reno808

thats pretty damn good

reno808

hence why i dont run covers

951Saga

WOW Sid, you've joined Laust with this most intelligent feature. Are their any down sides to this option? Is the CR same as stock?

333pg333

This one is not a stock motor. If yours breaks you will have damage.

Droops83

Because if the compression ratio of a modern high-revving motorcycle engine were lowered enough to the point of making it a non-interference engine, it would be a turd! I have not seen the insides of a Ducati engine, but I would be willing to bet that there are already valve reliefs cut into the tops of the pistons.

The 951, being a low-compression '80s turbo engine, has enough of a dish in the piston to the point that it is barely an interference engine. I have had 2 different customers luck out in that their 951 timing belts broke at a low enough RPM to prevent and bent valves. All we had to do was replace the belts/rollers and they were back on the road. Most haven't been so lucky, and if the breakage happens at higher RPMs you are guaranteed to bend valves. The higher-compression 944 NA engines will bend valves even if the belt breaks on startup.

I know that it is possible to have a strange parts failure, but the best we can do is keep on top of timing belt maintenance and replace the rollers/tensioner parts as necessary every time, no matter what engine we are talking about.

ausgeflippt951

Sid -- do you know if Refresh's motor (which used your design) is also non-interference? I seem to recall your build had some extra goodies from a machining standpoint; not sure if Refresh's motor also had some of that fun stuff.

refresh951

My motor is not a non-interference design but it can be done pretty easily. I just did not do it for scheduling reasons. My pistons would require minor fly cutting to make it non-interference. I should have delayed and got this done.

Nice work Sid.

ausgeflippt951

Thanks for the info. With the fly cutting, what is the dip in the compression one can expect?

refresh951

A very, very small amount. The fly cuts would only be about 0.060" deep IIRC.

blown 944

Yeah mine is a litle different than Josh's. I took another route regarding piston deck height and I still have stock valve size too.

I am really glad I went this route as it makes a lot of power, can use an edgy tune, and now has passed the broken belt test.

I just ran it tonight and went 125-126 on crap radials with a headwind so it's still in fine shape

I love this engine more all the time....

I won't build an interference engine ever again.

Lightningmcnulty

Thats awesome, so when can we buy an engine from you?

URG8RB8

Very nice engineering work Sid! Many people feel that how much one knows makes him a genius, I feel it better illustrates what ones accomplishes with that learned knowledge!

blown 944

Whenever the check clears..

86 951 Driver

What is the average wait time on one of these engines?

blown 944

Takes me about a month to get them done once all parts are in my hands.