Tach Race 2012...The Wrap Up...and Class Photo !

Yeah it is an oddly nice feeling to trust someone and just trust and not once think about them doing a runner with your engines but that is the great thing about this group of people here.
trust makes us.

nitroairplane wrote:Yeah it is an oddly nice feeling to trust someone and just trust and not once think about them doing a runner with your engines but that is the great thing about this group of people here.
trust makes us.

You know, normally I am very untrusting. I have only been a member of this forum for a few months. However, with this bunch I would trust my engines with just about anyone.

Same with me.

Hi Guys,

That was most certainly a GREAT event & I really want to thank Kim for
volunteering his time & effort on our behalf. THANK-YOU KIM! I have an AMA
national racing champ friend who wouldn't think to send his "good motor" to
somebody off in cyberspace. He figures the guy might swap your engine parts...!

I figure "falling in love" with your motor eventually will lead to being very serious
& along with that, seriously frustrated. I'm glad Kim enjoyed it. If this event EVER
becomes "LIKE WORK", then the fun will be lost. I hope that never happens...

Several entrants (me included) engines didn't quite perform up to expectation,
so the question is why? Well there are several reasons.
I think Chris's "Blue Mouser" has developed an internal flaw. Kim couldn't keep
it running very well & this certainly is indicative of either a fuel feeding
problem and or a reed problem. Wheather it's damage or dirt is hard to say
without a disasembly. I hope Chris can tell us... I think one can be way off on
the head shimming & still never drop 4,000 rpm, especially with a TD plug which
is very forgiving in that regard.

My meagre testing seemed to indicate that the lower nitro fuel & slightly
heavier prop load lowered my top rpm's by perhaps 1,000 or so. I say about a
thousand because I often turn over 20,000 & under these conditions, none
of my engines would even reach 20,000. 19,000+ was all I could get. But since
everything ran steady (more or less) I figured everybody would be in the same
boat & their RPM's would be down accordingly (and they were).

I think reliability has increased for me because I often disassemble my
engine(s) after every 15 minutes of high speed running. I don't think I find
much other than a lose ball-socket & maybe some carbon varnish on the piston &
cylinder. (none of which cause massive RPM loss by the way) Coxes can be fickle
that way...& there isn't a man alive who haven't been stumped at one time or
another by these rascals!

At home, my own unlimited motor certainly turned up nearly the same as my mouse
motor. I thought the crankcase/shaft (taken from my junk box)was a bit dodgy &
wouldn't have been surprised if it broke. As it turned out, it's just pretty
loose (and slow). It also has a Galbreath head which is VERY sensitive to head
shimming & so it's not unusal to see 1,000 RPM come & go IF the shimming is even
off by one shim. So, I can understand it being slower than expected although I
was a bit surprised...
I think weather can account for a much as 1,000 RPM drop from sea level
(California!) ideal conditions, but certainly not more than that. In fact, I'd
say less in this particular Missouri location.

Win some...lose some. Regardless it's all GREAT FUN! Thanks to ALL who took
part. Sure was exciting for me back here in -40C weather!

Cheers,Paul

I broke mine in and ran it with 24%. It would not even pop with 35%, and the threads in the crankshaft were off center.

Needless to say, I'm happy with the results.

By the way... going over the rules, I do not see anything saying this is an .049 race. I think I see an engine that looks like an .051.

MFD,

Huh, I never considered that. As far as I have known, there's no performance difference between

the #4 and #5 piston/cylinder sets. Of course I say that because I used the #5 set on my engine.

I'm pretty sure I included this info in the engine description I sent Kim. I used #5 for the old style twin

boost ports on each side. Probably could have done better if I played with cylinder and head shims

before I sent it in. I'm not being defensive, just thought I'd let everyone know.

Responses appreciated,

Bob

Not sure there is a whole lot of performance difference between the two, maybe next year the rules could be revised one way or another. Running a hot .049 against an .051 sounds fair to me.

I have been following the Tach Race since the first post about it. I would have sent in my Venom clone but my Killer Bee cylinder and piston was being used by a friend at that time for some winter competition up north. The Tach Race seems fun, I'll have to try to get a engine in it next time! Everyone's engines look awesome! Thanks to Kim for his effort and thanks to everyone who took part in it!

Matt's (exmodelengines) engine looks like it has one exhaust slit lowered/enlarged for SPI - was that for .051's only?

microflitedude wrote:Matt's (exmodelengines) engine looks like it has one exhaust slit lowered/enlarged for SPI - was that for .051's only?

No, it is a Killer Bee cylinder. They were used on both the Killer Bee .051s and Pre-2002 Killer Bee .049s. He could have lowered the port himself, its not very hard to do.




(You can see the lowered exhaust port, Venom Clone .049. This was taken after I got the cylinder and piston assembly back, he somewhat wore it out. I don't think he wrapped the hand warmer around the cylinder like I told him to for 10-20 minutes before starting it.)

Admin wrote:

microflitedude wrote:Matt's (exmodelengines) engine looks like it has one exhaust slit lowered/enlarged for SPI - was that for .051's only?

No, it is a Killer Bee cylinder. They were used on both the Killer Bee .051s and Pre-2002 Killer Bee .049s. He could have lowered the port himself, its not very hard to do.

Ok, makes sense.

.

Just out of curiousity did Indra's engines ever get run? I would be interested in seeing the numbers, that way I know what I am up against next time.

cribbs74 wrote:Just out of curiousity did Indra's engines ever get run? I would be interested in seeing the numbers, that way I know what I am up against next time.

Not yet but I believe they will be.