T4 - not the usual upgrades.

Discussion in 'Modified Shizzle' started by zedders, Oct 3, 2015.

  1. This engine will quite possibly be rubbish, but then again it might be ok. If it's rubbish I'll make it even bigger. :)
    You know what they say - when push comes to shove, if you want more torque you must make it bigger. Roughly speaking torque is directly related to capacity. Apparently.
    So, if one wanted to use a VW crank and attach the biggest barrels and pistons you can without moving the studs, what would that be? That would be 104mm pistons and a 71mm 2L crank = 2413cc's. I like the sound of that.

    They say that it's crazy not to use lightweight conrods, the originals are very heavy. Not cheap, but I decided I'd at least listen to this bit of advice.

    They say it's pushing your luckto machine out the case so close to the studs - these really are buckets. :D I suspect that maybe also due to people trying to build very high power engines with them, not what I want.

    I like 2L engines in buses, they are torquey and yet they rev freely too. I decided I'd use a stock 2L cam with bigger valves to compensate for the increased cc's.

    I then tried to get hold of a pair of 41mm valve 1800 heads. Not happening. I have a plan for now using 39.3mm heads and some extreme valve work for now. It's either that or deal with a US company that doesn't answer emails.

    It will have DRLA40 carbs and a boggo exhaust system to start off.

    I hope it'll be just like a 2L T4 engine, but with 2x the oomph. Who knows?
  2. Budget (not that there really is one) starting with nothing but the carbs and filters looks like about £2k, so that means £2.5k. Not too bad? We guess 140-150HP.
  3. i know I've said it before but I'd love to build a square engine ....
  4. When will it be done?
  5. Can you get a 104 mm stroke crank?
  6. Sounds like a perfect bus engine, it should make bags of bottom end torque. I wouldn't worry too much about the headline bhp figure, a wide spread of grunt is much more useable as you know.
    zedders likes this.
  7. ASAP as far as I'm concerned. The heads will get new guides and valves + seat cutting and some mild porting first.
    Then the bottom end mocked up to see where deck height is.
    Then I have to work out the best way to keep the CR manageable which might involve leaving a step in the head and definitely opening up the combustion chambers.
    Then it can be built, I have all the parts.
  8. I hope so. Most people increasing capacity increase the stroke to leave the strength in the heads and case, but there are a bunch of enthusiasts in Germany I came across who reckon these are great in a bus. Can't find them since.
  9. Merlin Cat

    Merlin Cat Moderator

    I'm afraid these posts make absolutely no sense whatsoever to me!
  10. Not sure what the biggest is ...I've seen 80mm t4 and 85 mm type 1.
    Or even what will fit in the case

    Forced induction ?
  11. It'll go better up hills, accelerate quite fast without sounding like a boy racer, not really cost much in the scheme of things.
    The downside is it will be more likely to break, but that's part of the fun for me, I don't mind, I'd just make it bigger and better the next time. It's just a hobby really.
    Bertiebot, Merlin Cat and CollyP like this.
  12. I think you can only really ask so much of the basic components personally and believe it's best to leave 20% of available power on the shelf as it were as insurance against early failure. An engine builder wouldn't warrenty even mine, that says it all for me, but then again other than being annoying, if it does break, ho-hum I suppose.
    CollyP likes this.
  13. You should get great torque numbers with the supercharger, that will be an interesting comparison with a big capacity NA engine.
  14. If he ever finishes it. :)
  15. With that it mind, wouldn't you be better of starting with something a bit more lairy as standard? A 914 engine maybe? I know you're doing it as much for the process as the finished product but reliability must be a factor?
  16. Have you seen the price of the parts? I don't want lairy anyway Fletch, I want grunt. :)
    Cost is a big factor, I like to build my few engines as cheaply as possible, just to see if I can. I nearly cried as I handed over £400 for conrods, B&P's were £500, but some things you have to spend money on.
  17. Must admit I'm not up in prices. I like the idea of sodium filled conrods though;)

    I've got a load of t4 stuff I'm going to sell if you're interested?
  18. Any 41mm 1800 heads? lol
  19. I'll have a look:)
  20. Valves ..sodium filled valves .....a 914 is the same as any other type 4 .just different heads and higher compression ,cam etc

    Supercharger takes time ....like you I don't have oodles money to spunk ...

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