I was expecting some positive feedback and descusion into how ANY oil could increase engine temperature.

ORIGINAL: mk1spitfire

I think the seafire was a much later version of the spitfire used on carriers. Not to be confused with seafury too.

Quetion 1 Is one type of oil better suited to tapered engines than ring engines?

Either synthetic or castor or a blend works fine in either application. For most ABC/AAC/ABL ringless engines, keeping a bit of castor blended in the fuel provides a bit of extra protection (temp capability, viscosity and film strength) should you encounter an accidental lean or careless lean run or a temperature spike. For me personally, I run about 2-3% total castor oil (15% synth plus 2-3%) in my fuel. Its not enough to cause a mess or get in the way, but I know its there. I dont mix my own fuel, and most mfgs supply it this way. No issues running full synth like the heli fuel, cool power, or any other varient in an ABC engine. Just have to be careful.

Question 2 Is their truth that a very rich run in on abn/abc/abl engine can over compress the engine and damage it?

It will not damage the engine. If it gets that rich where it is going to over-compress and hydraulic lock, its not going to run. You are more likely to damage the engine with a starter if it is flooded. Key on the ABC engine is keeping the temperature up near operating temp during engine break-in (run-in). Beyond that, the throttle alone will create differences in cylinder temps, combustion temp and mixtures - which are acceptable.


Question 3 Which engine requires more cooling, A ring or tampered?

You are burning fuel that is creating itself into mechanical power, sound and heat energy. The engines, running at the same energy input/output will tend to create the same heat, thus will tend to require similar cooling. Mechnical friction does not play much into the heat produced by the engine unless something is not working right.

Question 4 Which engine can produce more power a ring or tampered?

Typically an ABC/AAC (ringless) engine can produce more power. It is capable of higher compression when designed properly. Its big advantage is the reducded piston drag (no ring) on the remainder of the power and intake strokes. Worth noting, that the oil plays a part here in providing some of the piston seal on an ABC engine during part of the stroke.


Question 5 Which engine has a longer life, ring or tapered?

Both can last a very long time when properly taken care of. The piston of an AAC/ABC setup should not wear unless subjected to abuse (heat, lean, dirt, particles). The ring on a ringed engine does tend to wear, but should wear slowely if properly setup and lubricated. Typically the bearings are the first to go.

Question 6 why cant you just run and go on a new tapered engine?, Has longetivity been lost?

For most modern ABC/AAC/ABL designs, you can run it right out of the box. The piston fit is by design and machine, not by wear (like an older cast-iron piston for example). The run-in period is mainly to allow the rest of the engine rod, pin, piston bosses, bearings - to find their best fit before placing them under load and before getting the engine hot. A few cycles in temperature will do a bit of good for the piston/sleeve as well, mainly as they develop and optimize the seal for the rpm and temperatures they will see in operation. (if any wear occurs on the piston of a modern ringless engine, it is might be measured in the .0002" range - less than polishing). The run-in process allows the engine USER more of an opportunity to understand the engine, its baseline performance, rpm ranges, all under controlled conditions. So in that respect, it should not be skipped. A ring engine does require a bit of physical fit-up - but there too, most modern designs are fabricated with tolerances that are much better than 20-30 years ago.

Question 7 whats so special about os ax abl liner/pisten combination?

They just use a different combination of materials for the liner. Its not necessarilty cheaper or less/more effective. Heat transfer is actually pretty good, and the manufacturing tolerances can be held effectively. The ABL process is still ABN, but basically they use two layers of nickle alloy. One alloy bonds well to the sleeve material but is softer (if it were paint, would be considered a primer). The second layer is extra hard nickle alloy that tends not to bond well to other metals, but bonds just well to the first layer of nickle. Resulting performance and durability seems to be very good. In a world where Chrome and the process is sometimes considered hazardous waste and dangerous material, the ABN/ABL approach is a good alternative toward meeting RoHS and other world environmental standards.

ABL (Advanced Bimetallic Liner) uses two O.S.-developed alloys to provide a durable barrier between the brass liner and piston.

ORIGINAL: bob27s

I hope this is helpful......

Bob Brassell

ORIGINAL: mk1spitfire

Why do not car engines not use this abc/abn/abl technology? or do they