thunder tiger 10 conversion headaches
#1
![](/forum/images/badges/trading_plus_member.png)
Thread Starter
![Default](https://www.rcuniverse.com/forum/images/icons/icon1.gif)
Most of my 2 strokes are diesel conversions I do a lot of flying at an electric site
where the little diesels are accepted 061 and ,10 my .10 is an OS 10 fp, runs great
now out of production, next choice thunder tiger 10 (even same diesel head)
the tt10 was broken in on glow running a 7x4 about 12500 a little slow but figured
new and tight. put on the new davis diesel head awful turned only 8000 missing like
hell, being the OS has the same head swapped heads same thing. ran out of adjustment
on compression screw 1 guessed about 1/2 turn more needed but screw stopped on
shoulder . Called Bob Davis and he suggested putting in a 10-32 cap screw, measuring
very carefully to get about 1/32 more down on the contra-piston fired up then
9k 10k 11k 12k and finally 13.5 K THE ENGINE WAS OUT OF SPEC --This should not
have been needed, but Davis solved the problem now engine ready for a cub looking
50" span plane for the site,There is a lot of the os and tt 10s out there running diesel
but I get the one that was a little shy on compression, thanks Bob
where the little diesels are accepted 061 and ,10 my .10 is an OS 10 fp, runs great
now out of production, next choice thunder tiger 10 (even same diesel head)
the tt10 was broken in on glow running a 7x4 about 12500 a little slow but figured
new and tight. put on the new davis diesel head awful turned only 8000 missing like
hell, being the OS has the same head swapped heads same thing. ran out of adjustment
on compression screw 1 guessed about 1/2 turn more needed but screw stopped on
shoulder . Called Bob Davis and he suggested putting in a 10-32 cap screw, measuring
very carefully to get about 1/32 more down on the contra-piston fired up then
9k 10k 11k 12k and finally 13.5 K THE ENGINE WAS OUT OF SPEC --This should not
have been needed, but Davis solved the problem now engine ready for a cub looking
50" span plane for the site,There is a lot of the os and tt 10s out there running diesel
but I get the one that was a little shy on compression, thanks Bob
#2
![](/forum/images/badges/trading_plus_member.png)
Thread Starter
![Default](https://www.rcuniverse.com/forum/images/icons/icon1.gif)
Not done yet-per davis suggestion screw will be cut off with the dremel 1/32 longer
than stock one and end rounded and installed with a 10/32 nut as a lock down,so much for iso 9001 specs, but cannot complain too much still half the price of the eyna cx11
diesel.
than stock one and end rounded and installed with a 10/32 nut as a lock down,so much for iso 9001 specs, but cannot complain too much still half the price of the eyna cx11
diesel.
#3
![](/forum/images/badges/trading_plus_member.png)
Thread Starter
![Default](https://www.rcuniverse.com/forum/images/icons/icon1.gif)
Correction to TTGP10 fix Forget the homemade fix although the tt10 is a "copy"
in most respects of the OS 10 it is not and exact copy hence the compression diff
Bob davis will modify the head at his end so that this does not re-occur .If you
are going for TT10 diesel conversion check with Bob, By the way it makes a great
diesel very happy with it.This might have been a "one off problem" but davis has
solved the problem
in most respects of the OS 10 it is not and exact copy hence the compression diff
Bob davis will modify the head at his end so that this does not re-occur .If you
are going for TT10 diesel conversion check with Bob, By the way it makes a great
diesel very happy with it.This might have been a "one off problem" but davis has
solved the problem
#4
![](/forum/images/badges/trading_plus_member.png)
![Default](https://www.rcuniverse.com/forum/images/icons/icon1.gif)
Dan,
Have you tried using parts from a LA 10 to repair your FP 10? I know the crankcase and head are different but you may be able to use internal parts.
George
Have you tried using parts from a LA 10 to repair your FP 10? I know the crankcase and head are different but you may be able to use internal parts.
George
#5
Senior Member
Join Date: Dec 2001
Location: Middletown,
MD
Posts: 697
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://www.rcuniverse.com/forum/images/icons/icon1.gif)
I have a OS FP .10 Davis conversion and it did not have enough compression adjustment for an 8x4 mas prop. Per Davis's instructions I made another head gasket from a soda can metal sheet. That works well.
Oily in Germantown
Francis
Oily in Germantown
Francis
#6
![](/forum/images/badges/trading_plus_member.png)
Thread Starter
![Default](https://www.rcuniverse.com/forum/images/icons/icon1.gif)
OK up and running well thursday afternoon pulled head and drilled top hole were
screw goes about 1/32 then reused the original thumb screw and spring Davis is
having all the heads for this engine machined with this cut . evidently TT made a change
can adjust now for smooth running and can even back off about 1/2 turn from
bottom. zinger 7-5 wood (could not find my 7-4 ) about 12,200 also hot out near
90 in Florida the 8x4 should be close to this rpm, have to get out my notes but this looks a little
better than the enya cx 11 diesel.--- plain bearing a little wet nose though, a little blow
back from front bearing (davis) said could be blow out from carb also
Bottom line "runs like stink" Aussie lingo for very good.thanks for info guys no
repair parts needed.....martin
SO all set with the little stuff norvel 061 OS10 TT10 diesels the electric folks even
like them
screw goes about 1/32 then reused the original thumb screw and spring Davis is
having all the heads for this engine machined with this cut . evidently TT made a change
can adjust now for smooth running and can even back off about 1/2 turn from
bottom. zinger 7-5 wood (could not find my 7-4 ) about 12,200 also hot out near
90 in Florida the 8x4 should be close to this rpm, have to get out my notes but this looks a little
better than the enya cx 11 diesel.--- plain bearing a little wet nose though, a little blow
back from front bearing (davis) said could be blow out from carb also
Bottom line "runs like stink" Aussie lingo for very good.thanks for info guys no
repair parts needed.....martin
SO all set with the little stuff norvel 061 OS10 TT10 diesels the electric folks even
like them