sharp333

My Feedback: (11)

Had recently a debate with friends about who was company to launch a Schnuerle ported MODEL engine. Everybody thinks it was HP, with the 0.15 engine.
But one friend swears it was ST the first one, with the so called TST porting scheme.
so, here are the questions to the experts on glow engines:

1.who was the first? Engine and year

2. What was the first ST engine to use their TST porting? Engine and year

Jesse Open

There was another port upgrade en vogue about that same time, Perry Directional Porting or PDP.
The late Clarence Lee performed that work on domestic engines.

downunder

This all goes back to history and the problems with patents but as far as model engines go Super Tigre first used their (patented) TST porting in 1959 with their G.20/15V "Jubilee" for CL speed and was so successful that Bill Wisniewski (a competitor in 1960) asked ST for permission to use their porting for an engine of his own design. I won't go into the details of the shenanigans used by the Italian team to "win" the '60 world championships but the outcome was that ST refused to let him use their TST porting. BW then spent a few years trying to develop a different porting system which eventuated into a Schneurle ported engine (the 1964 K&B 15RS (WART) engine) when BW won the world championship. AFAIK the Enya 61X was the first production engine to use Schneurle porting in about 1977.

GREG DOE

Both the Super Tigre X40 and the K&B S40 were Schneurle ported, and in production several years before the date that you have for the Enya .61. The K&B S40's prototype was issued in approximately 1972, and the Super Tigre about the same time.

sharp333

My Feedback: (11)

I believe the HP engines predates the Enya 61X

tec7474

If it is a known fact that schnurle porting improves overall performance in an engine across the entire rpm range and also improves fuel consumption why then do most of the newer gasoline engines have cheap porting that is not much better than what you find in a basic crossflow engine? I have only looked inside a few newer gas engines but I was unimpressed

1967brutus

????

Can't remember having seen any crossflow engines lately... Schuerle (often without the boost port, but that is how Schürle porting started out originally) is used in basically every 2-stroke I know of.

FWIW: the boost port improves power, but NOT fuel economy. An engine without the boost port, for the same horsepower rating is a bit more economical, but will have to have a touch more displacement. But to be honest, I only know of the OS FP and LA series having that type of porting. Basically every other engine I have seen has either boosted Schürle or higher.

tec7474

From what I understand as porting types improved from perry directional porting and on to schnurle porting which is used today with glow engines those porting types do in fact offer better efficiency than standard crossflow induction but from my experimentation the newer gas engines will do the intended purpose and fly the model well but the level of quality in workmanship of gasoline engines like DLE or other similar engines have been vastly decreased in quality in comparison to a nice glow engine. I am flying with a glow moki 2.1 and it has far nicer quality to what is found in your typical gas engine of today. I have not looked inside a DA engine or a 3W so they might be a better engine

tec7474

A good example of the reduced quality in modern day DLE engines is if you get to look inside a K&B sportster engine they are ported the same way as newer gas engines they just have a couple channels cut out of the cylinder for ports and the sleeve only supports the piston part of the way around . I'm sure this method is cheaper to manufacture but I prefer a higher level of craftsmanship in engines I choose

Tphage

[QUOTE=downunder;12760206]This all goes back to history and the problems with patents but as far as model engines go Super Tigre first used their (patented) TST porting in 1959 with their G.20/15V "Jubilee" for CL speed and was so successful that Bill Wisniewski (a competitor in 1960) asked ST for permission to use their porting for an engine of his own design. I won't go into the details of the shenanigans used by the Italian team to "win" the '60 world championships but the outcome was that ST refused to let him use their TST porting. BW then spent a few years trying to develop a different porting system which eventuated into a Schneurle ported engine (the 1964 K&B 15RS (WART) engine) when BW won the world championship. AFAIK the Enya 61X was the first production engine to use Schneurle porting in about 1977.[/QUOTE]

I am certain that OS's 40 SR ( rear induction racing engine ) of 1973 was OS's first Schneurle ported engine and I think ( perhaps not incidentally ) coincided with their introduction of CNC machines.

J330

My Feedback: (3)

http://www.hpengines.com/history.htm Randy thinks the HP was first to introduce Schnuerle porting, in the 1960's. Evidently he didn't read this article;
https://adriansmodelaeroengines.com/...php?cat_id=163. 1964, K&B .15RS
I found it on RCGROUPS in this post; https://www.rcgroups.com/forums/show...5&postcount=51

1QwkSport2.5r

The Sportster is a budget type engine with port timings on the low side for low revs and high torque. Telephone pole type props are where it shines. Also, the piston is chrome plated instead of the bore. Again - budget oriented. No lack of quality though. The name of the efficiency and horsepower game is scavenging. Just because the port layout is rather agricultural doesn’t mean it doesn’t scavenge properly. The reference to modern gasoline engines having lower quality because of the ports is not necessarily a good indication of quality. Those port layouts don’t need to be fancy because the engine scavenges effectively at the rev range the engine is operated at. Take an agricultural engine with square ports and hard port angles and compare revs at 8k and 20k and you’ll see a difference. Where you can increase efficiency (and subsequently power level) is by reducing eddy currents and improve gas flow. The important part here is maintaining the proper surface finish to promote and maintain the boundary layer in the flow channel to prevent fuel droplets from “sticking” to the metal impeding flow. Buggy guys have their engines modified for this reason - increase efficiency and power production. Sometimes this involves smoothing the flow path only, other times (more often than not) the timings need adjustment as well. Production engines are mass produced; the personal touch of hand modification is taking a good setup and making it better. However, not all modifiers do it right. Eye candy on the outside of the liner with fancy fang cuts and polishing hurts power and efficiency because it disrupts the boundary layer within the flow path. Shiny smooth is bad.