- Joined
- Jan 24, 2015
- Messages
- 239
I have done no machining lately, but this is a tale about what I have done, with a bit of machine history thrown in. One thing I don't mention below is that the car in question was my mom's. She got it from my dad in 1953 for a Xmas present (when it was just a 19 year old used car). I took over stewardship of the car after my father's stroke in 2001. I grew up working on this car, and it was a big reason for my current love of old machines and physics.
Mike,
The car has a fully pressurized oil systems, with 9 main babbitt bearings, each being fed from pump after filtering. The oil then goes though the main journal to the rod journals.
The bearing conversion was done in 1986. It had many happy miles after that.
In 1986 the engine went in for a complete rebuild after rod 6 broke while my brother was driving it (probably far to fast). The rod conversion was done, all mains were re-poured, line-bored and scrape fitted, the cam was ground, cylinders 1-5, and 7-8 were over-bored .040. Cylinder 6 was too far gone do to the rod breaking. It was sleeved. Hardened exhaust valve seats, etc were also done.
In 2010 I detected a slight miss. The car had to go back to the shop for some warranty work (a body and frame restoration were done from 2002-2007). Tom (the restorer) found that cylinder 6 was hosed. The sleeve from 1986 had slipped. Luckily it was a dry sleeve. Some major welding was necessary because of the damage that was done to top of that cylinder, and some additional exhaust valve cracking in the surrounding cylinders. The welding warped the block, so it was decided to sleeve all cylinders and bring it back to stock size. I got the car back about a year ago, and have driven it about 500 gentle miles (including the F1 driver's parade). No work was done one the lower end, as inspection showed the bearings and journals to be in great shape and well within spec.
There was plenty of oil on the rod journals when I took them apart, so oil was not the problem. My project for Thursday was further investigation.
So, my project of the day:
Poke around with a flashlight and see what I can see. And what I saw was coolant dripping off the main bearing oil gallery. I looked up cylinder 6, and saw evidence of coolant mixed with oil along the cylinder walls. All other cylinders just had oil.
I took out the plug from 6, and there was no evidence that it was wet or burning coolant (nor had the car been putting white smoke out the tailpipe).
I wiped up the fluids in and around cylinder 6 (as best I could) and let it sit overnight. What I found upon my return was this:
It is a little hard to see, but those two drops of green are coolant, and they came from the bottom of the sleeve. For cylinder 6, because of how screwed up it was, we had to go with a wet sleeve. Obviously, there is a leak. More than likely, that small leak is what destroyed the bearings.
Enough with my tale of woe. Here is something that actually turned out nice, the outer head for the steam engine I am making:
Mike,
The car has a fully pressurized oil systems, with 9 main babbitt bearings, each being fed from pump after filtering. The oil then goes though the main journal to the rod journals.
The bearing conversion was done in 1986. It had many happy miles after that.
In 1986 the engine went in for a complete rebuild after rod 6 broke while my brother was driving it (probably far to fast). The rod conversion was done, all mains were re-poured, line-bored and scrape fitted, the cam was ground, cylinders 1-5, and 7-8 were over-bored .040. Cylinder 6 was too far gone do to the rod breaking. It was sleeved. Hardened exhaust valve seats, etc were also done.
In 2010 I detected a slight miss. The car had to go back to the shop for some warranty work (a body and frame restoration were done from 2002-2007). Tom (the restorer) found that cylinder 6 was hosed. The sleeve from 1986 had slipped. Luckily it was a dry sleeve. Some major welding was necessary because of the damage that was done to top of that cylinder, and some additional exhaust valve cracking in the surrounding cylinders. The welding warped the block, so it was decided to sleeve all cylinders and bring it back to stock size. I got the car back about a year ago, and have driven it about 500 gentle miles (including the F1 driver's parade). No work was done one the lower end, as inspection showed the bearings and journals to be in great shape and well within spec.
There was plenty of oil on the rod journals when I took them apart, so oil was not the problem. My project for Thursday was further investigation.
So, my project of the day:
Poke around with a flashlight and see what I can see. And what I saw was coolant dripping off the main bearing oil gallery. I looked up cylinder 6, and saw evidence of coolant mixed with oil along the cylinder walls. All other cylinders just had oil.
I took out the plug from 6, and there was no evidence that it was wet or burning coolant (nor had the car been putting white smoke out the tailpipe).
I wiped up the fluids in and around cylinder 6 (as best I could) and let it sit overnight. What I found upon my return was this:
It is a little hard to see, but those two drops of green are coolant, and they came from the bottom of the sleeve. For cylinder 6, because of how screwed up it was, we had to go with a wet sleeve. Obviously, there is a leak. More than likely, that small leak is what destroyed the bearings.
Enough with my tale of woe. Here is something that actually turned out nice, the outer head for the steam engine I am making:
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![00b0b_c3VA0arPPA0_600x450[1].jpg](https://www.hobby-machinist.com/data/attachments/84/84098-8dc44e6191c2a66f1396fe519370d3e7.jpg "00b0b_c3VA0arPPA0_600x450[1].jpg")