A bigger T1

Discussion in 'Modified Shizzle' started by zedders, Jan 17, 2015.

  1. No I haven't built another, but I'm going to start making plans.
    I have 76mm crank and 92mm B&P's. It's good, but it could be better/bigger. I have a new race case that will take 82m crank and VW rods without clearancing. But I could clearance/use chevvy style rods and go bigger.

    So - tell me about your T1's please. I want this to be the one. I don't want to be thinking I could have made bigger and more powerful, but it has to be a T1, no T4's even though yes they are better.
     
    68_early_bay likes this.
  2. Surely there is always something bigger and more powerful?
     
  3. There will be a point of self destruction. I'd prefer to stay the safe side of that.
     
  4. Loved your last build thread Steve and I'm looking forward to this one. Quick question, if you want to build the biggest, most powerful motor you can, why not a type4 even though you say yourself they are better?
     
  5. They cost a ruddy fortune to build and for me would be as wrong for my prototype as a Subaru.
     
  6. Two very good reasons!
     
  7. What cc's are you aiming for zed? 82mm crank vw rods and say 94mm p&b's is 2276, what difference does Chevy rods add ?
     
  8. Chevvy rods refers to the journal size which being smaller than VW journals allows more crank throw before clearancing. 94mm Barrels are too close to the head studs for my liking. 82/92 seems a common reliable spec but that gets you to 2180cc which is only 160cc more than my present engine. :thinking:
     
  9. If it's only a gain of 160cc , how about instead of stretching the limitations of the case/capacity, why not go down the low pressure turbo route to increase power? :)
     
    Zebedee likes this.
  10. A thought that has occurred since I have a set of 90.5's that were set up with too much deck height resulting in 6.8:1 CR.
     
    68_early_bay likes this.
  11. There are some 101,6 x 86 builds going on. 2789 ccm.
     
  12. T1 or T4?
     
  13. Go big or go home.:D
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    68_early_bay, art b and zed like this.
  14. Cripes. Thanks for posting that @Zebedee
    I would think building a monster T4 engine just might be cheaper!
    Food for thought though, 250BHP would be nice. :D
     
  15. Oversquare like that is good for power, but not for torque, as it won't breathe right until the revs are up. Turbo spec combustion chambers tells a story - the only way you're going to get those cylinders full at lower revs is to push the air in. It's noticeable that the head shown is still single plug, I'd be looking at twin plug to get efficient combustion with a big bore motor.
     
  16. I'm guessing turbo spec also = had to remove a lot of material to reduce the compression ratio for the whopping pistons. I have a pair of heads like that - semi-demi cut.

    I think I should at this point suggest I'm not really going to go hyper-crazy and budget is a consideration. I'm not after a quick buzz down the strip and rebuild after every other run. The 4" cylinders have virtually zero cooling so that style, IMO, is a bit of a non-starter for a street bus whatever the article says.

    The funny thing about air cooled VW engines is that for all the phenominal acceleration possibilities at the end of the day if you cruise at a decent speed it'll eventually overheat and bang.
     
  17. How can you improve the cooling significantly? My extra cooler keeps the oil temperature sensible, although it still starts to climb if you push hard for too long. I'm guessing that keeping the oil cool doesn't help a great deal with cylinder head temperature and localised hot spots, so how do big power builders combat this?
     
  18. As far as I can work out, not by having virtually zero fins on the cylinders for a start. More air, more efficiently delivered where it's needed, but how that's done I have no idea.
     
  19. T1 :)
     
  20. I see that now thanks to the article posted earlier. I imagine I could build a pretty good engine for the price of one of those heads.
     

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