Props and Questions

[Matt]

Some one has to worry about you!

[verytricky]

Originally posted by Jon Fuller
Agreed, without knowing this is accurate, everything else is pointless.

I have an optical/digital Tacho, accuracy +/- 1rpm, that aughta do.

Does this mean a test is in order?

[verytricky]

Prop guy has confirmed they are 28s early this morning. He said they have been 'worked', and 'thinned', and the 'cupping' is different from standard.

[Matt]

Apologies, just re-checked my sums and I got my 1.75 and 1.62's back to front. DOH! Assuming 10% slip throughout - in reality could be a bit either way - I would suspect a bit higher with the antifouling on.

With 1.62 gears, 28" props and 5100 rpm you'd see mid 70's.
With 1.75 gears, 28" props and 5100 rpm you'd see just under 70.

As you are seeing 82:
With 1.62 gears it suggests about 5560rpm
With 1.75 gears it suggests about 6000rpm

One way or another, it all points towards the rev counters telling porkies - would definately check them next before considering any drastic measures.

[Jon Fuller]

Originally posted by verytricky
Does this mean a test is in order?

Sounds like it, yeah!

[verytricky]

Also a speed test both ways to get the average high speed. If we are going to be doing this properly now, we should also have the correct GPS figures!