Same question : And why, pray, might that be ?
Step By Step Engine Build, No Waffel, Just Building..
Posted 21 April 2017 - 12:09 PM
In fact the guys who build the high hp V8 engines clean the block and big end journals and the back of the bearing shells with lacquer thinners - prevents the possibility of the shells spinning in the journal. Of course one then puts oil on the inside of the bearing and the crank journal.
Posted 21 April 2017 - 01:02 PM
Exactly......sorry for not getting back to this sooner. You want maximum dry contact between the shell and the block or the shell and the rod. Putting a layer of oil in there acts like an insulator, and it's like adding a tiny layer of ball bearings between the shell and the block. I agree with cleaning them with lacqer thinner or such.......
Posted 06 May 2017 - 10:11 PM
This was a very careful and meticulous build, with good attention to detail, and there is much to be learned from it. However, there are two errors, one serious because it can wreck the engine, and has done so to others on many occasions. It has resulted in many other broken things too.
The serious one is the practice of centre punching bearing caps to identify them, in a place where the part gets into tension. That is a sure recipe for fatigue fracture. I would not use the services of any engine builder who was doing that. If you must centre punch a bearing cap, it must be on the outer side near the split between cap and rod, where the clamping action of the bolt holds it in permanent compression. It is preferable to use paint or something similar such as Tippex.
The other one is the use of copper grease on the clutch plunger. Copper grease is not for moving parts, and even worse, the combination of steel, copper and aluminium alloy in close proximity is going to be a corrosion trap. A long life, water repellent grease such as Molybentone could be used, or normal graphite grease. Plain old LM in an emergency.
Posted 01 July 2017 - 02:34 PM
great thread, one question, when refitting big end caps, you say that you can feel a difference if the cap is on the wrong way round.
I can't feel any appreciable difference. Is there another way to tell if they are the right way round? I.e. should the two small bent tabs on the big end shells be opposite each other, like side to side?
Posted 02 July 2017 - 06:49 AM
John, thanks for the reply.
I just want to be sure though, facing each other on the same side of the crank (i assume this is what you meant!)? Or facing each other across the diameter of the crank?
**edited, info found elsewhere on this most helpful forum. The tangs do indeed go adjacent to each other on the same side of the crank**
Edited by jonlad, 02 July 2017 - 07:37 AM.
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