Fixing what’s not broke…

Discussion in 'Mech Tech' started by mcswiggs, Nov 11, 2022.

  1. MorkC68

    MorkC68 Administrator

    Pit oss, they know how to graft..Race oss, no staying power :D
     
    Chrisd likes this.
  2. 77 Westy

    77 Westy Supporter

    But a mechanical oss doesn’t have to be a pit pony to have staying power if it’s built right with the right parts.;)
     
    MorkC68 likes this.
  3. MorkC68

    MorkC68 Administrator

    That'd make a reet good oss :hattip:
     
  4. Get yourself a nice Type 1 engine. Easy to take out, parts readily available and cheap, and bits of the crankcase don't snap off if you overtighten stuff :thumbsup:
     
    Iain McAvoy, Lasty and matty like this.
  5. 77 Westy

    77 Westy Supporter

    A Type 1 is too small and wobbly for my liking.
     
    nicktuft likes this.
  6. Nowt wrong with small and wobbly...
     
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  7. 77 Westy

    77 Westy Supporter

    Big and stiff is better.
     
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  8. Ooh err, Missus!! :eek:
     
  9. Always bragging about the size of it, these Type 4 boys...
     
    MorkC68 likes this.
  10. mcswiggs

    mcswiggs Supporter

    Well, I had to make a decision on replacement gubbins, so here it is. I’ve opted for;

    Standard cam. I looked for info on the Scat C25 but couldn’t actually find much, but what I did pick up was;
    • It’s not great at very low revs
    • The lobe diameter is different (smaller I think) meaning the rocker geometry needs playing with, which I know is do-able but not something I want to get into
    • Needs higher compression to get the benefit from it
    • Couldn’t find a definitive answer on whether heavy duty springs are needed (they are for the Type 1, but not sure about Type 4)
    • No one has them in stock anyway!
    Bog-standard dished AA pistons - Yes, that will just replicate the paltry 7.3/1 compression, but if I leave out the head gasket as per the VW instruction thing it will up it a bit. I’ll do some calculations at some point.

    Now I know not everyone will think I’m doing the right thing so distract you while you mull it over here’s a gratuitous picture of the results from the home electro-plating kit… B1E2296F-7457-44C1-BCD1-DFE66BC4A224.jpeg
     
    Chrisd, paradox, snotty and 1 other person like this.
  11. Ooh. I bought a kit ages ago but haven't used it yet. What volts/amps did you use for the power supply?
     
    mcswiggs likes this.
  12. mcswiggs

    mcswiggs Supporter

    I’ve got the Glatros kit, or something like that. I used to use an old battery from the van but that tended to over do it, so it’s now working better with a smaller old car battery. When I measured the voltage it was 11.8v, so pretty furbarred but great for plating! The kit has a simple coil of resistance wire with it with crocodile clips to regulate the flow. For small parts I find using the whole resistance wire works best.
     
    snotty likes this.
  13. Must have a go with mine. My daughter's been eyeing it up for her jewellery...

    Is the yellow stuff passivator?
     
  14. I found the kits complete pants . And very hit or miss .. The yellow rubs off . I can get a bucket load done any colour professionally for £30
     
  15. mcswiggs

    mcswiggs Supporter

    Yes - nasty stuff.
    It is time consuming and can be frustrating, agreed. But kinda fun too when it comes out as you’d hoped.
     
    snotty likes this.
  16. But then you wouldn't be able to have kitchen full of toxic chemicals. Where's the fun in that?
     
  17. 77 Westy

    77 Westy Supporter

    You’ve made up your mind not to use a C25 cam anyway but to answer your comments.

    I had a Scat C25 in my 2.0l for many years and I still have one in the 2.3l, it was in perfect condition when I removed it from the 2.0l and I sold it to @Fruitcake last year, Paul is still using it in his engine as far as I know.

    I’m surprised you couldn’t find much about the C25, it’s a popular bus cam and the internet is full of info. I posted a bit about it from Aircooled.net earlier – ‘it’s an outstanding bus cam’.

    Compared to a standard cam It probably needs about 100 more revs to idle smoothly but it’s still good at low revs and improves as soon as the revs increase.

    It has a standard base circle diameter but the lift is slightly higher and a spacer shim under the rocker pedestals might be required. It’s good practice to check the rocker geometry even when using a standard cam.

    It does need a higher static compression but I used it with standard dished pistons and the head gasket deleted.

    Many use it with standard springs but I use heavy duty springs to keep the follower on the cam closing flank and reduce the risk of valve bounce at high revs – not that this a concern for a bus engine.
     
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  18. I just found the results pants compared to professional [​IMG]


    Sent from my iPhone using Tapatalk
     
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  19. mcswiggs

    mcswiggs Supporter

    Well you’re right, it’s never as a good a pro job but it does keep me amused for hours on end. Mind you, your temp probe plate on the right looks pretty pitted to start with!

    Meanwhile, just back from powder coaters (something definitely best left to the pros..) … Christmas has come early!
    DC32F701-26AA-4A51-801B-61E348CF9EC4.jpeg
     
    Last edited: Dec 5, 2022
  20. Lick them!
     
    mcswiggs likes this.

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