triumph. But you will have those from the previous engine and they will bolt on. John 1 Link to comment Share on other sites More sharing options...
haggis Posted May 2, 2018 Report Share Posted May 2, 2018 Same here, exactly the same problem on my now scrap engine. Valve springs too strong, I had an inner & outer spring. Looked back over PO’s previous invoices and he had fitted a Kent cam, wasn’t in there when I took it apart, wrecked the block cam journals. Ran perfect until it got to temperature. Apparently they can be line bored and bearings inserted, but specialist job. I bought a second hand engine in the end. Good luck, I know what you’ve been through. Hag Link to comment Share on other sites More sharing options...
haggis Posted May 2, 2018 Report Share Posted May 2, 2018 Sorry did this on my phone, couldn’t see page two, irrelavant to the current post. Hag Link to comment Share on other sites More sharing options...
Guppy916 Posted May 2, 2018 Author Report Share Posted May 2, 2018 Right the block is in the engineering shop along with the crank, the crank is only having a check over to make sure it's okay, this has already been lightened and balanced, the block is having it's internals cleaned, then the cam is being lined bored with new cam bearings fitted, a Newman fast road cam has been ordered, I just have to wait now, might as well go on holiday. Link to comment Share on other sites More sharing options...
Nick Jones Posted May 2, 2018 Report Share Posted May 2, 2018 Newman PH2? Suggest buying the followers from them also. Valve springs - I'm using the ordinary "red stripe" springs from Chris Witor with my PH2/PH3 hybrid cam done knocking on 10k miles now and all seems ok. You are fortunate to have a machine shop who can do the line boring. Nick Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 2, 2018 Report Share Posted May 2, 2018 make sure the bearings have the oilway groove around the outside so should the bush turn it doesnt block the supply route Pete Link to comment Share on other sites More sharing options...
Guppy916 Posted May 2, 2018 Author Report Share Posted May 2, 2018 Nick, I think I am lucky, although the cam bearing bores are scored, they are recoverable with new bearings, yes all the damage is on the bottoms, The block is in the machine shop as we speak Link to comment Share on other sites More sharing options...
Nick Jones Posted May 2, 2018 Report Share Posted May 2, 2018 7 hours ago, Pete Lewis said: make sure the bearings have the oilway groove around the outside so should the bush turn it doesnt block the supply route Pete Do such things exist? I've never seen any. They are really thin section 2mm -3mm max. Sames as use for Mk3 Spit. Oil hole in them is somewhat bigger than the feed holes in the block which is good as it's tricky to keep them precisely aligned while fitting. 1 hour ago, Guppy916 said: Nick, I think I am lucky, although the cam bearing bores are scored, they are recoverable with new bearings, yes all the damage is on the bottoms, The block is in the machine shop as we speak Yes, caught in time. Even more lucky that your local machine shop can line bore it! Not many can! Are you going to change or at least investigate the valve springs - would be a pity to have further problems. What cam was fitted before? Nick Link to comment Share on other sites More sharing options...
Guppy916 Posted May 2, 2018 Author Report Share Posted May 2, 2018 Just looking for your Red Springs, I had a Piper Ultimate Road TR6BP 285, with I think Piper Springs VSSTR6 Springs 246 LBS, I'm not 100% sure about the springs although they are in my expenses list but with no price, so i'm not sure, The valve springs are Rimmer's 'Uprated Fast Road " I don't know the lbs rating Part number RR1554, I'm sure it was these that I used, these are in my list with a price next to them so would you go with Chris Witor Part number CW2906 Has anybody ever had a cam bearing spin in the block ? how are they fitted ? is it just an interference fit,? Link to comment Share on other sites More sharing options...
Nick Jones Posted May 2, 2018 Report Share Posted May 2, 2018 They are an interference fit and not especially tight. But in operation the cam rides on a cushion of oil and should not be trying to turn them. If you've got enough friction to spin the bearing in the block, something is already wrong. If the block is bored right they'll be fine. Yes, I have had one turn. Several in fact, by hand. Removable by hand too. Machined wrong and fitted with loctite - badly. Fortunately I did a dry build, which included fitting the cam and noticed one of the cam bearing oilways was "blocked" afterwards - the bearing having turned enough for the oil hole to no-longer line up. Not a happy saga that one and not the block that ended up being used. Those are the springs I'm using. Nick Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 3, 2018 Report Share Posted May 3, 2018 Having a belt and braces oilway around the back i hought was pretty standard, obviuosly not There again i was a commer and rootes lad when I had hair Make sure the replacement cam does have the small flat on the rear journal to controll the interupted flow to the rockers You can see it on your last cam pic. Link to comment Share on other sites More sharing options...
Peter Truman Posted May 3, 2018 Report Share Posted May 3, 2018 Some very interesting discussions here, and very sorry for Guppy re the extent of damage to his engine. Ref the valve springs binding I understand everything locking up but I would have thought that the weakest link would be the valve pushrod wouldn't they bend, before the cam journals & bearings were damaged so badly? I do however accede to your combined extensive knowledge though. Eons ago around 1971whilst driving my wife to Teesside airport our Mk2 Vitesse which normally ran at 75psi (still does) the running oil pressure dropped to 40, I reasoned that as it was still 40 and all was quiet I'd get her to her flight OK, whilst there I removed the blow off valve, and refitted it all back the oil pressure reverted to normal ie 95psi on start up and running warm at 75, it only drops to 60 here in OZ on really hot days around 40C. It's only had the head removed once around 1973 a sticking valve we think, just before its shipment home to OZ. So why did the oil pressure drop, I always thought the blow off valve didn't seat properly, and removing and refitting; reseated it. I know you'll all say the oil pressure is too high, but its always been like that a change of oil pressure gauges didn't change anything, even fitting a works proven calibration test gauge. Last weekend I drove a friends TR4 as he has a hopefully temporary medical condition. The engine was rebuilt around 5yrs ago and has probably only covered 10Klm, I happened to notice the oil pressure had dropped to 20 running and around 5 at idle. Once again no noises we ran this way for around 25klm before finding a garage NO OIL a good top up and back to 60psi. My friends misfortune has enabled me to drive his concour fleet of TR4, Mini Cooper S, Jag 3.8 Mk2, and 68 series 2 E Type Roadster (bare metal restoration with everything NEW), and hopefully in the near future his Stag with Leyland Aus installed 4 litre P76 V8, married to a Supra 5 speed box, currently undergoing a strip and bare metal respray, I thought it was OK! Hope Guppy's rebuild fix's the problem but you always like to know the cause. Peter T Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 3, 2018 Report Share Posted May 3, 2018 think its fair to say cams and chains take an awful pounding , with the ever changing loads as lobes clatter around and around under the pressures of springs and such . it a harsh environment . up the loads above that of the basic design and troubles are never far away one reason they lasted 40+ years until they get an supposed ' improvement' !!! we all do things , nothing wrong with that , but there are often consequences Pete Link to comment Share on other sites More sharing options...
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