Rebuild F4R-774 engine

Discussion in 'Megane Projects' started by maece82, Aug 5, 2022.

  1. maece82

    maece82 RSM Club Member

    I'm going to rebuild a spare F4R-774 engine for my Mégane 2 RS, MY 2006, as the OEM engine is getting near to 300'000 km.

    Spare engine got sourced from a dutch car wrecker, 3 years ago, and luckily it's in quite proper condition, with not too many km's on the clock... they told me something around 70'000 km...

    Head is off at the moment and the bottom end will get dismantled as soon as possible to check if rebore/honing is necessary or not.

    My aim is to get a proper/durable engine, with at least 225 standard PS :-)
    So, no big power gains expected.

    Already purchased tools/parts:

    - OEM cam belt set-up/locking tools

    - All new sealings for head and bottom -> Victor Reinz
    - New head bolts -> Victor Reinz
    - New OEM injectors
    - Beru coils

    Parts going to purchase:

    - new oil pump and chain drive
    - new cam belt set
    - new water pump
    - OEM bearing shells
    - OEM Mégane 250 pistons, if no rebore needed
    - Wössner pistons, if rebore needed
    - PEC rods
    - OEM Mégane 225 turbo

    Any hint on needed parts really appreciated!

    Many thanks

    As it arrived:
  2. maece82

    maece82 RSM Club Member

    Mostly stripped
  3. maece82

    maece82 RSM Club Member

    Prior to belt removal

    Unfortunately inlet cam jumped a teeth during first try to get central nut undone due to locking tool not torqued enough...numpty me, piston 1 was still at TDC...hence inlet valves cylinder 1 touched piston :-(
  4. maece82

    maece82 RSM Club Member

    DIY locking tool
  5. maece82

    maece82 RSM Club Member

    All valves removed

    Waiting to get the ordered valve stem seal pliers delivered to remove valve stem seals.
    Lead times are a bit scarry these times...nothing in stock:-(
  6. maece82

    maece82 RSM Club Member

    All edges (exepct bearing journals and fire ring areas) slightly deburred with a small file and gave it a first clean with oven cleaner and a lot of water.

    Clean and even fire ring areas, without indents
  7. maece82

    maece82 RSM Club Member

    Immaculate bearing journals
  8. maece82

    maece82 RSM Club Member

    As there is no know history for this engine, I really want to replace all valves.

    My plan are Supertech inlet and exhaust valves (steel version, not inconel).
    Does anybody have installed Supertech valves recently and could tell me if new springs and collets are needed too or not?
    Single Catcam valve springs might be an option then, I think...?
    OEM cams getting reused!!!

    Valve seat cutting shouldn't be needed, right?
    Lapping new valves in should be enough... I hope...

    Renault manual mentions something about measurement of the old stem seal location and place the new one on same height. Isn't it possible to simply remove old stem seal and knock back in a new one later then?

    New INA/Schaeffler tappets are on the shopping list as well.
  9. Personally i wouldn't use PEC rods, it would be better going for Catcam rods.
    Also i would use King bearings.
    Wosner pistons had a problem a year or so ago, not sure if they have sorted the issue.
    Get your injectors cleaned and flow checked this will save you some money.

    Also i wouldn't bother with 250 pistons unless there second hand ones as new ones are more expensive than forged pistons.

    If you want to future proof the engine, then Supertec valves and springs or Catcam springs.
  10. I have fitted Supertec valves to all my engine builds, you only need collet (keepers) for the exhaust valves on Mk3 engines, Mk2 you can use the ones you take out.
    I would change the springs as a matter of course, the originals aren't that strong go for either Catcam ones or Supertec's own.
    if the valve seats are cut then you will need to reduce the valve length the same amount you have cut from the seat, so best just to lightly lap them in.

    Valve stem seals just push over the valve guides, it would be well worth getting the valve guides checked or just replace them, think last time i did mine there £90 a set, you best send it to a engineering company to do this as the head needs to be heated to get the old ones out and fit the new ones.
  11. Ive never replaced any of the tappets on any of my builds.
  12. Interesting. I thought my meg was the only one with more than 300,000km

    IMG_0476.jpeg IMG_0483.jpeg IMG_0488.jpeg IMG_0476.jpeg

    These aren't old pictures.
    Desperately in need of engine renovation.
  13. maece82

    maece82 RSM Club Member

    Thanks a lot for all your advice...really appreciated!

    Nice to hear Super Tech valves are the way to go, with Cat Cam single springs.

    Pistonwise there seems to be a Woessner oversize option only:-(...I'm going to check the appearance of the bores as they are right now...if rebore is needed or not really..
  14. maece82

    maece82 RSM Club Member

    Hehe, it looks like these engines might be good for some km...:-)

    Belt should get done on my car...5.5 years...but only a bit more then 100'000 km since last belt replacement.

    Power and noise aren't on OEM level anymore...power a bit less and strange sounds quite a bite more...:-/
  15. maece82

    maece82 RSM Club Member

    I'm waiting to get bottom end dismantled and decide what to do next
  16. I don't know. I just can't sell that car. He's been with me since day one. I drive it every day. He spent himself through fuel. I mean, he spent more money on fuel than his value when he was bought as new. 308000 km . Sorry for my English
    It's very hard for me to get all the parts for rehab. There's no corrosion anywhere. I kept everything to standard. No modifications to the engine. I only put another exhaust on it. (Blueflame). New turbo for mk3. And airtec intercoler. That damn noisy exhaust is stupid . I bought a new and original Renault back box and and I intend to bring all that back to standard. I was able to find a practically new catalyst. When I do the engine, I'll try to pull out at least 280 hp. I believe it's the maximum because of the exhaust restrictions.

    I follow your engine rebuild closely and expect a lot of details. :sunglasses:

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