TD 049 witha Throttle Ring?
10-13-2006, 11:31 AM
#2
RE: TD 049 witha Throttle Ring?
Nope, the TD was only sold as a competition engine. DickeyBird pressed a reducer bushing into a TD venturi, and if memory serves correct....he might have throttled it too. You gotta be willing to give up HP to be able to domesticate an engine that has been [nearly] optimized for power.
10-14-2006, 05:45 AM
#3
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RE: TD 049 witha Throttle Ring?
As far as I know, Tee Dee .049's never came with exhaust throttle sleeves...only Medallions. As you now, throttle sleeves don't work as well with SPI cyls.
Those Medallion cyls. should have the ground o.d., no SPI and a precisely fitted throttle sleeve. They're GREAT for anyone wanting to throttle a Tee Dee. They probably don't have the extra Tee Dee style transfer port flutes but still have good power. Those little jewels are a hard-to-find commodity these days.
To get a reliable 5000 - 18,500 rpm (some go as high as 19,500) on a black 5x3 and 25% fuel, just bush down the venturi to 3/32" using K&S alum. tubing bonded in with JB Weld and add a Babe Bee/SureStart style glow head with 2 - 5 gaskets. You've seen mine run at S.M.A.L.L....they run like a train and have great fuel draw.
For a big-prop "tractor" style engine, use the Medallion crankcase and crankshaft (has mild timing) but put on a Tee Dee front end so's you can bush the venturi down to around .060"; then stick on a Texaco head and reduce the nitro. They're BIG putt-putt (tapocketa-pocketa-pocketa?) fun on a lightweight, slow model.
Those Medallion cyls. should have the ground o.d., no SPI and a precisely fitted throttle sleeve. They're GREAT for anyone wanting to throttle a Tee Dee. They probably don't have the extra Tee Dee style transfer port flutes but still have good power. Those little jewels are a hard-to-find commodity these days.
To get a reliable 5000 - 18,500 rpm (some go as high as 19,500) on a black 5x3 and 25% fuel, just bush down the venturi to 3/32" using K&S alum. tubing bonded in with JB Weld and add a Babe Bee/SureStart style glow head with 2 - 5 gaskets. You've seen mine run at S.M.A.L.L....they run like a train and have great fuel draw.
For a big-prop "tractor" style engine, use the Medallion crankcase and crankshaft (has mild timing) but put on a Tee Dee front end so's you can bush the venturi down to around .060"; then stick on a Texaco head and reduce the nitro. They're BIG putt-putt (tapocketa-pocketa-pocketa?) fun on a lightweight, slow model.
10-14-2006, 08:08 AM
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RE: TD 049 witha Throttle Ring?
Dickeybird, Interesting comment about throttle rings and SPI. I have an engine that I pulled out of a mid to late seventies cox Skyraider. It came from the factory with a throttle ring but never seemed to throttle well. The cylinder on this engine seems to the eye to be internally identical to the number four cylinder used on many TDs. The outside is ground for the throttle ring. It does have SPI. Maybe thats part of why it never throttled well. My brother and I both got skyraiders at the same time from the same store. Neither of us had much luck with the throttle ring but we learned that we could remove the ring and the engine would make loads more power than the babe bees we had been using. In fact the power seemed similar to a friends black widow. Now I'm wondering were the engines designed with throttle ring and SPI or did some employ mix up some parts?
