Chain tensioner adjustment, turned in to major failure
Moderator: alh
Re: Chain tensioner adjustment, turned in to major failure
Motor arrived at Nose2Tail in Holland safely, and I received some news regarding the for standing rebuild.
It seems to be a bearing failure at the lower cogwheel that caused the disaster and set of a chain reaction of internal damage..
Good news, the crank seems to be all right but unfortunately the left bank cylinder head are beyond repair, so I need to salvage one?
Springs, valves, rods etc. have more or less some traces of damage, but they had to be replaced anyway.
Now, the will be made a list of parts that needs to be ordered and the rebuild can start in a month or two?
It seems to be a bearing failure at the lower cogwheel that caused the disaster and set of a chain reaction of internal damage..
Good news, the crank seems to be all right but unfortunately the left bank cylinder head are beyond repair, so I need to salvage one?
Springs, valves, rods etc. have more or less some traces of damage, but they had to be replaced anyway.
Now, the will be made a list of parts that needs to be ordered and the rebuild can start in a month or two?
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Re: Chain tensioner adjustment, turned in to major failure
Interesting find, I'm sure you'll feel some consolation knowing that it was not related to the chain tensioners! By the way, the last picture makes a beautiful poster. What an engine! Imagine what it will be like when it's all back together looking better than ever. I know it's not original, but I painted my valve covers red with the Dino showing through in metal. The sight when you pop the hood is just great. Good luck!
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- Posts: 167
- Joined: Sat Feb 21, 2015 8:42 am
- Dino: Fiat Dino 2.0 Coupe
- Location: The Netherlands
- Contact:
Re: Chain tensioner adjustment, turned in to major failure
Dan,
I was there by coincidence last Friday and they were just opening up your engine when i walked in. Really sad to see the damage that occured.
But what i heard from them and what i could conclude myself was well was the following.
The studs from the camshaft bearing caps are made of 5.6 grade steel. The torque spec. for the nuts that torque down these bearings are actually to high for a 5.6 grade steel stud. Therefore if you torque these bearing down to the specified torque these studs stretch up. I have seen and measured these studs at their facility and they really are stretched, all of them at every cilinderhead from every engine. You will notice that because the tread is stretched and the nut will not get on it without resistance. So what they do over there with every Dino cilinderhead is replace all the studs with 10.9 grade studs and special notched nuts that can not come loose.
What happened in this case is that one of the studs was so stretched that the nut came completely loose, it feel off at some point and ended up falling between the teeth of the drive gears for the camshafts. This damaged the gears and because of the high force needed to sqeeze that nut between the gear it also ruined the bearing from that shaft.
This got worse rapidly until it really broke down. Probably by tensioning the chain to try to get rid of some unwanted noised the forces on the gears and the broken bearing got even higher and death penalty was declared...
Well it's in good hands now. Keep us updated because this can be informative to everyone over here.
I was there by coincidence last Friday and they were just opening up your engine when i walked in. Really sad to see the damage that occured.
But what i heard from them and what i could conclude myself was well was the following.
The studs from the camshaft bearing caps are made of 5.6 grade steel. The torque spec. for the nuts that torque down these bearings are actually to high for a 5.6 grade steel stud. Therefore if you torque these bearing down to the specified torque these studs stretch up. I have seen and measured these studs at their facility and they really are stretched, all of them at every cilinderhead from every engine. You will notice that because the tread is stretched and the nut will not get on it without resistance. So what they do over there with every Dino cilinderhead is replace all the studs with 10.9 grade studs and special notched nuts that can not come loose.
What happened in this case is that one of the studs was so stretched that the nut came completely loose, it feel off at some point and ended up falling between the teeth of the drive gears for the camshafts. This damaged the gears and because of the high force needed to sqeeze that nut between the gear it also ruined the bearing from that shaft.
This got worse rapidly until it really broke down. Probably by tensioning the chain to try to get rid of some unwanted noised the forces on the gears and the broken bearing got even higher and death penalty was declared...
Well it's in good hands now. Keep us updated because this can be informative to everyone over here.
Re: Chain tensioner adjustment, turned in to major failure
Thank you guys...
Yes, it is a relief knowing that it was not the adjusting of the chain that caused the failure, I knew that all along, but to be certain is nice..
What concerns me most, are the damaged cylinder head, that needs to be replaced, I hope I can find one, that are not to expensive?
Now I just wait for N2T to send me a list of parts, needed for the rebuild, also hoping some of the original parts are still in a good condition to be reused..?
I´ll keep you all posted along the way...
Yes, it is a relief knowing that it was not the adjusting of the chain that caused the failure, I knew that all along, but to be certain is nice..
What concerns me most, are the damaged cylinder head, that needs to be replaced, I hope I can find one, that are not to expensive?
Now I just wait for N2T to send me a list of parts, needed for the rebuild, also hoping some of the original parts are still in a good condition to be reused..?
I´ll keep you all posted along the way...
Re: Chain tensioner adjustment, turned in to major failure
Hello. Dan,
ir you come out of such a desaster with your offer price in the web will by a good business model for the future....or !?
regards
Peter
ir you come out of such a desaster with your offer price in the web will by a good business model for the future....or !?
regards
Peter
Re: Chain tensioner adjustment, turned in to major failure
Hi PeterPeter B wrote:Hello. Dan,
ir you come out of such a desaster with your offer price in the web will by a good business model for the future....or !?
regards
Peter
I´m not sure where you going...?
Re: Chain tensioner adjustment, turned in to major failure
The last of a very long list of parts are about to be ordered and delivered to N2T.
It´s been a very pleasant surprise to see all those parts needed to make the motor running again, there are absolutely no short cuts made, so I´m sure that it will be a blast, and most important, a reliable car for the next owner and caretaker...
While I´m at it, all bushings in the front, including new steering parts will be replaced to, just to make sure everything are done properly.
It´s been a very pleasant surprise to see all those parts needed to make the motor running again, there are absolutely no short cuts made, so I´m sure that it will be a blast, and most important, a reliable car for the next owner and caretaker...
While I´m at it, all bushings in the front, including new steering parts will be replaced to, just to make sure everything are done properly.
Re: Chain tensioner adjustment, turned in to major failure
Hello Dan,
I was talking about the 89T€ on mobile...
Good luck
kind regards
Peter
I was talking about the 89T€ on mobile...
Good luck
kind regards
Peter
Re: Chain tensioner adjustment, turned in to major failure
And negotiable....Peter B wrote:Hello Dan,
I was talking about the 89T€ on mobile...
Good luck
kind regards
Peter
Re: Chain tensioner adjustment, turned in to major failure
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Last edited by DanWils on Thu Jul 11, 2019 8:27 am, edited 1 time in total.