Rolling road; before and after investigation.

Discussion in 'Mech Tech' started by KarlB, Jul 11, 2014.

  1. Twin Brosols all the way...:D
     
  2. Baysearcher

    Baysearcher [secret moderator]

    Loads on here have recently bought the VS exhausts and rave about them though.
    Must just be the placebo effect of looks and price!
     
    snotty likes this.
  3. Do you mean "Bristols"?
     
    Lasty likes this.
  4. Zed

    Zed Gradually getting grumpier

    They're for when you have a good set of carbs though, not a performance booster without i would guess.
     
  5. This just shows why many people regard power figures from a rolling road to be fiction. On the before run you had transmission losses of 35.3% and on the second run it was 24.7%. That makes no sense at all, so there's something up with the run down part of the test on the before set up. Seems likely that the 24.7% figure is the realistic one as 35.3% losses are huge. Use this on your before figure and you have 38.6 BHP at the engine before and 48.6% after, a 25.9% improvement, which is quite a lot for carbs and an exhaust.
     
  6. I know @Owen Snell, the transmission has remained constant throughout but the results have varied across all three tests.

    It must be a nightmare trawling through these figures if that was your job.

    I'd like a nosey at an engine dyno though..love the idea of 'live' feedback while you tune. I really must plan a holiday around the Scottish isles one summer and pay a visit to this legend :)

    [​IMG]

    In the meantime I'll stick with how the engine feels and performs. After all, I'm the numpty who has to drive it :)
     
    Lasty likes this.
  7. The camper engine will remain as is now.

    Next job is to work on the beetle and get to play with a more involved modified Vw engine.

    78.4x90.5
    2014.15cc
    Engle k8
    1 3/4 exhaust
    6.96x1 compression
    Dellorto 48 DRLA's
    Berg equaliser pulley....
    All the happy bits...

    Built in 1995 by Harry Harpics
    Cam broken in...never ran since :)
     
    snotty likes this.
  8. Zed

    Zed Gradually getting grumpier

    Why the low compression?
     
  9. No idea! That's just the way it was built. I didn't commission it :)

    I'll see how it goes and take it from there. I have a suspicion that the carbs are too big as well but I'll be able to sell them and fit smaller ones. We'll see :)

    Looking forward to working with something a bit different to stock.
     
    Last edited: Aug 7, 2014
  10. I just realised i have the same bluebird back box as you too :)
     
    KarlB likes this.
  11. Get a room...
    :)
     
    KarlB likes this.
  12. I am going to resist the overwhelming urge to post the photo of that bloke and his exhaust. You know the one! ;-)
     
  13. The work safe version?
    [​IMG]
     
    KarlB likes this.
  14. Crikey...can’t believe this was back in 2014!

    Van still running beautifully with just normal servicing. I use the van all year round and it’s my ‘daily’ (although I walk to work!)

    My only issue are when facing hills when loaded up. Last summer we did a lot of camping taking my girls and their friends away which meant multiple bikes, people, bags, the awning and everything else (it seems girls don’t pack light!)

    We regularly have a lovely clear road ahead of us on the A9 with no traffic to be seen...unless you count the tailback in the mirrors!

    Add to this my girl’s growing interest in kayaking and the prospect of roof racks and boats means my mind has turned to TORQUE.

    I have absolutely no desire to go any faster than 60mph in the van. 55 is his ‘sweet spot’. I can point the speedo needle straight ahead and relax :)

    My thoughts have turned to the stroker mentioned in the post above which is still sat on an engine stand beside my unfinished (but primered!) Beetle.

    2014cc
    Engle K8
    Low compression ratio 6.96x1 compression.
    Mildish valves (I’ll look them out later)

    This was (to put it mildly!) a bargain and has never been used since it was built in 1995.

    No idea what it was built for (a buggy I think) but it came with brand new Dell 48’s which are ridiculously mahoosive.

    My thoughts have turned to fitting stock heater boxes, my header and quiet pack (still going strong), remove the MSD ignition and fit my stock vac distributer and (shock!) the dellorto 34 FRDs (but look into the Venturi and jets.

    Like I said - absolutely no desire to go any faster than I can now but would like a really lazy torquey engine which will tootle up and down the hills I frequent fully laden without breaking a sweat.

    I’ve seen strokers with reworked single solexes!

    Wondering if anyone has any thoughts/opinion etc.

    There may well be a rolling road return ;-)
     
  15. 35hp at wheels.
     
  16. That’s it decided then.

    Engines coming out next weekend ;-)
     
  17. 77 Westy

    77 Westy Supporter

    Wrong cam for torque and the 48 DRLA's are too big. If the CR were higher to get the cam working it would be a good bug engine but not much torque low down and with that CR it won’t have much power anywhere - unless it has a supercharger or turbo. It might work better with 34 FRDs but the cam is still very wrong for a bus engine. Just my opinion of course.:)
     
    Last edited: Jan 28, 2018
    paradox and KarlB like this.
  18. Opinions are all very welcome.

    I’m not adverse to some cam jiggery pokery!

    I have no intention of using the 48’s. Probably end up selling them as they are HUGE!
     
  19. I do wonder why the compression was set so low. I have the original bill and there are 1mm spacers to drop the compression....

    Just dug out the 1995 receipt (from Harry Harpics) and amongst other things it has 40mm inlet and 35.5mm exhaust.

    Odd combination of low compression and massive carbs?!
     
    Last edited: Jan 28, 2018
  20. 77 Westy

    77 Westy Supporter

    1mm spacers to get a minimum deck height maybe? A very strange combination of parts in that engine, almost as if someone found a box of various bits and just put them together. The CR is wrong for the cam, the cam is wrong for the valve size and the valve sizes are wrong for the carbs and the carbs are wrong for the capacity.

    Say you want the engine to produce power from just off idle to 4500, the theoretical carbs size should be about 38mm, with 30mm chokes. Valve sizes are okay. Change the cam for an Engle W-100 or maybe W-110 or Scat C25 or C35, all with standard 1:1 rockers. W-110 or C35 would lose low rev torque but produce more overall power at higher revs.
     
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