Don Terrill’s Speed-Talk

Here is a picture of the torque-cone inserts: http://images.motorcycle-superstore.com/ProductImages/OG/0000-Kuryakyn-Torque-Cones---.jpg When I got my bike it came with on in the box of spare parts. Never even thought about trying it - I built a pipe to PipeMax specs which has a smaller 1st primary....

As for the compression, as of next year (2014), compression is going to be restricted to 15.1 on SIR motors in SCCA racing, but that's another topic. Regardless, let's steer this back to Kyle's issues with mixture. Just thought it was interesting that Mike also said to think of the motor as a runnin...

Bill, Here is a Mike Jones (camking) post about an engine restricted via a SIR: With computer controled timing and fuel, you can design the engine to turn much higher then the restriction. You need to go as high as possible on the compression ratio(16+:1, if you can get it). Don't look at it as a re...

Madbill, I get your reasoning on "choke point" and the increasing enrichment at successively higher RPMs, with ultimate enrichment when the SIR goes sonic. Since the rules mandate a restriction BEFORE the carburetor bellmouth, would there be any benefit to using a 25mm venturi in the carb...

Perhaps the biggest issue with such a wrong-headed rule would be if the car had to compete against similar vehicles equipped with EFI. Bill, He does and there is no weight penalty or SIR size change for EFI vs carb. t is likely that you would benefit from putting the 25mm restriction between the ca...

Just to be absolutely clear, you have a plenum feeding the carbs and it in turn gets its air through a single 25 mm orifice? I'm not Kyle, but I am friends with him and know the ruleset he has to run under. It is a 25mm SIR that feeds into a sealed plenum. They have to perform a 'stall test' per ru...

I remember when this site was dominated by professionals and every thread was a gold mine of information. As time as went on, it's gotten less so- mostly because a lot has already been said, but people are still developing engines so there should be something to be said. Erland, MadBill, BigJoe, Joh...

This was posted on a different forum: http://www.youtube.com/watch?v=xbB1qwhKaaE The pattern making starting around 28 minutes in is really neat. Real craftsmen. With today's methods they could build an equivalent pattern to far closer tolerances in about 10% of the time required by the band-saw an...

This was posted on a different forum: http://www.youtube.com/watch?v=xbB1qwhKaaE The pattern making starting around 28 minutes in is really neat. Real craftsmen. Here is part two of that video. http://www.youtube.com/watch?v=gqfVAGOaGEc I believe these videos were not about Duckworths V8 that I pos...

This was posted on a different forum: http://www.youtube.com/watch?v=xbB1qwhKaaE

The pattern making starting around 28 minutes in is really neat. Real craftsmen.

Something to add, There aren't a whole lot in the ways in purses in road racing. There are contingencies, if you're fast (usually a free set of tires). Probably no different than it is in circle track. Politics, like in any series, are strong. SCCA has a reputation for a lot of politics. Being a mem...

It's possible, even likely, that a check valve leading to atmosphere will create a higher vacuum than would the exhaust. It sounds though that you just want to use the exhaust regardless, in which case have at it. BUT if what you care about is the benefits of crankcase vacuum, a crankcase check val...

MODNROD, Thanks, those look interesting. The Yamaha SR/XT/TT 500 is a bit of a hybrid dry sump set-up, with the top tube of the frame holding oil. On flattrack 'framers' the oil is held in a tank behind the motor. The valve cover is vented into the top tube of the frame, while the crankcase is vente...

BigBro74 wrote:is it a splash oil -like a 5 horse? would wonder about how it might affect this oiliing setup.

536cc single running to about 7500rpm with roller bearings on the crank and big end of the connecting rod.

Thanks Bill. Just curious is all.

It's been hashed out on this site on the importance of pulling crankcase vacuum on multiple cylinder engines. If not through vacuum pumps or dry sumps, through exhaust breathers. I think the best method with exhaust system set-ups was to center it in the middle of the collector. So what about single...