Don't go to your Renault garage - they are incredibly expensive. Instead go to your nearest engine reconditioners and they will order some for you. They will need the engine number as there are two types used. Have you removed the liners? If so you'll need some base gaskets. If not I hope you've secured them with bolts and washers to the block to prevent them from moving. You'll also need to de-glaze the liners with a glaze buster to allow the new rings to bed in.
The thing is that this Renault 4 engine that I have was mounted in my boat (a Weedo GT with an inboard engine based on R4 1108 cc, when used as marine engines they are called Mercruiser 60). Instead of 33 hp, this engine has 60 hp with double carburators.
The compression seems to be really low, I haven't yet had the possibility to measure the compression, but when I rotate the flywheel there is almost no resistance. Of course I need to open the cylinder head to see if the cylinders isn't worn out/damaged, but I need to see if I can ever find spare parts before and then get onto it.
I bought the boat and engine disassembled from each other, so I don't really know the status of the engine, just suspecting something bad.
If it's a basic 1100cc engine as fitted to the cars then you can get all the spares for the engine. However you first need to give it a proper compression check by spinning the engine with the starter, spark plugs removed and using a compression tester. The carb butterflies will need to be kept open during the test. Turning the engine by hand gives a false impression.
If, after the test, the compressions are low it's more likely to be the valves than the piston rings. However, it's worth checking the tappet clearances and if some are tight, adjust them and carry out another compression test before removing the head. If the engine is 1970's then it's designed to run on leaded petrol, but it can be converted. Let us know how you get on.
Can you post a picture of the twin carb set up? - I'm sure some of us would be interested in seeing what's fitted.
It's similar to the Renault 4 1108cc engine but not the same (we run 688-CIE engines), and in any case the year of manufacture for your engine would be late '60s, and the 1108 didn't find it's way into a R4 until the early '80s.
I'm not sure what changed over the life of the engine. Possible the engines in the Renault 8 or Renault 10 engines might be closer to your engine, but I can't find any engine types for these engines.
Steve's point about the valves - if the engine has been sitting for a long time there could be a little rust on the valve seats which loses the compression. This will normally clean itself off after a little running.
REALLY?????? But isn't that even harder to get spares for? Things like pistons and piston rings should be possible to find too? Where would I find such things?
Do you possibly know if there exists any oversized pistons, in case I ever have to bore the block?
With this boat I got two spare engines, one with modelnumber 688-30 and the other with unknown modelnumber. None of these are possible to rotate fully. One is stuck and the other goes ALMOST one lap. Possibly a broken valve since there are traces of loose metal in the 4th cylinder. I haven't opened the cylinder head but I looked using a lamp and I vacuumed the cylinder.
Hmmm... As far as I can see from http://en.wikipedia.org/wiki/Renault_8 it seems that the same block was tweaked to 90 hp (Renault 8 Gordini) instead of 50 hp (standard Renault 8). Any chance you know what they did to increase the horsepowers?
Do you intend to strip the engine anyway as part of your restoration? If you have never heard the engine running then it would be a wise move. Alternatively, could you rig up a fuel supply and a battery and 'bench test' it to see how it sounds?
If you decide to strip it then the main components you will need are shell bearings, piston rings and valves/springs. You cannot rebore these as these engines use wet liners and you have to buy piston and liner sets.
I would suggest that you email Gosnay's - these are a well established engine reconditioners and suppliers of parts based in Romford, Essex UK. Quote the engine number and kindly ask them what parts they can supply. They do have a website so Google this and take a look.
If the whole engine needs work the parts alone would be, at a guess, around £300 plus any machining required. If you want the head converted to unleaded that would be around £200. It is highly unlikely that the whole engine is messed up as they are very well built. If you do a bench test and there is no blue smoke coming from the exhaust and the oil pressure is good after it's hot, then just give it a head job!
Hmmm... I did some additional digging. Is it possible that this engine (the R8/R10 1108 cc engine) is the same type as the engines found in DAF 55, DAF 66 and DAF 66YA cars?
Ok, I know this is a Renault forum, but you never know...
It's certainly a Renault engine in the DAF, so if it's not exactly the same it should be interchangeable.
Actually there are a lot of variations on this engine that should fit. Pretty well any Renault made up until 1983 with an 1108cc, 1289cc or 1397cc engine fitted longitudinally should have much the same engine block. After 1983 the water pump moved to the other end of the engine.
I've picked up a 1397cc gordini engine from a Mk1 Renault 5 to fit in my Renault 4. It's rated at 93bhp (cross flow cylinder head and high compression).