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Everything posted by rgh0

  1. Yes I would check clearances and then do a leakdown test when the engine is hot and lost compression to try to see where it is leaking to
  2. clearances especially on the exhaust will close up when the engine is hot
  3. I dont think you would see any change in oil pressure with changes is cylinder compression pressure Its easy to get a valve clearance wrong or for a follower to jam or for a shim to get moved off the top of the valve stem or for a too thin shim to cause problems with clearance so I would double check all of those areas
  4. Yes maybe a valve sticking open when hot ( maybe a bent stem) also I would recheck the cold clearances on No3. I assume no head gasket leak issue when hot with gases into the coolant system ? cheers Rohan
  5. My very one of the last S1 cars had the automatic belt tensioner. I thought this was standard on S2 cars ? May you're car had a change some time in its history back to early S1 manual adjuster spec ? Shortening the stud and using a half height nut should get you belt clearance if needed with you're current set up ? If you want to go that way cheers Rohan
  6. A bit of heat releases the bond with expansion of the alloy. ultimately enough heat will melt the Loctite but you need to be careful not to over heat the alloy. Best to use a hot air gun with temperature control
  7. No outer race should ever be allowed to spin. Using a suitable bearing fit compound is clearly a good idea especially if the fit is at the loose end of the typical tolerance band for this sort of bearing in an alloy housing running at say 130C maximum. cheers Rohan
  8. You have looked at the insides of more of these gearboxes than me, so its good I am not a betting man If they were machined separately it would be interesting to understand the setup method used as I know of no practical way to do it to the accuracy required to get the two halves centre lines aligned with each other and in the right location versus the diff centre and with the correct bearing interference fit. But if done separately it certainly would help explain the assembly issues experienced. cheers Rohan
  9. I find it hard to believe that the output shaft bearing supports between the GB and bellhousing were not machined as an assembly. May be not on the centre line of the split or on the centreline of the diff carrier but i believe impossible in a practical sense to do separately rather than as an assembly. A measure of vertical versus longitudinal diameters would confirm if not a a true circle - but hard to do. Certainly if on assembly the output shafts are being moved as the centre line of the output bearings is a few thou different form the diff carrier centreline the preload would be affected cheers Rohan
  10. When the gearboxes were made the bell housing and gearbox casing would have been bolted together and then the 80 mm hole bored. Nominally this bore would have been centred on the split line but it appears there is some ( systematic?) small error in the machine setup used to do this boring so the centreline of the bored hole is moved 7 thou from the split line to the gearbox side. This type of tolerance / error is not uncommon in machinery fabrication which is why it is always wise to check the location of the centre line of bored holes precisely as done, rather than assume the split line is also the centre of the hole cheers Rohan
  11. Most synthetic and mineral base oils actually tend to cause rubber seals to shrink so appropriate rubber swell additives are added as part of the formulation in quality oils to counteract this. "High mileage" engine oils or supplementary lubricant additives have additional swell additives to help counter wear on seals by additional swell to minimise leakage from places like the rear main seal cheers Rohan
  12. I dont believe the Polyol Ester molecular size is significantly different to any other lubrication oils. In any case fluid leakage does not really relate directly to molecular size but more to bulk properties of the fluid such as viscosity. In my experience with MT90 in my S1 esprit at least its leakage rate is similar to other modern synthetic oils. If leakage is a problem then you have something wrong that needs fixing. The common leak point in the Citroen boxes is the gear change shaft. You put up with it normally as its small or you fix it if you really want a totally oil dry rear of your transaxle. The advantages of polyol ester base oil are huge in terms of thermal stability and lubricating properties so even if they did leak a little more they are worth it in my personal opinion but from my experience they dont. i will stick with MT90 cheers Rohan
  13. You could talk to these people - never tried them but looks like what you need cheers Rohan
  14. You can work out the original design valve stem install height as follows if you have a bit of time and some measuring tools. Valve tip must be the following distance from the cam centreline standard cam base circle radius + design clearance ( say 0.010") + follower thickness ( std is 0.220") + standard shim (nominal 0.120") You can then measure cam centreline to spring pocket base buy measuring the cam carrier depth to cam centreline and spring pocket base below cam carrier mounting face You can then calculate how much spring stem tip needs to be above the spring pocket base when setting the valves in the head. If fitting a high lift cam then you may need a smaller cam base circle and longer valve stems and thinner follower to fit in a suitable spring that is 0.060 away from bind at full lift cheers Rohan
  15. The 0.060 inch figure is the usual minimum distance of maximum spring compression from coil bind for any engine. You can push it to be a little less but you must ensure everything else is perfect if you do. cheers Rohan
  16. Looks like someone who did not know what they were doing attempted a number of modifications somewhat unsuccessfully back when the previous owner did engine work in 2016. Looks like they tried to port the engine badly. Fitted valve stem seals badly. Got the timing or something else wrong in the valve setup resulting in the valves hitting the piston tops which was probably also the cause of the extreme bearing wear You are lucky to have picked up the issues and stripped the engine down when you did before a more catastrophic failure. cheers Rohan
  17. I would measure up the followers and carrier for wear. if its all within the factory specs then it does not matter which goes in which location. You need to measure top middle and bottom of the follower and carrier as the follower wears in a barrel shape and the carrier in a hourglass shape. The other issue can be wear on the follower top to cam so check the cam lobes and follower for any signs of wear also. In the end a new set of followers is not that expensive if you find enough wear to give concerns about reassembly in different locations cheers Rohan
  18. It would be great to get a copy. it would inspire me to pull one of my spare heads off the shelf and start measuring it up for the 220 HP 907 engine I want to build for my S1 one day cheers Rohan
  19. Looks like something has failed in the distributor / oil pump assembly allowing the shaft to move forward, Pull it off and investigate cheers Rohan
  20. The thinner followers are typically needed when using high lift cams that have both a smaller base circle to keep the lobe tip radius acceptable but also to enable a longer valve stem and larger valve tip height and long valve spring that can accommodate the higher lift. Of course the thinner follower can also be used to hide bodges with valve seat over cutting or reground cams. I deal with this when building competition twin cams for my Elan and have a design spreadsheet to manage all the variables. One day I will set up a similar design spread sheet for the 9xx engines when I finally get around to building a big engine for my S1 Esprit but so far the original engine keeps working. cheers Rohan
  21. Is this the Rover Forums or Lotus Forums. Personally i never see any Lotus 6 on the roads these days cheers Rohan
  22. Get a copy of the parts manual as that helps to identify what may be missing cheers Rohan
  23. The small thread knobs are probably from the 5 speed Elite / Eclat which used the same gear box and change lever as the 5 speed Elan +2 and had the gear pattern logo cheers Rohan
  24. I understand how the regulator adjustment works to hold the fuel pressure above the carb pressure and that the regulator will "try" to hold a constant fuel discharge pressure relative to atmospheric pressure if the sensor hose is disconnected. As the throttle opening increases and the boost increases the pressure in the carb bowl increases. This means less fuel will be delivered as the back pressure on the float valve increases and the float has to drop to deliver the required fuel. The lower fuel level will lean out the engine leading to loss of power. The fuel regulator is a simple proportional controller and its delivery pressure will increase with increasing fuel back pressure due to increasing carb pressure if the reference pressure line is disconnected There are multiple influences fighting each other here but the end result is a lower fuel level in the carbs and the engine running lean and loosing power. Connect the sensor tube to the plenum and assuming everything else is correct it will work. Unfortunately the odds of everything else being correct are not that great cheers Rohan
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