BS Nymph in Jersey

edgedj · Post by **edgedj** » Mon Mar 28, 2022 12:33 am

Following a few days of careful wiring loom placement, soldering and simplification we’re ready to go, final pre-flight checks to come but I‘m about to find out if the following works: rebuilt 875, 2nd gear synchro, rumbling input transaxle bearing and re-built transaxle, new clutch, FBW throttle, ms3 pro ecu, sequential injection, electronic fan (pwm control), ecu new inputs (car speed, oil pressure, fuel pressure, fuel level).

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The Nun · Post by **The Nun** » Mon Mar 28, 2022 7:57 am

And what happens if it doesn't?

Lotus-e-Clan · Post by **Lotus-e-Clan** » Mon Mar 28, 2022 7:59 am

So good.

Can't wait for the report.

edgedj · Post by **edgedj** » Mon Mar 28, 2022 9:30 pm

what awful video quality, sideways, crap resolution - I've made this a link only video. Anyway, the camera microphone is picking up more clattering than the ear does, this is a very sweet running imp engine.

I've been out for a little drive and everything is working. Trouble is I haven't wired in the fan yet, nor the fuel gauge or temp gauge so it's bit of a lottery - oh and the oil pressure warning light (well the sump has 2.5 litres and showed 40psi cranking). FBW is a revelation as I thought it might be, the response curve is not a curve yet but a linear progression from 0-100% - going to make the first half of the pedal operate the first 20% of the butterfly motion.

Oh and Tim Morgan was right, I've cursed my water pump! Hoping this will bed in...

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impmann · Post by **impmann** » Mon Apr 04, 2022 9:51 am

Sorry, Dave!!

edgedj · Post by **edgedj** » Tue Apr 05, 2022 12:26 am

impmann wrote: ↑Mon Apr 04, 2022 9:51 amSorry, Dave!!

Driven it twice now and each time it leaks a little less after, it‘s down to about a teaspoon now, hoping it will continue to bed in. Note to self, never leave the pump dry off the car

The Nun · Post by **The Nun** » Tue Apr 05, 2022 8:01 am

This is why we now need modern spec plastic housings and stainless internals to stop them corroding up.

edgedj · Post by **edgedj** » Wed Apr 06, 2022 1:43 am

So it’s all up and running now, the rebuilt 875 is actually kicking out more power than the blowing 998 was. Ok not all is identical, I’m now running fully sequential injection and it was semi sequential before and I can guarantee the throttle is 100% open with the DBW setup but the head is the same and the ignition’s identical. DBW is just brilliant to drive with nice low end throttle response, zero lag and a very light pedal. The pwm fan works nicely, I can’t really tell it’s running, maybe a light hum is noticeable and because it’s a curve of fan speed starting at a low spin @86c and getting to 100% @90c, the needle sits at 88 and there are no jumps in fan speed. Engine warmup is noticeably quicker as the rad isn’t blasted by the fan when the stat first cracks open. Yellow and red dash warning lights are driven from the ecu, yellow is programmed to less than 15 psi oil, red is programmed to voltage less than 12.7v or fuel tank less than 1 gallon. The yellow oil light flickered tonight on a drive under hard left cornering and acceleration, which meant a careful drive straight home as I knew what that was! I was trying to stretch the expensive millers running in oil for a potential future use of the other 2.5 litres, bad idea, now topped up to the dip stick high mark.

I would video it but sadly one major flaw is my brand new clutch rattles like a ******* even at idle, so engine back out at the weekend to change that, oh well. Promise to do that and I hope the purr of this setup comes over on video, I’ve never heard an imp engine like it, at idle it almost has that whistle that a big motorbike engine does.

bazzateer · Post by **bazzateer** » Wed Apr 06, 2022 8:47 am

Looks like you're on to a winner Dave!

edgedj · Post by **edgedj** » Mon Apr 11, 2022 1:46 pm

Water pump now fixed, took it apart and found that these gritty lumps of corrosion had made their way under the seals. The seals and the sealing faces look completely fine, so wire brushed them all with a brass wheel in the dremel, new housing gasket and it's not leaking anyway - yay

I think the issue was taking the studs off to remove the fan cowling and not keeping the studs in place, or at least some other means of squeezing the whole thing together on the springs of the seals while the cowling was removed. Easy fix anyhow.

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edgedj · Post by **edgedj** » Mon Apr 25, 2022 11:53 pm

Quick update on the FBW/DBW setup on the Nymph. Here's a video that shows it running last week:

That was targeting 950rpm and I had to restrict ignition timing to 8 degrees BTDC to get it capable of that steady hum you see. What I noticed on inspection was that the linkages I'd setup weren't closing the butterfly completely so tonight I re-drilled the hole to achieve a little more throw and now the engine will target 800 rpm with 11 degrees advance at 14.7:1 AFR (sport cam and large valves too) and because it's closed loop you can set off by just lifting the clutch like a modern car and it just adds throttle subtly for you to get a smooth start. Oil pressure is getting a touch low now at 800 when hot as it's still got the thin millers running in oil for another 300 miles, I expect with a decent 20w50 this might stop the oil light flickering. It would be cool to see if I could get a sport cam to idle at the 750 rpm like the standard camshaft and single solex.

Oh and you can just see the fan spinning slowly in this video too, fan speed is proportional to coolant temperature, spinning very slowly at 86 degrees to flat out at 90. Can't hear it at all when driving, it just seems to waft along and the engine stays at 88. Hardly mid-summer yet but we've had some nearly 20 degree C days here in Jersey.

This scatter plot shows warmup with the thermostat reaching equilibrium at 86 degrees and the fan steady at about 20%

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This scatter plot shows how poorly oil pressure drops off with this thin oil, cold oil pressure at 1000rpm is roughly 50 psi but that drops to 13psi when hot

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Dave ' Linwood ' Lane · Tue Apr 26, 2022 6:02 am

That does sound smooth

Uncle Henry · Post by **Uncle Henry** » Tue Apr 26, 2022 8:17 am

Great update. Fabulous development work, Dave.

AG

edgedj · Post by **edgedj** » Thu Apr 28, 2022 11:34 pm

Next on the list is tuning the injector timing table, this table defines the end of the injector opening in degrees BTDC so the theory being that you schedule the injection event to dump all the fuel onto the back of the closed inlet valve just before it opens so at no point is the inlet drawing air without fuel in the mix. In megasquirt injector timing TDC is 360 degrees; an imp sport camshaft opens at 23 degrees BTDC so in theory I need to set this to finish injecting in each port at 383 degrees and then as RPM increases (so other rule of thumb theories go)! move back 10 degrees per 1000rpm to allow for something air speed related. My brain hurts a bit thinking of it!

I hear from other people tuning engines on rolling roads that they are seeing some gains from this but time will tell, I'm sceptical until I feel it under my seat. Certainly I've changed this table recently across the board to suit idle and I've noticed that the cammy or almost turbo build feel higher up at 6krpm has gone so perhaps there is something in it.

There's a pure results way of deriving this timing too according to my research. Just pick a cell in the table and adjust until the exhaust sensor shows the most rich, this indicates you're getting the most fuel so must be the best injector timing. Do this for a couple of locations and extrapolate for the rest.

The Nun · Post by **The Nun** » Fri Apr 29, 2022 8:37 am

All sounds very complicated, I just turn the screw on my strommies 1/8 turn, that's it done.

edgedj · Post by **edgedj** » Tue May 03, 2022 11:22 pm

Injector timing made quite a noticeable difference, here's the table. Throttle response is probably the biggest plus, it needs less acceleration enrichment and the torque difference is stark on mashing the pedal at any RPM over 2500 or so. The cammy/turbo sensation beyond 4-5krpm is back too, I think I need to rolling road this to show some results on paper. One other subtle difference is the lack of exhaust smell in reverse, previously it used to smell not exactly rich but none too healthy either. Being a very open back lid on a Nymph you get to notice this whiff.

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Idle is dead happy at 750rpm and 14.7:1 AFR with 12 degrees total advance and an average vacuum of roughly 15 in. HG (map 52). From this idle I can set off uphill with no throttle (OK the electronic throttle helps a bit but still it's impressive)

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edgedj · Post by **edgedj** » Sun Jun 19, 2022 4:18 pm

situation update 'farking water pumps'! Just put new bearings in and faced the seals in my spare water pump, stuck in car and went for a drive. Not quite as leaky as the one that's just come out but man it still drips - argh!

bazzateer · Post by **bazzateer** » Sun Jun 19, 2022 5:55 pm

It might take a while to fully bed in.

Dave ' Linwood ' Lane · Mon Jun 20, 2022 9:00 pm

edgedj wrote: ↑Sun Jun 19, 2022 4:18 pm situation update 'farking water pumps'! Just put new bearings in and faced the seals in my spare water pump, stuck in car and went for a drive. Not quite as leaky as the one that's just come out but man it still drips - argh!

As Baz has said , might take a while to bed in , did you spin it up on a drill dry for a few minutes before fitting it , this helps no end

edgedj · Post by **edgedj** » Thu Jun 23, 2022 12:05 am

Dave ' Linwood ' Lane wrote: ↑Mon Jun 20, 2022 9:00 pm As Baz has said , might take a while to bed in , did you spin it up on a drill dry for a few minutes before fitting it , this helps no end

No, I hadn’t read that tip so didn’t know to try it, makes sense though. I’ve been running it today with the rad cap on the dashboard (to remind me it’s not where it should be) and after about 20 mins of driving the drip has stopped. I also drove for nearly an hour in mostly 3rd gear, I figure this will all help to smooth out that cast iron face I skimmed on the lathe. Fingers crossed a few days of this will do the job…

On another note, I seem to have sprung an oil weep in a really odd place, around spark plug # 1. I’ve mopped it up and put a fresh piece of white tissue paper there so I can see where it is coming from. Visually it seems to be coming from the first ARP nut, is that even a possibility?

edgedj · Post by **edgedj** » Sun Jul 03, 2022 2:40 pm

Stuck a tissue here to identify the weep. Definitely coming from the ARP nut. Does this mean the pressure sender hole is compromised to the bolt hole, guess it could mean that. I can’t think of another source of oil for the leak.

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John A Ross · Post by **John A Ross** » Sun Jul 03, 2022 4:24 pm

Dave,

Scary thought for the day

That bolt is not too far away from the O ring seal for the oil gallery block to head, not beyond realms of possibility the O ring failed or its not compressed properly and its found its way across the gasket ?

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mikeyhearne · Post by **mikeyhearne** » Sun Jul 03, 2022 5:47 pm

A friend had a similar leak recently that turned out to be the head gasket being thicker than the o ring in its grove . Therefore the o ring was not being compressed to provide a seal .

edgedj · Post by **edgedj** » Mon Jul 04, 2022 3:14 pm

Hmm, I suspect you might both be right. I haven't yet re-torqued the head after the initial setup (361 miles of the 500 done so far), so time to prioritise that I guess.

Out of interest is anyone else running ARP studs who knows the torque figure? I went for 31 lb. ft. as a guess but maybe I should go closer to the standard 36 lbs on the evidence of the weep? Rationale for lower torque is the finer pitch of the UNF thread on the head stud gives more pressure for the same torque...

John A Ross · Post by **John A Ross** » Mon Jul 04, 2022 3:29 pm

Dave

As far as I know its same torque figure as normal which if I recall the last facebook discussion which included Mark was staged to 40 ft lb

I tried to find that discussion but facbook can just be a black hole when searching for something in particular.

My engine is coming out for some attention and I was actually going to order a stud kit from Mark myself so I can shim the head on the bench.

Perhaps Peter has a better recollection

Lotus-e-Clan · Post by **Lotus-e-Clan** » Tue Jul 05, 2022 9:21 am

Hello all.

I'm going to Mark Maynard's tomorrow (Wed 6th July 2022) to pick up engine bits that are in for a refresh (new guides, bore hone, pistons machined for the new ring type, etc).

I'm also converting to head studs with ARP nuts, so I'll get the full torque info from the horse's mouth and report back.

But it will be tomorrow night before I can hit the keyboard again, as I have to get back to North Yorkshire same day, so you might have already found the info by then.

John A Ross · Post by **John A Ross** » Tue Jul 05, 2022 9:47 am

Dave

As Pete mentioned Mark i just phoned him and asked what the torque settings should be and advised 38-40 ft lb on mine (wills rings).

He is always so busy but helpful you feel guilty about calling him and holding up his day, so Pete will get the full skinny later

I am sure.

edgedj · Post by **edgedj** » Tue Jul 05, 2022 11:27 pm

Thanks both, will go for that then. Probably just go for 40 since I've got a weep It's a fair bit tighter than 31 now the gasket has had time to settle. If it is the O ring (which is definitely there by the way as I remember paying attention to it and sticking it down with a bit of grease) then a weep would probably only need a little nip more to stop otherwise it would likely be a deluge of oil at 60psi.

Lotus-e-Clan · Post by **Lotus-e-Clan** » Wed Jul 06, 2022 11:35 pm

Just back from picking up the engine work from Mark's...£2500+ lighter!

As you already know by now. 40 lbft is the target for the ARP nuts on the head studs.

Full Procedure for head stud/nuts is:

1) nip-up studs in head (use anti-seize / coppa slip on threads). No need to over tighten.
2) oil the ARP nut threads /stud threads
3) Stage 1: 20 lbft
4) Stage 2: 30 lbft
5) Stage 3: 40 lbft
6) leave 24 hrs to settle.
5) At 24 hrs. Don't loosen nuts, but retorque to 40 lbft. It's the middle nuts that are likely to be loose after 24 hrs says Mark, the others may just 'click' the wrench.

BTW. Whilst I was there today, Mark did a great job trial fitting my (modified) rods to the (modified) crank to ensure that 38 Ibft on the big ends equals perfect roundness with no spread. Rods on new bearings span very free with no play at the specified 38lbft BE bolt tightness. Happy days.

moose · Post by **moose** » Thu Jul 07, 2022 7:02 am

ARP usually supply with their bolts the correct thread lubricant which is better for the material of their nuts and bolts are made out of, than coppaslip. As thread lubrication or lack of it greatly alters the torque reading to achieve the same thread stretch I would use the ARP recommended lubricant. Something in the back of my mind is saying don't use coppaslip on steel into aluminium I could be wrong.

https://www.google.com/search?q=arp+lub ... abhqqoBg20

Lotus-e-Clan · Post by **Lotus-e-Clan** » Thu Jul 07, 2022 8:36 am

moose wrote: ↑Thu Jul 07, 2022 7:02 am ARP usually supply with their bolts the correct thread lubricant which is better for the material of their nuts and bolts are made out of, than coppaslip. As thread lubrication or lack of it greatly alters the torque reading to achieve the same thread stretch I would use the ARP recommended lubricant. Something in the back of my mind is saying don't use coppaslip on steel into aluminium I could be wrong.

https://www.google.com/search?q=arp+lub ... abhqqoBg20

Hi Mike

The CoppaSlip /anti-seize is for the studs to block NOT the nuts to stud. The studs aren't torqued, just nipped. Oil is for the nuts.

I've been using Coppa Slip in head threads for years. It's all OK as long as copper/aluminium (dissimilar metals) isn't exposed to unpure water (contains mineral salts) or road salt splash. For electrolysis to occur, it needs an electrolyte (salts). Anyway, no chance for electrolytic erosion in my water jacket as I use waterless coolant. Elsewhere in the engine, studs are exposed to oil (ie no electrolyte present there either).

Mark's stud kit is a hybrid btw. The NUTS are ARP, the studs are not. No idea of the source for the studs, mind you.

Pete

edgedj · Post by **edgedj** » Mon Aug 29, 2022 10:11 pm

woodyard in Jersey, chap at the checkout says in a Glasgow accent ’nice van‘, I’ll take it

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Uncle Henry · Post by **Uncle Henry** » Thu Sep 01, 2022 12:36 pm

Champions ? I've bought many lengths of twisted, rubbish timber there when working in Jersey.

UH

edgedj · Post by **edgedj** » Thu Sep 01, 2022 7:30 pm

no it's Normans builders merchants, pretty good quality stuff on the whole but wood prices are crazy these days.

update on the Nymph and it's been rattling more and more recently, clonking as I take up drive and go over holes so the last thing I haven't replaced is the suspension bushes and these put up a hell of a fight coming out. Even snapped an M8 bolt trying to press them out. In the end only one came out this way and the other three had to have the blowtorch treatment and get melted out (fumes mask on)! - yuk. Still they are out now. Had to cut the outer two bolts as whoever put this subframe in, did so with the suspension already on and the outer bolts the wrong way around, doh.

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When it was stripped down I found these in the lower shock mounts, they are the wrong bolts - grr. Look at the shiny bits on the threads where they have been banging around, even though they were tight. New ones on order now, so maybe I didn't need to change the suspension bushes too as this was probably the clonking all along.

Uncle Henry · Post by **Uncle Henry** » Fri Sep 02, 2022 7:47 am

Ah, yes "Normans". Sorry, got that wrong

right next to the harbour with the posh yachts ! As I recall, I was told that Jersey often got the lesser quality timbers as it would be difficult to send things back to the mainland. Maybe things have improved. Not worked there for 12 years maybe.

I too have a clonking noise : offside suspension, that can be induced just by bouncing the front of the car that side. I'm expecting similar things, and have bought new polybushes in anticipation, along with replacement shock absorbers.

UH

edgedj · Post by **edgedj** » Fri Sep 02, 2022 3:27 pm

amazing difference over lumps and bumps in the road, having just changed all four rear bushes and replaced the shock bolts with temporary plain shank 3/8 unf bolts (not quite long enough but better than all thread). bit of a fiddly job but the old bushes were in a bit of a state. had to scrape out a bit of
corrosion in the arms because the new poly bushes will only go in when the housing is clean and the right diameter

edgedj · Post by **edgedj** » Thu Sep 22, 2022 12:33 pm

so after success with the rear suspension, decided to tackle the front now. Nice little horror show in there on closer inspection. Holes for the sub frames drilled in the GRP are offset by 19mm to the left (visually always noticed the left tyre more visible than the right) - easy GRP fix. Will be beefing up the GRP around the mounting points anyway as they are a bit thin on the Nymph.

Second thing, most of the bolts holding the stub axles in are metric and therefore not a good fit plus the shock bolts are wrong with all threads and no plain parts on the bolts. Another easy fix, bolts on order from the club spares.

edgedj · Post by **edgedj** » Sun Sep 25, 2022 7:48 pm

right, this is staggering - I can only assume the suspension was fitted from below as an entire unit with something like a scissor jack and a drill with major hit and hope, so far off to the non driver's side it's crazy.

So now to clean these up, repair the old holes and drill some new ones and also generally beef up the GRP here as it's a bit thin in places. One good thing is that they are so far off centre the new holes won't be even close!

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edgedj · Post by **edgedj** » Fri Oct 14, 2022 8:12 pm

well these looked good albeit a touch surface rusty - turns out one of the wishbones needs a spot of weldage, fortunately the local chap who is doing the power coating is welding them for me for an additional £20. The powder coating them for me, will drop them back to me tomorrow apparently...

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edgedj · Post by **edgedj** » Sat Oct 15, 2022 6:30 pm

super shiny bits!

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edgedj · Post by **edgedj** » Sat Nov 05, 2022 9:29 pm

While the tank is out, I'm changing the fuel pump location. Previously this was suspended from the sender in the centre but it does get in the way of the sender and is generally less than ideal. The new version is a large 8-an supply line to a modified mig CO2 canister tin welded to the tank at the top and with straps at the sides with a 12 bolt petrol safe rubber gasket on the top, high pressure fuel is delivered to the 6-an fitting on the top and there's a bleed to tee into the fill breather in the nose of the Nymph. The pump is now about 2 inches lower than the entire tank and should be able to use all of the fuel while leaving the gauge completely stock. Wiring goes through the sealing pass through not/bolt thing (not sure on the official name for it)

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Uncle Henry · Post by **Uncle Henry** » Sun Nov 06, 2022 10:14 am

Great work, Dave. I'd have liked to have seen this stuff in a steel bodied Imp I have to say. Never been a lover of the Nymph, although yours is exceptional. Great fun on an island 12 miles long, I'm sure (I love Jersey - it's one of my favourite places) but not conducive to mainland mileages, I'd suggest. I work on one locally for a lady club member on occasion. Its looks have grown on me, but not by much

AG

The Nun · Post by **The Nun** » Tue Nov 08, 2022 7:18 pm

I noticed the hydraulic fluid reservoir is fitted in what looks like a rain gutter? Isn't there a chance of water contamination with it there?

edgedj · Post by **edgedj** » Tue Nov 08, 2022 10:37 pm

The Nun wrote: ↑Tue Nov 08, 2022 7:18 pm I noticed the hydraulic fluid reservoir is fitted in what looks like a rain gutter? Isn't there a chance of water contamination with it there?

Yeah the whole of that front nose gutter is a bad design - see how it's causing the bonnet latch to sit in a perma-puddle too.

Uncle Henry · Post by **Uncle Henry** » Wed Nov 09, 2022 4:34 pm

Needs a funnel moulded in at the lowest point with a drain tube. Can't be difficult for a man of your calibre, Dave

AG

edgedj · Post by **edgedj** » Fri Nov 11, 2022 8:49 am

Uncle Henry wrote: ↑Wed Nov 09, 2022 4:34 pm Needs a funnel moulded in at the lowest point with a drain tube. Can't be difficult for a man of your calibre, Dave

AG

That's a good shout, probably at least two needed though especially as the brake fluid reservoir is the lowest point on the drivers side so needs a drain either side of it...

John A Ross · Post by **John A Ross** » Fri Nov 11, 2022 11:10 am

Or just move the resevoir to the cabin bulkhead and close off the scuttle hole with some off the shelf rubber bung and just add a drain ?

Peter Hurst · Post by **Peter Hurst** » Fri Nov 11, 2022 6:41 pm

The Clan has a similar design for the bonnet aperture, but it has a drain hole drilled in it. Then a rubber bung with a length of plastic tubing plugs into the hole and the tube takes the water though the bonnet space to drain below the car.
With the Nymph perhaps the designers thought it would only be used when it was sunny!

mikeyhearne · Post by **mikeyhearne** » Sat Nov 12, 2022 12:28 pm

My nymph has a hole in that channel that drains into the space between the two skins of the shell then drains out of another hole to the ground .
I think a lot of the drilling of holes was left to the builder of the car which explains the misaligned suspention holes aswell

The Nun · Post by **The Nun** » Mon Nov 14, 2022 11:31 am

Peter Hurst wrote: ↑Fri Nov 11, 2022 6:41 pm With the Nymph perhaps the designers thought it would only be used when it was sunny!

Doesn't always work in the UK though, perhaps the intended market was the Sahara area?
Oh no, thinking about it they put an imp engine in it so couldn't have been.

You need somewhere warm and sunny but not hot or wet, wonder where the heck that is