im not sure what is "precision cracked type". Let me explain what's in the red circle. There should be a hole in there, just like on the other side ( on the same photo). When assembling, the hole is supposed to be inserted by a sharp obtuse object which is part of the connecting rod. The purpose is to make the connecting rod and the cap to be positioned precisely. The "obtuse object" broke off from the connecting rod, so I circled it. hope that explains it. Is it called precision cracked type?
I don't see a lot of F430 engine data to be posted here or in the service manual ( it was left blank) So I'd think i can contribute something to the forum. And a lot of questions , if I may. to be continued Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
CYLINDER LINER DATA: Maximum wear limit 0.05 mm Minimum concentricity ( IS THIS THE RIGHT WORD? is it called "runout"? ) : 0.03 mm DN = 92 mm +/- 0.008 maximum roundedness( correct wording?) at D3 = 0.015 mm maximum roundedness( correct wording?) at D2 = 0.015 mm maximum roundedness( correct wording?) at D1 = 0.02 mm
Crankshaft data Axial clearance after installation 0.12-0.24 mm Main journal maximum position difference ( I TRANSLATED IT, NOT SURE WHAT IT IS, PLEASE CHIME IN): 0.035 mm Main journal and connecting rod surface hardness : 690-850 kg/mm^2 (HV=525, 0.3-0.35mm) Maximum parallel difference relative to the main journal ( I TRANSLATED IT, NOT SURE WHAT IT IS, PLEASE CHIME IN): 0.01 mm Connecting rod perpendicularity relative to the flywheel flange plane maximum difference( I TRANSLATED IT, NOT SURE WHAT IT IS, PLS CHIME IN): 0.025 mm Main journal perpendicularity relative to the flywheel flange plane maximum difference( I TRANSLATED IT, NOT SURE WHAT IT IS, PLS CHIME IN): 0.03mm Main journal diameter : 62.982-62.995 h5 Rod journal diameter: 43.621-43.637 h6
CONNECTING ROD AND PISTON DATA wrist pin circlip wear limit (use tool ALZF 09206): 0.8-1 mm axial clearance of connecting rods on the same journal: 0.2-0.339 mm piston diameter at D1 in photograph: 91.947-91.963 mm piston diameter at D2 in photograph: 91.917-91.933 piston diameter at D3 in photograph: 91.467-91.483 wrist pin to rod clearance: 0.015-0.03 mm wrist pin to rod clearance wear limit: 0.05 mm wrist pin bushing interference with SOMETHING that im not sure: 0.04-0.09 mm rod bearing to journal clearance: 0.015-0.048 mm rod's small end maximum out-of-roundedness ????? : 0.005 mm rod's big end maximum out-of-roundedness ????? : 0.005 mm wristpin diameter 19.995- 20.000 mm
I translated these from chinese, somebody who's been building engines chime to correct my English? It took me 2 hours to translate them......
In my opinion, yes. YMMV IF YOU were to decide to not do above, DO NOT leave a pit. Needs to be completely removed with smooth transition, i.e. blend. This would require removing more material, i.e. the blend will be deeper than the current dent/pit/spalling. I do not deal with rotating machinery in my day job, but I do deal with surface finish issues, e.g. scratches and corrosion. We completely remove such discrepancies. Good luck.
I've looked at the photos on a desktop PC and now see much better - yes, you're correct: that's a broken dowel (roll pin in this case) to locate the rod cap onto the rod. These are not precision cracked rods but the standard type which have machined mating surfaces and then the bearing surface is machined after.
I am no expert but in my opinion a pit on the bearing surface is a big issue. The bearings are supported on an oil film created by oil pressure from the pump. The pit will impact that film thickness and stability and that can cause the surface to not be properly supported. This is why cranks are precision machined.
I forgot to mention: thankfully the prices for F136 engine components are relatively low. In line with Mercedes or BMW.
yep, now our biggest concern is the crankshaft. That's one single big ticket item. A new crankshaft is more than US$6000. Rods are well within a few hundred dollars a piece. Bearings are under $25 a piece.
That "pit" on the crankshaft looks like the hardened surface peeled off. If that is the case, you'll need a new/used crankshaft.
Doing shake down testing on this in next few weeks. Ready for install Q1 next year.. Part of a reflash. That's it
it is confirmed that the crankshaft is beyond repair, it is roughly 0.2 mm deep. Image Unavailable, Please Login
I would be very surprised if it was a roll pin- these are called location dowel and generally a solid ground steel pin- roll pins at 9000 revs wont last long.
It will depend what range of oversize bearings are available, plus 40 thou bearing used to be common on fords etc.
The bearing is supported by the crankcase and its main bearing cap, or the piston rod and its cap. The crank pin and crank journals are then supported by the oil film pressure- ie they float in the oil film due to the pressure.
new information. the car does NOT knock whatsoever before he had an oil change about 45 days ago. The oil we used 45 days ago is 5w40. The oil could be a knock-off. (it is rampant in china to have sub standard oils with top brand bottles) Then the small knocking sound was cured by replacing the knock-off 5w40 with genuine 10w60 about 10 days ago. We are not sure if it would have a small knock if we replaced the oil with genuine 5w40. The cold rev happened about 5 days ago.
So what did you say that I didn't? Unless you are trying to differentiate between the bearing and cap. The two surfaces of the bearing are the bearing and (in this case) the crank. The crank has a pit. How is that not part of the bearing surface? Am I missing something you are trying to say?