Discussion
Mark to give you idea, a 2.5 crank will cost around £2400, plus you will need main bearings at just under £400, plus you will need a rebore plus new pistons at around £1000. Then you have to add labour costs. So it’s an expensive option. I know as I’m considering it currently. But in return you get around 30 Bhp and a fair bit more torque. A new 2.3 crank will be a fair bit cheaper to buy and less rebuild costs. I boils down to what you want to spend really.
Dr mtree said:
Mark to give you idea, a 2.5 crank will cost around £2400, plus you will need main bearings at just under £400, plus you will need a rebore plus new pistons at around £1000. Then you have to add labour costs. So it’s an expensive option. I know as I’m considering it currently. But in return you get around 30 Bhp and a fair bit more torque. A new 2.3 crank will be a fair bit cheaper to buy and less rebuild costs. I boils down to what you want to spend really.
Ouch! That said, I'm pretty sure I can get the crank for a sizeable chunk less than £2400 though. If you want me to check (for your own) I'd be more than happy.
You'll need to excuse my ignorance (I've been trying to learn as I go since first starting to modify my s14) but do you mean I will need a rebore/pistons due to this failure or if I went 2.5?
Well I just spent a couple of hours reading all manner of stuff on the 2.5 swap and have decided to stick with the 2.3. Admittedly, if money wasn't an issue, I would go all out with the 2.5 etc but all I ever wanted was a reliable 250 brake and that hasn't changed.
I'm off to work shortly but am hoping to finally speak with the engine builder this week and make a decision on where I go next.
I'm off to work shortly but am hoping to finally speak with the engine builder this week and make a decision on where I go next.
You should only need a rebore if going the the 2.5 route.
If you’re going to rebuild at 2.3 then you will need a crank (£1500 ish) new rod bearings (£130), rod bolts (£100) full gasket set (£200) and labour. You should be able to get it done for around £3500-4000. I would check the mains (they should be ok) but worth checking. Also check for out of roundness on the big ends of the piston rods. As said already flush out the oil cooler etc. Who ever rebuilds it need to warranty their work. These engines should not fail so soon after a rebuild. They are not a fragile unit. I’ve been hammering my original 170k mile engine for the past 10 years. Lots of track days and Nurburgring trips most years and it’s never missed a beat.
If I was in your position (god forbid), I would send my engine to JC, it’s not worth the expensive gamble after everything you’ve been through. Good luck.
If you’re going to rebuild at 2.3 then you will need a crank (£1500 ish) new rod bearings (£130), rod bolts (£100) full gasket set (£200) and labour. You should be able to get it done for around £3500-4000. I would check the mains (they should be ok) but worth checking. Also check for out of roundness on the big ends of the piston rods. As said already flush out the oil cooler etc. Who ever rebuilds it need to warranty their work. These engines should not fail so soon after a rebuild. They are not a fragile unit. I’ve been hammering my original 170k mile engine for the past 10 years. Lots of track days and Nurburgring trips most years and it’s never missed a beat.
If I was in your position (god forbid), I would send my engine to JC, it’s not worth the expensive gamble after everything you’ve been through. Good luck.
Mark
My m3 was an ex rally car, did the Scottish championship for 2 years, then I used on lots of track days inc spa an the ring as on a stock engine. I had no troubles with oil starvation on corners so whilst the oil pan may mitigate the risk I doubt it is the source of the problem and I would not spend money in that direction
Feel you pain we had 2 engines built for endurance racing by a US Honda specialist at over 10k$ each combined they lasted 17 laps. every thing was new but when they where dissected it was poor tolerances, bores where out, crank journals where out and a mismatch of components that did them in.
Now we pay for experience and only go above oem spec in a few areas, the engine has done 1 24hr and 2 race seasons and cost less than 10K$
This car is your keeper put in storage save the pennies and when you get it sorted it will be worth it.
My m3 was an ex rally car, did the Scottish championship for 2 years, then I used on lots of track days inc spa an the ring as on a stock engine. I had no troubles with oil starvation on corners so whilst the oil pan may mitigate the risk I doubt it is the source of the problem and I would not spend money in that direction
Feel you pain we had 2 engines built for endurance racing by a US Honda specialist at over 10k$ each combined they lasted 17 laps. every thing was new but when they where dissected it was poor tolerances, bores where out, crank journals where out and a mismatch of components that did them in.
Now we pay for experience and only go above oem spec in a few areas, the engine has done 1 24hr and 2 race seasons and cost less than 10K$
This car is your keeper put in storage save the pennies and when you get it sorted it will be worth it.
Hi Jason, yes I know you're all right when you say I should stick with it. So, that's what I intend doing.
I got an extremely good deal on a brand new, crated crankshaft today. The only negative being my letting down Kirby and his offer on his spare. I don't like messing people around but going with new parts, whenever possible, just seems the sensible option.
Right now I am just waiting for the builder to come back to me with his findings from stripping the engine. Once I know that, I can start looking at getting the rebuild done and by whom.
I got an extremely good deal on a brand new, crated crankshaft today. The only negative being my letting down Kirby and his offer on his spare. I don't like messing people around but going with new parts, whenever possible, just seems the sensible option.
Right now I am just waiting for the builder to come back to me with his findings from stripping the engine. Once I know that, I can start looking at getting the rebuild done and by whom.
Hi Mark,
I wouldnt take it if he comes back and says its because the crank has been reground, you can go 3rd oversize and it not be such a bother, it's only 30 thou and the standard case hardening is at least that deep but generally more. There's plenty people in your position but cant afford to buy a new crank so go for another grind to get the crank surfaces right and they dont go bang after such little use, they do seasons of racing!
It's sad to say but a lot of people are under pressure to get jobs out quick and things dont get done right all the time with some places. The short motor i got with my car for example was nothing worse of shocking and was supposed to have been rebuilt and only done running in miles!
Glad to hear you're getting somewhere though!
Scott
I wouldnt take it if he comes back and says its because the crank has been reground, you can go 3rd oversize and it not be such a bother, it's only 30 thou and the standard case hardening is at least that deep but generally more. There's plenty people in your position but cant afford to buy a new crank so go for another grind to get the crank surfaces right and they dont go bang after such little use, they do seasons of racing!
It's sad to say but a lot of people are under pressure to get jobs out quick and things dont get done right all the time with some places. The short motor i got with my car for example was nothing worse of shocking and was supposed to have been rebuilt and only done running in miles!
Glad to hear you're getting somewhere though!
Scott
Spoke to Arrow this morning (via email) and am sending the rods back for inspection and (hopefully) reconditioning. I still don't know if the CP pistons were damaged though?
I had mentioned to them about the theory behind the failure and the +0.75 regrind and they said the few s14 cranks they have had experience of, ground to that size, have failed on track. Obviously that doesn't mean my crank failed but it's still interesting to hear their experience.
Right now I'm sat waiting on the crankshaft being delivered but it's already close to 2 weeks since the failure. I'd hoped to be enjoying the car this summer and instead, it's back in the bloody workshop. I just hope it doesn't turn into months of waiting.
Am I right in thinking that, so long as everything is thoroughly inspected, cleaned etc parts like the oil pump and timing chain can go again? If so, are there any specific methods one should follow?
This rebuild is it. There won't be another in my ownership anyway, unless I win the lottery and I can go balls out 2.5?!
I had mentioned to them about the theory behind the failure and the +0.75 regrind and they said the few s14 cranks they have had experience of, ground to that size, have failed on track. Obviously that doesn't mean my crank failed but it's still interesting to hear their experience.
Right now I'm sat waiting on the crankshaft being delivered but it's already close to 2 weeks since the failure. I'd hoped to be enjoying the car this summer and instead, it's back in the bloody workshop. I just hope it doesn't turn into months of waiting.
Am I right in thinking that, so long as everything is thoroughly inspected, cleaned etc parts like the oil pump and timing chain can go again? If so, are there any specific methods one should follow?
This rebuild is it. There won't be another in my ownership anyway, unless I win the lottery and I can go balls out 2.5?!
e30m3Mark said:
Spoke to Arrow this morning (via email) and am sending the rods back for inspection and (hopefully) reconditioning. I still don't know if the CP pistons were damaged though?
I had mentioned to them about the theory behind the failure and the +0.75 regrind and they said the few s14 cranks they have had experience of, ground to that size, have failed on track. Obviously that doesn't mean my crank failed but it's still interesting to hear their experience.
Right now I'm sat waiting on the crankshaft being delivered but it's already close to 2 weeks since the failure. I'd hoped to be enjoying the car this summer and instead, it's back in the bloody workshop. I just hope it doesn't turn into months of waiting.
Am I right in thinking that, so long as everything is thoroughly inspected, cleaned etc parts like the oil pump and timing chain can go again? If so, are there any specific methods one should follow?
This rebuild is it. There won't be another in my ownership anyway, unless I win the lottery and I can go balls out 2.5?!
There should be no concerns with reusing parts as long as the have been correctly inspected. My concern would be who is doing that inspection/making the decision that they're OK.I had mentioned to them about the theory behind the failure and the +0.75 regrind and they said the few s14 cranks they have had experience of, ground to that size, have failed on track. Obviously that doesn't mean my crank failed but it's still interesting to hear their experience.
Right now I'm sat waiting on the crankshaft being delivered but it's already close to 2 weeks since the failure. I'd hoped to be enjoying the car this summer and instead, it's back in the bloody workshop. I just hope it doesn't turn into months of waiting.
Am I right in thinking that, so long as everything is thoroughly inspected, cleaned etc parts like the oil pump and timing chain can go again? If so, are there any specific methods one should follow?
This rebuild is it. There won't be another in my ownership anyway, unless I win the lottery and I can go balls out 2.5?!
With the issues you've had and the repeated 'don't use a re-ground crank' info from people in the know I'd have to wonder (even if he has done nothing wrong) if your engine builder know enough about the S14/race engine building.
king about eh! 
Glad to see you're persevering! Sounds like you're on the right lines with the crank; I personally wouldn't use a reground crank in a race motor due to the loss of surface treatment, which is expensive and difficult to re-apply. The theory on flex is interesting though... I don't know these engines to comment!
I would echo previous comments on the map; I'd definitely be having this checked (and tweaked if necessary) by someone reputable. Wayne or Dale Bladen (Bailey Performance) are my two go-to's for this. It's still feasible that the issue is being caused by too much advance and the weak link in the system is the crank, which is flexing and the bearings have taken a hammering.
Measure, check and check again. Don't leave anything to chance!
All the best with it
I would echo previous comments on the map; I'd definitely be having this checked (and tweaked if necessary) by someone reputable. Wayne or Dale Bladen (Bailey Performance) are my two go-to's for this. It's still feasible that the issue is being caused by too much advance and the weak link in the system is the crank, which is flexing and the bearings have taken a hammering.
Measure, check and check again. Don't leave anything to chance!
All the best with it
Heard back yesterday. The bottom line is the bearing shell span due to a lack of oil. As there was no pump failure (the pump is still working fine) I can only put it down to oil surge under braking or a suspect bearing or the regrind being so aggressive at +0.75? Several people with experience in s14's have said they would not use a reground s14 crank on track for this reason.
I'm looking at either improving the VAC sump or going for the MS version that Steve mentioned a couple of pages ago. It's not ideal, as I would obviously much prefer something specific that I can lay 100% blame at but there isn't. I spoke at length with the builder, who has done a fair few s14's and other BMW competition engines, so I have no reason to doubt his abilities as a builder.
I'm looking at either improving the VAC sump or going for the MS version that Steve mentioned a couple of pages ago. It's not ideal, as I would obviously much prefer something specific that I can lay 100% blame at but there isn't. I spoke at length with the builder, who has done a fair few s14's and other BMW competition engines, so I have no reason to doubt his abilities as a builder.
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