oh crap

[Rob Gaskin]

Understand what you are saying Alan and you may be right, that's why I don't like my car to tickover too long when hot. However I would have thought it would have stalled at tickover before a rod broke.

Anyway it's all hypothetical - get it stripped Grolls and let us know

 

[BIGSSS]

It's Mr Humphries!

(Mr Grayson was "Shut that door" and "Ooh, I'm all cock-a-hoop!")

Jak demonstrating his knowlege of all things camp!
He'll be dressing up as the only gay in the village next

 

[zpuppy]

power mius weight = speed and the problem is?

:lol::lol:It may take some weight off the rear wheels ,,hmmm might make for an A#1 burnout car Looking forward to seeing you on the 26th

 

[SKiddell]

Sorry to hear your news Paul, if I can be of any help PM me

 

[grolls]

Major failure after long tickover is very likely to be linked to prolonged low oil pressure & volume, and possibly involving localised 'hot spots' due to low speed / volume of coolant circulation. It's probably picked up a conrod bearing........

Low oil pump speed, low water pump speed, low wallet contents.

This could be an interesting debate as many many years ago I worked at a garage where an engine was rebuilt and about 100 miles after the cusomer collected the car the engine siezed solid. The isnpection began as the garage was liable and before any one asks I didn't do the rebuild...lol.

The first check was the engine full of oil? Yes
was is clean or dirty..................................clean...........mmmmmm

upon inspection, the plonka that had put the engine together had not installed the oil pump gears correctly and the engine had not had any oil pressure.
Upon further testing it appeard that the oil pressure bulb had blown and so could not given any warning to the the Mechanic or the driver.

The ouitcome was they sacked him as he should have checked all of this.




What really shocked me was the fact the mechanic was a loony driver and would have canned the car on its test drive and the owner drove a further 90 miles with no oil pressure.

my conclusion......would it fail on tick over for low oil pressure?....fook knows.....lol:lol: let you know shortly"!!!!!!

 

[grolls]

Sorry to hear your news Paul, if I can be of any help PM me

Ta Skiddy, will do.

 

[grolls]

Well took the engine out today, the result being the crank is in two bits. Broken on number 6, Head all a ok, rest of mains and ends all ok, no.6 main now damaged obviously. There appears to be no reason as to why.

Crank, bearings needed.

 

[Rob Gaskin]

I am amazed that a L series crank will break at tickover. Any sign of the seizing Alan thought might have occurred?

I have heard of a problem with the rear main but a crank breaking is too bad. Perhaps it was already cracked - this is an 'opening' for Skid to tell us about crank-dampers.

Any pics?

 

[grolls]

I am amazed that a L series crank will break at tickover. Any sign of the seizing Alan thought might have occurred?

I have heard of a problem with the rear main but a crank breaking is too bad. Perhaps it was already cracked - this is an 'opening' for Skid to tell us about crank-dampers.

Any pics?

The rear main was fine one assumes, no vibration felt via the clutch pedal and no noise. Bearing in ming the engine has done little mileage. Obvioulsly the bearing has taken some flack when it crank broke and with me turning it over. One point being that the rear main oil seal did not leak, a fair clue something is wrong when the rear main is on its way.Oil pressure was good at tickover as was the water temp.


Out of habit I do check the pressure on a regular basis and all was fine just before so lost here.

Well for the first time in years i'm at a loss as to why, I can only think the crank had a fault from day 1 and the extra bhp turned it sour......anyone got a spare crank in good nick?.....suggestions most welcome!!!!

 

[tel240z]

Lets think about this, when the crank snapped, no 6 main journal stoped turning, probably just got joseled about by the rest of the crank, but you say no six journal not in a good way so was it starved of oil before the breakage ocurred also no oil leakage from the rear oil seal but there wouldn't be would there

had the shells spun in the bearing cap
do they appear to have got hot

just some thoughts

 

[johnymd]

I had a crank brake on me many years ago. It was a mini and it snapped at the center bearing. This also happened on tickover and the engine just stopped. I managed to get the car started and drive it 5 miles home.

Would the crank be under increased stress the slower it turns?

 

[grolls]

Lets think about this, when the crank snapped, no 6 main journal stoped turning, probably just got joseled about by the rest of the crank, but you say no six journal not in a good way so was it starved of oil before the breakage ocurred also no oil leakage from the rear oil seal but there wouldn't be would there

had the shells spun in the bearing cap
do they appear to have got hot

just some thoughts

I dont think i'll ever know the true cause and no the bearings hadn't spun and yet lots of oil on all bearings, When I get it all out i'll take some pics... Its a fooker!!!

 

[malcolm]

Would the crank be under increased stress the slower it turns?

Torsional vibration is highest at low engine speed under no load. Add some load and the peak in vibration increases to maybe 1400rpm, then tails off as engine speed increases.

Had the crank been reground? If so possibly the radius at the edge of the bearing surface hasn't been done well - stress is highest there anyway with the change in section, and a sharp edge can be a crack initiator.

Sorry to hear it is broken, but will be Interesting to see the photos.

 

[grolls]

Pics attached, 1st pic with red line shows extreemly poor casting to left of line, the high and low points are more evident on pic 2. I note that bearings were fine. New crank damper etc etc etc......

 

[Rob Gaskin]

Pics attached, 1st pic with red line shows extreemly poor casting to left of line, the high and low points are more evident on pic 2. I note that bearings were fine. New crank damper etc etc etc......

Might be worth dropping a line to Nissan offering your parts for evaluation and analysis - you never know what the outcome might be!

 

[moggy240]

Pics attached, 1st pic with red line shows extreemly poor casting to left of line, the high and low points are more evident on pic 2. I note that bearings were fine.

that looks nasty !!!!!!!!!!!!!!!

 

[SeanDezart]

Somebody should have x-rayed the block before playing with it.................Nissan won't give two farts - it's over 30 years old !

 

[rhanagar]

Somebody should have x-rayed the block before playing with it.................Nissan won't give two farts - it's over 30 years old !

Sadly I agree.

 

[grolls]

Somebody should have x-rayed the block before playing with it.................Nissan won't give two farts - it's over 30 years old !

Yes ya right, Nissan etc....but would you xray every nut, bolt and washer too??? A crank failure to this degree is very rare indeed.....now if it was a 3.1!!!

Just how far do you go???

 

[rhanagar]

The problem you will have is proving that the engine hasn't been abused etc etc. By all means I would give it a shot. There is some definate evidence of improper casting there. You never know.