Mr Cox

The head is recesssed into the liner in the TT07, unlike the Norvel ones, so it is not a drop in but they could maybe be machined down....

Mr Cox

Just thought I ought to give an update on my engine. Power was fine with the proper head, but rather shortlived. The crank to case was quite sloppy when new and mine is now worn out. I've used 25% castor and apart from some fuel draw problem (tank too low and touching the frame, those ARF stuff are a false shortcut) I can't really see why the case-bushing would wear out so quickly. Don't think that I've had much more than 1 liter through the engine in total...

combatpigg

My Feedback: (3)

Mr. COX, just a guess...there might be different grades of bushing material? If you combine that idea with a crank fit that is already loose before the parts get worked in andthere you go. I'm going to have to learn how to re-bush crankcases for a handful of worn out AP .061s.......when I can come up with a week of free time with nothing else better to do.

grassroots

Ihave an .074 norvel head, it will not work as the TT head is larger.

Mr Cox

It is not so much the size as the fact that the shape is completely different...!

Mr Cox

I've taken a foto of both heads together but I can't upload any picture...

One final attemt using netscape, Norvel head is to the left if it works...

jeffie8696

Got it, the TT head protrudes inside the cylinder liner. Hate that.

Pond Skipper

Published on Nov 19, 2017
Thunder Tiger GP-07 / Cox 6x3 Peak: 18,572 RPM .179hp / 134w / 21oz thrust / 53 mph pitch speed
Average 18,330 rpm / 20.5oz thrust / .172hp / 128.3w / 52 mph 25% nitro / 20% castor -

Published on Nov 19, 2017
TT GP-07 / APC 6x4 / 17,440 / 148w / .198hp / 18oz thrust / 66mph 25% nitro / 20% castor

Published on May 6, 2017
HQ 5x4.5 carbon / nylon prop 30% nitro / 20% castor Ran in about 2oz of fuel prior to test. 4 heat cycles to break in rich.
Best Static 19,864 / 12.1oz thrust / 85 mph / 118w / .16hp I would imagine it will hold 20k ish after a few more tanks.

aspeed

There is a necro bump to a long thread. Haven't heard from Jeffie or Combatpigg for a long time. I made a few turbo heads for the TT .07. They helped a fair bit. One of the three motors I got just would not go well at all. I soldered up the bearings to remove the slop and leaking which helped get a steadier run. How long? IDK. Two of them pretty much equalled the Norvel .074 with the turbo head and some tweaks I read about in another thread a while back.

ffkiwi

Aspeed-do I assume you kept the spigot depth and chamber shape the same as the standard glowplug head for your turbo head-or did you introduce some more variables with shape, clearance etc....a photo of both head inserts side by side would be useful....

ChrisM
'ffkiwi'

PS ..haven't we had this same discussion before recently-on the G-Mark 061.....?

aspeed

Funny, Mr. Cox coaxed me to copy the T Tiger bowl shape when I asked at the time, so it is just the same as the T Tiger. I made about a dozen blanks with that ball end mill with some varying ODs. I used one on the G Spot as is. I was going to use a countersink on the Gmark, but the c/sink did not clean up the existing radius. I use the same blank on the .10s and .15s but face the diameter a bit bigger with the same ball endmill (reshaped centre drill) Other existing heads seem to use the same radius like the blue head ASP .15, so I use it on most heads and just back the diameter up until the squish band looks about right. I have gone up to .25 size motors with the turbo heads. After a .21, they don't seem to gain much from what little experience I have. Kind of odd how much time I put into the TTiger .07 to finally get them working well, and I never even put them in a plane. They idle really well and run up pretty good. The carbs are not really suited for control line but that is OK.

aspeed

I'll show some old pics here that you may have seen already. It take me a half hour to load new pics and then I can't always find them again on the computer. There are three blanks. I made a .100" deep step at .500" diameter on all the blanks with the prepared thread. The other side is changed for each separate motor using a 1/2" collet. Most blanks I plunged down with the ball endmill that I made, but some I left with just the 3/16" hole.

top blank is the prepared thread and step, other two are semi prepared. The little one at the back might be for the TTiger or Gmark button style?


pretty much the setup for the second operation.

Pond Skipper

Such a long thread lots of input I wanted to add my vids proof of what I was getting out of the original stock versions. I own three
of them and find them to be clean running no fuss engines. I use an elect. starter and plenty of nitro, no need to hand flip these
with light weight props. These are the smallest displacements that have that traditional look of larger engines with a very nice
mini muffler keeps the noise down quite nicely. I may need to check the timing might try a tuned pipe with one just to see.
The TT GP .10 has 160 deg. the .07 may as well and if so would certainly benefit from the pipe use / cool factor / sound and
goo control.