John Bonnett
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Everything posted by John Bonnett
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I don't know Hazen. They came from Autosparks.
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Using as a basis, the circuitry I designed for the Triumph I've made a start on the wiring; a job that is being done from scratch. An auto electrician is modifying the bike loom to mate up with the car electrics which is a relief for me. I'm transferring my circuit diagrams to a bread board which will make it easy to test out the individual circuits. This time left and right hand headlights are individually fused and independent of each other, controlled by the four relays R4 -R7. R1 and R2 operated by the ignition switch provide 60 Amps for the ignition controlled circuits. This takes a big load off the ignition switch. R3 is the headlamp enable which prevents them being left on when the ignition is switched off. One more fuse box and an additional relay for the fuel pump have yet to be added. But it's a start. Eventually I'm hoping the relays and fuses will fit up under the dashboard but will be hinged to allow the assembly to drop down for access. I've had a lot of trouble in the past with connectors on relay holders so this time I've got rid of them and connected directly to the relays. Not so elegant perhaps but if it prevents bad connections then it will have been worth it.
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A great find Harry; thank you. It's interesting that they give caster as 7 degrees which is what my chassis had. This was a replacement chassis made by Ginetta. The caster is determined by the kick up of the longitudinal chassis rails not by the towers as on the Triumph. Unfortunately the body will only accommodate 6 degrees which is why I had to change the angle. Being light on the front it could probably have benefited from the extra degree to give more self-centring and straight line stability. I had to change it because the body wouldn't sit down properly on the chassis. So we get what we get. Fingers crossed it isn't awful. I think the quoted weight of 534kg might be a bit fanciful although I would be delighted with anything under 600kg. I'm doing my best to build light but may have overdone it with the battery; an Odyssey PC680. Tomorrow I'm having a little jolly. I'm going to see Tavistock Steve to get a 1500 Spitfire steering column which I want for the cowl and the switches. The G15 has one multi function column mounted switch and everything else is on the dashboard. I have the 1500 Spit set up on my Triumph and I really like it having the controls that are used the most at the finger tips. I'm not sure how easy it will be to incorporate it but I'll know better tomorrow.
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As always it's good to get back into the workshop after Christmas. The engine conversion held up by the gearbox rebuild is still a long way off but the time isn't being wasted; there are a lot of non mechanical jobs to be done. The main one being the wiring which is being done from scratch. I'm using a sa basis the one I did for the Triumph but with left and right headlights powered by independent fused circuits. This does add a bit to the weight with the additional relays and fuses but worthwhile I think. As Triumph owners we are a bit spoilt having most things available off the shelf. This is not always the case with the G15. I have had to buy Imp handbrake cables and shorten them to suit. This turned out to be a very easy and straightforward job. I cut off the cable adjusters and using the lathe drilled out the cable. After shortening the new cable I inserted it into the adjuster and silver soldered it. Having assembled the cables i was dismayed to find that they appeared to be different lengths and that I'd made an error when I shortened them. But it turns out that the cable guide had been welded incorrectly offset on the chassis cross member. So if I chop it off and re-weld it all should be well. This was just a trial fit. The linkage and handbrake lever will be refurbished.
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As you know Roger we don't have deadlines any more but it would be nice to have it ready for our petit tour de Bretagne in May.
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Although I have done quite a bit since the last entry it has all been very much Ginetta specific and probably not of much interest to the world of Triumph. Work includes shortening the Imp handbrake cables to suit, mounting the radiator and glassing in dashboard fixings. There won't be any progress on the engine installation until at least Easter which is when the rebuilt gearbox is promised for. In the meantime the plan is to finish everything else so that once the engine is in the car will be finished. So, on the road by the Spring......perhaps 😉
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I managed to lose nearly 100grms in weight on the hinges which are now finished and ready to fit. Some more photos later on will clarify how they work. And speaking of lightness the Cosmics are only 4kg and the tyres under 6kg. Compare this with just under 20kg per wheel and tyre that I ran initially on the Triumph. And this is unsprung weight.
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The clutch is now removed from the engine and I'm just waiting for a rattle gun to remove the flywheel. Everything about the engine is amazingly light weight and beautifully designed. I've sent the exhaust manifold up to Clark to be modified rather than do it myself. He has a jig and for sixty quid it was an easy decision to make. The trailing arms are now rebuilt with new bearings, u/js and brakes and ready to fit. The tyres have arrived and will be fitted once I have the wheels some time next week. The tyre wheel combination should be very light. The packed weight of two wheels is 10kg and one tyre weighs less than 6kg. A chap over on the Ginetta Club rallies a G15 using these tyres, Uniroyal Rain Expert 3 and reckons the grip is phenomenal. And at £25.50 a tyre incredible value. I'm well on the way with the new door hinges which are in stainless steel. All the piece parts are cut and ready for welding.
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The wheels that came with the car, 5.5J ET20 Revolutions stuck out beyond the wheel arches so I sold them. And now I have had an amazing bit of luck. A set of 4.5J MK1 Cosmics fitted as OE to the G15 have just come up for sale and I've bought them. So I'm really pleased how it has worked out. Regarding tyres I have heard very good reports of Uniroyal Rain Expert 3s so I have bought a set for twenty six pounds a tyre; amazing value. Size 155 80 13.
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I think it will probably be alright providing it didn't go for a swim.
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You may remember that i said I am going BMW bike engine on the G15. Well it arrived yesterday. A DOHC K1100 that's done 43k miles. Not only the engine but all the ancillaries including the ecu and loom. In fact, everything needed to do the job. I now have to wait for the bits to mate it to the Imp transaxle. Mechanically fitting shouldn't be much of a problem. Just the fabrication on the engine mounts and turning the throttle bodies through 90 degrees to allow clearance with the parcel shelf. The wiring and plumbing on the other hand could be a bit more of a challenge.
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Proper job as we say in Devon 🙂
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The chassis works are nearly finished. Over three months and well over a hundred hours spent. I've removed the old flat folded cross member and replaced it with one folded to the correct angle of eight degrees. This allows the shocks to angle forward to connect nicely to the trailing arm pick up points. Everything is just tacked up for the moment until we see how the body sits.
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I don't know at what stage you are but I've got an awful long way to go. I've been working for three months now and apart from a few breaks and a holiday pretty much full time every day. Being retired and able to play every day does have its advantages. I've now started on the replacement of the wrongly made top rear cross member. You may remember that I said this has to be angled downwards toward the rear of the chassis at an angle of 8 degrees so that the shocks line up with the pick ups on the trailing arms. Outboard of the cross member on each side I'm fabricating a a triangulated frame from 20mm square tube. The whole thing will only be tacked up until the body is dropped on to make sure it all sits right. If there's a problem with it not being quite right it shouldn't be difficult to unpick it. The breaking news is that I have ordered the engine; a BMW K1100 16 valve twin OHC. I have also ordered the kit of parts to mate the engine to the Imp transaxle. Unlike the Triumph, the G15 has no heritage and I'm quite happy, well very happy really, to fit a modern bomb proof motor. With 200BHP/ton the car should be quite nippy.
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The day went well. Amazingly well in fact. It was a matter of only an hour to rectify the chassis problem. A 1mm cut was made into the chassis tubes and the weight of the chassis on the rotisserie closed the gap and I just welded it up. Corner pieces will be fitted to strengthen the joint. I then moved on to the MX5 type adjustable toe for the rear suspension. . The cam bolts which move the pivot across a slotted hole which alters the toe.. This allows very accurate setting which is a whole lot better than no adjustment where in my case one wheel was parallel and the other toeing out. To finish off I've tacked the brackets on for the tower brace A few pics follow.
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Ginetta were within a month or so of going into administration when the chassis was made so one can understand the level of morale and the slipshod build.
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So what's the problem with the chassis I hear you all ask? In their wisdom Ginetta produce the caster angle by bending the chassis legs up at the required angle which should be five degrees. On mine it is six degrees which puts the front end of the chassis and body mounting 12mm too high. This has had the effect of lifting the body off the chassis along the line of the mounting bolts. This effect has put the suspension towers in the wrong place on the body to the point where there is little room for the rear top wishbone pivot bolt nuts. So what to do? The problem lies with the chassis and not the body so it's the chassis which needs correcting. The plan is to remake the angle to six degrees and hopefully all will be well. The rotisserie is once again proving its worth and puts every job at a very convenient working height. While the body was on I was able to measure and make a brace for the suspension towers. This passes through the car. It is made from 20mm stainless round tube with M8 Rose joints at each end.
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Ah but there's a problem with the chassis Richard. Pics and explanation to follow.
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Right, I've made contact with the man who does the conversion parts and I'm really impressed with his expertise and professional approach. He supplies a billet cnc machined bell housing to mate the Imp transaxle directly to the engine and lightened flywheel with a roller bearing to suit. Clutch cover and concentric slave cylinder off modern engines and a bespoke driven plate. He recommends the K1100 16 valve engine which has a Motronic system simpler than the Bosch one on the smaller engine. Performance wise the 1100 will get away from 500rpm and deliver power right up to eight five. In his words you have the best of both worlds; a good 875 Sport engine at the bottom and a full-house 1100 Imp engine at the top end. This does seem to be the way forward. On the chassis the right hand side bracing is finished and I've made a new gear linkage shaft and rebuilt the lever assembly. More jobs ticked off.
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In desperation I've actually bitten the bullet and messaged him on Facebook Hazen. And still no response.
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That's very kind of you Clive. Thank you. My biggest challenge seems to be contacting the chap in Scotland who does the conversion parts. He has no email or landline and poor signal for his mobile. I've been told to try messaging him on facebook and that's serious. I don't do facebook.
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The odd mm in difference between 4" and 100 mm is enough to bend the studs and cause a heap of trouble down the line. I believe Minilite offer a range of offsets up to the E26 which is what I need so all will be well. I'm currently looking at fitting a K series BMW engine which might be the cheapest way to a hundred horsepower. There's a chap in Scotland making the adaptor plates and hybrid clutches and quite a few Imps, Clans and I believe at least one G15 have versions of this engine fitted. The K series engines are built on car lines and don't produce maximum power at silly rpms. And there is only a 2kg weight difference between the Imp engine and the K. Worth a bit of research methinks.
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We're getting there Hazen. There's the bracing on the right hand side to finish and then the replacement of the folded rear cross member. The top of it should slope down at eight degrees which angles the shocks so that they fit nicely on the trailing arm brackets. On my chassis the top is flat and the shocks can only be connected to the trailing arm by straining the top mounts. This is just another example of some very shoddy work. But looking at it in context Ginetta at that time were in dire straits and went into administration very soon after this chassis was made. One can imagine that morale was low and people just couldn't be bothered. The chassis never was a great design but in conjunction with the body the whole package worked and even passed a Government crash test at 30mph.
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The Gaz adjustables have just arrived and having done a trial fit all looks reasonable. Taking a notional ride height there is 32mm of free movement before squashing the bump stop. I've also cut out a panel of unnecessary metal from the suspension towers. This has saved 1/2kg.
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I never doubted you for a minute Hazen. I knew you could do it 😉 But having carried out the same operation myself on my newly skinned doors I can thoroughly relate to the stress at that point.