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'84 300SD engine ?
I was getting combustion into the coolant-cold or hot, so I removed the cylinder head and took it to the machine shop for pressure testing, by the head gasket there is no breakthroughs, but the fire rings are all black in certain areas, which they thought was a high possible cause for a leaking head gasket, they called me and said the head is .015" warped from one end to the other, they also noted that there is some small hailine cracks at the pre combustion chamber area, but they noted it was not a concern, I cleaned the block deck and one cylinder liner is .0035" below the deck, is this going to be a problem with combustion getting into the coolant, should I put it back together with a resurfaced head and new gasket, or pull the engine down and reset the liner? Engine has 200,000 on it, runs good and runs on Biodiesel. Thanks for your time. Broken Wire
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The head you have with .015in warpage was flat when bolted to the block. The problem with using it in this manner is the tention on the gasket isn't even. When you cut the head flat on the bottom and reinstall it will pull evenly but the warpage will stay on the top. In this amount you will probably gall the cam and it will break. The head would have to be cut on both side to avoid this. In order to cut it on both side everything must be removed including the valve guides which when reinstalled will require the seats to be ground, etc, etc.
Besides the above fun I think the head will be bellow tolerance after two clean up cuts have been made. It will be close. The prechambers will then have to be reshimmed for proper depth. To make matters worse a motor overheated enough to warp the head that much is basically toast. It will be lucky to go 25k before it uses so much oil it cokes the rings and won't start. It would be that way with 100k let alone 200k. I'd fix it right (a whole rebuild with a new head) or put a new gasket on and give it a couple pounds extra torque and throw it away when it fails. Use a headgasket sealer like Hitack on installation and it might work till the rings fail, which probably won't be long.
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Steve Brotherton Continental Imports Gainesville FL Bosch Master, ASE Master, L1 33 years MB technician |
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