I have not been active in these forums for quite a while now. The reason is that my 3.9 RV8 broke down (again) and I just got a bit sick of it. So I put aside my SD1 in a shed and, after my girlfriend had nagged at me for 2-3 years to scrap the car, I broke up with her and took my Rover out again.
The engine went to my trusty machine shop to put a diagnosis on the problem it was having. Symptoms were loss of power and a valley gasket that was arched out by about an inch. Turned out that the pistons are too small for the bore. So I thought "Well, that sounds familiar" and went on searching what I had written on this board quite a few years back.
http://www.v8forum.co.uk/forum/viewtopi ... sc&start=0Vulture wrote: My guess is that the machine shop where I had the engine rebuilt and honed should have used oversize pistons but didn't.
It is not the same shop where my engine is at the moment, by the way.
So my initial plan was to rebuild the 3.9er once more, with oversize pistons. But a 4.4 liter engine turned up on ebay last weekend and I just had to have it, so after a bit of haggling I bought it. Here's what I know about it:
- built by John Eales and run about 6000 miles in a Ford Escort, then stored away
- based on a 3.9 block (94 mm bore) with a reground "Iceberg" crank to give 80mm of stroke, for a total of 4441 ccm
- standard size Omega pistons with valve cut-outs, 10.25:1 CR (using a thicker composite gasket, according to seller)
- lightened and balanced, but otherwise standard, con rods
- stud girdle
I am planning to use the gear from my old 3.9 on it, that is:
- RPi Engineering Stage 3 Heads
- Piper 285 camshaft
- Weber/Edelbrock 500 carb
Additionally, I was going to buy Rhoads lifters, as the 285 cam is supposed to deliver power up to 6500 and the original lifters won't allow that kind of revs. Am I correct in assuming that the bottom end should be strong enough for these rpm ranges? It was previously fitted with a Crane 256 cam with solid lifters, which I think shifts the power curve up even further.
Would using a thinner head gasket (or two of them, even, one on the left bank and one on the right) give me a higher compression rate? Or is this too risky for the valves to hit the cylinders, despite the cut-outs?
My carb is currently fitted with the needles and jets suitable for the 3.9. Is it safe to install "as is" or should I change those? And if so, where do I start?
I was going to use my bog standard (though well-maintained) ignition. This is one of the components that I always plan on upgrading "later". Is it advisable to use the same plugs as on a standard Vitesse engine?
Any other thoughts/suggestions I might not have considered?
