newbie with a clio cup race car

[Chip-mk1]

Chip what generally causes the centre mains to spin? Crank flex?

I think its probably a combination of:
crank flex
block flex
harmonics
possibly also not amazing design of oil circulation to the bearing but I havent sectioned a block to investigate
bearing location not massively positive (its clamped to give some crush but no tags to increase inertia too)

TBH its not something I really know a lot about I am afraid mate, Ive only personally had it happen on two engines Ive built, both of which were porkies, one we are pretty certain the pump failed and took out the bearing (happened without seeing massive load, was only just onto the dyno for mapping when it failed) and the other was caused by a mis-shift so would have no doubt had things like crank flex as a contributing factor.

Ashfords do a girdle that will certainly help with changing the harmonics and with stopping block flexing, and you can tag the bearings .

Porkies new engine (which a friend of ours is building this time as I am too busy) has got the tagged bearings, but the couple of grand for a girdle seemed like overkill and so we havent gone for that.


Fingers crossed its ok and this doesnt happen to it as well, it certainly wouldnt be a massive surprise if it did, but that said there are examples of these engines seeing lots of rpm without an issue (my mrs daily revs to 7850 and we take it there pretty often on track)


Another potential issue is cornering if on slicks and causing oil starvation that way, only takes a split second of low pressure to start that bearing moving round.

 

[Porkie]

Porkies new engine (which a friend of ours is building this time as I am too busy) has got the tagged bearings, but the couple of grand for a girdle seemed like overkill and so we havent gone for that.

only coz I was sulking at the time... wish I had kinda gone for it now as you persuaded me to spunk all that money on gear thingy, fanimold and exhaust very easily last week

 

[ian-speedy]

did you buy tagged bearings or modify the block and standard bearings , when reading this morning about bearings spinning that was my first thought is if I can modify the block and bearings to tag them so they don't spin , or less likely to , I have read that some of the rally guys with the Ford Duratec engines have issue's with mains spinning

Got the car on the ramp and looking through the hole in the block I can see most of the piston jammed half way up the bore , would be real nice if it jammed there before reaching the top !

 

[hordog]

Looks good to me.

Any one know what the spoiler is on this amazing looking clio

 

[Porkie]

did you buy tagged bearings or modify the block and standard bearings , when reading this morning about bearings spinning that was my first thought is if I can modify the block and bearings to tag them so they don't spin , or less likely to , I have read that some of the rally guys with the Ford Duratec engines have issue's with mains spinning

Got the car on the ramp and looking through the hole in the block I can see most of the piston jammed half way up the bore , would be real nice if it jammed there before reaching the top !

Hope the piston did jam in there


bought tagged bearings and modified block. I have pics if you wanna see?

 

[Dan@SJM]

only coz I was sulking at the time... wish I had kinda gone for it now as you persuaded me to spunk all that money on gear thingy, fanimold and exhaust very easily last week

Not to mention some very nice Jenvey's

 

[ian-speedy]

Hope the piston did jam in there


bought tagged bearings and modified block. I have pics if you wanna see?

Yes put some pics up

 

[HrRACING]

Any one know what the spoiler is on this amazing looking clio

Its a genuine Super1600 spoiler, same as on my car;

http://www.halridge.com/wp-content/uploads/2011/06/hal-ridge-clio.jpg

 

[HrRACING]

And gutted for you Ian, that rods a mess! I hope the piston didn't make it to the head...

 

[Porkie]

here you go Ian.

 

[Dan Cup]

Firstly awesome car, I've seen this thing in the flesh at the xmas stages and on Eypnt. It is truly epic I've got some pics which ill try and pop up later.

Having seen the car being driven in anger and now reading this thread to see all the hard work you put in its truly outstanding, I have raced myself its so so so much harder than it looks, takes up all your time (and money) but they don't call motorsport a drug for nothing! Its also really refreshing for you to go into so much depth and be so open about the car, and take the time to document it on here, most people scowl at just just for looking.

Secondly sorry to here about the engine, it's a pain in the arse! Engine trouble is ultimately what ended my racing but I regret stopping now and looking to start again!

I may be able to help with you new engine, ill pm you.

​Winners never quit, quitters never win!

 

[Dan Cup]

As promised!

 

[ian-speedy]

what oil pressure do people run ? is there a way of upping the pressure in the standard oil pump , or does anyone do an uprated one
​Cheers Ian

 

[Kenny.s]

Made a good job of that! Even if the piston has hit the head ( Which I suspect it probably has) it will only have hit it once, admittedly probably pretty hard but it might not be too bad.

Personally I'm going to be logging oil pressure (as well as various other things) in the ECU for exactly this sort of reason. It can also be programmed to reduce power in the event oil pressure drops below a pre-determined threshold for more than 'x' many seconds for a given engine speed/load.
I appreciate this doesn't really help you now Ian but its maybe something worth considering? An ecu that costs £1k could potentially save you a lot more than that by preventing things like this.

As for the reason the crank bearings spin, block and crank flex is perhaps a plausible explanation but for the relatively low torque/ power these engines produce, I can't really see that being the route cause.
Personally I'd be more inclined to think its bearing clearance and or oil pressure related.

If however the bearing manages to spin without picking up on the crank first, that will obviously cut off its oil supply which initially won't make any difference to the system oil pressure. The dip in oil pressure observed is likely to be as a result of the bearing having welded its self to the crank and spinning in the block, which will cause a big clearance and a drop in oil pressure.

Be interested to see the pictures when it comes apart, assuming your willing to post them.


Sent from my iPhone using Tapatalk 2

 

[Fred@BTM]

I'm with kenny on this, there's no way the block or crank will flex unless you put about 30tons on it! I "think" that the failure is down to the oil pump drive sprocket loosing drive (i think i'll be keying them from now on!)

 

[NorthloopCup]

I'm with kenny on this, there's no way the block or crank will flex unless you put about 30tons on it! I "think" that the failure is down to the oil pump drive sprocket loosing drive (i think i'll be keying them from now on!)

Would that mean that the bottom pulley had come loose then Fred? I would've thought that if the oil pump drive sprocket came loose (causing the loss of drive) it would friction weld itself to the crank within a matter of a tenth or so of a second anyway. Be interesting to see what you find out though Fred.

 

[Fred@BTM]

well if you miss a gear (not going to happen with a sequential) or buzz the engine even slightly on down change, its plausible for the oil drive to slip (even for a split second) could be enough for it to cause loss of oil pressure and BOOM

I'm not blaming Ian at all, but i think maybe i underestimated the environment the engine is in and need to go a bit overkill in areas!

Never once lost an engine on circuit (similar power/torque) and clocked over 5000miles between rebuild inspections, but a circuit engine doesn't have to go through 3ft of water and jump 5ft in the air!!!

 

[ian-speedy]

Good news is the head is ok , the piston has made some contact with the valves as the soot on them has been cleaned off , but a quick check the head seems ok , haven't checked the valves yet but if the 4 need changing its not the end of the world , I was expecting to see a right mess in there , so the rallying gods have been kind to me

Spoke to Fred earlier today and will be getting the head back up to him for him to build me a new bottom end , haven't had the sump off this engine yet to see what mess that's in , will have a look tomorrow.
​hopefully he can sort it out so I can do this other rally the end of aug , we have unfinished business there !

 

[Porkie]

Good news Ian!

I'd be going for that Girdle that Ashfords recommend if I was you as its a competition car... and also that you have spent so much on it already BUT mainly because the cost of your events is so high in terms of effort and time.

 

[Chip-mk1]

Ian, what are the journals like in the head?
​Got a picture of it from the top?

 

[ian-speedy]

Ian, what are the journals like in the head?
​Got a picture of it from the top?

They are good , as are the cams , there was oil everywhere , and the oil is clean , it is not contaminated at all , I was expecting to find copper from the bearings , but there is nothing

 

[Chip-mk1]

They are good , as are the cams , there was oil everywhere , and the oil is clean , it is not contaminated at all , I was expecting to find copper from the bearings , but there is nothing

Wow, that was a lucky escape considering the amount of swarf that must have been generated by the bearing spinning enough to cause the rod to discolour that much.

 

[Kenny.s]

Given the potential for carnage it certainly looks like you've been lucky!

Be interesting to see what the rest of the bearings look like and try to figure out what caused it.

 

[steveboyslim]

I'm with kenny on this, there's no way the block or crank will flex unless you put about 30tons on it! I "think" that the failure is down to the oil pump drive sprocket loosing drive (i think i'll be keying them from now on!)

Most crankshafts flex when you rev engines,that is one reason for using a steel crankshaft.
Four cylinder engines wear/pull the center main bearing, which is why some engines have four bolt main caps.
Not the same engine, a Ford 1600 Atlantic BDA engine which produces 230bhp with a thick wall AX block, less with a 711m block.
Oil pump dive sprocket cannot come loose even for a split second, either the front pulley bolt was loose or it was not, also the timming belt pulley would have slipped.
I would be interested to see pictures of the center main bearing and the condition of the cam shaft journals in the cylinder head.

Steve

 

[ian-speedy]

Might have been a rod bolt breaking if it hasn't done the bearing like you would expect ??
I'll get the sump off today and have a look

 

[ian-speedy]

Cam belt pulley won't slip on mine if the bolt was slightly loose as it has a keyway , I'm making max Power at 7200 revs so I cannot see flexing being an issue with me , the BDA will probably rev another 3k over mine so would need a steel crank , mine won't at those revs

 

[Chip-mk1]

Might have been a rod bolt breaking if it hasn't done the bearing like you would expect ??
I'll get the sump off today and have a look

Possible, as that would release clamping force on the big end bearing and allow it to spin, which it clearly has to have that much heat in the rod.

 

[Kenny.s]

If a rod bolt had failed you wouldn't see any discolouration on the big end, it would just snap and spit the rod out.
Also the fact in hindsight you felt it go a bit off song and have since seen that the oil pressure dropped 1 bar suggests that there was something developing.

 

[Chip-mk1]

If a rod bolt had failed you wouldn't see any discolouration on the big end, it would just snap and spit the rod out.

Not always the case, as if one bolt fails then the other can still hold on for a while which allows the bearing to spin then the 2nd bolt fails and the rod breaks loose.

Also the fact in hindsight you felt it go a bit off song and have since seen that the oil pressure dropped 1 bar suggests that there was something developing.

Agreed.

 

[Kenny.s]

I heard what your saying.
Just that in all the instances I've seen or known of a rod bolt either snapping or coming loose the failure of the remaining one happens within a split second.
Did the rod the was ejected from James engine have any signs of heat on it? I can't remember now.

Hopefully the rest of the bearings will help explain the chain of events, be nice to know before building the new one.

 

[Chip-mk1]

No point guessing further till the caps are all off TBH, with more info readily available like that its silly us guessing more without it.

Bottom line though we almost certainly wont get a definitive answer.

 

[ian-speedy]

the oil pressure dropped a bar and blew straight away , it was at this pressure for a split second , I only know this after watching the incar video a few times , I didn't see all this happening on the rally

 

[Chip-mk1]

If it was that brief, it explains why the head survived i guess.

 

[ian-speedy]

does anyone know a programme so I can crop the video , I left the camera rolling until the battery went flat and its over an hour long , I only need the first 8 mins or so of it

 

[steveboyslim]

Might have been a rod bolt breaking if it hasn't done the bearing like you would expect ??
I'll get the sump off today and have a look

If the rod is blue it has suffered oil starvation.

Steve

 

[steveboyslim]

Cam belt pulley won't slip on mine if the bolt was slightly loose as it has a keyway , I'm making max Power at 7200 revs so I cannot see flexing being an issue with me , the BDA will probably rev another 3k over mine so would need a steel crank , mine won't at those revs

Formula Ford crossflow engine also show a difference when using a AX block which does not flex.

Steve

 

[Kenny.s]

does anyone know a programme so I can crop the video , I left the camera rolling until the battery went flat and its over an hour long , I only need the first 8 mins or so of it

If you have a fairly new PC it'll have windows movie maker, not the best editing program but good enough to do what you need.

 

[steveboyslim]

the oil pressure dropped a bar and blew straight away , it was at this pressure for a split second , I only know this after watching the incar video a few times , I didn't see all this happening on the rally

As with Porkie's engine first time around swarf everywhere, second time next to nothing in the head.

Steve

 

[Porkie]

As with Porkie's engine first time around swarf everywhere, second time next to nothing in the head.

Steve

So I am going in the right direction then huh LOL!

 

[Chip-mk1]

Flol!

Pretty sure your first one was a pump failure, especially as it happened without the engine ever even reaching max rpm, and it died a slow death, second one was mechanical over rev which spun the centre main and was a lot quicker.


Will be interesting to see Ian's centre main.