The V8 Owners Forum -

Because the crank has a component of the piston mass considered to rotate with it ie acting on the crank pin, as well as the 'bottom half' of the conrod. The calculation is 100% of rotating mass(big rod ends and rod bearings)+ 50% of reciprocating mass(pistons,pins,locks and rod small end) per cylin...

That's not correct. Will the crank balance be affected - yes it will, when manufactured the crank was balanced taking a nominal piston mass into account. Does it NEED to be re-balanced. Not necessarily, a few grams of valve relief probably won't be noticeable but if you were building a race engine y...

If as you say all 9.35cr 3.9 engines have the same pistons So an early 3.9 with 9.35cr with 14 bolt (36 cc heads )with standard factory fitted tin 4cc head gaskets and 23 cc pistons ,will have a gap above the piston including the dish of the piston of 63 cc agreed ? But the later 3.9 9.35cr engine ...

stevieturbo wrote:
Sweeping statement.
You dont need....it all depends on the build, the application, the tuning.

Well true, but I was kind of assuming you wouldn't go to all the trouble of a twin turbo build unless you were going for some extreme power - turns out he's not . . .

So, your second combination has a total compressed volume LESS than the standard 3.9 9.35:1 set up (your first example). CR is compressed volume divided by swept (+ compressed) volume. Your second example therefore has a HIGHER CR than the std 9.35:1 (your first) set up. Something over 10.6 : 1 with...

No, if they both small pin crank then they are completely identical with 23cc (?) piston volume. 28cc head plus thick (8cc) gasket is the same total as 32cc plus thin tin (4cc) gasket. Piston volume (plus dead volume at TDC) and swept volume are the same for both - hence both then end up as 9.35:1 (...

28cc plus composite gasket has the same total volume as 36cc plus tin gasket. You cant easily use 36cc plus composite to increase the total 'head' volume because your inlet manifold won't fit very well. - it won't be 'wide' enough.

I know the heads are a bigger cc so 3.5 and 3.9 heads are exactly the same and are interchangeable. The compression ration differences in RV8s come from differences in piston bowl volumes between high comp and low comp and for the different engine capacities. The only change in head bowl volume com...

sidecar wrote: don't like the idea of just using the thrust created by the oil pump to control the end float of the cam.

Corrected that for you. Don't disagree with your sentiment though.

What wrong with Chesman Engineering. Pretty sure they do a 96mm top hat block mod.

They normally are quoted at 0.050 lift but it doesn't really matter does it ?

You won't time against start and end of lift in anycase - it's more normal, and considerably more accurate to time at a small (nominal) angle before and after peak in order to locate max lift.

The easy answer is, yes, they are (but not X308 onward, that is altogether different - non 4HA/HU based).

Things get a little more complicated if you want to use the gears (input shaft particularly) because of the long input pinion spigot most of them have.

the water pump on the SD1 covers is crap AND hard to obtain, is this correct? No, on both counts I think. It has a longer nose which may or may not cause you an issue - done so that the viscous fan ended up close to the radiator in the relatively long nose of an SD1. The pulley is different - think...

yes, but . . . you'll also need sump and oil pick up pipe to match from a non X bolt engine (sump front bolt pattern is different), cam swap to one that will take a distributor drive, a spacer to take up the extra length of cranknose that will poke through th old P6 crank pulley which you have to re...

In the sump. Baulk oil temp is what you are interested in. You can't do much about the temperature rise caused by it going through the pump or whatever. Your best solution is to control the temp of the oil going into the engine and your best indicator of whether a cooler will be beneficial is the te...