Second race as a combined group

[John Kwong]

Observations:

This class is looking really good this year. I think we had 13 for this event.
Clockwise is always prone to having more contact on the first lap. The bus stop chicane seems to be a real pinch point and because we are all so close together it seems to be the main culprit of accidents. I hope in future races when we run this direction that more room is given so that we can all get through there. I know in the Final, I had Tony on the inside of me but even though I was slightly ahead I still gave him racing room. Unfortunately, there was someone on the inside of him and I heard the inevitable screaching and bumping bodywork.
That headwind made for some interesting conditions and drafting.
My Clone after 8 or so races now will be getting new valve springs and tune-up. It was making all the right noises and rpm but didn't have any power. Hopefully, this is the fix as it was lonely watching the front four duke it out. Still fun though.

If any of you have questions on set-up, let me know and I will try to help out.

John K

[Dave Barlass]

One bit of tuning that seemed to really help the Hondas was lapping the valves every 3 or 4 hrs. Even with the G200 springs the valves tend to float above 6K. (it is hard to find anyone that sells fine lapping compound anymore!)
And we changed valve springs after an hour on track. Bought them by the bag. Compare free length between used and new ones and you would see 3 or 4 mm difference. They don't like heat and all that revving.
Did you check your timing? Just hook up a timining gun and a car battery and calculate the distance along the flywheel from TDC. Looking for 31 degrees advance. That door stop (ie. my seized clone engine ) I dropped off has an 8* key in it and that should get you to 31* from stock.

The LO206 performed very well. Right out of the box, didn't even adjust the valves. Just changed the oil.
Interesting to watch the rev limiter cut in on the Mychron data but only at the end of the straight. Lose some here but gain more elsewhere with lower gearing. Engine seems to have a broad power range which helps.

Looking forward to the next race!

[John Kwong]

Jack looked good out there. He and Max had a good battle as they reeled me in. I think it is great to have the younger drivers in the class to show its mass appeal.

In retrospect, I knew I was on borrowed time with the valve springs but wanted to see what would happen by doing nothing other than changing the oil. Oh well, time for some minor maintenance.

John K

[Maxxxi]

Out of curiosity what kind of vavle springs should I be looking for as I will need some before the next race I attend as I'll be doing T&T over the next month and a bit as I work on the next race weekends.

Going to look for a Mycron or Alfano so I can do some tuning and see if I can make up a little more time with some tuning of the chassis and motor. Maybe get closer to the front in the qualifying so when I do finish my third rookie race I'll be able to start closer to the front. Although starting at the back does make it lots of fun battling the way to the front.

[Mark]

Is there not a race-specific spring out there ? Seems silly to be replacing springs every few races. It would be worthwhile to pay more for a set that would last at least a 10-race season with practice...so what's that, maybe 15-20 hours ? Not a lot !

[John Kwong]

For the clone we have mandated the Honda G200 valve spring - part number: 14751-883-000

Locally at Action Engines they are about $5.50 each. If you buy them in bulk on Ebay they are much cheaper: http://cgi.ebay.ca/ws/eBayISAPI.dll?Vie ... :MEWAX:VRI

EDIT: This ebay seller's auction has ended but I did buy 30 valve springs from him. Let me know what you need and I will sell them individually.

I got 7 good races out of my springs. It was the 8th race that they went limp.

John K

[Dave Barlass]

These springs are designed for 2500 rpm and lower operating temps.
One way to extend their life is to have them cryogenically treated and you can get a bag of them done for a few dollars as part of someone's larger order(have done this for my F2000). Might be the answer for longer races such as the enduro.
But they are relatively cheap and it takes only a few minutes to change them out.

The exhaust spring is the most important. During compression and exhaust strokes the valves are helped by ...compression..to seal but on the intake stroke the negative pressure (Ie. suction) works against the exhaust spring. The exhaust valve may not close as crisply and this apparently interferes with exhaust gas flow. Some engine builders shim the exhaust spring to produce a little more effective spring pressure. But not too much as there is plenty of data to show that the increased friction against the cam by the follower begins to have a negative effect on power. Never mind wearing the lobes off the cam.
But heh, if you are going to spend $2,000 on a lawn mower engine.....

[Mark]

I got 7 good races out of my springs. It was the 8th race that they went limp.
John K

Oh. Well that's pretty decent; I thought they were only lasting a couple of races. 7 race days is about 5 hours -not a stellar number but good enough for an enduro.

[robkozakowski]

Just wondering - what are you guys running for max rpm's on the clones?

[John Kwong]

Hi Rob,

About 6100 and the valves start to float.

John K