cross-drilled Kurbelwelle

[pravg]

Wer weis ab wann die TR Kurbelwellen cross-drilled waren? In der Zeicnung Fig12 auf Seite 14 vom Service Instruction Manual TR2 ist dies schon eingezeichnet.
Siehe auch die Diskussion https://kaskastnersforum.yuku.com/reply ... oueFNKX7Nk

[pravg]

ich glaube es müsste 'bis wann' heissen.

Wenn Sie meinen, dass von Anfang an Cross-Drilled Kurbelwellen verbaut wurden dann bitte genaueres denn im Kas Kastner Forum ist mann offenbar andere Meinung.
Wenn Sie wissen "bis wann" die Kurbelwellen Cross-Drilled waren dann auch bitte näheres. Meines Wissens trifft das nicht zu auf den TR2-TR4 Motoren.
Übrigens "Cross-Drilling" kann unterschiedlich ausgeführt werden. Hier findet man näheres https://www.google.de/imgres?sa=X&espv= ... ,s:0,i:107

[head_guy6]

Und dieser mod ist vollig zwecklos.

Die 2L rennmotor hab ich bis 9000 (max ps 7900) absolut problemlos in 1988, und mein freund mit ihrer Spitfire 1300 ganz die selbe.

Vergess es was Kastner schreibt dabei.
Wir haben bis 115ps/L problemlos mit die ganz originale KW.

[pravg]

aber das ist gerade der Punkt der ich versuche zu klären!
Wenn die TR Motoren alle schon cross-drilled Kurbelwellen hatten dann handelt es sich auch um "ganz originale KW"

Ich bin doch etwas weiter gekommen denn auf der Revington site https://www.revingtontr.com/shop/produc ... tID=301815
fand ich, dass ab TS881E die TR Kurbelwellen cross-drilled sind!

Es ist wahr, dass cross-drilling aus der Mode gekommen ist aber Einige schwören noch immer darauf, schau mal hier https://www.cambridgemotorsport.com/EN4 ... l-Lip-Seal

[head_guy6]

aber das ist gerade der Punkt der ich versuche zu klären!

Wenn die TR Motoren alle schon cross-drilled Kurbelwellen hatten dann handelt es sich auch um "ganz originale KW"

Dolomite 16V hat auch gehabt aus EN40B.
Und? Auch zwecklos....

Dieser kw hat viel von wucht moment MEHR zu tun (aus ENGL)

TR5 crankshafts are "semi balanced", like Jaguar XK.
The balance factor is made up by the rather flawed system of a huge central balance weight + "conrod balance factor".

This causes HIGH centre main bearing loads and fundamentally poor balance.
Severe torsional vibration component is also a limiting factor, and is directly related to output torque & crank flex.

When this gets out of control, things get broken.

The Dolomite 16V was a good illustration of this problem.
It suffered high order crankshaft resonance problems resulting in REGULAR FRACTURE of the centre main bearing supports, especially at racing rpm exceeding 7000-7500rpm.

The TR4 crankshaft suffers very similar problems.
Out of balance resonance and crankshaft flex because of the very high loads centred over the single centre main, and poor design.

This nearly always results in fatigue failures at the front or rear of the crankshaft.

The problem is exactly the same on the TR5/6 crankshaft, (but can be improved by using much lighter pistons & conrods, to move the failure point away from the critical areas) as they are inherently balanced in primary and secondary balance.

If you want to know why I totally redesigned the TR6 crankshaft for manufacture in steel, and moved to a FULLY balanced (but out of phase) design this is WHY.
It is the ONLY way to reduce main bearing loads properly, and can result in a stiff crankshaft lightened by as much as 35%.

The cross drilling was always an irrelevancy.
It just serves to increase the flow into the 4 CENTRE conrod bearings which have shared oil supply.
(The outer ones are NOT shared).
You are therefore NOT strengthening anything, you are making additional demands on the oil supply.

The current oil pumps being supplied by Bastuck for TR4 in this respect are knowingly DEFECTIVE.

Really, if you cross drill the crank you must be aware you will REDUCE the oil pressure in the main line.
Also,- for high revs, they are not known as being "low pressure" cranks, so they will suffer from cavitation as well as centrifugal starvation.

It is important to use top quality (VP2) bearings in this case, as the loads/film strngth will exceed the design limits of Glacier (Sn-al) type bearings at high speeds,, and result in them being DEFORMED out of shape.

FYI, the reason modern 16V engines usually work better and are more reliable is simply because they have 5 or 7 main bearings, cradle type main line support, and have FULLY counterweighted cranks, as well as properly designed oil galleries, which resist cavitation and centrifugal starvation.

Take a look at a modern FORD 16V Zetec or Rover K series, and you will see this principal in action.