ACL Conrod Bearings (Brand)

ACL has been a world wide manafacture of bearings for many years. RPW has had significant success utilising there products and will contine to exclusivly use the ACL range in future years.

ACL Recently released several types of bearings for standard to modifide and race use. The three types are

(1) The Duraglide

Plain and flanged bearings are manufactured in a number of material options, including ACL's Duraglide F780 heavy duty, trimetal copper-lead material, to suit every performance requirement The Duraglide has been the base product from the ACL Company for many years and will still continue to be succesfully used in engines in the future.

(2) The new Auglide bearing

The introduction of Aluglide™ bearings is an example of ACL’s commitment to understanding and adapting to customer requirements. ACL’s new Aluglide™ engine bearings combine the proven advantages of aluminium tin metals with silicon to make this the very latest generation high performance alloy and have met with global response which proves these Australian developed and made components are at the leading edge of a competitive international industry

(3) The new Race Series

The unique combination of design, metallurgy and engineering come together to deliver what drivers expect from high performance Trimetal engine bearings.

Designed to withstand higher RPM conditions, ACL Race Series Engine Bearings are available for many of the popular 4, 6 & 8 cylinder applications and feature:

1. High strenght overlay plate with reduced thickness
2. Hardened steel backs on all conrod bearings
3. Increased crush and elimination of flash plating
4. Tight consistant wall tolerances

Choose from the following part numbers - to ascertain what your vehicle needs, check the ACL Catalogue link on www.acl.com.au

Link : http://www.rpw.com.au/shop/index.php?page=shop.product_details&flypage=shop.flypage&product_id=1084&category_id=213&manufacturer_id=0&option=com_virtuemart&Itemid=31&vmcchk=1&Itemid=31



Connecting Rod and Main Bearings
Topic: Data Posted:2005-04-17


The
connecting rod bearings are metal inserts that go between the crank and
the connecting rod. The main bearings go between the crank and the
engine block. These are made of a softer metal so that you don't wear
out your crank or engine block. Additionally, a thin layer of oil
lubricates the connection between the bearings and the crank. The
crank, essentially, floats on a thin layer of oil between the crank and
the bearings. This thin layer is gap of approximately .001 to .0015 on
our engine, when it is set correctly (measurements in inches in this
article). You can measure this by using plastigage, which is a small
thread of plastic that flattens out when comressed. By measuring the
flattened plastic, you can tell how much clearance you have for your
cushion of oil to live. Supposedly, the softer metal bearings are then
just replaced when they wear out. Now, if you wear your crank out
instead, since it is spinning inside the set of bearings, you may need
to get a machinest to regrind and polish your crank and get slightly
thicker bearings. I'd expect that the technology of bearings has
matured a lot over the last 40 years. The link at the bottom does
discuss some different schemes for the layering of metals in the
bearings. The bearings are sold in .010 increments. So, say you have a
STD engine. That is, it takes regular size bearings. If your bearings
wear, and your crank doesn't wear, you could just get the bearings
replaced. If the crank wears, then you make the metal on the crank
where the bearing connects, the crank journals, smaller to the closest
.010 increment and polish it. Now, the engine itself can be
manufactured with differing sizes. It appears that our L Head 195.6,
from the stamps, was standard, but the crank was ground. We had some
STD bearings, that we got at auction, frankly, before we knew what we
were doing. True, they were cheap, but if we don't need them they are
only useful for learning. Now, it could very well be that our 440H
could use them. We'll see. Anyway, I took some measurements on the
bearings. Here is a measurement of the new STD rod bearing:




Here is a measurement of the old rod bearing:





It appears that these are .01 over, and that, at least with this crude
measurement, that the bearings are not worn too much. Note that this
measurement shows that the bearings are .005 over in thickness;
however, the diameter of the crank has two of these bearings, one on
each side. The rod bearings, at least, are marked .01 over:





Here is a picture of the old main bearings and a bearing cap. You can see copper on some of the main bearings:





Here is a picture of the rod bearings and a bearing cap:





Source: http://www.fixrambler.com/art38.html

THE BENEFITS OF USING KING ENGINE BEARINGS Tri-metal vs. Bi-metal Bearings Traditional rod and main bearing construction is based upon a three layer configuration composed of a steel backing, a copper-lead layer and a very thin overlay of babbitt material only .0005" - .0008" thick. King’s bearing uses just two layers, a high strength steel backing plus a bonded layer of "Alecular" bearing material .012" - .015" thick. Alecular material is used exclusively by King. It is an alloy of aluminum, tin, copper and several other elements. Because it is an alloy, it maintains its properties throughout its entire depth, delivering consistent and reliable performance. Benefit No.1 - Particle Embedability More than half of engine bearing failures are caused by metallic particles which scratch crank journals and tear or weaken thin babbitt overlays such as in the tri-metal bearing. Since King’s Alecular bearing layer is much thicker than the babbitt overlay (.015" vs. .0008"), it provides eighteen (18) times more embedability than a tri-metal bearing to catch and hold particles so they don’t scratch the crank journals. This is especially true for particles over .0004" in diameter which cause most of the damage. Benefit No. 2 - Conformability The much thicker layer of Alecular bearing material (.015" vs. .0008") allows the bearing to conform to problems such as metal to metal contact when there is mis-alignment present or the connecting rods stretch. Greater conformability means fewer bearing failures. Benefit No. 3 - Temperature Resistance The Alecular material’s melting/fatigue point is over 11000 F, almost three times that of the thin babbitt overlay in a tri-metal bearing (400OF). This means added protection against localized overheating due to mis-alignment, detonation, overloading, loss of coolant, etc. Benefit No. 4 - High Load Capacity Alecular bearings successfully withstand the stresses of blown, nitro-methane burning Top Fuel dragsters generating 5,000 hp at 8,000 rpm and in 700 hp circle track engines running for extended periods of time. The same metallurgical alloy is used in King’s street bearings that is used in King’s High Performance bearings, so the regular bearing user gets the advantage of the alloy developed and used in race engines. Benefit No. 5 - Control of Wall Tolerance Bearing -to- journal clearances on main and connecting rod bearings can be affected by several variables, all of which the engine builder must try to control. King has removed concerns about inconsistent shell to shell bearing wall thickness by the use of statistical control methods to keep wall thickness to very limited variation. Other manufacturers produce bearings whose wall thickness at the crown can vary by up to + .00025". King bearings are produced using "Bull's Eye" specs which set a higher standard of controlling the wall thickness, permitting no more than + .00010" variation of the desired thickness. The benefits of tight control of wall thickness tolerance are: Improved consistency of bearing to journal clearance. No more trying different bearings within a set to get the "right" fit. Superior eccentricity and crush relief values for a better oil "wedge" and less journal wear. Less taper across the bearing face, meaning superior wall stability, a more parallel wall and better oil film development. Crankshaft grinder does not need to grind cranks "fat" or "thin" to compensate for bearing variations. Benefit No. 6 - Crankshaft Endplay All bearing companies solve crankshaft journal wear by supplying oversized bearings. However, King went two steps further with the development of Max Flange and Pro Flange. Max Flange reduces endplay by supplying the flange on the high side of the tolerance to compensate for crankshaft thrust surface wear; this process is used on all King bearings. Pro Flange are bearing sets supplied with oversized flanges allowing the thrust surface to be ground to .010", .020", or .030" undersize. KING BEARINGS GIVE YOU EXTRA INSURANCE AGAINST ENGINE BEARING FAILURES!

Source: http://www.kingbearings.com/advantages.html