Jensas vega B20. "expriment rekord B20 motorn"648hk 2.95bar

[Tommy Luhr]

jag har åkt på sunoccos racemetanol.
Skall väll inte vara någon större skillnad kan jag tycka.
Tror ingen av dom är "kemiskt ren" metanol.

[Jens Gustavsson]

fins det aluminium lager till volvo B23-B20?

http://www.enginebuildermag.com/Article ... trong.aspx" onclick="window.open(this.href);return false;

här är det mest intresanta

With regard to bearing materials, the aftermarket has generally been forced to follow whatever the OEMs decide to do as far as bearing technology is concerned. However, the aftermarket has at least one thing on its side that the OEMs don't - hindsight. Aftermarket bearing manufacturers can watch what the OEMs do and study their failures and successes to see what works best. Most late model engines are now designed to use aluminum bearings.

"The biggest reason that we're finding for going to aluminum bearings is that it seems to be a better choice for late-model applications," says Jeff Richardson, Federal-Mogul Corporation. "And even going back to some of the older applications, we're finding that aluminum is just a better overall fit for light-duty replacement applications."

Clevite also offers a few aluminum bearings for some of the more popular applications, mostly for production engine rebuilders. However, tri-metal bearings are still popular choices for heavy duty and performance applications.

"We still offer our tri-metal bearings, but the aluminum gives engine builders another option," says Jeff Schaerer, Clevite. "One of the reasons we use aluminum is that it's a harder material, so the aluminum silicon actually conditions the journal after it has been reground."


Material

Aluminum bearings are not new technology. In fact, they have been around for a long time, but today's materials are superior to yesterday's aluminum bearings. "Our old corporate material on aluminum goes back into the '60s," explains Federal Mogul's Richards. "A couple of years back we created the material we termed 'A-500.' This is what really pushed us over the edge to what was better."

A-500, the material makeup of the lining material itself, is an aluminum-silicon lining. The silicon is what bearing manufacturers have determined make aluminum a preferred material for late-model bearing applications. The small particles of silicon, finely and evenly dispersed throughout the lining material, give it a better fatigue rating and better seizure resistance. And those small particles of silicon will actually polish the crank if you have any imperfections on the crank.

Another bearing manufacturer, King Engine Bearings, uses what is called 'Alecular' bearing material in which the alloy is made up of aluminum, copper, tin and several other elements. In addition, since it's an alloy it can maintain its properties throughout its entire depth resulting in more consistent, reliable performance. King's Alecular material can be used in high-load applications as well as street applications and has been able to withstand the stress and strain of blown, nitro-burning Top Fuel dragster engines that produce up to 5,000 hp. Also the Alecualar material has a melting/fatigue point that is over 1,100° F, which is about three times higher than the babbit overlay in a typical trimetal bearing.

Embedability

Because they're harder, aluminum engine bearings don't offer the embedability that tri-metal bearings do, says Clevite's Schaerer. So the particles will wash through the bearings."

Clevite's Don Sitter says that due to the material makeup and design aluminum bearings can compensate for some crankshaft irregularities. "If there are weaknesses in the crankshaft finish, then the nature of the aluminum bi-metal is forgiving to those weaknesses and helps address that."

Compensating for those irregularities, however, means that metal from the crankshaft has to go somewhere, says Sitter. "We're not convinced that it's a good thing to remove that metal and rely on the filtration system to collect it. But that's going to happen; there's nothing for free there."

The 'grinding' or surface conditioning from aluminum bearings occurs when there's less oil film present. "If you've got the total of peaks and valleys that are less than the oil film, then the oil film is going to go away from the surfaces and the surfaces are going to touch until the high points are equalized," Sitter continues.

"Polishing of a cast crank normally reduces the surface finish disparities to a point that the total roughness of the bearing and the total roughness of the shaft if you oppose those, is less than your oil film. So the oil film fills in and carries the load, which is what we always design them to do," says Sitter. "The purpose of the bearing is always to support the oil wedge, not to support the crankshaft."

Federal Mogul's Richardson agrees but says that not all of the aluminum bearing is harder than trimetal. "Pieces of the lining material are harder but not the entire thing is harder," Richardson explains. "We were getting debris, scoring cranks with a broached bearing that had a flat ID surface. So what we did was we started boring the ID to get what we term 'micro grooves on the ID. And what that helps to do is if you do get debris in there it'll go into one of those microgrooves and get flushed out of the bearing itself, so it won't embed. What happens is if you get a piece of particle embedded in the lining it will score the crank.

Once we started looking at it, we figured out that embedability isn't what we wanted. We don't want stuff to get stuck in the bearing. We want debris to flush out of the bearing. How do we get it to flush out? We put the micro-groove or bored finish on it to help flush that material out."

Trimetal vs. Bimetal

Traditional main bearing construction is based on a three-layer construction made of a steel backing, a copper-lead layer and a thin overlay of babbit material.

"When you stack the tolerances up, one bearing may measure 2? exactly and another may measure 2.001?, so it's off .001?," says Federal Mogul's Richardson. "It's difficult to keep the bearing shell consistent because all the layers and the tolerances stack up. With the aluminum there are only two layers. You've got the steel backing and the aluminum lining. So when we talk about being able to reduce tolerances, we're mainly talking about reducing the stack up of tolerances. We're only stacking two tolerances up versus 5 to 7."

"We use both aluminum bimetal and the copper-lead trimetal bearings; we're starting to get into a little of both," says Eric Grilliot, Mahle Aftermarket. "When it comes to trimetal or bimetal applications it seems as though some companies have aligned themselves to one or the other, or carry specific lines of each. We have really not established ourselves one way or the other. We look at the OE bearing and if it's a trimetal bearing we'll stick with that; if it's a bimetal bearing, we'll go ahead and develop a bimetal bearing."

In comparing bimetal to trimetal in severe load applications Grilliot says that it really boils down to trying to get more from less. For higher specific loads there are some cases where the bimetal will outperform the trimetal. Still, he says Mahle is starting to shift toward aluminum and bimetal bearings. "The last time I spoke with the people in our bearing facility they said they would like to see it move in that direction because for the OE-replacement applications they're doing, trimetal products are becoming fewer and far between," says Grilliot.

What's Ahead?

The future trend for bearings may be headed toward more aluminum, but don't write off trimetal's existence just yet. There is still plenty of demand for them and many applications where trimetal bearings are better for the job.

Aluminum and tri-metal may continue to co-exist for quite some time, according to our experts. OEMs are primarily using aluminum right now, and part of the reason is because they can get the material for less than tri-metal bearings. Aluminum bearings are also bored so they can achieve tighter tolerances on the wall sizes, which allow them to select-fit the bearings. The tri-metal surface's plated overlays provide, regardless of what thickness they may be applied at, embedability, conformability and the surface action for a dry start separate from the structure of the bearing.

[Kadett4wd]

undran sa flundran..

Glyco-lagren som finns till massa nyare bilar..
De har en helt annat yta och vikt än ett trimetallager från exempelvis Kolbenschmidt.
Lagret är lättare samt ser ut mera i ytan som just aluminium.

[fredde_vit_pv]

Jens: ring o prata med uffe på motorslip han snackade jag med om alu-lager och stål-babbits!
han hadde info om bla rådstöms isracermotor tycks jag minnas där dom hadde "special"bly-brons old-fashion typ B20 lager på vev

/F

[Jens Gustavsson]

men varför har man babbitsen? på en race motor så måste det ju räcka med att ha aluminium direkt? då fins det ju inget som kan släppa.

[fredde_vit_pv]

tror han nämnde att om det gick igenom oljefilmen så var det bättre förutsättningar om det
inte var alulager!?

[turbodart]

Tro om QMI, FX1 e.l. Oljetilsetninger kan hjelpe mot slike hotspots/pittingproblem?

[Erland Cox]

Dom hjälper inte mot Jens oljepumpspickup, den kan inte suga ordentligt.

Erland

[Jens Gustavsson]

erland lagren såg ut likadant (värre) före jag byggde om sug sidan till pumpen det va därför jag byggde om den.

[Erland Cox]

Men den pickupen kan inte suga nåt vidare, vad hade du innan?
Blev lagren kass i bänken då också eller bara på banan?

Erland

[Jens Gustavsson]

orginal då.
vet ej jag körde både dyno och race med de lagren men de va typ 2mm slitna

[Jens Gustavsson]

hej jag håller på lite med den nya B20 toppen nu till B20 version 4.3 och här kommer lite grund data och minnes anteckningar mest åt mig själv men kanske nån annan som är intresserad också?

B20 -75 topp som ska få 8mm 44.8mm insugnings ventiler och 38mm custom lätt vikts ventiler som jag bearbetat fram själv från LS1 ventiler.

styrningarna blir B23 gjutjärns 52mm långa med 15mm uppstick över toppen.

blocket är planat ca 3.5mm och det används plana kolvar med 0.85mm E-packning ska bli ca 8.5:1 med 50cc förbränings rum och 2.8mm klämspalt. (33mm kolvbults höjd och 158mm stakar). (första uppmätningen med sätes jobb och rätt ventiler var det ca 47cc i toppen)

toppen är planad till 85mm höjd.

med comp lyftare och mina anpassade stötstänger och ca 1.5mm under stället för att stötstängerna blir lite för långa+för att få mer lyft så får jag 1.6 i utv med mina omsvetsade vippor och 13.0mm lyft vid noll spel på insug (mindre på avgas) kamaxeln blir nu en snällare agap 258 (240 grader vid 1.27mm på kammen) med 110 nock och den speciella förstärkta stommen som satt på nyare B20.

[Jens Gustavsson]

jag gjorde ett snabbt flödes test med nya toppen som har lite plast i golvet som inte är klar än bara för att se lite vart man va och det vart upp mot nära 190cfm med ca 2cfm tapp över 14mm helt ok med tanke på att den bara är grovt portad och med ett skabbigt 44mm standars säte. jag tog sen och gjorde ett sätes jobb för 44.8mm ventilen med vanliga 4033 stålet (60/45/30 1.5mm) då vart det lite sämmre på låga lyft sen turbulens över 11mm och 178cfm inte så lätt som många tror detta haha, blir att ta nya tag om nåra dagar nu har jag inte tid med mera B20 mek i dag.

[Erland Cox]

Får du inte problem med gjutjärnsstyrningar och metanol?
Dom mängder du skickar in borde tvätta insugningsventilen rätt bra.
Dalhems har styrningar som passar i brons, jag brukar ha sådana hemma men just nu är dom slut.
Kör solid brons på insug och sleeves på avgas.

Erland

[Magnus]

blir det metanolmotor till sommarn?/mvh magnus