2056 or 2000cc cylinders and barrels

Discussion in 'Mech Tech' started by Jackrobbo, Jul 20, 2022.

  1. Completely agree, I like performance things. So I get the thought. And That’s what my bug will be for but the bus just needs to be solid and reliable. Sounds a good reason not to fit them


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  2. Zed

    Zed Gradually getting grumpier

    Indeed. Probably gain a whisker at revs but at the expense of slower air speed at low revs. Funny really when a stock valve is 39.3mm that a 41mm is so alluring. Mine has 1700 heads with 42mm valves in the original seats which were cut specially. The last angle was formed from the head itself! It's 2.4L though. Eek!
    IMG_20151110_153857975_zpsbqs7f3cd.jpg

    IMG_20151204_152617090_HDR_zps8fcggmbt.jpg

    Different!
     
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  3. mikedjames

    mikedjames Supporter

    That thing about the engine failing on the drive way- the valve seat was loose for a while.
    Usually when you start up you drive off, revs become high and so it heats up quickly and gets tapped rapidly into place by the valve then held by heat expansion.
    But when idling on the drive, the head didnt get as hot, and the constant slower operation of the valve at idle allows the loose valve seat a chance to have enough time to drop out.

    One thing looking over at the Samba.com .. is that certain generations of FI (the ones with lambda sensors and catalytic converters) did deliberately run the engine leaner than is happy. But theres a trick you can do with some external wideband AFR meters where you map the "narrowband" output of the meter to a different threshold rather than lambda=1.0 to make the engine run richer by lying to the ECU.
     
  4. Eek. Is that Mr Parry's work?
     
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  5. Zed

    Zed Gradually getting grumpier

    Yep, the inlets are match ported and the port is shaped like a venturi.
     
  6. I went with 2000cc b+ps AA, from heritage I’m super impressed with the quality even have Teflon skirts?! All look well finished and not dirty at all.


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  7. [​IMG]

    [​IMG]


    The new B+P then I measured the cc’s of the head new AA. And the dome etc and worked out the compression which I was well pleased with.


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  8. Make sure you check the ring gaps AA are often on the tight side ;)
     
  9. 77 Westy

    77 Westy Supporter

    You’ll still need to thoroughly clean the pistons and cylinder bores of course and be very careful with skirt clearance and ring gaps on those pistons.

    What cam are you running with that low CR?
     
  10. Standard cam. I was told the CR must be between 8-8.25 so I was well happy with that. What CR do you run?

    always clean first, but I was just pleased it didn’t take lots of cleaning lol
     
  11. 77 Westy

    77 Westy Supporter

    I run 9.0:1 CR but it’s a C25 cam (and 2316cc). 8.2:1 should be okay with a standard cam.:thumbsup:
     

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