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Engine rebuild - rod bolt failure

Old 11-04-2018, 09:50 PM
  #16  
docdrs
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Originally Posted by street rod View Post
What is the rationale for switching to 10w-60?
I was wondering the same. Are the tolerances in a rebuild greater ? A thicker oil will be harder to push and thus reduce lubrication , flow and cooling capacity? It might reduce piston slap in larger tolerances?

oh no , is this turning into another oil thread
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Old 11-05-2018, 03:49 AM
  #17  
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I was told the new motor would run 10w-60 but will have to ask why. I have a feeling that it's not an issue of tolerances but more about heat tolerance. The new motor will generate more heat and must withstand being run hard with the existing cooling system.
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Old 11-06-2018, 03:53 PM
  #18  
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Originally Posted by Coopduc View Post
Racer- are you sure the crank can be saved? These main and con rod journals look bad, and there is indication of excessive heat in the area. Hope I’m wrong, and like to hear the shop’s rationale and/or plan to rework it. It may help others save their engines.



Not worth the risk reusing that crank. Anything that looks like that we fail.
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Old 11-06-2018, 03:56 PM
  #19  
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Originally Posted by racer5j View Post
I was told the new motor would run 10w-60 but will have to ask why. I have a feeling that it's not an issue of tolerances but more about heat tolerance. The new motor will generate more heat and must withstand being run hard with the existing cooling system.
There is no reason to run a 10w60 unless trying to band-aid something.

I just had to reply to this thread as I've seen people try running 10w60 and end up causing engine failures (spun rod bearings specifically) because of the thicker oil. Pressure is restriction to flow and unless the clearances are opened up significantly, there won't be enough oil flow and you'll have cavitation and end up causing elevated oil temperatures due to increased friction.
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Old 11-06-2018, 04:00 PM
  #20  
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Originally Posted by racer5j View Post
Coopduc- The crank has been confirmed to be repairable. Initially, Vision didn't think the damage was too bad. Mainly, they were concerned with whether the crank was cracked. I am going with their "sport" crank which is knife edged so perhaps some of the damage gets machined off in the process. Also, according to some websites, it seems that even significant damage (excepts cracks) can be repaired without compromising strength. The repair process involves welding on material and then machining the excess off. I'll ask about the heat discoloration on the journals. I used to run 5W-40 with high zinc content but will switch to 10w-60 in the new motor.

Thanks everyone for the input. Much appreciated. I have a feeling that I won't be able to replace/upgrade all these items but will do my best to cover as many of them as possible. Please keep it coming.
We've tried welded cranks in these engines and maybe they might hold up for street use, but on the track, they won't last long. I broke a repaired crank in my Boxster over a decade ago. Not worth it in my book to try to save a damaged crank when a good used one can be sourced or a billet one made. Crank failures or any on track failure for that matter renders cores pretty much junk. Again, not worth the risk.
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Old 11-06-2018, 04:01 PM
  #21  
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Originally Posted by JustinCase View Post
Based on what I did in my rebuild, everything you have above plus low temperature thermostat, LNE's billet aluminum paddle for the chain tensioner (and replacement guides), ARP carrier through bolts and head stud kit, and coated main and rod bearings. I assume you are getting the liners plated with Nickel Silicon Carbide ("Nickies") to replace factory Lokasil. I went with the pressure-fed oil plain bearing "IMS Solution" to avoid using a ball or roller bearing altogether as my extravagant upgrade, but if I could have afforded more, I would have upgraded the rods, too. I did take the opportunity to replace my clutch since the engine and transmission were already apart and it only really cost me the price of the parts (original clutch was at about 50%, so it was kind of a "push").
Vision doesn't use Nickies. They use iron liners.
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Old 11-07-2018, 03:58 AM
  #22  
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Just a quick update. Charles and Coopduc were correct. It turns out that we cannot use my old crank.

As for the oil, we can run a higher weight oil here in Socal because it rarely gets colder than 50 degrees at night and is regularly 80-100+ during the day all year round.

Vision uses chromoly. Sure, there are certain benefits to Nickies and RLers have been conditioned to believe they are the only option. They are not. I was at SEMA last week and talked to several sleeve manufacturers for Hondas to top fuel dragsters. The majority of them use some form of steel alloy. Also, I have not seen Nickies in 4.2L bore sizes.

If Flat6 was closer and didn't have a 6 month wait list, I might have given them a second thought but outside of them and Vision, I don't know of any other shop that offers a proven engine package.

I have no doubt in my decision to use Vision for my rebuild. Their reputation and service is second to none here in Socal and amongst the PCA community. Their motor is a developed package proven on the racetrack. I'm sure it's more than good enough for my purposes. Another plus is that they are just 10 minutes away from my house and if I wasn't so busy I could drop in whenever I want to.
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Old 11-07-2018, 06:00 PM
  #23  
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Are you doing ECU flash? Just wondering.
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Old 11-08-2018, 03:38 AM
  #24  
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Yes, will have to do a custom tune on the dyno.
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Old 01-09-2019, 04:21 AM
  #25  
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Just wanted to provide an update. I got my car back a week ago after the 4.2L engine rebuild and I cannot be happier with the results. The car accelerates so effortlessly that it feels like a few hundred pounds were removed from the car. There's more power throughout the entire rev range. I read somewhere that going to a really large bore would move the power curve downward in the rev range but that was not the case. Peak power occurs at slightly beyond 6600 rpm. Stock intake and exhaust before and after.

I have to really thank Vision Motorsports for doing a stellar job and turning around my car quickly despite the holidays and being super slammed. They are truly a top notch race shop.

I really look forward to the coming weeks and falling in love with my car all over again.
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Old 01-09-2019, 04:33 AM
  #26  
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Glad things worked out. Give us an update every now and again.
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Old 01-09-2019, 05:42 AM
  #27  
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some vid and pics always help
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Old 01-09-2019, 09:39 PM
  #28  
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Is it rude to ask the cost? I'm interested, hopefully far in the future...
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Old 01-10-2019, 07:05 AM
  #29  
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Flat 6 Innovations gets all the Nickies larger than 4.0 liters. Jake does all the product testing for LN and for his involvement in developing these solutions, there are certain things he only gets. There are two 4.3 builds in progress now. I believe one of them is for a Rennlister out of MN.

I've done Nickies for Hondas, Nissan GT-Rs, and even a four cylinder that was SBC based. Yes, for some applications steel sleeves will suffice, but there are performance gains to be had with aluminum cylinders and nikasil bores. We are currently working on applying SUMEbore to our Nickies as that's the next innovation in the industry. We're looking forwards, not backwards, for innovation.
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Old 01-11-2019, 01:23 AM
  #30  
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No one doubts that Nickasil liners have certain benefits but, as I said, they are not the only viable option and now you just admitted it on the record. Further, as it stands, the only options larger than the typical 4.0L builds are Vision and Flat6. Flat6 uses Nickies and has 6-12 month wait. Vision uses chromoly, is 10 minutes from my house and is at the track basically every weekend where their cars/motors are pushed to the limit. My choice was pretty clear.

I certainly was not going to send my car to a shop that buys 4.0L Nickies off the shelf and just slaps it all together. I wanted a developed and proven product. I am sure the reason why only Jake gets the 4.3L liners is because they aren’t plug-and-play like the 4.0L liners. That is, you can’t just install 4.3L liners without modifying other aspects of the motor. Those modifications require development and testing, which again only Vision and Flat6 has done.

I would have gladly used your 4.3L Nickies in my motor if it were an option but unfortunately it was not. I made my decision based on my own research, talking to other sleeve manufacturers and my previous experiences with Vision. Having had my car for a week now, I have zero regrets and could not be happier.

I get the sense that there is history between you and Vision, hence, your motivation to continually poo-poo my rebuild, which I do not appreciate. Regardless, my car is done so I’m signing off now. Rest assured, there are plenty of other current build threads on which you can push your product and clearly biased opinion.
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