jpayne wrote:
Still struggling to find a reasonable argument why USA dry sump systems are better than UK ones. lots of blank opinion but no hard and fast evidence or explanation
JP
I agree that the majority of pumps out of the US are better, and here is my explanation.
The major factor that leads to this assertion is the style of oil pump. Pretty much all US pumps use a spur gear/roots style pump/vaccum stage, where as pretty much all pommy pumps use a gerotor style stage. And before anyone has a whinge at that, yes there are exceptions, but this has generally been the rule for a long time.
There are pros and cons to each style but the roots style just moves more air/oil hands down, this makes it much better at creating vacuum and generally performing it's duties. The US pumps are also usually a bit bigger which also helps. Both these factors probably stem from the different styles of engines that pumps like these have been developed with (i.e big drag motors in the US)
The other factor is that when it comes to our motors the pommy options have typically only been from one of two options (titan/pace). I have taken quite a few pumps apart over the past few years and in my opinion, they are just not a particularly well built pump, the tolerances weren't that great, they leak more, the US pumps have O-rings in places the pommy ones don't etc etc, and you generally get AN fittings on US pumps and many pommy ones just have a large barb for a hose and hose clamp! even the Millington uses hoses and clamps on the scavenge stages! Out of all the high performance exquisitely engineered fitting solutions out there, this one baffles me. And yes I know sometimes the simplest solutions are the best. But go and look at any arena in the higher echelons of motorsport, and you won't find a single engine with it's dry sump lines held on with a hose clamp. There's a reason for this.
Without a doubt I have been left with the impression that pumps like Peterson/autoverdi(actually Swedish)/barnes etc were much better made.
Having said all that, The pace/titan options that we compare them all too have been around for a long time. I suspect there is a better quality of pump coming from some of these players now and they are starting to use the roots style stages too.
But like most things, there are many die hard opinions that were formed many years ago, and become less relevant as time goes by and things develop. But having said that, I'd still choose a pump from the US.
And for the record, I use a Dailey engineering pump. And it was custom built to my exact needs, with many custom features you wouldn't find anywhere else. And it's one of the best pumps i've seen.
Llew
peterson and pretty much all other mainstream US manufacturers have been making either spur or roots style for the best part of the last ten years!