Spy Photos - Gentlemen what think you?

Sirs

I keep my ear to ground when it comes to engines, and recently I found these pictures of a KTM 525.

Much shorter link

This much I know -

The eagle eyed among you will spot that the barrel is a 450 barrel but on a 525 bottom end. This is done so that a 100mm piston can be used without thinning the water jacket too much, the 450 being thicker than the 525. I think that this engine is 600-630cc I know that this size was run by a few teams last season, they all used the 450 barrel but with more or less adventurous strokes. The unusual amount of tappings are for an oil cooler.

What I really want to know, and hope you might enlighten me on is this why the hell are the rocker covers packed up by an inch? I'm puzzled, what do you think?

Ben
JBSracing

Ok here is a list of possibilities that I thought of and dismissed for one reason or other.

Does nothing (but then why do it, to create mystery, that’s not typically done in Sidecarcross)
Increases the volume of the head (but why do you want to do that)
Increases the clearance between the tappets and cover (but why by so much)
Holds a filter for the breather tubes (but why there its not a convenient place)
Houses a high speed non-return valve (but why there………..)
Houses long valves (but how do you get to the top of them with the rocker)
Has extension springs to relieve the valve springs of having to lift the weight of the rocker (may be, but I can’t see any fixings or how you would assemble it)
Houses a sensor of some sort, leads coming out through breather (but sensing what and why there, it seems a bit high tech to be measuring valve speed etc… this ain’t Formula 1)

Any ideas? Anyone!

People do indeed do weird things but this guy has a very fast and very reliable engine so what ever he does works. He didn't have the spacers last season thought. I wonder why you would want to put a filter in the head or if it to avoid oil loss why the pipes don't just go up to a higher spot on the bike then to the air box???

It is very interesting what you have said about the crate motors I did a little digging and found this site

http://www.ktmduke.de/rennmotor.pdf

It would appear that I have been given wrong info' by the guys running KTM's at the races. Looking at the .pdf they are KTM 610 RFS crate motors, and the barrel is a special barrel for that motor not a 450 sx as I have been told. I have never personal run a KTM 525 or developed one for anyone, but the guy I'm doing the Husaberg 750 for is interested in doing a 525 once the Bergs done. Needless to say our cc target is not even in the 600's, so if all goes well I may get to play with one of these one day.

Thanks for the thoughts and info'

Ben
JBSracing

I feel we may be getting warm

Many thanks Greg_in_Oz

Thats that one solved then

Hi Maichusa

You are right, I contacted KTM and they said that they are not selling the 610cc Crate Engine any longer.

I have seen a few guys running Sidecar 2-Stroke engines in Quads, i.e. Zabel 700cc lumps. I hope all goes well with the Husaberg 650cc Quad, if ever you want a bit more power I am just putting the finishing touches to my 750cc kit. I am almost there with it now, just waiting on a part from the USA (liner) which will be 5-6weeks

I will be posting a report on how it runs and power it knocks out here, hopefully by the end of March. I will them be selling the kits.

By the way thanks to Lineaweaver and Greg_In_Oz for the info' on KTM's and the high rocker cover mod. It looks like a KTM 525 might be one of my next victims, after the Husaberg.

Ben
JBSracing