head coming off again

[ricster]

I'll have to hunt around for the p[art numbers for the pistons. I still have a set of rings for 2 pistons ( might be for 1 piston as I think I broke a ring when I was rebuilding the motor) in a the box. I'll look for it and post the part numbers.

I can't believe that the cost to piano wire the block is the same as re doing the sleeves. The stainless steel shimstock I bought cost probably R400 and a few hours to cut the perfect rings. But it they set the sleeves 100% and a proper head gasket with correct torque settings and you should be puffing diesel smoke like a champion !!!

Thanks again to Frans...

[Michael]

Ricster,

Just want to have some more info on this piano wiring the block.
Is this different from o-ringing the block where you have the engineers cut a 0.4mm groove on top of the sleeve and then you insert a copper/piano wire of 0.8mm inside the groove?

Like the following pics

[ricster]

The principle is the same, just that the way you show is far more professional. The copper will squash and form to the shape and space between the head and the sleeve. For example if the one side of the sleeve is 0.1mm lower or higher than the other side, the copper ring/wire will squash to form a perfect seal. On my block I notices that the sleeve is some places was slightly proud, but still way below max spec and other places were flush or a fraction below the height of the block. The stainless shimstock I used ( used stainless due to its high melting point, and that they didn't have stock of copper shimstock ) i cut into rings that sat perfectly on top of the sleeves. I lay them on the sleeve tops and placed the head on carefully to ensure that the rings don't move at all. This creates a perfect seal between the head and the gasket and a perfect seal between the head gasket onto the stainless ring and the sleeve. If I recall correctly, I didn't use the thinnest head gasket, and was working on the principle that there was more "spongyness" in the thicker head gasket and that with the massive torque on the head this would give a better squeeze onto the rings and sleeve tops.

I have since done 65 000 Km and service EVERY 5000Km on this motor. I don't play silly buggers when I drive, I work the motor..... I don't abuse the motor, but I use that 4.2L like it should be used, and whether loaded to 3.5ton pushing through Botswana snotty mud in the pans, or through the snow in Lesotho, that motor chugga chugga's like a sweet kitten purring with laryngitis.......

Would I Piano wire the block over putting the rings on...... yip that's a much better way to do it. My way was a little cruder and cheaper, but done properly the effect is the same. I recon that motor of mine will still comfortably do 500 000Km!!

[Michael]

Thanks for clearing up the confusion I had

what thickness shimstock did you use? Did you cut them out by hand?

I will give those guys you recommended a ring and get some prices. You said you may have some shimstock left when we spoke? will gladly purchase it from you if you still have

[Andre Steyn]

Good morning everyone, thanx Cedric I need those numbers. Concerning the piano wire vs the resleeve in ou area the guys tell me straight they don't feel confident doing the piano wire besides the engineer is charging me R83 per sleeve for resleeving cos its the second tine! Did you use genuine headbolts and head gasket?

[ricster]

Cant recall the thickness offhand. I'll get it out the garage tonight. I think it was 0.5, and seem to recall that the highest point on my sleeves was 0.2 with most of the sleeves flush or 0.1 under.

Its a bast..... bliksem to cut. I sat with a compass with a sharp needle and scored the outer ring and inner ring, I cut the outer ring once a deep grove had been made and then cut carefully with sharp sissors. The inner is a little more difficult to cut, as its only about 4mm wide between inner and outer. It took a bit of time to do, so If you can cut the sheets into squares and sandwich it between 2 plates and get it lazer cut, then that would be the best and quickest. You don't want to kink the ring in any way.

[ricster]

Andre, I'll get into the garage tonight and get them.

Thats a good price to resleeve !! No offence meant to ANY engineering shop by what OI'm saying here, but to get the correct protrusion is no easy task, and not many Engineering shops can do it successfully. I mean 0.7mm is such a tiny protrusion to start with, but It can be done !!

Piano wiring, in my opinion is not a well known thing, and doesn't get done often, so I can understand and relate to the caution shown by the Eng shops.

I think the guys that race engines will be able to give you better info on piano wiring a block than anyone else.

[Michael]

Cedric,

Is the spec not 0.02mm to 0.09mm for the sleeve projection?

I found this in a manual I downloaded but not sure how it compares with yours

[ricster]

Oops yes sorry..... then I think my shim stock is 0.05mm. That zero can make a BIG difference....hahaha

Was nearly 4 years ago that I did the rebuild

[Andre Steyn]

Jip cedric, I nogal spoke to a guy that builds race and drag engines his opinion was the whole piano wire thing is a load of rubbish but admits to having done it to some diesel race car in the past only cos they were running 2.8bar boost. My engineer said to me today that its going to be a task to get the sleeves absolutly right, with a range of 0.02 to 0.09 what should mine be?