Damaged Crank - Part Of My Rb26 Track Car Rebuild

[Noddy]

The 2 key set up is a problem on the RB engines. they are often the problem of making it difficult to remove the balancer. The key usualy slips and locks the pully on and if a water pump has had a leak the job can be 10 times harder. Using the correct type of hydrolic puller to remove the pully makes light work of the situation.

I have had the 2 1/2 moon keys removed and use 1 single long key in thier place and have no problems. A highly recomended mod for any RB rebuild. I will have to take some pics on my new race engine when it gets back from the machine shop.

[Beer Baron]

hey mike, if you need new bits to repair the crank i have some genuine nissan half moon keys.

[Beer Baron]

single key set-up sounds like winner too. the stock ones are definitely pussy.

[wrxkilla]

I was just going to buy a new one to be honest ..

thanks though.

no thanks to workshop for not returning my e-mail.

[Redsuns88]

that sucks .... im sure u could fill it in with something..

hope it works out for u bud!

[our12]

Hi.

The damage on your crank snout looks like fretting and was probably caused by your original balancer being loose. The small bits missing are definately signs of fretting.

If damage was caused removing it the marks would be along the nose not around it. The grove around the nose may have been caused by the swarf generated by the fretting however you have to have a broken key (s) to cause this. Damage could been there for years from its Japan days.

Just dress it up and reuse it ive seen worse. As Richard stated the balancer uses the snout to locate it the keyways do all the work

Some advise obtain new keys.

[Beer Baron]

Hi.

The damage on your crank snout looks like fretting and was probably caused by your original balancer being loose. The small bits missing are definately signs of fretting.

If damage was caused removing it the marks would be along the nose not around it. The grove around the nose may have been caused by the swarf generated by the fretting however you have to have a broken key (s) to cause this. Damage could been there for years from its Japan days.

Just dress it up and reuse it ive seen worse. As Richard stated the balancer uses the snout to locate it the keyways do all the work

Some advise obtain new keys.

another one whose seen it before too! so often you get RB26 balancer comes loose after not being done up to spec. they then start to wear little groves into the crank snout and eventually snap off keyway and then just spin freely. that's when you'll notice it as you suddenly have no power steering/water pump/altenator....

in all likelihood this may not have been what caused your oil pump failure. they are common enough on their own! as I said earlier as long as the journals weren't damaged from the oil pump failure and if the crank is not bent then that snout damage is an easy enough fix. but there's a couple of "ifs" in that sentence...

anyway, if you need a new key I have some spares and they cost bugger all.

[rtune]

exact same thing happened to my gtr, and I lost the bottom end because of it.

"tuner" in sydney with known workshop, with his own skyline, does a timing belt change

and oil service (my instincts were telling me not to give him more work) and

he didn't install the stock balancer right, or damaged the whole thing getting it off and on.

Result was a short time later on another tuners dyno the oil pump fragged and took

out the bottom end.. stock balancer was found to be welded to the crank, due to heat

from it moving around slightly all the time. Metal powder, burn marks, and so on

and so forth..

Racepace tell me that they see it all the time.

Don't let anyone touch your engine that doesn't know the exact why and wherefore of

this issue, and can explain to you the sequence of events in gory detail..

[our12]

Just a little modification on crankshaft keys. If you have access to a machine shop who know what they are doing you can machine the groove in the balancer wider and have keys made to suit the wider groove without machining the crank. This is procedure is usually used if you want to save a balancer which has become loose or perhaps beef up this area of the engine. The key(s) will usually damage the balancer as they are designed to do if incorrectly installed (tool steel- key cast iron factory- balancer) takes a lot to break or wear a key if correctly installed and torqued down to correct specifications. If you have a loose balancer always remove the key and check the fit in the balancer you will usually find the groove is not to specifications.

[BezerkR32]

im not sure how you can direct blame as it looks like balancer has come loose, it happens. its easily repairable. id have no problem putting that back together as it was on a standard engine. there is no way you could cause that damage by removing the balancer, possibly the crank gear. not sure what you want us to do, guess we could just leave the gear on there if its to tight and tell you to call a tow truck and come and get your car. you guys that slag workshops make me sick.......

I was just going to buy a new one to be honest ..

thanks though.

no thanks to workshop for not returning my e-mail.

[wrxkilla]

I can direct blame because the workshop told me at the time they had some troubles and made some slight damage around the keyway, nothing to worry about 'apparantly'. My suprise is that to me, this is more than 'slight' damage.

thanks for your input.

Richard - I am gunna have a chat with my builder he was wanting a new crank, but I'll have a chat and see about repairing and give you a call mate if I need those bits.

Cheers

Michael

[BezerkR32]

sorry but its still unclear how that damage was done by removing the balancer.....by the looks of it the balancer has come loose. Looks like it has rubbed on the cover too. To remove the balancer you use a puller that bolts to the front of it and pushes on the centre of the crank. How could you damage the crank under the pulley? Id say damage was existing, thats why it was difficult to remove. and in all seriousness the damage is minor and wont cause any issues. The fact that you were made aware shows that they are a reputable shop.

Ive had to burn crank gears off engines, CA18s in particular are bad for siezing them on. It is possible when removing them that you can mark the crank. but you are limited for options when nissan in there wisdom dont tap holes in the gear as to attach a puller. Sometimes things are damaged and have to be replaced. Fortunately in your case the damage was minor and able to be put back together.

I can direct blame because the workshop told me at the time they had some troubles and made some slight damage around the keyway, nothing to worry about 'apparantly'. My suprise is that to me, this is more than 'slight' damage.

thanks for your input.

Richard - I am gunna have a chat with my builder he was wanting a new crank, but I'll have a chat and see about repairing and give you a call mate if I need those bits.

Cheers

Michael

[Rowdyr32]

Michael I believe you should have started this thread like your g/box thread. For example - How would this occur? and show the pics

I like the comment on making it out of balance. Made me smile

I'm with all the others looks like bad spalling to me from a loose balancer.

I also don't see the problem with it and would be happy to re-use an item like that if the diametre is still within tolerance and the keyway isn't flogged out. I'd be more worried about the diametre of the shaft and keyway width over the pitting if the balancer was loose. It wouldn't matters if the engine is std or modified as it spins at the same speeds and forces and it is unlikely to crack since the bolt protrodes further into the crank than the damage and the balancer is is also held by the bolt(sandwiched). If it was damaged on removal by tools it would have sharp edges from the tools. I've used many a dodge tool removing tight balancers in my shed and you would have to be a real butcher to impact damage a crank in that location. If they had managed to get it far enough out to impact that area it could have been easily tapped off lightly with a hammer.

Are you unreasonable? I believe your are with the statements you have made. You have no facts linking the type of damage on the crank to the allegations being made. Your lack of knowledge in the area being discussed shows a little.

If the balance wasn't loose when you stripped the motor you have nothing to blame the person who changed the balancer as it didn't make your engine shit itself. They made a profesional decision to leave it and thats why you pay them. You said you would have replaced the crank at the time but the pump would have still shit itself and most likely damaged your new crank so they did you a favour and saved your soon to be new crank. Also if you were going to replace the crank back then why is it such a big drama now? Just change it if thats what you want to do.

I will quote one of your recent comments to another user "please dont post your opinion as a clear fact as it can mislead people".

[Beer Baron]

I can direct blame because the workshop told me at the time they had some troubles and made some slight damage around the keyway, nothing to worry about 'apparantly'. My suprise is that to me, this is more than 'slight' damage.

thanks for your input.

Richard - I am gunna have a chat with my builder he was wanting a new crank, but I'll have a chat and see about repairing and give you a call mate if I need those bits.

Cheers

Michael

no prob. they cost f**k all. a pack of smokes would just about cover a pair of them! hell if you need them they're free.

[wrxkilla]

thanks for the feedback there rowdy.

I dont want to drag this on. i will take some time and make up a reply when i get some time. I do lack technical knowledge in the area, and as time has shown, i have approached this in the wrong way. its all fair. I think perhaps I havent spent enough time making my posts and have made 30 sec efforts. I still beelive I have cause for complaint. But thats okay, that can be between me and the shop.

I have really appreciated all the feedback from guys in this thread with info.

and yep, pwned with my own comment. My pet hate on forums is people posting an opinion as a matter of fact. when alot of younguns get on here and will take it as gospel...

thanks rich, will be in contact soon. just waiting to get all my bits together and decide a plan of attack.

cheers

michael

[Noddy]

I know this is an old thread and here is the pic as promised. I remembered this thread as I was about to put the engine back together, and grabbed a pic while I could still see it. The hole is tapped with a 4mm thread so I can get the key out if need be, the slot is wider and deeper than the original because of 2 reasons.

1, strength

2, the original harmonic came loose and flogged the 1/2 moon out some and the cam drive was frozen on. I stuffed up drilling and splittingthe original 1 off.

All good now, 10 000km racing and going strong.

Edited January 13, 2010 by Noddy