JK Preservation Parts 1641

Discussion in 'Engine Gearbox' started by mikedjames, Dec 27, 2018.

  1. mikedjames

    mikedjames Supporter

    As most people know, just before Techenders Sptember 2018 when I was wondering what major repair I would need to be doing just to get to Techenders, my home built 1641 dropped a valve and managed to hole the crank case.

    So I was allowed to buy a Preservation Parts 1641 from Just Kampers. It is described as being all new apart from crank and con rods.
    It features AA pistons and cylinders and an Autolinea case and heads.

    This arrived very quickly, ordered Friday it came next Tuesday, it took me a couple of weeks to collect parts needed, and a day to strip down the old engine tinware etc, and a day to install the new engine.

    The engine is delivered post break-in but empty of oil, needing running in.

    It carries a 120 degrees C temperature recording sticker on the top of the case: exceeding this voids the warranty.

    The main difference is the case is thicker in places than the originals so tinware needs some snipping with tinsnips where case corners have rounder fillets of case material in them, basically round the crank pulley area.

    Also the dipstick tube is aluminium not steel with thicker walls and the stock dipstick locked in and then pulled the whole tube out when I first tried to check the oil level.
    A quick splash of carb cleaner then high temperature epoxy stopped it moving again.

    I noted some pitting on the end of the crank where the pulley fits.

    Also there has been an oil seep from the underside of the engine, it looks like the nuts are leaking on the oil strainer plate.

    On first oil change at 500 miles there was a small amount of RTV and one small swarf spiral caught on the strainer.

    Much less glittering metal than my previous engine which never really stopped having metal in the oil.

    I will buy it some Dowty washers to see if they do better than the stock style copper washers.

    Oil pressure at hot idle is 20+ psi, at 4300 rpm it maxes out around 46 psi.

    The engine runs cooler than the previous engine: with an oil cooler I see 100 degrees max rather 115 with the old engine.

    Cylinder head fins were well cleaned up by the builder and these too seem to show a drop in CHT at the same place as the old Autolinea heads I used before.

    In general driving, low end torque is improved, I can accelerate from 25mph on 4th and it climbs hills about 10mph faster than my previous engine.

    But it really does not want to go much faster than 70mph/4300 rpm, the old engine would have less torque to reach 70mph but could run faster , I recorded 5700rpm in second gear when I forgot to change up on the old engine.

    It starts easily as expected and now it has run in I need to slow down the fast idle on the choke mechanism.

    I am running this with a progressive carburettor jetted for the old 1641 engine but re bushed to stabilise idle speed as it had an air leak on the throttle spindle.
    That carburettor has a stock oil bath cleaner with preheated air feed.
    The exhaust is a JK stainless single quiet pack.
    Last edited: Dec 28, 2018
  2. Good report, thanks.
  3. Is the JK one built by SSP?

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  4. mikedjames

    mikedjames Supporter

    No I dont think its SSP ..
    Does the use of grey RTV send any messages?
  5. redoxide

    redoxide Guest

    I have the same motor but supplied by VW Heritage . 1641, performance cam and fitted with twin carbs ..

    I changed the oil every 500 miles for the first 2000 miles and noticed that the oils was a little blackened at the start with a fair amount of glittering which I was concerned about at first.. After 2 changes I dropped the strainer andfound the customary metal swarf.. not so great for a supposed factory built motor but with some of these parts you never can tell where the swarf comes from.. Any way, no damage done. I also noticed from day one a slight oil leak from the strainer but I replaced the supplied dome nuts with proper nuts and the problem was solved ..

    5000 miles on, the engine pulls well and returns great fuel mileage well into the high 20s tipping 30 plus mpg on a good day.

    I was meticlous at running the motor in adhering to strict rev limits and speeds. I woud say that the engine was a bit disappointing to begin with, but that was probably due to self imposed limits. As the motor got miles on it I stepped up the speeds, never lugging it.. It just got better and better . There is just a very minimal amount of glittering in the oil but generally less and less each change .. now every 1000 miles with Castrol GTX My guess is that without adequate oil filtering there is always going to be evidence of glittering so really nothing to be to worried about.

    Two problems I encountered one of my own making was that the righ bank cylinder head didnt have the casting flash removed where the thermostat rod should pass through.. I had to oppen this up with a burr tool .. When I originally tried to fit the rod it took its path via the fins and unfortunately knicked one on the pushrod tubes.. I never realised that at first and did think the motor was using a bit more oil than it should have.. There was no residue when it sat and when it was running the oil was being urnt on the silencer ... so no oit slick just a big stain on the can..

    I fitted expensive spring loaded push rod tubes and since then no issues .. no leaks.. just a decent running motor, although I do thinnk it can do with some additional cooling ..

    One other thing.. this is user error again.. I have a very slight oil misting at the oil filler ( aftermarket alloy thingy) I think I might have put the louvred strainer under the alternator tower in the wrong way up. I believe this can cause some splashback up the filler tube.. I also fitted the alternator tower with bolts to facilitate easy fan removal if it needs to be done at the roadside ..
    F_Pantos likes this.
  6. Heritage is an SSP built motor (I have the same one) which is why I asked the question. Possibly not the same as the JK one from what @mikedjames has said

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  7. I believe the correct nuts are dome nuts.
    davidoft likes this.
  8. mikedjames

    mikedjames Supporter

    I believe its from the VW Engine Shop.

    Anyway, its now done about 8500 miles this year, and it carried on freeing up to about 5000 miles in.

    The first oil change post fitting the full flow filter showed a small amount of metal sheen in the oil draining from the filter, but the rest of the oil was dark and free of any sheen. Previous worn engines continued to leave metal in the oil despite the filter.
    F_Pantos and davidoft like this.
  9. Same engine as Mike, very happy just had issue fitting the single carb stand as the crankcase mounting point is much chunkier, a bit of milling on the stand later and all is well
  10. mikedjames

    mikedjames Supporter

    I have now done 25000 miles with this engine, and still have about 20psi idle oil pressure. I just changed the flywheel O ring seal when I replaced the clutch because this has been leaking oil onto one face of the clutch causing slipping on the flywheel side, and starting to burn on the pressure plate side, because that side is doing all the work.
    Looks like the O ring got pinched maybe when the flywheel was fitted.

    Otherwise, still no issues with the engine. Used on motorway and A road fast runs e.g. Southampton to Swansea at sustained high speed with the full flow and additional external oil cooler, heads still stay reasonably cool.

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