Jump to content
SAU Community

Recommended Posts

Hi all..

Just rebuild my engine and have been running it for a week and today it died!!

It seems that the crank angle sensor completely seized up and snapped the end of the exhuast cam off!!

Has anybody ever had this happen??

Also, the 4 bolts that hold the exhuast cam gear on were scrapping against the crank angle sensor and there are metle shavings everywhere!!

Anybody shed some light on this????

Link to comment
https://www.sau.com.au/forums/topic/102397-this-has-never-happened-before/
Share on other sites

I actually installed it and did it to the book...

Why is it touching the bolts???

I left the timing belt cover off, I think the sensor bolts onto this after the cover is put on so in theory, if I don't put the cover on, then, the sensor would bolt up that much closer to the cam gear, therefore, touching the bolts??

Does that sound possible???

It seems that the crank angle sensor completely seized up and snapped the end of the exhuast cam off!!

This is very unlikely.....almost certainly the camshaft was cracked, possibly at installation. Under load with the engine running the crack progressed until the camshaft failed completely. The metal shavings, etc are probably from when the cam pulley bolts contacted the back of the CAS or the CAS mount at failure - the engine would have continued to turn for a short time after the ex cam failed.

I've seen a few failures of cams in RB engines as a result of incorrect installation - when doing up the cam cap bolts it's quite easy to put a bending load on the camshaft, and cast iron doesn't take kindly to that.

Anyway, that's my theory, I could tell for certain by examining the camshaft.

One other thing - you need to hope that valves didn't contact pistons.

Thanks for all your comments mate, I will take them on board....

The actualy cam is in one piece, it's just the very tip of it that the crank angle sensor slips onto that snapped off.. that piece is still in the shaft of the sensor when I took it off....

Does that clarify things anymore...

The actualy cam is in one piece, it's just the very tip of it that the crank angle sensor slips onto that snapped off.. that piece is still in the shaft of the sensor when I took it off.... 

Take some pictures if you can, I'm intrigued by how much of the cam has broken off.

Yeah, I will try and take some pics of it.... keep an eye on this thread.. I'll post them here tomorrow..

I will be sure to put spacers in when I put it back together.. an expensive lesson!!

If I were to put aftermarket cams in, what would you all recommend and can I run cams with more lift and longer duration with the standard ecu??

I'm guessing that I can but I just won't get the power gains until I get the ecu changed....

Thanks all..

damn, I did so well with the rebuild too... Did it all and I stuff up something like this... feel like a damn idoit!! Ahh well, you live and learn I guess.....

If anybody has an exhuast cam for the rb25det, let me know..

I have been told that the rb20det is exactly the sam cam so I can use that if I have to......

The half-moon is only an aid to getting the angular relationship between the cam and CAS correct. The CAS keeps turning because of intermeshing of the teeth set on the CAS and the cam.

Without the half-moon, you need to visualise where they would line up. If you get it wrong, the engine won't run (but no damage is caused).

I would love to be able ti use the cam still but it didn't just snap off the half moon part of it, it snapped the whole spline off of the cam down to the end!!!

The whole piece was jammed into the CAS!! Nothing left for the CAS to grab onto caus it got snapped off down to the base!!

I just brought another cam and fitted it last night... Runs like a dream and yes, I've now put some washers in place of the timing belt cover so the CAS doesn't touch the cam geard bolts....

A valuable lesson learnt but if this is the only mistake I've made with the rebuild, then I'm as happy as a pig in....... ;-)

  • 3 weeks later...

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • It's unfortunate what Tomei USA has done to Tomei's name in general. I'm very weary of ordering parts from them now. I only order direct from a Japanse source (e.g Nengun). At least their logos are different, so you end up knowing what you have. 
    • Update Issues 5 (plus #4) - 10 After making a claim about issue #4's missing part, DeAgostini Japan sent a whole new issue #4 and it arrived about 2 weeks after that. That was back in early March. It took another 4 weeks to receive issues 5 - 13 though. This update is for issues 5 - 10. Ove the 5 issues the front left suspension and most of the engine have been completed. The quality of the castings and fit of the parts is quite good, it seems better than DeAgostini's BNR34 Skyline GT-R from the Fast & Furious 2 movie, which (to me anyway) doesn't seem to have as tight tolerances or quite as accurate castings.  Each issue has a lot of info about the 1989 - 1993 Skyline range and other Nissan models from that era, but the focus is on the BNR32 Skyline GT-R Nismo and the various racing it did in Japan, Europe (Spa 24hrs) and of course Australia. I've included some text translated with Google Lens in some photos and will add to them if there's anything worth including. 
    • If it's for a SR20, make sure it's not the American Poncams, might as well call them Poocams. Had a set in a friend's car, all scuffed up after a few track days. Like the metallurgy Tomei USA used is junk. Went back to JDM OG Tomei Poncams, no issues till now.   Tomei USA is not the real OG Tomei.   Random rant over, fk the US of A, bunch of c u n t s. 
    • Most of the industry in North America either runs on Siemens or Allen Bradley. I have two redundant S7-1500's on my desk right next to me for simulation. Siemens has been losing ground though since Stuxnet, as cybersecurity is a big thing. In my line of work that is federally regulated, you must by law have a cybersecurity management program in place and its audited and inspected every so often.  I work with Emerson PLC's daily (RX3i's) and have done large biogas/refinery projects with their DCS's. Their PLC's are somewhat OK minus the way they do PLC redundancy (You have to download on both PLC's separately every time you make a change )  As for their DCS's... you'll be limited financially first before anything else stops you. Costs are exorbiant at roughly 10x what it would cost you to do with any other system (e.g AB PAC).  1990's, those suckers are brand new haha! Kraft-Heinz (An old client when I use to work for an ESP) still runs Siemens TI505 PLC's from the mid 80's. Ohh how I don't miss working with those... you could only do a certain number of online downloads until it's "Change" buffer would be full and you would then need to go offline to do a full download. There was no warning of when this was coming up and it generally would happen when you would go in at 2am to make changes before production -_-.     
×
×
  • Create New...