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  1. #1

    Williams F7R Vs. Megane F7R

    Evening,

    (It is 6 years since I've been involved in this stuff every day, and my memory isn't what it was, so I thought that I would consult the collective knowledge, and get some POV's).

    I have two engines sat there, a Williams F7R & a Megane F7R (Electronic Injection). Has anyone got a full parts (number) teardown of the two?

    TL;DR:
    • What are the specific differences between the two engines
    • Do they share gaskets, do they share bearings - WHAT don't they share?
    • What could be the problem with using a megane head on a williams bottom end
    • Will the Williams rocker cover fit the Megane
    • Are there additional things to consider


    I (think that I) purchased the Megane F7R (MF7R) with the belief that it actually had a marginally better engine (larger exhaust ports maybe?) than the Williams F7R (WF7R) if one were to get headwork done to it, and that it had a better oil system that the WF7R.

    I have both engines sat there, along with most of the parts, and ready to go to to get put together, but need to make a decision as to the best package to put together. I will go and get another Williams engine if needs be.

    The intention is;

    11.3 Woessner Pistons
    7105137 Catcams
    CTTO018 Pulleys
    ARP Rod bolts
    Stainless Rods
    Maybe bigger injectors (R19 or other appropriate)

    Engine management is also a challenge - but we will get to that, at a later date. I think I might hit up Danish Michael for another one of his ECU's to be made up, but again - that's more challenges with sensors etc.

    The questions remain about the more wholesale part of; which core engine to reside all these parts in. Mr Brown and I chatted at length about this last year, and whilst there's not any major reason to go with one or the other, visually, there's not any discernible difference between the MF7R & the WF7R - what are the practicalities of it all?

    /y0z

  2. #2
    Depends what the engine code of the megane block is, if it's 710 it's virtually identical to the williams block so all parts are the same, if it's 714 the main difference is a chain driven oil pump.

    If it wasn't for not being able to find that number of catcams (comes up as for the toyota 4age engine) it sounds like the spec you want is almost the same as mine

    Basically the willy head is shit, the rocker wont fit the meggy head but why would you bother when the plastic meggy item looks better and is a shitload lighter.
    The meggy makes slightly better power and more torque with much milder cam profile than the williams & it's all down to the smaller inlet ports - with the bigger valves of course - being more efficient and the inside of the exhaust ports are much much better, just stick your fingers inside them & you'll see what I mean, just seems to be a better quality & smoother casting with no massive weird bumps inside it.

    Are you going with itb's or standard inlet? I've got a megane manifold that's been modified for a willy throttle body to fit so all you'd need is the meggy head machined to accept the dizzy & you can use standard management.

    But the main thing here is that the best thing all round is to use the megane head but you'd need to decide what you want to do management wise as that's what will determine what you have to or don't have to do. If you're going for something better than the casio calculator spec standard ecu you can pretty much leave the meggy head as it is

  3. #3
    Cheers Paddy.

    I will have to check, but I think that it was the 714 (intentionally) - albeit 6 years ago that I purchased it.

    RE: Catcams - That is the number that they came back to me with last year - I found toyota when I looked at it recently.

    I want it to look exactly like a Williams engine - IE - completely factory standard Williams One.

    So basically, the Megane Head is the better starting point, preferably with the Megane bottom end however, what would the visual difference be between them once on a car? Any pictures?

    If I can't use the megane head due to the visual differences, then I presume that I could use the chain driven bottom end with a Williams head.

    Intention is to use the standard inlet.

    What is the machining required - before & after for the dizzy fit?

    Let me talk to the mad danish man, and see what he thinks can be done. I am chatting to someone else about the options on management too, but will have to see how that goes - as he will likely come back to me with Sodemo or Motec. I am imagining that due to everything inside the car being manual (Guages / Speedo etc, that running Motec or Sodemo for the engine will not be too much of a problem, but to have it all plumbed into the standard fittings & sensors / connectors. Motec will likely require a trigger wheel I think.

  4. #4
    For the Motec & most others you just use the megane flywheel instead, none of that trigger wheel nonsense required

    The machining is pretty simple for someone in the know, it's a case of making a hole that's already there a little bit bigger so the dizzy fits, there's tapped holes already there so the dizzy bolts straight on.

    Unfortunately the visial difference between the 2 heads is pretty big so might not be an option for you, I've got the manifolds in the garage so I'll dig out a pic for you so you can see the differences

    As for using the 714 bottom end, it wont be an issue as others have done it successfully it's just a few different bits & bobs in the bottom end gasket sets to accommodate the different pump setup afaik

    Ignore the itb's & yellow but this is what the meggy cam cover looks like




  5. #5
    FFS - I tried to reply 3 times.

    Thanks mate - appreciated.

    Difference is pretty vast isn't it. I got a megane fly just in case of a rainy day when there isn't a spare loom floating about and I need to "make the change".

    Do you have a bottom end build list for the parts (bearings, shells etc) on that F7R 714, and is it the same for the 710?

    /y0z

  6. #6
    Not got a list unfortunately but afaik the list of parts to rebuild the 710 bottom end will be exactly the same as the williams, 714 should be the same for shells & bearings etc just different gaskets & seals

  7. #7
    I've just been through dialogys for this
    Big end shells are the same part number for the 700, 710 and 714 77 11 130 061
    The crank & main bearings are the same for the 710 & 714 Bearings: 77 01 478 839 or 77 01 466 537

  8. #8
    Paddy +Karma.

    Appreciated fella.

    There will likely be more questions

    /y0z2a

  9. #9
    Final question today - are the Williams Cam covers machined as a pair with the head, or are the covers inter-changable, as I have a powder-coated cam and cambelt cover.

  10. #10
    Quote Originally Posted by y0z2a View Post

    There will likely be more questions

    /y0z2a
    I'm on 12 hour night shifts atm so should work quite well with the time differences

    As for your final question, this is the result of mis matched cam carriers






    The shape of high comp pistons was the only saving grace for me as the valves hit perfectly square on & weren't able to dog in and break off to cause more damage.

    They are machined together but I think the more critical thing is that they wear together evenly & on mine the carriers were unknown if they matched or not as the head came with some valver carriers as well (I used that as a reference for the machining place that machined the head for the dizzy) so although it's speculation, albeit it from some people much cleverer than me, it's thought that the cause of my failure was uneven wear between the 2 surfaces that the locating ring on the end of the exhaust cam sits in, weren't evenly worn eventually leading to the cam nipping up at 100+mph & turning the head into expensive scrap
    Last edited by 16v_paddy; 23-06-2015 at 01:38.


 

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