Engine re-build
Discussion
Well after setting a 8:07 lap of the ring (having the time of my life) my engine let go, Jetstream have confirmed that the bottom half of the main bearings have failed, believed to be the first failure of the upgraded type of bearings.
The crank is going for some checks/machining and will take it from there. The rest inc big ends 'seems' in tact but it's getting a full strip down and started from scratch again. Oddly it seems the big end bolts were just the ford items and not ARP, this must have been the engine builder I used up in Aberdeen when the big ends were upgraded but they held up to the power, getting changed now though.
Will add more info when I get it,
Graham
The crank is going for some checks/machining and will take it from there. The rest inc big ends 'seems' in tact but it's getting a full strip down and started from scratch again. Oddly it seems the big end bolts were just the ford items and not ARP, this must have been the engine builder I used up in Aberdeen when the big ends were upgraded but they held up to the power, getting changed now though.
Will add more info when I get it,
Graham
What did they think caused the failure Graham? and how was the clutch?
Pain in the butt cause you like me had only just got back on the road .
Are Jetstream replacing the bearings like for like or is there a better option? thinking maybe I will get a similar problem again.
Should have some news on gearbox very soon, it will be a completely new gear set, have been told it should be good for 650lbft, We are are also looking at what the best ratios would be to make it a little longer leged through the gears,it has been mentioned to me by some very influential people and good friends on here.
that a 10% increase in each gear would be a good option. what's your views Graham ? I agree a little longer in each gear would be better.
Pain in the butt cause you like me had only just got back on the road .
Are Jetstream replacing the bearings like for like or is there a better option? thinking maybe I will get a similar problem again.
Should have some news on gearbox very soon, it will be a completely new gear set, have been told it should be good for 650lbft, We are are also looking at what the best ratios would be to make it a little longer leged through the gears,it has been mentioned to me by some very influential people and good friends on here.
that a 10% increase in each gear would be a good option. what's your views Graham ? I agree a little longer in each gear would be better.
Some more news, the crank is bent and where the bearings sit are ovalised. Nice but it's fit for the bin! In fact I might make a hallway table out of it. 
Pistons and Rods and all the rest are fine, so it'll be a new crank, bearings and oil pump just in case. Can't think of anything else worth doing.
Craig, yeah would be interested to hear more about a gearset with better ratio's
Pistons and Rods and all the rest are fine, so it'll be a new crank, bearings and oil pump just in case. Can't think of anything else worth doing.
Craig, yeah would be interested to hear more about a gearset with better ratio's
Oh also, the clutch looks like new, no signs of wear so I will just carry on using the Helix 6 paddle unit.
Mike, according to the footage, the oil pressure dropped maybe several corners before I noticed the horrible noise (had a helmet on).
The bearings were already the upgraded type, apparently all mountune engines use ford bearings which have been fine bar 1 car. Now I've killed the updated type, maybe the ford ones are the better type.
Mike, according to the footage, the oil pressure dropped maybe several corners before I noticed the horrible noise (had a helmet on).
The bearings were already the upgraded type, apparently all mountune engines use ford bearings which have been fine bar 1 car. Now I've killed the updated type, maybe the ford ones are the better type.
there have been quite a few engines fail on the main bearings - this is usually a sign of loss of oil pressure
i suggest to everyone that they consider an engine friction reducer like slick 50 to protect the engine in the event of a similar incident
do you think the oil pressure dropped due to high oil temps ?
i suggest to everyone that they consider an engine friction reducer like slick 50 to protect the engine in the event of a similar incident
do you think the oil pressure dropped due to high oil temps ?
The oil temprature was fine, I always keep an eye on it and it stayed about 100-110C
The only thing I can think of is the oil pump was failing or damaged and the lack of oil pressure (dropped from 50+ to 20psi) then a few big straights and corners combined with the full torque as I was on the happy button, caused the bearings to let go. (4 laps done using full boost)
I don't think any of those oil additives would have helped in this instance. Dave said the oil filter was full of metal and the whole block needs stripped and cleaned.
The only thing I can think of is the oil pump was failing or damaged and the lack of oil pressure (dropped from 50+ to 20psi) then a few big straights and corners combined with the full torque as I was on the happy button, caused the bearings to let go. (4 laps done using full boost)
I don't think any of those oil additives would have helped in this instance. Dave said the oil filter was full of metal and the whole block needs stripped and cleaned.
Graham
I'm of the opinion that the uprated (not to be named) mains aren't suitable for our application & am having some thorough checking & testing done to verify, in theory they should be better but i've had a problem & like you no issue with the uprated bigends only mains. Wonder if Mountune knew this which is why they used the standard Ford ones ?
l don't agree with Gadge as there have been very few main bearing issues & any that have theres probably other causes.
I will advise on the uprated mains when a conclusion has been reached.
I'm of the opinion that the uprated (not to be named) mains aren't suitable for our application & am having some thorough checking & testing done to verify, in theory they should be better but i've had a problem & like you no issue with the uprated bigends only mains. Wonder if Mountune knew this which is why they used the standard Ford ones ?
l don't agree with Gadge as there have been very few main bearing issues & any that have theres probably other causes.
I will advise on the uprated mains when a conclusion has been reached.
Gadgeroonie said:
i suggest to everyone that they consider an engine friction reducer like slick 50 to protect the engine in the event of a similar incident
This is something I've often wondered about, is it a good idea to add this to the oil or could it do more harm than good? Does anyone else use it in the noble engine?Gassing Station | Noble | Top of Page | What's New | My Stuff