Help/advice needed

[Jerry Wyss]

Just wanted to show the guy's in Malaysia what a Tiger looks like with it

cut-out for a pipe

 

[jaxracer]

heck at one time they made a 1.46:1 gearset,,Gezz

what were they thinkin' about :blink:

Thats thinking outside the box or I guess numbers. lol.

~Mitch

 

[MalaysianFlyer]

Jerry, nice pic, hopefully two of the guys over here will have their tigers running on pipes this evening. Your advice is paying off big for quite a few people over here. Maybe TT needs to get you on their payroll??

Now just waiting to see your 5cc version :blink:

 

[Jerry Wyss]

Jerry, nice pic, hopefully two of the guys over here will have their tigers running on pipes this evening. Your advice is paying off big for quite a few people over here. Maybe TT needs to get you on their payroll??

Now just waiting to see your 5cc version :blink:

One more thing I wanted to mention on the "cut-out" is that you can

leave the small section in the back of the muffler uncut. It will hold

the water pickup tube that way without making a new one and you'll

have another screw to hold the case halves together.

I cut it all out since I started using the "Silver Bullit" pipes which make's

the bend back around right thru where that uncut post would be.

Thunder Tiger could go along way with their OB if they were willing

to talk to a few boaters that use their motor.

 

[Jerry Wyss]

I tried to get another pic of the TT lower cut-out on here but it's not lettin' me

do it

With the lower unit halves bolted together and just the pto bolted to the lower,

The area to the rear of the pto where it mates-up to the lower,,That area will

have to be "concaved" somewhat to make room for the header cup that holds

the header silicone gasket. Don't go too far cause there's a bolt goin' thru there.

I've taken that area down (dished in) to where I see "half" of one of the aluminum

"locator pin's" that key the two lower halves together,,on most headers you don't

need to go that far. Tape-up the pto shaft plate so no aluminum cuttings get in

there.

Take great care if you deceide to cut-down the "skeg" or rudder, I use my vertical

metal cutting band saw and shape a "bed" out of styrofoam to back the skeg up

while cutting. The skeg should be sharpened evenly, the one in my last pic is a

rough shaping,,there's more to sharpen from that shown.

 

[Tim_Duggan]

progress

 

[Slideblues]

Nice wompy Tim That tank mount looks familiar :lol:

Gener B)

 

[Jerry Wyss]

Hehehe, Now Your Talkin'! :lol: The Heck with that Water Crap,, ay?

That's lookin' GOOD,,,So That's what'cha been doin' Yeah! That'l work.

So it's a air head motor now, is that head off a TT car engine?

Otta call that one "Woody" :lol: :lol:

 

[Tim_Duggan]

re: head off a TT car engine. Yes, it's from an early PRO21BX-R but has been modified to work with a head button from the O/B, and has most of the fins removed. I'll need to run it to establish how much more I need to remove from it. (it has a lot of surface area still)

Notice the pipe length to the start of the stinger? short hey!

 

[Jerry Wyss]

I noticed it was somewhat short but you have the silencer in there

that has some length, probably be fine.

It's shame you couldn't get a better head button with the car head,

are they all the same as a stock one? wouldn't surprise me

 

[Tim_Duggan]

I noticed it was somewhat short but you have the silencer in there

that has some length, probably be fine.

It's shame you couldn't get a better head button with the car head,

are they all the same as a stock one? wouldn't surprise me

no - they are better than the stock button but harder to modify or change bowl volumes on beacuse they are 1 piece. Thats the only reason I modified it. Once I establish if it's getting hot enough, I'll clean it up a little more.

That silencer makes little to no difference to the effective pipe length BTW. It is just a can - no baffles. Normally I'd run a factory muffled pipe but it's harder to fine tune the singer diameter. This one will allow me to get at the stinger easier. Should be under 90dB anyway.

I still have to deal with the trail edge to drive dog measurement issue, and put the TT engine on the Jenny Craig program. Crank, piston and rod will eventually get "the treatment"..... but that's not for weight saving!

 

[Tim_Duggan]

re: the tank mount.

My Buddy MJ gave that mount to me - it's a villain one that I've modified slightly. I thought about using a router and cutting into the deck to get the tank as low as possible, but when MJ gave me the villain mount I thought I'd give that one a shot.

I like this style of tank mount because I can sit it on the CG, and still move the tank fore and aft if I want to try things. Also it will allow me to put lead ballast under the tank if needed.

I don't think the tank height for fuel draw is that much of an issue - as I can always fit a little hopper tank to the top of the cowl if it does present problems.

 

[MalaysianFlyer]

Holy lovely tiger Batman!!!! :lol: :lol:

Nice one Tim, look forward to hearing about its performance.

Now I am going to have to bug Jerry about my engine

 

[Jerry Wyss]

"That silencer makes little to no difference to the effective pipe length BTW. It is just a can - no baffles. Normally I'd run a factory muffled pipe but it's harder to fine tune the singer diameter. This one will allow me to get at the stinger easier. Should be under 90dB anyway."

I was counseled before 'bout cuttin' the stinger to one inch but with a .300

opening that's a mite big for my Tiger, so I just left it full length to compensate.

Fuel pressure was a little low last year so I added the OS20J OB carb and stuck

the check valve back in the tank pressure line and I think I like it like that

 

[Tonymods]

Hi There!

Sorry I am a little bit late on that topic (I was on hollidays...).

Well just read all the posts and I must correct one point. From what I know, Tim D and Jerry W are the men who tried and devlopped a lot of knowledge on the TT (sorry If I forgot to mention someone). I have today a really competitive TT because of their knowledge. (thanks guys for sharing all this stuff). I spent a lot of time on engine modifications and what Jerry and Tim said is the only way to really gain power then you can go for specific timings and sleeve work to squeeze the last drop of power

I ran a great muffler made out of carbon fiber, really light and never got any problem. You can do it yourself if you find the epoxy made for high temp.

Lastly I tried to gain weight with the TT and I grind everywhere I could: Flyweel, leg (reshaped by the way) engine supports...at the end it losts almost 100 grams which is quite good. To be honest I don't think I gain 2 miles in top speed but I always tried to get my models really light to be able to add weight on the CG if it was necessary.

Good luck with the TT

 

[MalaysianFlyer]

Thanks Tony, I saw the picture of your engine with the carbon pipe, gadjetcraft from fastelectrics if i remember correctly. really looks great

 

[Tim_Duggan]

I was counseled before 'bout cuttin' the stinger to one inch but with a .300

opening that's a mite big for my Tiger, so I just left it full length to compensate.

Fuel pressure was a little low last year so I added the OS20J OB carb and stuck

the check valve back in the tank pressure line and I think I like it like that

Jerry,

Stinger length does have an effect similar to diameter, but lengthening it is nowhere near as noticable as reducing diameter. Shortening a stinger has a similar effect to making the diameter fractionally larger

The pipe in the pic's has a 0.270" stinger for initial testing, and can be reduced if needed. Give's plenty of fuel pressure and hopefully in this case, some engine heat without getting deto

I will initially be using modified 8mm and 9mm TT carbs with a remote mixture valve and retaining the low end needle in the carbs.

Tony,

My reason for wanting to make the engine lighter is not solely for top speed, but more to do with boat stability. How much of that 100 grams do you think would be from the flywheel?

Tim.

 

[Tonymods]

Hi Tim,

it is hard to say exactly how much I removed from the flywheel because I do not remember the numbers. What I am sure is that you can remove almost half of the weight of this flywheel. I am using 30% nitro and I never boke the rod. I noticed that the heavier parts were the flywheel, the leg ( I grinded inside too ), engine supports. When I removed all the weight I noticed the hull behaved better. I will create an album and will post the pics.

Tony

 

[Tonymods]

Here is my gallery:

TT OB 21

or maybe this link

https://www.intlwaters.com/gallery/index.php?cat=10228

Tony

 

[MalaysianFlyer]

Hi Tony, I was looking at your gallery, and wanted to ask, is your lower unit sealed with silicone gasket maker between the halves, or is that red residue something else?

Also, the pipe supports look like the bolt is going all the way through the lower unit, is that using the original bolt locations or something new you added in?

And is that a pressure nipple for lubing the flex shaft that you have added there? And how did you determine the depth/height to cut out below the boost port?

Sorry for so many questions, after "killing" one engine, I think I had better be prepared before i touch the next one

Thanks