Power sapping

I had suspected at Brands that the car was down on power, and at Cadwell i was convinced as i could only hit about 117 down park straight and the car really wasnt pulling well up the hill. Nearly everybody i asked was hitting 125mph+ up there, even the MNR boys in there mobile bricks. I checked the compression and valve clearances while in the paddock at Cadwell, and although maybe very slightly low and a couple of tight valve clearances it didnt seem to tie up with the loss of power, especially up the top end. But i decided to swap out the engine with my spare, which by all accounts stands a chance of being a better engine if what the guy i bought it off was telling the truth. So tonight we were just about to start removing it, but while i was just making a start, dad rolled underneath to have a listen to the noisy bearing in the diff that John had picked up on at Cadwell to discover a huge amount of backlash in the diff. When dad had rebuilt the diff at the start of the season he said the crownwheel and pinion where pretty worn and looked as if the case hardening had just about worn through. He said we should change as soon as possible when one popped up for decent money, but up until now it had been put to the back of the list. So after stripping it down we were greeted by the sight of a hugely fubared gear set:-

I think i was lucky to even finish the last race at cadwell as there isnt much left on those teeth!! At least this means no need to swap the engine and i still hopefully a have a decent spare. But was it does mean is a hurried hunt for a replacement 3.54 crown wheel and pinion.

Dad also brought up with him the modified lightweight bonnet, now sporting a rather huge growth

As the bonnet doesnt have a the central bulge like the old heavy bonnet, so a modification was required to the new light nose cone fitted for cadwell, the part removed has left space for a new air intake scoop, again made by dad from GRP. Its a bit like a Rolf Harris drawing at the moment, but you will all see how it works in the next instalment 

Lightening the load

Before Brands we smoothed out the new front end into the bonnet and cast a mould. This meant the front was even heavier than before, but it means that we can now start the next step, reducing the car by 30kg! I doubt we will get this Fury down to the 530kg, although it would be very easy by just remaking all the bodywork, but the amount of time it takes will hold up the new car. But remaking the front endand using the lightweight front bonnet we have should reduce the car by about 10kg without trying too hard.

The front undertray was a bit battered n the existing front, plus we wanted to leave the existing front entact as a spare, so we made a new undertray. This was done with our existing mould, just a piece of hardboard and some D shape trunking. we tried using 2 layers of 300GSm this time, but it was just too floppy, so added another layer to the bottom surface, which also closed off the open sections left by the trunking.

Its looks good and very strong, but has turned out only marginally lighter than using 5mm ply, so next car we will use ply rather than going to all this effort!

Next up was the actual front end, 2x layers of 300gsm, with an extra single layer strip around the edges, produces a great piece, strong enough around all the curved syrfaces and corners, but the flatish front was still ver soft and would break if just pushed in with a finger. Adding another single layer to just this area increased it rigidity by about 3 times. With all the brackets and braces added the front is very stiff and only weighs 6kg, compared to old front end weighing 14kg! The lights are still to be added, but we should have saved 7kg making this front end!!!

Dads on holiday this week but will get it sprayed for Cadwell. Meanwhile i will be checking the car over, cutting down the the lower wishbones slightly to allow us to run slightly less negative camber and resetting all the geo based on this

New Axle build

Luckily we had another casing spare, but unluckily the brackets that needed adding were not simple, and cannot be bought from fury as they make them up on a jig on the axle. So initially i built up the simple bracket for the upper and lower pick ups on the bench. I used a piece of 40mm square tube, cut, notched and bent to fit the axle casing

After bolting all the suspension links back to the chassis and attaching the brackets to the links, we then lined the axle up in the car, using wooden supports bolted onto the axle flanges to hold the axle at the correct height and angle and aligned the brackets made into position. We checked the diagonals and centre lines relative to the front axle and centres of the chassis and adjusted it as required before tacking the upper brackets in place.

The axle was pulled out from under the car and the bracket welded in place a bit more securely and the tabs bending round the axle tube.

The same process was repeated with the lower brackets

The tabs were then trimmed and everything fully welded up.

The picture below shoes the jaunty angles everything has to be fitted at for the suspension to move freely and inline

We then added the panard rod mount (cut from original axle) and braced everything.

The diagonal checking showed that one side of the car (or wheelbase) was longer than the other by about 15mm, so we took the opportunity to resolve this by altering the angles of the axle mounts (rather than cutting off the front suspension pick up points and moving them. This does mean that they are not symmetrical either side and does look a bit horrible, but at least now the wheelbase is square!!

The new wishbones, panard rod and uprights had also arrived back from the powder coaters as had the replacement front discs from Hispec.

Suspect suspension

I have always struggled with the car understeering when trying to get out of the corners coupled with high roll angles by trying to run the car soft to keep the rear axle under control . I have tried various settings and springs but felt that this was the biggest downfall of the car in its present state. Family friend John Bentley offered to look into the geometry of the car and see if he could come up with some improvements. After a few hours of measuring and putting it all into his suspension program he could easily see why the car was rolling so much and suffering from understeer. The roll centre was far too low and moved around a great deal during roll. Also the geometry meant that at 2.5 degs of chassis roll, the outside wheel was over 1 degree in positive camber. We didnt want to start from scratch with the suspension, and wanted to keep the escort uprights and existing dampers (to save cost). We also didn't want to be hacking off the complete front end and remaking everything, so john started to look at what fairly simple changes would gain us benefits. He calculated that by dropping the upper wishbones to the lowest and most outboard pivot holes on the existing pickups would be beneficial in on all counts, in fact actually keeping the wheel in negative camber during roll. It also meant no changes to the lower wishbones, or damper pick up points. The only new items required would be upper wishbones, and these again only needed minimal changes, leaving the outboard parts the same as standard, and just modifying the angles and lengths of the inboard parts. This would also give the opportunity to gain a rising rate spring rate during compression.

We ordered some wishbones from Fury, but asked just for just the outer parts, we could then add our own inner geometry. After setting the ride height f the car using some blocks under the chassis, we used some MDF and blocks to set the uprights at the same height as if the wheels were fitted. We could then check the movement of the wishbones and the associated positions and movement of the dampers during bum and droop.

With the pivot point decided upon and marking it on an MDF jig fitted to the wishbone we built up the inboard parts and tacked them in position.

We then added a brace and made the the otherside. The picture shows the difference between the old and new wishbones. The tacked up wishbones where then sent off to the Tig welding man and powder coaters.

The rear axle links after the powder coatings and new bushes

Shiney and radiant

Since the r1 install the engine temps have never been as cool as I wanted, so thanks to dad a nice new thick core aluminium radiator was ordered at the Autosport show. Its the same size and fitting as the standard polo radiator and is used in lots of road and race kits cars. A number of people have said it will drop temperatures by about 10 degs, which will get the car down to my "happy" operating temperatures. It will hopefully mean i can also put a floor on the engine bay again, something i had to remove (and cut up to use for other bits) when temperatures were rising after the new front end was added. I will definitely fit some mesh to try and save the fins this time

The new rad dropped into place, but was 40mm narrower than the original unit as i had forgotten i had fitted the slightly wider polo version last year. This was easily fixed by adding a couple of small aluminium brackets.

I had been advised not to bolt the radiator directly to the the chassis brackets as the contraction and expansion of the radiator would cause the aluminium sides to separate or split from the core. So i drilled some oversize holes in the steel mounts and inserted a small length of rubber fuel pipe, and sandwiched this between 2 washers and bolted into the radiator mounts through this.

If you read my blog on a regular basis you may wonder what has been happening to my posts recently, well i decided to try and keep up to date by posting pictures via my phone as and when i take them, along with a bit of a description, then when i get 5 minutes jump on the pc and edit the post. I find leaving it for a few weeks then trying to catch up a bit daunting and end up never doing it. So if you see a short post, try coming a back a couple of days later and it may have grown (like this one)

Mallory Test = Disaster!

I was nervous about the the test day, Mallory isn't my favorite circuit and i find it the most intimidating, but i was more worried about a serious mechanical problem with the car. My concerns would soon turn into reality........

It didn't start too well, battery was dead on the bus, then i damaged the rear tub mounting bracket as i drove the car over it. The trip there was at least uneventful and we arrived bang on 8am ready to sign on. After unloading i took the car for a slow spin around the paddock and everything was fine. I went out for the first session at 9 and did about 3 laps, taking it very steady, but could already tell it was going to be a flying machine compared to the blade!! Coming back to the pits and removing the bonet showed i had a small oil leak somehwere around or near to the oil level sight glass. It was only a small amount of oil and the levels was still fine so i headed out again. I started to push a little harder, but was still taking it very easy, i had no gear indicator or shift lights as these were still set for the blade so probably went no where near the rev limit. Returning back in we then set about trying to track down the oil leak.

The oil leak was only minor, but was coming from the union between the oil cooler and hose and it wouldn not tighten anymore. So we decided to remove the pipe to investigate further, this showed that the end we had had fitted on the old hose was the wrong type and would never seal properly, bugger! The leak was very very minor so at least it wouldn't stop the day, but dad being dad, came up with a solution using an o-ring, and "bang, the leak was gone". Whilst dad was doing this i set up the shift lights and gear indicator, something that would have been less fiddly if i had remembered to bring my laptop along!! By the time this was all done the 2nd session was well underway, but it was still worth a run out, but as i went to use the reverse the car went dead, no power!!! Bugger!!! I thought it was the master fuse, but a flick of the master switch and it came back alive again, but as soon as i tried to crank the engine it died again. I started to fear a serious electrical sort, until a waggle of the battery terminals showed they were lose!! A nip up with the spanner and i managed to get out on track for 1 lap before the flags came out!!

We again checked over the car, the oil leak from the cooler union was cured, but there was still dampness around the sight glass, very very minor but a leak none the less. It was either the glass seal itself or the cover plate directly above it, but not something we could sort with stripping the engine down a bit. The oil level was still perfect and not dropped so it would be fine for the final session. With 15minutes to spare we set up the new video vbox camera system and refueled.

In the final session I slowly started to build up the pace and started to use the full rev range, although still not really ragging it, and getting to terms with the swapped over gear change. I saw Al in my mirrors and thought oh dear this could messy (actually i thought wahoo a race!!), the circuit was damp and i was still being cautious (as was Al), but now the purple peril was behind i was hoping to start stretching the cars legs, unfortunately the following lap, whilst going down the start straight, there was an almightly bang, a horrible vibration, plumes of smoke and no engine power. I quickly pulled off onto the entry slip road of the pits and contemplated jumping in the lake.....

Pushing it back to the bus i knew something big had happened, i was hoping it was an exploded diff, but was pretty sure it was the engine. After removing the bonnet the damage was obvious, a hole in no1 barrel and crankcase, bugger!!!!

I was pretty sure it wasn't oil starvation as i had been keeping a very close eye on the oil pressure around Gerrards during the day, but unfortunately my data logger wasn't running. Luckily watching back on the video, the oil light is just visible in the bottom right hand corner. It does flicker on coming into the hairpin, but this is because the engine revs have dropped right down due to changing all the way down the box. Nowhere else does it come on so i was then confident it was not oil starvation, but a strip down of th enegine would need to be done to confirm this.  At least my new video kit worked well, and it captured the moment of destruction very well



Back home we took the engine out and stripped it down

 As you can see the big ends and crank are perfect, so the conrod failure was caused by oil starvation and the a seizing big end. So we can only conclude there was a fault with the conrod, either in caused in manufacture or by an excessive stress load during the its lifetime in the bike.

So making Mallory race 1 was looking fairly dubious on Thursday, until i decided to take the bull by the horns and start a nationwide hunt for a replacement. Malc at Yorkshire engines who supplied this engine offered me a replacement at cost price, but hadn't got one in stock, Andy Bates was on the look out for me, but then i stumbled across one in Stoke for a good price, so i shot up there and picked it up the same day.

So its now operation fit engine 2 and hope for the best next time out!! Fingers crossed!!

Final jobs and Prep for Mallory Test Day

With Mallory test day only a few days away there were lots of jobs still to do, mainly tidying and binding the loom up, plus lots of there bits and bobs. It was one of those times where you are 99% complete but still have about 25% more time needed to complete. After a long day of jobs and a blast up and down the lane in the car at full operating temperature, we decided that the 9th was going to be too early to test, a water leak from the lower hose exit from the block, the throttle not returning properly, plus a few other bits and bobs made us decide to put it back a week. This took the pressure off and meant we could be fully prepared for a good mornings run. It also gave another couple of days to have a go at the front splitter. We are creating an GRP front lower valance, that will replace the lower half of the bonnet, hopefully creating more down force and creating a new look for the car, The fury Evolution??????

Rather than trying to match up to the returning underside of the bonnet, we decoded to cut this off to make a horizontal flange to mate between the valance and bonnet. Bonnet pins mounted to the front suspension mounts now hold the bonnet in position at the front.

Using a plub line we marked out the silhouette of the bonnet, then added 50mm to this, this gives us a maximum projection for the splitter (to comply with RGB rules) and cut it out

We then added the upper parts which follow the lower edge of the now shorten bonnet. This gives a buck to build up a mockup of the valance.