Hi All,
Its my first day here and I need some advice from the knowledgeable people who know and inhabit this forum.
Its a question about crankshaft bearings, big end bearings, bearing codes and general engine bearings.
Before joining the forum for 'real' today I have looked through a good number of posts regarding crank bearings but unable to find an answer I need.
I have bought a 400/4 in many, many boxes, you know, the 90% complete project with the vital missing 10% made of unobtainium materials.
I have completed stripping the half stripped engine and need advice about crank bearings. Knowing from experience what a minefield measuring cranks is I used plastigauge to measure the clearances. The stamping on the rear crankcase half are: BBBBA. One of the crank webs has a number of 50106 although I am not sure if these actually mean anything. I reassembled the crankcase with the crank installed and plastigauge placed on each bearing journal. I assembled the crankshaft in the bearings dry, no oil added to the bearing shells. I torque set the lower crankcase bolts to the required tension. On disassembling I measured the plastigauge on the crank journals. The readings were 0.050, 0.045, 0.063, 0.055, 0.050 (metric measurements).
Question 1: Can anyone please tell me if the bearings are within wear limits, I cannot find any reference in the Haynes or Clymer manuals advising what the wear limits of the shell bearings are? I have a nasty feeling they are terminally worn. This leads to:
Question 2: How do I measure the crank journals accurately? I have a mic but this only reads down to 100th of a mm, Honda measurements are in microns (32+0 -0.010u)! Having measured the crank journals using the mic I have obtained the following readings: 31.76, 31.70, 31.82, 31.80, 32.00. Unfortunately I cannot believe any of the readings I have obtained as I get a slightly different reading every time I measure each journal, I'm talking of differences of 100ths of a mm but its enough to cast serious doubt.
If I do need new bearings I think I need Black, Black, Black, Black, Yellow?
Question 3: If I need black bearing shells does anyone know of a supplier, DS and CMSL don't have any. Should I start crying yet?
Question 4: Big ends - Any advice please on a type of socket to use to remove the big end nuts, the nut is obscured by the curvature of the big end, a 3/4 socket is too big and a 1/4 socket wont move the nut. It doesn't hep that someone has already been there previously and rounded a couple of the bearing nuts, not badly but Mr Honda obviously didn't put them in like that!
Question 5: The con rods are marked with what appears to be a number and a letter, I though they should only have a number. The numbers (and letters) I have found on each con rod are: 1D, 2D, 21(should it be an 'I'), 21 (same as rod no.3). The rods and ends are correct pairs, I can see they haven't been swapped with each other as the numbers and letters are stamped half on the main rod and half on the lower shell cap. Can anyone advise what bearing shell colours I need?
Question 6: Can the con rod bolts be reused once undone or are they stretch bolts? (exxxpppeeennnsssiiiveee
)
Question 7: Does anyone know the OD and ID of the main engine bearings, the parts manual only provides part numbers, can anyone recommend a bearing supplier? Do I, or should I, replace the main engine bearings considering I have the engine in bits and never heard it running?
Apologies for all the questions, its just the crankshaft bearing issues appears to be a can of worms!
One last question, can anyone recommend a good painter, I have a tank with a slight dent in primer and a couple of new sidepanels from DS that also require painting in the F2 maroon with the pinstripes.
Thanks for reading this far
.
Dave