A Dream Fulfilled - MY 904FF

[Kirklands 904]

I am amazed to find that it has been two years since the last post on this thread and thought some of you might be interested in what has been going on in the interim.

The cable change mechanism mentioned before was finally made up and fitted and after a couple of iterations it was working better than the rod change but was anything but foolproof. It was all too easy for it not to work and to find no or the wrong gear. It was particularly bad coming from 2nd to 1st and this led to us thinking that the dog teeth on 1st were not up to scratch. This resulted in a new dog tooth ring being fitted and the inevitable trip to Mike Bainbridge to remove the ring and fit a new one. This helped but was still liable to error. The next thing to try and help was to manufacture a gate and fit that to a housing around the Boxster shift to give a positive position for the shift lever. Slightly better but still anything but perfect.

Whilst we were working to get round this the engine developed an intermittant misfire. You were never sure how many horses would turn up on a day or even on any particular run. Everything on the ignition side was changed from plugs,plug leads, points, condensor and distibutor cap. We checked the distributor operation, altered timing but to no avail. The misfire would come and go and of course Sod's law would apply - engine fine then gear shift would be crap and vice versa. Total frustration!

Finally the FF was taken to Mike Stewat in Errol who finally discovered that the fault was the wire from the points to the condensor was shorting on the distributor body. Of course, you could not see that when the cap was on but Mike had been brought up on VW and had seen the same problem before.
In other words the points had not been fitted correctly. Mea Culpa!

This resulted in 8 clean runs at Bo'ness in September but still the gearchange was not precise eńough. However all the runs without tearing something apart was a new experience.

In one of the trips to Mike I mentioned that years ago I had bought a 911T 2.0 engine in parts in a number of boxes and that had sat on the mezzanine in my garage for the last 10 years. Mike suggested that I brought it down to him to have a look at.

Even on one of the few good runs at Shelsley Walsh it became clear even to me that there was not enough power. The run up the hill was without drama to the Esses and the perceived wisdom was that SW was a power hill and 200HP/ton was required. My engine produced just under 120HP on the Aldon rolling road so with the FF weighing 740kgs that equated to roughly 150HP/ton. More power was required!

On looking over the engine parts, Mike was of the opinion that the engine could be built up into a 150HP unit with new pistons etc but the "T" spec was not the best base to be used with its cast crank etc. We finally came to an agreement that the T would be used as part exchange against a 2.4S engine built up on 7R cases but with E cams for torque. Using the original Weber carbs, Mike thought that it would give 200HP ay 7000+ revs. Since the gearchange was still problem, Mike suggested that the gearbox be converted to 4 close ratios with sideshift rather than the tailshift. So that was the plan and both units would be available this winter ( now hopefully January).

Since we were moving house from Scotland to Lincolnshire at the beginning of Setember for all the usual reasons at our age of downsizing and to be nearer the family, it was obvious that I would not have the time, space or facilities to do the the engine swop on my own. So on the Monday after Bo'ness the car was trailered down to George Laycock in Norton for the old engine to be removed and the space to be checked with a dummy engine that Mike had provided. We thought that a couple of tubes in the chassis might have to be moved but that and new engine mountings would be all that was required. Even after 60 years working on cars, I have still not learned what looks simple never turns out that way.

When the 6 cylinder dummy was fitted besides having to cut out chassis tubes and insert others to maintain rigidity, we had a major "Oh shite" moment when it became clear that the radius rods running forward from the rear uprights to the rear bulkhead were in the same space as the engine. What to do now? We realised that the only practical solution was to retain the same suspension geometry and convert to rear wishbones. The chassis mods and the new wishbones were made by Andy Lockwood of Lockwood Fabs who works with George and produces the most exquisite TIG welds. Since the FF was up on a rotator, when the bottom was inspected to determine the damage resulting from bottoming going into the top paddock at Bo'ness, it became obvious that it was worse than originally thought (does that sound familiar). Andy has now fabricated a lower seat pan which should allow me to get in without my crash hat touching the roof, strengthened the seat belt mountings, modified the throttle pedal to minimise the chances of hitting the brake and throttle pedals at the same time, made new engine mounting brackets and a number of other small improvements. The car is now beginning to look much more professional compared to my original amateurish efforts.

Whilst at Bo'ness, when the tail was open for scrutineering, Paul Farrell was admiring the 914 engine and his eyes lit up when told it would be up for sale on the Monday after the event. The oucome is that the engine is back in Scotland in Paul's safe hands and the proceeds will help to pay for the 6 cylinder unit from Mike.

I should also mention that my 1967 Porsche 912 has been sold at the Silverstone Auctions at the NEC to an Australian couple living in Switzerland. I like the idea that some of the the proceeds from the sale of one Porsche is going into another Porsche rather than some frivolous use such as garden, furniture, clothing, holidays etc!

So that's the current position. I intend to have a full season next year at Shelsley, Blyton, Curborough etc as well as a trip back north to Bo'ness. I am looking forward to that even though I am already apprehensive of 60% more power but all my pals tell me that the pedal on the right may be involved. The plan is to be at the first Shelsley meeting in May and hopefully for the rest of years programme. If anyone is interested in seeing the final outcome do come and say hello

I will try to post some photographs when I can work out how to that again and give a further update when it is completed.

[jwhillracer]

That's great, Bill! Looking forward to seeing you and the FF at May Shelsley.

I hope you're not causing too much chaos among the Lincolnshire Porsche mob..........

Best Wishes,

Jonathan

[911hillclimber]

Now you are far closer, get across to the Loton hill climb!
210 bhp will be more than enough for a few thrills on the long hill.
We have a practice day in late March, 3 months to get it all done.
Www.hdlcc.com

[bjmullan]

Thanks for the update Bill, looking forward to seeing you at Bo'ness next year!

BTW did you see the Motorsport TV coverage? Here it is on youtube: https://www.youtube.com/watch?v=xh_PDt5wwUQ&t=14s

[Carl2]

Great project! Any chance of putting the pics back up?

[Kirklands 904]

I'll try but have to work out or be shown how to do it!

[911hillclimber]

There was a thread in 'General' how to remove the stupid Photobucket blanking and the pictures were restored about 2 months ago.

[PeterK]

There is an add-in when using Chrome that allows you to see the pictures, but nothing that I know of yet to fix the issue with Safari or Explorer

[Kirklands 904]

Another part of the upgrade has just arrived. After all the the ignition problems with the 4 cylinder engine, Mike pointed me towards a Clewett system which does away with the distributor and uses a crankshaft pulley to fire three coils. It is not cheap but hopefully will give bullet proof timing.

It came from California to Stansted in three days and then TWO WEEKS from Stansted to Lincolnshire due to the shambles which is British customs. Do we do anything well in this country?

Rant over so can I wish all DDKers Happy Christmas and a safe but fast 2018

[hot66]

I’m running clewett on my car and really like it. Mine is the one that has 3 dials to set the timing advance. Gives a rock steady ignition timing . I have found the spark lead fittings at the spark plug end can be fragile so be a bit careful with them ... I’m contemplating buying a few extra leads to have a s spares

[Kirklands 904]

Yes. That's the one that I have. Thanks for the tip to be careful with the plug leads.

[hot66]

It’s the metal connectors inside the rubber housing... I’ve had 2 different ones damaged

[Kirklands 904]

Having read the Clewett manual, I realise that the tachometer signal it gives is a 12 volt square wave with 3 pulses per crankshaft revolution. This will not drive the VDO tacho from the donor 914 which is currently fitted and which gets its signal from the coil and which I had hoped to retain as it is period and big enough for me to see. I thought that the Dakota Digital rev counter amplifier could convert from 6 cyl to 4 and amplify the signal to drive the VDO unit. Unfortunately they say that it won't.

Any ideas of what to do since my head hurts!

[hot66]

I used a later rev counter from a 6 pin Cdi car ... Ultimately got it back dated to like an early one

( I'm referring to 6 pot motor and 6 cylinder tach


Sent from my iPad using Tapatalk

[RichardJ]

Have you tried the 914 tacho with a 12V square wave? To my surprise I found the late model ('75) tacho does work from a 12V square wave, unlike every other early VDO electronic tacho I have ever tried (mostly VW). I make an electronic module which converts a 12V square wave to a signal suitable for the older VDO tachos which do not work direct from a 12V square wave. It does not alter the frequency though, so a 4 cylinder tacho on a six would show 150% of the actual rpm.
Petrol VW VDO tachos can be recalibrated, and have enough adjustment to work with a six. The recalibration process is easy in theory on 80's VW models, where the potentiometer is accessible. I believe the Porsche tachos are also recalibrateable in this way, but the potentiometer is not accessible. I have not tried with a 914 tacho yet, although I did recalibrate a '66 911 or 912 tachomany years ago. It was for someone who already has the tacho casing apart.
In practice the recalibration process isn't as easy as you'd expect. The VDO moving coil mechanisms have quite a lot of hysteresis, so finding the sweet spot so the revs read as close as possible to correct when they are both rising and falling can take some time. Obviously you need an accurate, adjustable signal source, or a means of reading the exact engine rpm too.