Dateline bikini shaft coupling

Discussion in 'Jet Drives' started by bullet, Jan 25, 2007.

  1. DavidTombs
    Joined: Aug 2007
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    Location: Kent, UK

    DavidTombs Junior Member

    I've cut out the bottom of the bell housing. I've made a template that will allow me to make a replacement out of steel if it breaks in use. Typically I found out to late that with the coupling/jet drive etc all in place there's just not enough space to physically get the housing in and out ( in my installation there's only a couple of inches between the transom and the rear bell housing mount so I have to tilt the engine forward) but there is enough room to have it 'in the area' but moved to out of the way to easily get to the final 3 jet drive shaft bolts. It's all coming apart again next week to fit the supercharger drive belt so I've not sealed the jet drive yet so not testing till then. On that note, anyone got any recommendations or otherwise on what's the best thing to use to seal the jet drive to the hull ?
     
  2. DavidTombs
    Joined: Aug 2007
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    Location: Kent, UK

    DavidTombs Junior Member

    Tony, Am I understanding your solution correctly. Do you do away with the engine to jet drive mounting completely and have the engine effectively sitting on 4 mountings to the hull ? Also, can you suggest a supplier for the metalastic doughnuts, though complete I'm thinking I probably should replace mine whilst it's all in bits anyway.
     
  3. anthony goodson
    Joined: Mar 2007
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    Location: Dorset UK & Murcia Spain

    anthony goodson Senior Member

    Paul
    Yes this is a lot of work but otherwise lining the engine and jet shaft up is difficult because you cant see what you are doing You must use mid block mountings that are as solid and heavy as those used in the car there is alot of torque The rear mountings need not be so heavy but should curve right round the rear face of the block it is a little difficult shaping the metal for the mounting on the starter motor side but it is possible, you will have to grind off the dowels for the belhousing if they wont pull out ,whilst your at it weld a nut on a piece of studding so that you can reach the bottom starter motor bolt from the front all four mounts must be adjustable to some degree.Try www.gmt.gb.com for the rubber parts If you are not completely confident of your fibreglassing skills you may be safer to stick with what youve got Although the doughnuts are supposed to allow out of line running ,in my experience they dont ,unless they are lined up dead square they vibrate The halfshafts on an elan rotate a lot slower than a crankshaft The acid test is to be able to move the bolts by hand with the bands still on the doughnuts. If you have to reuse your old doughnuts they can be refitted by compressing them with several jubilee clips joined together
    These doughnuts were used on early elans and some 1970s Triumphs ,1300cc or 1500cc cant remember which ,try your local motor factors they may be able to locate some old stock be careful they were produced in different sizes for other applications and vehicles ,problem is its all old technology and dicontinued parts now ,its increasingly difficult to make and mend things
    There is only one sealant to use ,Sikaflex check the date on the tube and press it with you fingers ,if it feels hard reject it it has a notoriously short shelf life and its expensive best buy it from someone with a quick turnover
    Good luck Tony
     
  4. DavidTombs
    Joined: Aug 2007
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    Location: Kent, UK

    DavidTombs Junior Member

    Thanks Tony, After a bit more digging I think the doughnuts I had were old Ford Granada ones, which are a bit rare and very pricey. Later Ford Cortina/Sierra ones are of a different design (better in my mind) with the same hole spacings, but a bit thinner. Also found that Land Rover ones for the P38 Range Rover/Discovery fit (in fact they appear identical in size to the Cortina/Sierra ones, but are half the price on certain auction sites) so I've got those instead. Making a set of ali spacer to make up the difference in size. Given the longevity of Land Rovers over Fords, I hope they will be available for a while more. Also, I'm hoping that the additional spacer along with my 'removable' bell housing will allow me to change the doughnuts without removing the jet drive.
     
  5. rbtlen
    Joined: Jul 2007
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    Location: virginia

    rbtlen New Member

    The rubber mount is very similar to the Merkur xr4ti transmission to driveshaft coupling (ford 2.3ltr turbo with c3 transmission) I would have to say identical but without having them next to each other couldn't be sure.
     
  6. DavidTombs
    Joined: Aug 2007
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    Location: Kent, UK

    DavidTombs Junior Member

    Everything is back together and working brilliantly. The new bearings and doughnuts have made a noticable difference to the smoothness of the boat - previously there was a low pulsing/humming which has gone. In the end I trimmed more from the bottom of the bellhousing (still leaving the lowest mounting holes) so I could remove it easily without tilting the engine and with everything else in place. Having an additional spacer inbetween the doughnuts (my setup is now flywheel fitting-doughnut-original spacer-my new spacer-doughnut-jet drive fitting) allows me to remove/replace the doughnuts without removing anything else. The only other thing I had to do was carefully grind a slight cutout into the top of the jet drive front bearing housing to allow the doughnut bolts for the jet drive fitting to be slide in and out. Now all I need to do is get a better (fast) impeller or a small 1:2 gearbox to get more speed!
     
  7. petebagski
    Joined: Oct 2009
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    Location: birmingham

    petebagski New Member

    I have just bought a Dateline bikini with a PP jet. I have previously owned a Simms superv also with a PP jet. On the Simms the bell housing/cover over the drive was open underneath which left just enough room to unbolt the rubber donuts from the coupling roatating the engine to get at all three bolts. On the Dateline the drive coupling appears to be covered all the way round by the bell housing. Does any on know the proper procedure for uncoupling and removing the rubber donuts. Is there a spined shaft which withdraws when you unbolt the bell housing and move the engine forward ( there was no splined shaft on the Simms). Is there an inspection hatch on the bottom of the bell housing which can be got at by unbolting and rotating the bell housing. There must be a proper way of doing this job?
     
  8. gixerdale
    Joined: Oct 2009
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    Location: Blyth

    gixerdale New Member

    I find the only way to do this is to remove the jet drive 1st. Remove the 3 bolts from the coupling gaining access by rotating the shaft (as you did for the simms) I then use 2 bottle jacks to support the engine. Remove the rear mount from the bearing block and the thru transom mounting bolts releasing the jet drive.You can now remove the bellhousing it has no inspection hatch and there is no splined shaft on the donut.Since its off I would replace the bearings and seals on the drive available from any bearing supplier just remember to change the seal springs for stainless I have had the stator bush modified to a needle roller bearing much better. Once the donut is changed I re-assemble as follows. With the bell housing back in place remove the shaft from the jetdrive (remove the impellor and undo the 4 bolts on the front bearing block). Connect the shaftcoupling thru the transom hole to the donut, slide the casing onto the shaft bolt the bearing block to the casing bolt the casing to transom using silkaflex refit the rear engine mount lower the engine and refit impellor etc . I considered modifying the bell housing to make this easier but feel the engine bellhousing is very close to the hull and like the idea of metal between the flywheel and hull for protection failed engine mount would be fatal. It is a pig of a job and you will curse and swear but it is well worth the effort i love these boats
     

  9. petebagski
    Joined: Oct 2009
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    Location: birmingham

    petebagski New Member

    I have been talking to another Dateline owner and it is apparent there are 2 types of drive couplings used on Datelines.
    First type: (similar to simms super v) This can be identified as there are 2 grease nipples either side of the aluminium bearing housing on then jet just inside the transom of the boat. The bell housing is exposed underneath giving access to the rubber donuts in the drive and the bell housing rests on a mounting on top of the aluminium bearing housing above. The bolts connecting the drive and the donut nearest the aluminium bearing housing can be undone by working at “4 o clock” underneath the bell housing, one at a time and rotating the engine/drive to get at the next one. If one side of each bolt head has been ground off to the shaft the bolts can be extracted just missing the aluminium bearing housing or alternatively once the bolts are undone (and rear engine mounting) the jet drive can be unbolted from the transom and the bolts will pull out of the donut as the jet drive is pulled rear ward. The aluminium straps round the donuts I found were best removed before assembly otherwise they were difficult to reconnect. With the jet drive in place on the transom working again at “4 o clock” slide in the first bolt (with one side of head ground off to the shaft). This should go in fairly easily. For 2nd/3rd bolt, use a screw driver as a lever against the bolt head to force it through the hole in the drive/donut and a large tyre lever/cold chisel against the side of the donut and bottom of boat to line up the holes. There is a bit of a knack to this but once mastered comes easy. This worked fine on the Simms and I believe the same parts are used in the Dateline.

    Second type. This can be identified by the grease nipple on top of the aluminium bearing housing just inside the transom. The bell housing is completely enclosed underneath and there does not appear to be any rear engine mounting. I have no idea what the proper way to take the jet drive off is. There are tree bolts on the end of the bell housing holding a cover which the propeller shaft goes through. I may split this here and try and get an endoscope in to see what is inside. Boes anyone know the proper way to disassemble?
     
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