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Discussion Starter · #361 ·
Just some fun shots of the stripped down crankcase. It’s quite a work of art. I stop and admire it every step of the process.
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97.0 VT Roadster / 08 Gallardo Spyder
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I’m really disheartened to hear this because at 92,000 km I would not expect a full engine tear down much less twice. If those are aftermarket pistons this engine was already taken down previously which points to 40,000 mile pistons? Seems way too early.
 

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All pistons are out. They are Mahle pistons which I believe are aftermarket. Please correct me if I’m wrong. All big end bearings are worn. There were no broken rings.
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I thought Diablo Oem pistons are from Mahle ?

Btw from the worn bearing pic it seems like there’s lack of engine oil flow through and probably one of the cause of many worn out areas at the bearings , have you checked is your Cranshaft still within spec ?

 

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Discussion Starter · #365 ·
I thought Diablo Oem pistons are from Mahle ?

Btw from the worn bearing pic it seems like there’s lack of engine oil flow through and probably one of the cause of many worn out areas at the bearings , have you checked is your Cranshaft still within spec ?
I have not checked the crankshaft but I'm pretty sure it will need to be ground. I agree on the lack of oil. Possibly some debris in one of the oil passages...? Unless all this happened before I bought the car and it lost oil pressure then. When I got the car it had been running so rich that the oil was full as gas. Not sure if this is enough to cause this amount of damage but its certainly not good. I guess it would depend on how long it was run like that. My pistons are at least very similar to those. They don't appear to be in bad shape but I need to mic them. Does any one have a pic of the backside of an original piston? Mine are a greenish color and say Mahle on them.
 

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Lamborghini did use Mahle pistons in the Diablo all the way to the Murcielago 6.2L. Here's a pic of my Murci's engine when I did a top end rebuild.
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Discussion Starter · #367 ·
Lamborghini did use Mahle pistons in the Diablo all the way to the Murcielago 6.2L. Here's a pic of my Murci's engine when I did a top end rebuild.
Ok great. Thanks for the info! At least I know they’re oem.
 

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Btw may I check where can we get the Mahle piston rings other than directly from lamborghini ?( which are very expensive) . Any direct link on the Mahle Diablo piston rings ?

I found another source (not Mahle) , price is reasonable , has anyone tried these piston rings ?

 

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Discussion Starter · #369 ·
Thanks for the link Leslie. Those are reasonably priced and might be a good option if I can keep my pistons. I haven't started seriously looking at rings yet as I don't know yet what pistons I will be using. Does anyone have experience with Total-Seal gapless rings? If I'm replacing parts I want to make sure I'm getting the best I can within reason. I'm looking for a source for new liners. Any suggestions?
 

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Discussion Starter · #372 ·
I've been doing some measuring to determine just what needs to be replaced other than the obvious (bearings, sleeves, and rings). The crankshaft has not been resurfaced so that it very good considering it can only be done twice. The pistons are looking to be within spec too but I'm still considering replacing them since I'll be doing so much else. Any thoughts on this? I certainly don't want to be replacing perfectly good parts but at the same time I don't want to replace everything but the pistons and leave them as a weak point.
 

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I have determined that at least in my car setting the throttle butterflies to 82 degrees is not possible on at least one of the uppers. This may be due to improper fitment but it seems to be fully closed. For the bottom butterflies it just doesn’t make sense to set to 82 degrees since these are adjusted beyond 82 to set the proper idle.
 

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Discussion Starter · #374 ·
The original pistons all look ok and measure within spec but at the upper end of the specified dimensions so I think it's best to replace them. Looks like I will be going with custom JE pistons made of forged 2618 aluminum alloy with s Tough-Skirt coating. This is a coating applied to the skirt that has unique properties to help with cold startups which I think will be helpful based on how I use the car. Conrods look good so far. I think I will be sending the crankcase to Millennium Tech to have them re-plate the sleeve in nickel silicon carbide. The crankshaft I will be getting refinished. Still in search the right shop to do this. Any suggestions?
 

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I've been doing some measuring to determine just what needs to be replaced other than the obvious (bearings, sleeves, and rings). The crankshaft has not been resurfaced so that it very good considering it can only be done twice. The pistons are looking to be within spec too but I'm still considering replacing them since I'll be doing so much else. Any thoughts on this? I certainly don't want to be replacing perfectly good parts but at the same time I don't want to replace everything but the pistons and leave them as a weak point.
May I get more information about the Cranshaft can only be resurfaced only twice and the reason ? Is this due to the no suitable over/under size bearing ?

Thanks
 

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Discussion Starter · #376 ·
Sorry, I didn't really mean that it CAN'T be ground twice but just that Lamborghini only makes bearings for two undersizes I believe so they probably only intend for you to undersize it twice and beyond that you may be compromising it's structural integrity. I suppose you could get custom bearings and have it ground as many times as it can take until it breaks. It's hard to say where that limit really is I think. Some engine builders actually grind them as small as possible to reduce weight and increase performance. I'm just glad it is original spec to start with.
 

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Sorry, I didn't really mean that it CAN'T be ground twice but just that Lamborghini only makes bearings for two undersizes I believe so they probably only intend for you to undersize it twice and beyond that you may be compromising it's structural integrity. I suppose you could get custom bearings and have it ground as many times as it can take until it breaks. It's hard to say where that limit really is I think. Some engine builders actually grind them as small as possible to reduce weight and increase performance. I'm just glad it is original spec to start with.
Thanks for the info !
 

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Discussion Starter · #378 ·
Progress has been slow due to being so busy with work but I have made some progress lately. I have found additional damage to the oil pump due to debris as well as to the both heads. I brought the heads, the crank and the oil pump/timing cover to the machine shop this week. They think that the cams and crank will polish out without actually grinding them so that's great if thats the case. I should know more next week once they start checking tolerances.

My custom pistons from JE Pistons will be finished next week and will be shipped to Millennium Tech so that they can hone the cylinders after the nickel silicon carbide plating. I'm hoping to have everything else finished up and ready to reassemble by the time they finish with the block but my project seems to be snowballing a bit as usual doing all of the "while you're in there things".
 

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Discussion Starter · #379 ·
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Here you can see the scoring on the timing cover from debris inside the oil pump. (The darker lines from three to six o’clock).
 
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