Heenan Froude G4.... - .................How fast?

[BCjohnny]

Posted this on another site with little luck...

I have a froude G4 (early alum case type) that has a 350bhp/6000rpm rating. The year after they went to an iron case (external...the absorber remained the same) and re-rated to 600bhp/6000rpm. A Froude engineer said mine will do 600bhp as well (apparantly the 350bhp early rating has more to do with the prime mover they had to hand at the time......).

This dyno was also available as "GB4" spec, the "B" standing for Bronze internals (pump impeller, rotor & stators) and had oil mist bearings. This was rated at 1000bhp/10000rpm.

I don't really want to convert mine to full GB spec (though the conversion parts I saw consisted only of the main power absorbing rotor) and have been told that the std internals are good to 8000rpm, if I just go with the oil mist bearings (all ordinary G4's are grease filled).

Does anyone have first hand knowledge/experience of the above? I'd rather not grenade it (it's having a full rebuild prior to commisioning anyway). The pump vanes look a bit weedy to me.

Cheers John.