Hobbsy

My Feedback: (102)

I found among my Davis heads an unused SuperTigre .90 head, I have an old .90S that has squishy compression. I ran it anyway. I could not flip start it but it fired right up using a starter.

SuperTigre .90s
Prop====APC 15x8
Fuel==Davis ABC blend
Rpm=======8,100
Idle=======1,700
Muffler=====Quiet Swing muffler.

Frank Bowman, here I come.

AMB

Hobbsy Awsome the thrust must be out of sight, anything to put it in ( not a park flyer Ha Ha) martin

PS I have its twin same setup now know why I have those 15 inch props, been a while since run

1QwkSport2.5r

Hobbsy - what will your S90 turn that same prop at on glow fuel?

Hobbsy

My Feedback: (102)

Thanks Martin and Qwik, I had a Webra P-5 .91 the smallest recommended prop was a 14x12 which the P-5 would turn at 9,500 rpm on 5% fuel. Being the curiouser type that I am I tried that 14x12 on an MVVS .91 and a newer made in China ST .91. The MVVS could only manage 8,800 and the SuperTigre only 7,000 and it quickly got very hot.

The prop range for the Webra P-5 .91 was 14x12 to 16x6, it was timed for that load and rpm and was sturdily built weighing several more OZ than the other two. It would have made a fantastic Diesel.

AMB

Heres my trio of 90S ST90 Davis head, ASP91 AND TS (tiger shark) 91 I do not know if the TS line of engines is still out there
goes back to the days when I had to have them all, the ASP AND TS are AJCs heads
the ST 90 is the only one that was run so far do not remember the numbers think a 15x8,16x6 the props show the right bore and
impression marks from the back drive washer

fiery

My Feedback: (2)

The TS / TSI line metamorphasised into the SK range, and then (current) the JBA range, which are fairly well regarded. A chap who calls himself "Turk" has a thread on them on the glow forum.

I have a low time TS .46. It was given to me as few months ago as "chinese junk".

Apart from a carb with the usual rich mid range, it is a very good sports R/C engine. Piston and Liner are ABC. Fits are excellent. I installed a current spec ASP .46 size carb on it (bought inexpensively from 'the King'). It performs perfectly on nil nitro fuel. It may be a candidate for a diesel head conversion.

AMB

Fiery THX for the update on the TS forgot "back when" got a JEN56 with a diesel head from Just engines, got it at the same time as one of my Irvine 53s, (6 I think total now) Davis heads
on all the irvines UK made of course

martin

1QwkSport2.5r

What I was curious about, Hobbsy, was what the S90 would turn the 15x8 at on glow?

Hobbsy

My Feedback: (102)

Sorry, I've never run the the 15x8 on glow, maybe that can be a tomorrow project.

AMB

well all Here is the biggest conversion OS1.08 Davis head the Irvine 53 is for size comparison, pretty small compared to the OS
prop for the 1.08 18x8 right up there with the gassers It almost pulled my black and decker folding bench over, I was behind it, grabbed it . shut down
and tossed a cut off I beam about 40 lbs on the bottom that kept it in place
8 head screws in the head

Hobbsy

My Feedback: (102)

Much better results today, I discovered that the APC 15x8 used yesterday was way out of balance, I used a different perfectly balanced one today. Yesterday I used a ST .51 carb, same as the .91 except it has a fat spraybar, today I used the .91s own carb. I also used a Davis In cowl SoundMaster Muffler and a Cline regulator using crankcase pressure.

SuperTigre .90s with stock carb and Cline regulator.
APC 15x8 well balanced prop
Fuel====Davis ABC blend
Muffler==Davis In cowl Muffler

Picture #1 reads 9,372, its a terrible picture.

Highest recorded rpm=====9,470, it had a lot of the secondary knocking so reduced compression to 9,400 where it was very smooth
Idle 1,500 and rock steady

Hobbsy

My Feedback: (102)

Q, I remounted the glow head on the .90s and ran it on WildCat 10% with 18% syn/castor blend with 2.6oz of added castor, it turned 8,400 with heavy knocking. Up to about 6,500 it acted pretty normal, then above 7,000 it sounded very labored. They make a hollow metallic knocking sound when they're overloaded.

1QwkSport2.5r

Thanks for testing that out. I didn't think it would do all that well with that much load. I suppose running 10% nitro doesn't help. My S90 barely tolerates 5%, but its just barely broke in. It turns close to 14k on a 12x6 and about 13k on a 13x6 both APC. I use 20% castor in it though. It might turn a little faster with a 70/30 or 60/40 blend of oils.

Hobbsy

My Feedback: (102)

Since I ran one .90 I might as well run another. I have an ancient Webra .91 ABN that has many hours as a Diesel. I'm going to swipe the head off of it and put it on a ringed Webra .91 with a just broken in Frank Bowman ring and a new sleeve. Hope you don't mind me running it with the SuperTigre .90 carb. The only Webra carb I have for the .91 is a DynaMix. I may try it too just for kicks.

1QwkSport2.5r

I think SuperTigre has fantastic Carburetors. If they had some with larger bores, I'd use them on all of my engines except my Enyas. They are a breeze to set up, although new engines need lots of fuel before they throttle nicely in the midrange.

I doubt I'll ever convert a glow to diesel, but someday I might get a diesel. Probably something in the .40-.60 range.

Hobbsy

My Feedback: (102)

If you want something. simple and easy jut grab an LA .46, it'll turn a Graupner 12x7 at about 9,450, same with the Fox .46 ABC. AN ols SuperTigre .45 is also one of the stronger .45 to .50 sized conversions.

1QwkSport2.5r

That's good to know. I have an old fox .40 that needs to be traded in, although originally I was going to trade for an Eagle IV .60. I'll kick it around. Thanks for the info, Hobbsy.

Hobbsy

My Feedback: (102)

The eagle .60 also makes a very good conversion with a .905" bore and a .937 stroke it is long stroke engine with a very similar bore and stroke to a MOKI .61 longstroke, the OS .61SF and the MVVS .61 Diesel.