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 Marcel As it arrived:
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 :-(
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:-(
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
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.
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.
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.
Interesting. I thought my meg was the only one with more than 300,000km These aren't old pictures. Desperately in need of engine renovation.
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..
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...:-/
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.
Some progress done... "Hazet 791-8" valve stem pliers were perfectly suitable to remove old valve stem seals...30 min work with pleasure:-)
Engine bottom end mounted onto engine stand and ready to remove oil sump and all it's internals. For better handling by 2 persones and to get this bottom end strapped down properly in the back of my Mégane, a small laser part/welding construction got created.
No writing for a long time, but meanwhile, there was some progress. Complete bottom end is stripped down now and most of the parts got cleaned, sprayed with WD40 and then stored in various bags. Luckily, all crankshaft bearings are immaculate, wheras the main bearing shells show some signs of wear, but not severe at all
Inside the cast iron motor block, there were quite a lot of nasty burrs and casting residues. It took quite some time to carefully "dremel" off these burrs. Prior to doing this, I tried to block off all oilways with some small rags, to not collect a lot of grinding wheel sand/burr chips inside the hidden oil passages, waiting to spread all over the freshly rebuilt engine, during initial running-in period
Next is to wash/degrease/blow dry the motor block and get it properly protected against rust and oxidation, till reassembling might start. A thorough layer of WD40 might do this job... right...?
All 4 cylinder bores show no really obvious signs of severe wear/scratching. Beside the still good visible honing cross hatches, there are only some minor (I hope so...) "scratches" in the bore surfaces. I'm going to lend a proper bore gauge to measure bore diameter and its ovality. But I think according pictures below, these cylinder bores might be good enough for a daily-runner engine with not more than standard power expected. I mean it might be a good amount of money thrown away to dismantle all 4 oil spray nozzles, get it honed to first oversize diameter, buy new oversize pistons and install 4 new spray nozzles... I try to source some Megane 250 pistons/con rods and install them with new rings into these used cylinder bores. Might this be a doable route, or is this an absolute no-no in any kind of way??? In my opinion, some faffing arround with some kind of a Flexhone brush won't do any good to the used bore surface, if not even make it worse...or am I completely wrong and this could be done with oil spray nozzles still sitting in place??? Any hint/experienced feedback highly appreciated...
If the bore measures up and not worn/needing to go oversize, you could run a flex hone through to re establish a good cross hatch and fit the 250 pistons with new piston rings. Ive done a re ring on a 1.5dci k9k in situ. I took the head off, pistons and rods out, covered crank and covered oil squirter jets with a bit of cardboard and flex honed the cylinders. The cardboard protected the oil squirter jets ok from the flex hone and no issues doing it. Cross hatch was class and bore cleaned up mega and engine went from using 1ltr of oil per 400 miles to half a ltr over 8000 miles. Flex hones are very good if used right and leave a great cross hatch if the bore is not knackered, yours looks like it will deglaze fine with one. So yeah you can get away without removing the jets if your careful. A 3 legged hone tool wont be as kind and will prob damage the jets, but im not a fan of them anyway so wouldnt personally use that type of hone.
