systemlord

My brother and I would like to know specifically what makes a turbo glow plug better than a standard glow plug? If you know of a website that explains why turbo plugs are better I would be grateful! Thanks Systemlord

longdan

Turbo plugs seal at the bottom of the plug rather than at the top.In standard plugs, there is a small volume in the clearance in the threads which works to reduce the compression ratio. This doesn't make a lot of difference on larger engines, but on smaller ones, the volume in the threads can make up a significant part of the volume of the combustion chamber. It tends to 'absorb' the compression without adding anything to the force of the combustion.

Charley

My Feedback: (2)

So what holds the plug in the head, if not threads?

CR

longdan

A turbo plug still has threads. But it also has a tapered section at the bottom. Screwing it into the head forces the tapered part against a matching taper in the head, creating a seal. The seal is between the combustion chamber and the thread. Is a standard plug, the thread is between the combustion chamber and the seal.

huck1199

Here is the explanation from Os web site:

The "right" glow plug for your engine is the one that gives you the best performance. And you can choose the right plug for any situation, just by following the guidelines below.

1. Engine Type
Guideline 1: Know what type of engine you have. Is it a standard - or a turbo?

Standard engines (engines with a 1-piece head) are most common. Standard plugs are easily available, inexpensive and fit almost all standard engines. Standard plugs are installed with a washer, which creates a compression seal with the head.

Many new O.S. engines are turbo engines, which feature a special 2-piece turbo head. The biggest benefit of turbo plugs is superior performance. Unlike standard plugs, turbo plugs (identified by a "P" in the description) feature a tapered "seat" that matches perfectly with the head. That creates a superior compression seal and with it, maximum efficiency and power. Turbo plugs are the choice for racers who want - and need - top performance.

A word of caution: you should never install a turbo plug in a standard engine or vice versa. Doing so risks doing serious (and expensive!) damage.

systemlord

On another note, my brother and I were in the desert two weeks ago at high elevation (not sure how high) running our SuperMaxx's in the worst place possible. My brothers friend's OS .18TM gave a reading of 426F on three different temp devices (give or take a few degrees) from all different manufacturer's, next my brothers Sirio .23TM read 388F. What I don't get is why they were running so darn good, so we richened up and they ran like crap at there specified operating temperatures. Is there something about high elevation that I don't know about? What a debocal?

Charley

My Feedback: (2)

Re: Os's expnnation. Huh! Reminds of the 18mm spark plugs we used in some of the old Ford automotive engines.

CR

on pipe

Even though they were running hotter than normal, a perfect (stoichiometric) fuel mixture makes an engine run the best. The air is thinner at elevation so the engines would run richer at the same carb adjustments. By richening the mixture you make it even worse.
Over-rich won't cause the engine to die out on a long pull like over-lean does, but the engine won't have the crispness, or acceleration it would it it were "right-on". I noticed this the first time I dialed in (jetted) a Holley carb. The engine ran SO much quicker with the correct jets in the carb. (1 step richer than lean stumble) Of course in a two-stroke leaner mixtures mean less lube in the engine, so having good oil is a must. Maybe part castor for the high temps.
Another thing about running too rich is the wear it can cause an ABC engine. The engine runs cool and the tapered cylinder does not expand, causing excessive wear to the piston/liner. This, of course, would take away power as well. Ross

systemlord

So 388F and 426F is ok at high elevation? Our engines never gave us any hints that they were overheating, no steam coming from around the head, they had smoke coming from the pipes and we were 3/4 open 90% of the time moving fast? Mmmm.......