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GavinT

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  1. 🧐Missed the * on item 22 17.07A. Can’t be too crazy as I already used a little Hylomar AF on the threads 😉 . However, Sometimes I think I am totally bananas for owning two Esprits. Frustrations out the Yin Yang. Thanks for the help 👍
  2. Continuing with my engine rebuild, 88 Stevens….can’t remember if the oil pressure sender screws into the block with or without a copper crush washer. Parts manual doesn’t mention one. Anyone enlighten me. Thanks.
  3. Finally started to assemble my 88 engine. Using other peoples threads for reference, inspiration and comparison ( one of the great things about this forum ) I couldn’t help notice the quality of the castings. Comparing these two blocks, one is mine (bottom) and the other is Ian’s - chillidoggy. You can clearly see mine is so much rougher on the inside. If you look at #4 on my block it almost looks like the liner is not seated correctly but it is. The casting is just not uniformed across the block. There is much more material around #4 which is giving the visual impression that the liner is not fully seated. Looking at Ian’s the liners all look seated equal and the general appearance is much smoother and machined better. Almost like mine is a Friday casting and Ian’s was a Monday morning. I guess Lotus changed the process or supplier.
  4. The cranks are expensive but there are just not that many to be had. I paid $1600 for a ‘ good standard ‘ crank from JAE. I have a spare 2.2 crank that is .030 under on the mains. At this point I’m holding on it with intention of using it in a 2.2 upgrade on my S1.
  5. I had the exact same failure on my 88 Esprit Turbo. Thrust washer spat out, found in the oil pan, and the crank had drilled the block. Crank toast and debatable whether the block was repairable. This is becoming more and more common on 9XX as the miles and driving styles take their toll. I opted to buy a used engine. However that became a rebuild rabbit hole after discovering the bearings were scored. Ultimately I am combining the best of the two engines to make one. I am still in the process of rebuilding mine but I’m up for the challenge. I have all the puzzle pieces just need to find a free weekend to do the build. Suggest reaching out to Garry Kemp as he has some really good components…such as NPR Piston Rings. Good luck.
  6. Or… https://qedmotorsport.co.uk/product/crankshaft-en40b-steel-2-0-2-2-litre/
  7. Good luck Phil. Keeping my fingers crossed for you
  8. From what I’ve learnt….the original non dimpled studs are fine for the old metal type head gasket but not for the later Goetze ones. The Goetze gaskets require a much higher torque load to seat and seal correctly. The original studs are not up to the task. Upgrade the studs and use the later torque specifications. Lotus Service bulletin 1993/07 TITLE: Introduction of revised cylinder block, head & gasket REASON: Quality improvement. The cylinder block and cylinder head of the Lotus 910/920 engine have been re-cast and upgraded in respect to stiffness, lightness, cooling efficiency and dimensional control. In addition, a new type of cylinder head gasket has an increased tolerance to severe thermo-cycling, and improved durability. ACTION: The new components have been introduced on engine serial number: 28096 (last 5 digits of engine number) - January 1993. With the exception of the block deck height and various core and blanking plugs, the new block and head share all functional dimensions with the old type, and when service stocks of the older components are exhausted, the new parts will replace them. New heads may be fitted to old blocks and vice versa, but the new head gasket should be used in both cases. The new block and head may be readily identified by cast Lotus logos on the front and rear faces of the cylinder head and at the top right hand rear of the block. Cylinder Head Gasket The steel and asbestos laminated gasket, B907EO026Z (Coopers - silver incolour) has been replaced by a reinforced fibre-composite gasket A912E7029Z (Goetze - grey/brown in colour) This uses a built-in silicone sealing bead around the periphery and a Viton seal around the oil feed hole. The compressed thickness of the new gasket is approx. 0.5 mm (0.020") greater than the old gasket and the deck face and liner seats of the new cylinder block have been lowered by a corresponding amount. Service Replacement i) New engines must be fitted only with the new type gasket. Fitment of an old type gasket to these engines may result in piston foul and/or detonation due to the raised compression. ii) When stocks of the old gaskets are exhausted, old engines should be fitted with the now gasket, which will also replace the 'extra laminate' thicker gaskets (A911E1292, B911E1292) used on some low compression 912 N.A. engines. Note that the extra thickness of the Goetze gasket will result in a slight reduction in compression ratio (typically about - 0.5 numerically) when used on old engines. This may be advantageous to fuel octane tolerance, especially if the head face has been machined to correct distortion or erosion. Goetze Gasket Fitting Procedure There are two points to note when fitting the new type gasket to new or old type engines: a) New engines must be fitted only with the new type gasket. b) The cylinder head nut tightening procedure has been amended and requires the use of an angle gauge. A Sykes Pickavant tool under Lotus Part No. TOOOT1235 will be despatched and invoiced to all dealers shortly. Use the latest type cylinder head studs (B907E0224Z) identified by the dimple machined in the top end. Tighten into the block (with oiled threads) to 37 - 41 Nm (27 - 30 lbs.ft). Fit head gasket (dry) and cylinder head. Fit washers, oil head stud threads and fit nuts. Using the existing tightening sequence (from the centre outwards; see Service Notes EB.7), Tighten the head nuts in the following stages: i) 20 Nm (15 lbs.ft). ii) + 75 degrees iii) + 40 degrees iv) Wait 5 minutes v) + 20 degrees Cylinder Liner Adhesive The sealant used between the base of the cylinder liners and the block (formerly Hylomar) has been changed to Loctite 572 adhesive/sealant (A912E7030V) in order to reduce fretting and noise; improve sealing durability; reduce the risk of liner disturbance with the cylinder head removed. The use of Loctite 572 has been introduced together with the new block and head castings, but may be used on all Lotus 900 series engines. Loctite 572 Application Procedure: Thoroughly clean the liner spigot and seat, and the corres­ponding areas in the block. Dry fit the liners and check that there is a nominal clearance between the top ends of the liners. Check the stand-out of the liners above the block deck face (liner 'nip') which is unchanged at: - 0.03 mm to + 0.05 mm (- 0.001 to + 0.002 in); Maximum variation between adjacent liners: 0.03 mm (0.001 in) Apply a small bead of Loctite around the seating face of the liner. Apply a thin smear of Loctite around the outside of the liner spigot. Apply a thin smear of Loctite around the top edge of the liner spigot bore in the block. Slide the liners into the block and fit the cylinder head within 4 hours to ensure that the liners are seated correctly before the adhesive cures. If this procedure is used on an “old” engine, apply a red paint mark for reference to the cylinder block at the end of the engine number stamping. Note that when assembled as above, the liners will subsequently require the use of a liner puller tool (TOOOT0012A - existing part of the dealer special tool kit) in order to extract a liner from the block. The improved security of the liners also means that if care is taken, there is no necessity to reseal the liners in the normal course of cylinder head removal/refit Cylinder head layout and orientation Lotus Esprit cylinder head tightening sequence Summary Vehicle manufacturers specify torque values for certain fasteners such as cylinder head studs and nuts. This is to make sure that fasteners are not over-tightened or under-tightened. The torque wrench is used to apply a specified amount of torque to a fastener. The torque angle gauge is used to make sure there is equal tightness across all fasteners on a particular component. Just looking at the ARP head stud kit supplied by JAE, instructions say to torque to 110 ft lbs using the ARP Ultra Torque lube. Also when installing the studs in the block, only hand tighten them. The final seating of the stud happens as you torque down the head.
  9. Thanks for the link Steve. The issue I’m concerned about is that .010” is right at the top of the spec range and NPR say not to re-gap the rings. So I’m looking for some validation that it is ok to install with a .010” gap.
  10. Test fitting shows a gap of .010” on #1 ring across all 4 cylinders. The NPR fitting instructions say not to adjust the gap as the rings are manufactured to meet Lotus specs and are 910 engine specific. Does running right on the edge of clearance specification bother anybody?. Engine is an 88MY 910 Turbo with Bosch CIS, USA Spec. Thanks!
  11. This is a great video on how to trouble shoot the Bosch CIS injection system. Esprit Turbo HCI 1986 - 1987 and 1988 Stevens USA. Although the engine in the video is from a 70’s Porsche 911, the injection system is the same. You just need to check your workshop manual for the Lotus spec’s.
  12. This transaxle also has pretty badly worn primary shaft splines and really needs a rebuild. Not something I’ve budgeted for. Good job it’s a spare.
  13. Happy Christmas all you Lotus lovers !
  14. Visually I can’t see any damage. This box is an unknown to me and was purchased as a spare. Not witnessed it in action. Told it work fine but you know how that goes.
  15. Taking the bellhousing off the gearbox to do the circlip upgrade. Checking things over I’m presented with is. Not too far away from totally failure. I have no idea what could have caused this type of wear but somebody has been in there before and the bearings are not original. The spacer rings and collar were inserted out of order when I removed the output shaft housing.
  16. Lotus Service bulletin 1993/07 TITLE: Introduction of revised cylinder block, head & gasket REASON: Quality improvement. The cylinder block and cylinder head of the Lotus 910/920 engine have been re-cast and upgraded in respect to stiffness, lightness, cooling efficiency and dimensional control. In addition, a new type of cylinder head gasket has an increased tolerance to severe thermo-cycling, and improved durability. ACTION: The new components have been introduced on engine serial number: 28096 (last 5 digits of engine number) - January 1993. With the exception of the block deck height and various core and blanking plugs, the new block and head share all functional dimensions with the old type, and when service stocks of the older components are exhausted, the new parts will replace them. New heads may be fitted to old blocks and vice versa, but the new head gasket should be used in both cases. The new block and head may be readily identified by cast Lotus logos on the front and rear faces of the cylinder head and at the top right hand rear of the block. Cylinder Head Gasket The steel and asbestos laminated gasket, B907EO026Z (Coopers - silver incolour) has been replaced by a reinforced fibre-composite gasket A912E7029Z (Goetze - grey/brown in colour) This uses a built-in silicone sealing bead around the periphery and a Viton seal around the oil feed hole. The compressed thickness of the new gasket is approx. 0.5 mm (0.020") greater than the old gasket and the deck face and liner seats of the new cylinder block have been lowered by a corresponding amount. Service Replacement i) New engines must be fitted only with the new type gasket. Fitment of an old type gasket to these engines may result in piston foul and/or detonation due to the raised compression. ii) When stocks of the old gaskets are exhausted, old engines should be fitted with the now gasket, which will also replace the 'extra laminate' thicker gaskets (A911E1292, B911E1292) used on some low compression 912 N.A. engines. Note that the extra thickness of the Goetze gasket will result in a slight reduction in compression ratio (typically about - 0.5 numerically) when used on old engines. This may be advantageous to fuel octane tolerance, especially if the head face has been machined to correct distortion or erosion. Goetze Gasket Fitting Procedure There are two points to note when fitting the new type gasket to new or old type engines: a) New engines must be fitted only with the new type gasket. b) The cylinder head nut tightening procedure has been amended and requires the use of an angle gauge. A Sykes Pickavant tool under Lotus Part No. TOOOT1235 will be despatched and invoiced to all dealers shortly. Use the latest type cylinder head studs (B907E0224Z) identified by the dimple machined in the top end. Tighten into the block (with oiled threads) to 37 - 41 Nm (27 - 30 lbs.ft). Fit head gasket (dry) and cylinder head. Fit washers, oil head stud threads and fit nuts. Using the existing tightening sequence (from the centre outwards; see Service Notes EB.7), Tighten the head nuts in the following stages: i) 20 Nm (15 lbs.ft). ii) + 75 degrees iii) + 40 degrees iv) Wait 5 minutes v) + 20 degrees Cylinder Liner Adhesive The sealant used between the base of the cylinder liners and the block (formerly Hylomar) has been changed to Loctite 572 adhesive/sealant (A912E7030V) in order to reduce fretting and noise; improve sealing durability; reduce the risk of liner disturbance with the cylinder head removed. The use of Loctite 572 has been introduced together with the new block and head castings, but may be used on all Lotus 900 series engines. Loctite 572 Application Procedure: Thoroughly clean the liner spigot and seat, and the corres­ponding areas in the block. Dry fit the liners and check that there is a nominal clearance between the top ends of the liners. Check the stand-out of the liners above the block deck face (liner 'nip') which is unchanged at: - 0.03 mm to + 0.05 mm (- 0.001 to + 0.002 in); Maximum variation between adjacent liners: 0.03 mm (0.001 in) Apply a small bead of Loctite around the seating face of the liner. Apply a thin smear of Loctite around the outside of the liner spigot. Apply a thin smear of Loctite around the top edge of the liner spigot bore in the block. Slide the liners into the block and fit the cylinder head within 4 hours to ensure that the liners are seated correctly before the adhesive cures. If this procedure is used on an “old” engine, apply a red paint mark for reference to the cylinder block at the end of the engine number stamping. Note that when assembled as above, the liners will subsequently require the use of a liner puller tool (TOOOT0012A - existing part of the dealer special tool kit) in order to extract a liner from the block. The improved security of the liners also means that if care is taken, there is no necessity to reseal the liners in the normal course of cylinder head removal/refit Cylinder head layout and orientation Lotus Esprit cylinder head tightening sequence Summary Vehicle manufacturers specify torque values for certain fasteners such as cylinder head studs and nuts. This is to make sure that fasteners are not over-tightened or under-tightened. The torque wrench is used to apply a specified amount of torque to a fastener. The torque angle gauge is used to make sure there is equal tightness across all fasteners on a particular component.
  17. I was under the impression that when you install the Geotze gasket you must upgrade to the newer head studs or the ARP ones. Reason being, the. Goetze gasket requires a greater clamping force over the old metal gasket. The old studs are not up to the task. Tim Engle…. the current Goetze composite gasket requires high-strength cyl head studs, and the nuts are tightened with a torque angle meter, not a torque wrench. Using the old torque wrench spec won't get the head tight enough for the new composite gasket. Use a Torque Angle Meter (initial set with a Torque Wrench) Initial Load = 14.7 Lb-Ft / 2.0 Kg-m / 20 N-m (torque wrench) Then, using a Torque Angle Meter. Tighten an additional 75 in one step, then. Tighten an additional 40. Wait 5 minutes, and then. Tighten an additional 20
  18. Update….The issue with 0.030+ bearings is availability. The lower shells are the problem. Getting OEM quality is the next issue. SJ offer alloy 2 ply which I was advised not to installed. I emailed all the usual suppliers. LotusBits and PNM didn’t respond. SWLC didn’t have any options. Garry Kemp could offer OEM grooved lower bearings but they are not suitable for a turbo esprit. JAE are out and their supplier is not doing another run anytime soon. The winner was QED. They have both OEM and aftermarket bearings. Aftermarket in 0.030 lower bearings, but their aftermarket bearings are tri metal and are OEM spec. Ultimately I had a stroke of good luck and scored an extremely lightly used 910 crank that is still standard from JAE. Shout out to Tim Engle, Garry Kemp, Dave(Changes) and Mike Sekinger for all their advice, extremely grateful for their time.
  19. Reached out to Garry Kemp. He has original OEM .030 bearings available but they are all grooved. He didn’t express concern about taking it down to .030 under. Tim Engle also didn’t express too much concern about taking it down to .030. But added it would be beneficial to have the crank journals nitrided. His main issue was that the crank has gone as far is it can go. So any future need for crank work would result in a new crank.
  20. Gents, unbelievably frustrated with this one. Machinist messed up #1 main journal and cut it down to .025 under, was meant to go .020 under. +30 mains are available from some of the vendors but is it a good idea to go this deep?. Machine shop will correct the situation, I just need to determine the correct course of action. options: 1. Cut to 30 under 2. journal repair and cut to 20 under 2. Replace crank This is on my 1988 910HC Turbo. Thanks all.
  21. I’ll do a plastigage clearance check with the .010 bearings and see where we are at.
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