Here are a few things I figured out while building Renault hemi's for my europa over the years. These are things that I came up with to solve many failures and I now have an engine that has lasted quite a while.....even under autocross and track use.
For what it's worth, my engines are 1796cc (largest you can go without staggering the liners). The last dyno showed 161hp at the wheels.
You would think that it would cost a fortune to build an engine like this but not really. I'll try to estimate costs with the info below, although it has been about ten years so...inflation rules.
1). The stock renault rods are ok, but not great. I use ESP H-beam rods that are intended for a Toyota MR2 turbo. They are lighter and really strong....meant to spin up to 11,000 rpm.....don't try this at home. About $400/set These rods have the same size lower end but a larger wrist pin (and are 1mm longer) so you will have to use custom pistons. Rods about $400/set
2). Custom pistons were around $400/set. Better pistons than are commercially available. Lots of suppliers out there. I am running about 12.5:1 compression and it runs perfectly....just needs a little boostane additive in the gas.
3). Because of my larger bore, I have my sleeves custom made. About $400/set I have Cometic make custom head gaskets for less than $100ea. They don't include the rubber piece so you have to buy a stock head gasket to get the rubber piece.
4). I created a dry sump system because I used a cast aluminum oil pan (with a flat bottom) and kept spinning rod bearing #2 from starving the oil pump in hard cornering. I don't regret it but, in retrospect, probably not necessary. The stock oil pan is a great design with the pump in lower section of the pan. Cost me about $2500 to put in dry sump but, as I said, really not necessary for most of you.
5). Use the high capacity oil pump. They are available but not sure of the cost. They will fit on any of these engines, even the non crossflow. It has a longer rotor and the difference is in the pump itself with a recess to accept the longer rotor. On these pumps, and the lower capacity ones, take out the cotterpin and shim the spring with about the thickness of a dime to increase oil pressure.
6). Have a pro go through your head for porting, spring tensions, etc. I have mine with larger valves. Go big or go home! No down side here....more flow=more power! This is the single most expensive thing easily costing $1000 or more.
7). Every time I build an engine, it is more than the previous version. And they still run flawlessly....idle perfectly, purr like a kitten. I can put my car in fifth gear at 35mph and put my foot on the floor and it doesn't skip a beat. I keep using more lift on my cams to no detriment. I currently have about 290mm cam lift!
. Some other goodies I have just to make you jealous....aluminum flywheel (currently running a 200mm clutch but am going to have a flywheel modified to accept a small multi-disc tilton clutch...fits right in with the original throwout bearing) Total clutch and flywheel weight around 7 lbs). Also, I made a batch of anodized roller rockers about 15 years ago...sold some, kept two...maybe some of you have them??
That's all I can think of off the top of my head but there is probably more.
Nick
