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#1
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Aluminum block honing
Hi
I didn't find any pics of aluminum block honing in this forum, so here are some. Honing this blocks is a 4 stage process. this are the stones used for the first 3 stages. Left to right: Course stone (first stage) medium stone (second stage) polishing stone (third stage) This are the felts for the 4th stage Sorry, i don't have any new ones on hand right now. The silicone paste used in the 4th stage. A pic of the block in the honing machine. A cylinder just after starting the honing process. Notice the wear ridge from the first piston ring, also faintly visible the one from the second ring. Cylinder after the first stage. Most of the material is removed at this point. 0.08 to 0.1 mm remains in the cylinder. After the second stage. About 0.02 mm left. After the third stage (polishing). Notice the reflections in the cylinder. Hone marks are still visible. Cylinder is at final size. After the 4th stage. Cylinder is finished. Reflections and hone marks are gone. The surface is dull gray and featureless. 4 cylinders in 4 stages of machining.
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76 240 D. Bought in 1998 for $25. 85 300D. Got it for free with a bad engine. ( Sold ) 60 Unimog 404. What was left of it, was given to me. Now powerd by 617A. 88 560 SEL. Bought without engine and trans. Now powerd by 617A. 67 250 SE. Cuope. For resto or sale. 64 220SE. For resto. |
#2
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That is cool, thanks.
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#3
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I always believed you wanted the crosshatching per your stage 1 photos.
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'02 BMW 325i '85 300D 450k '93 190E 2.6 170k(killed by tree) '08 Ducati Hypermotard 1100S 6k '06 Ducati S2R800 14k(sold) |
#4
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On cast iron cylinders you shoot for about stage 2, but not on this aluminum ones.
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76 240 D. Bought in 1998 for $25. 85 300D. Got it for free with a bad engine. ( Sold ) 60 Unimog 404. What was left of it, was given to me. Now powerd by 617A. 88 560 SEL. Bought without engine and trans. Now powerd by 617A. 67 250 SE. Cuope. For resto or sale. 64 220SE. For resto. |
#5
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Great photos! Thanks a bunch for posting.
I really did not know the repair process for the aluminum cylinders. The photos really show the patterns with good detail.Are you a tech at a dealer, indy, or?
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Providing a home for these cars: 1951 Buick Special De Luxe 1977 Rolls-Royce Silver Wraith II 1970 Rolls-Royce Silver Shadow 1986 Mercedes-Benz 420 SEL 2005 Mercedes-Benz E 320 CDI 2012 GMC Sierra 1500 4X4 1927 Pierce-Arrow Series 80 1931 Pierce-Arrow Series 43 1926 Ford Model T coupe |
#6
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Quote:
but I still have the equipment. Got hold of a damaged 560 block, that I could mess up for this thread.
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76 240 D. Bought in 1998 for $25. 85 300D. Got it for free with a bad engine. ( Sold ) 60 Unimog 404. What was left of it, was given to me. Now powerd by 617A. 88 560 SEL. Bought without engine and trans. Now powerd by 617A. 67 250 SE. Cuope. For resto or sale. 64 220SE. For resto. |
#7
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Do you intend to rebuild this engine? I ask because MB has a special process for their aluminum bores. While I don't understand all of the nuances it is my understanding that the castings have a high silicon content. For the surface finish the aluminum is chemicaly etched leaving a predominately silicon surface for the rings to wear against. That is how Mercedes gets such an unusually long service life from such a soft material.
FWIW, when BMW first tried to build its aluminum V8, it failed miserably. I've seen those with 10K mi and completely worn out bores.
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90 300TE 4-M Turbo 103, T3/T04E 50 trim T04B cover .60 AR Stage 3 turbine .63 AR A2W I/C, 40 LB/HR MS2E, 60-2 Direct Coil Control 3" Exh, AEM W/B O2 Underdrive Alt. and P/S Pulleys, Vented Rear Discs, .034 Booster. 3.07 diffs 1st Gear Start 90 300CE 104.980 Milled & ported head, 10.3:1 compression 197° intake cam w/20° advancer Tuned CIS ECU 4° ignition advance PCS TCM2000, built 722.6 600W networked suction fan Sportline sway bars V8 rear subframe, Quaife ATB 3.06 diff |
#8
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No ,I am not rebuilding this engine.
I just got my hands on a junk block. See my thread: Another reason to change your timing chain It's the same block. The process shown is the one that Mercedes recommends to re bore this blocks. The 4th stage removes a few thousands of a mm of aluminum from the cylinder walls, leaving the silicon behind. This is done by rubbing the silicone paste into the cylinder wall, using the felts instead of stones in the honing machine.
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76 240 D. Bought in 1998 for $25. 85 300D. Got it for free with a bad engine. ( Sold ) 60 Unimog 404. What was left of it, was given to me. Now powerd by 617A. 88 560 SEL. Bought without engine and trans. Now powerd by 617A. 67 250 SE. Cuope. For resto or sale. 64 220SE. For resto. |
#9
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I assumed those were liners. Is that just the block material we are looking at? How common are unlined aluminum blocks?
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1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine) 1988 F150 144,000 miles (leaks all the colors of the rainbow) Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra |
#10
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All 116 and 117 alu blocks, and to my knowledge all 119 blocks are unlined.
Liners are available for repair purpose. 112 and 113 blocks are made from "normal" aluminum and have alusil liners.
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76 240 D. Bought in 1998 for $25. 85 300D. Got it for free with a bad engine. ( Sold ) 60 Unimog 404. What was left of it, was given to me. Now powerd by 617A. 88 560 SEL. Bought without engine and trans. Now powerd by 617A. 67 250 SE. Cuope. For resto or sale. 64 220SE. For resto. |
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