thunder tiger break in
 

Looking for lee von der hey's article on breaking in the thunder tiger pro 40.
Anybody have a link??

RE: thunder tiger break in
 

this is what I do ........get a 8x6 apc prop, run the engine RICH, but high rpm on this prop for around two minutes- then go and race. You'll have absolutely no trouble.......but I do use castor oil! trevor h:)nz

RE: thunder tiger break in
 

I have that write up on one of my computers. If I find it I'll post it later, but there's an excellent write up by Dubb Jett on his website that explains the correct methodology. The above post will work, but the time on the bench is insufficient. Here's Dubb's link:
[link=http://jettengineering.com/tech/breakin.html]Engine breakin[/link]
It's written for his engines, but the theory is applicable. There's more here (with less detail):
[link=http://www.darrolcady.com/Racing_Info/Tips-tech/tips-tech.html]Cady-Breakin[/link]
this one is directed towards Nelson's.

For a TT40 we're talking running in the 16,000 RPM range to 17,000 RPM on the test stand. Three cautions though. 1) Wear safety glasses 2) Wear ear protection and most importantly
3) Wear safety glasses!

SD
Here's the Lee Von Der Hey breakin procedure:

RE: thunder tiger break in
 

Hey... you forget the first part of Lee's article on how to race prepare a TT 40 prior to the first run. Course he did'nt ask for that either!

RE: thunder tiger break in
 

Dave, here's what I did for Gale Enstad's 1:27 and some change, TT Pro 40.

Mounted engine to the plane. Ran 1 tank with a 9x6 APC prop on the ground,,, rich-lean-rich-lean,,, etc.

Next tank full, I set the engine to a fast 4 cycle speed,,, I don t know what RPM it was because I don t use a Tach.

Launched the plane,,, climbed up HIGH,,, and dived for the ground. I did that several times.

Race needle setting was approx 1/4 back from peak rpms,,, the rest is H.O.F Racing History :D


BV

RE: thunder tiger break in
 

that is all you need to run in a TT- anything more than this in my mind is time wasting- if everything is made correct then all you are doing is running in the bigend( and that has good clearance) and cleansing the engine................but we all have our different ideas!
trevor h:)nz

RE: thunder tiger break in
 

How about Head Clearance on these babies???

RE: thunder tiger break in
 

never changed head clearance on a TT- you can get the same results by changing gloplugs in both length and heat range, trevor h;)nz

RE: thunder tiger break in
 

Dave, the engine came straight out of the box and onto the plane. Plugs used were the MC-9.


BV

RE: thunder tiger break in
 

Yeh, but what RPM's are you turning? Of my 5 they turn from 16,600 (worst) to 17,400 on a APC 9x6 and 15% PM fuel. I had one that turned 17,800 but it threw a rod and trashed the cylinder.

I did some messing with head clearance and found that the factory setting is fine. Any shims I tried either resulted in the same RPM or less RPM.

Sorry but, this is not true. You're not "cleansing" the engine. You're honing the various ABC metals at the expansion and temperature ranges where the engine will be expected to operate. Several engine manufacturer's disagree with you and running the engine too cool will ruin the piston/cylinder fit.

From K&B:
Although breaking in an engine in the air maybe ok, you can better control the process on a test stand for the first few tanks and then taking to the air.

SD

RE: thunder tiger break in
 

of course they are allowed to disagree with me.......thats fine, but you miss a very important point- read #2 and I do say 'high rpm and rich'. Refer also to my prop diameter, smaller than flying propeller, we have to get the heat up very quickly for expansion of the liner.
Contrary to your commets I believe a fair amount of cleansing does occur at the initial running, anything offensive left in the engine at time of manufacture will be tossed out the exhaust port in a similar way to the gloplug element disappearing- have you ever found one inside your engine, coz I certainly haven't! I use enya #3 plugs................ trevor h[:@]nz

RE: thunder tiger break in
 

I prefer to do my engine cleansing of new engines by disassembly, washing with a solvent, and inspection prior to running rather than hoping any Chinese machining residue will blow out by turning high RPM on the first run. I at least remove the head and back plate of any engine prior to the first run.

I used to replace the C clips and Lock Tite the wrist pins to prevent wear at the piston and wrist pin, but TT has evidently fixed that problem long ago so it is a waste of time.

My purpose here is to present an answer to the original post and to provide the theory behind the current state-of-the-art methodology and thinking behind the theory's of getting more performance out of an ABC racing engine.

It would be interesting to hear what RPM's various TT 40 Pro's are turning and what the original break-in procedure was. I have always followed fairly closely the Van Der Hey procedure and run at least 3 tanks of fuel on the test stand. I do notice that after that it takes a gallon or more of fuel in the air flying before the engine really reaches it's best.

As an aside, I have done some testing with a new bag of 9x6 APC props all on the same day and fuel etc. The results were that the RPM could vary from prop to prop by as much as 400 RPM.
Because of this I have one prop that I have labeled with a marker "test" and I use it only for RPM testing so that I can get a fair assessment of the ranking of my 5 engines.

And other questions to consider, what effect does balancing an APC have on the RPM turned? Anybody done some actual testing, unbalanced and then balanced? How do you balance a prop? Do you go as far as the hub balance 90 deg. relative to the blades? Is there an effect if the nose and mount are not stiff enough from vibration? Do you blunt the prop leading or trailing edges or blunt one sharpen the other?

SD