Trying Out The New Engine

August 17th 2013

Now that we have a bigger engine in the car, and prior to the first event after the summer break we needed to give it a run to see if all the work has had the desired effect. Ie: more torque and the ability to climb hills at very low revs.

We went to my friend's fell-side farm at the South end of Windermere again for a shakedown run to see what broke or fell off.
The answer was ..... nothing.

A small water leak from a hose. Tightening the clip sorted that.
A bit of fiddling with the mixture.
Slight overheating (up to 95°C) but seemed to solve itself (Purging air?).
Re-connected the vacuum advance which had been giving trouble when trying to set the basic timing.

There was enormous torque from the Suzuki 1600cc engine after being used to the 1040cc Imp engine.
It would drag itself up hills in 2nd and 3rd gear instead of just 1st.

Trialling is not about top end power, but the acceleration in (for instance) 2nd gear from just above tickover was brutal.


The farmer's grandson arrived with a friend in a Defender on his way up to the tarn to go fishing. I offered to give him a ride up.
"There's a big rock step you won't get over" he said. (We'd been up and down it several times already.)

I passed that no problem but nearly lost him out the back when I floored the throttle on a flat bit of meadow. It may not be that fast in reality, but in a small open car on bumpy grass with a loud exhaust next to your ear, it feels very fast.

There isn't actually any extra power. The Imp engine produced 80bhp. However that was at about 7000rpm.
The Suzuki has 82 bhp but at a much more useable 5400rpm.
The torque is the big story. The Imp probably had getting on for 55 ft/lbs but at approaching 4000rpm.
The Suzuki has 93 lb/ft at about 3000rpm.
This means that at low rpm there will be a fistful more torque than the Imp engine had.

However the throttle did deem a bit sharp, not very smooth in application.

Practice Day

In August we went for the club Practice Day at Firbank near Sedbergh on the edge of the Yorkshire Dales. It’s only about 20 miles from home so very handy.

It was a bit of a mixed day. Blistering sun and heavy rain, but overall very passable. The normal format was a bit different with us members laying out the hills and Ian and I did the stupid thing of laying out a Hill (test) that we ourselves had trouble getting up. Mind you, so did everyone else as well. In fact as I remember it we set it up going to the left of a tree. We all got stuck going to the right of that tree. Someone moved the poles.

As it's a practice day the older (what, older than me?) and more experienced members took the time to analyse problems.
This worked very much in our favour.
Our major problem has always been tight turns up hill just after the start.
With help from one of the venerable members we identified that it is not pure momentum we need but a steady throttle. With the smaller Imp motor (1040cc) this has never been possible as the extra load of the hill would either stall it or need a bit more power. That squeeze of power breaks traction and you are stuffed.
With the new 1600cc engine we can approach the corner at a steady speed and turn using the fiddle brakes whilst not having to use any throttle to overcome the incline.

Great.

However it has highlighted the new installation's downfall That I’ve already noted in that the throttle response is linear and too sharp at low speed. I need to get a progressive throttle linkage which feeds power in gently at low speeds.

The video show a corner which stopped everyone. Doesn't look hard but it stopped our best men. Brian (who I bought my car from) went straight round again and tried a different approach which just got him past it.

The video shows Ian's growing aptitude for arm-waving. The first car to get stuck is Rob. We get stuck and so did everyone else. Then we have in-car video by Ian, but he claims he nearly fell out of the car (he films the exhaust) which I'm not sure about.
Then we have a successful attempt at the hill that caused us grief.

The big problem in the pics and vid is that it doesn't give a sense of how steep the hills are. You have trouble walking up them. By the end of the day we had cleaned all the hills. So were well pleased. My bulge was much-admired, as was the installation of the new engine.

The major disaster of the day was that I tried to knock down a (big) tree using my new (very) pancake airfilter. Bit of bending back into shape is required there.

The only mechanical malady was a clutch problem which saw the clutch pedal lock up solid. At first I suspected the release lever in the bell-housing, but am now thinking the pushrod from the slave cylinder is not enough in-line with the piston and the piston is jamming. Luckily I left the bracket supporting the slave cylinder bolted in place instead of welded, so I can adjust it (I hope).

After the Practice Day I decided that the throttle response was too sharp and we couldn’t  improve our performance much if I couldn’t modulate the power delivery.

To this end I went crawling around scrapyards in search of a “snail” cam to fit to the throttle spindle on the carb to make the power delivery more progressive.

This is what I found on a Jaguar.

Once fitted, with some more mods to the cable bracket it looked like this

The theory is that it moves less initially and then speeds up the further you push the pedal. However it didn’t seem to make a huge amount of difference when trying it out in the drive. We would only know when we got to the first event.

Of which more later........

First Event After Summer Lay-Off

Sept 28th 2013

I'd made use of the summer hiatus to stick my bigger engine in. Now was the time to try it out under the white heat of competition. Usefully the event was at Gale Hall where we had had a decent enough day previously in pretty dry conditions, using the Imp engine.

Gale Hall

We turned up on September 8th (May 5th had been the last event) to a dry day with bright enough weather, but a cool breeze. It was a BTRDA round so there were plenty of cars and some of the Southern hot-shots were there.



In deference to the status of the event the hills were a bit harder than we are used to.
See how steep some of the slopes are in the background in this shot.

The first thing we noticed about the car was that the sharp transition from tickover to moving was still a problem. In fact it seemed to be worse.
I'd put some thicker oil in the dashpot to try and slow down the response to the throttle ( I never know if that's the right way round) but we still had an on/off throttle.
This was a real pain. Most of the hills were dry grass and dead bracken, so any sudden throttle movement could lead to a spinning wheel and sudden lack of progress.

I was trying to go softly, softly, I really was, but it just wasn't happening.
Not only was the engine picking up revs more quickly that I wanted, but backing off was also a bit sudden so instead of maintaining pace we slowed. So then I had to open the throttle again and the vicious circle was complete.
We had the good fortune to be running along with Andy Woodhead. I didn't know him as he said he hadn't been doing trials for a year, but he knew his onions and kept offering advice, which I would love to have been able to put into practice.
The problem seemed to be getting worse.

Someone pointed out we seemed to have a water leak. We couldn't find a source for it so carried on, thinking about topping up the radiator at lunchtime.

What really interested me was the performance of Joss Veale from Somerset who was storming up the hills (I mean he was doing well, not that he was going really fast). It interested me because he was using a car not unlike mine, in that it had a live rear axle rather than independent suspension. I'm sure he had some other nice bits on, like shockers and brake callipers as it seemed to have had a complete rebuild, to a very high standard. He is at 2 minutes 04 seconds in this video.

Lunch time arrived and we changed the dashpot oil back to a thinner one. I topped up the radiator. However I didn't actually check the motor was full of water (there is a high point which could lead to airlocks) and this was a mistake.

On the run back to the afternoon hills I noticed the car was pluffing ( very specific technical term) through the exhaust and wondered if we had some valves on the way out, or if the timing had slipped back.
The jerky throttle was no better. On one occasion we kangaroo-jumped from the start-line. It was a bit like watching a learner-driver.
Andy suggested that he didn't think that was what I'd intended to do. I claimed to have done it for comic effect.

But then the water temperature gauge started going very high and I couldn't budge it. I went back to the pits (in top gear, to try and get airflow through the radiator) and after releasing the pressure using a towel on the rad cap and jumping away as the fountain erupted, I discovered we had sod all water in the engine. There had indeed been an airlock, To ensure I filled it properly I took the hose off the thermostat housing (the highest point) and filled it through that until water flowed out of the thermostat elbow. (Luckily I am not running a thermostat, just a flow-reducing plate).

I dashed back to the course and we carried on. The car was running a bit better now and we got further on some of the hills. However, true to my constant-failing I had not walked the further reaches of the hills as we hadn't been bothering the higher parts. Suddenly I arrived at a gate I hadn't walked around.

 ....and arrived at a downhill turn, through a deep hollow from the wrong direction.

 See Roland Uglow arrive about 4 feet to the left of my route

You may also notice his passenger Laura seems to attract

more attention than my passenger ,Ian.

This resulted in me getting my wheel hard up against the exit slope

(it's just cleared it here)

This had me leaning the whole car and crew's weight on the outside front wheel which was on full lock. Bystanders suggested I stop as the wheel might collapse. But I carried on and hit the post anyway, so I would have scored better by stopping where  I was. Luckily the wheel didn't break. Still, I should have stopped. Looking at the pics that Glenn took you can see I was 4 ft too far across compared to other cars. This meant I was falling into the hollow instead of driving across it's rim.

So it was a rubbish day. The car hadn't worked well and I hadn't been able to compensate, even adding some of my own mistakes. There was also some some doubt about whether my rear brakes were working properly. Following a suggestion by Andy to test them it looks like they are sort of on or off with not much in between.

So. Back at the ranch. 

I have designed a throttle mechanism to slow down the initial surge of power. However it occurs at the very smallest twitch of the throttle butterfly. In fact "twitch" is proper word, as we had found that my boots had been bouncing as the car bucked about and causing some of the unintended throttle action.

Looking for a Plan B I found a Weber 28/36 carb on ebay. It was only on my side of Kendal and went (to me) for just over thirty quid. My rationale was that if I fitted this and it worked better than the SU (which isn't actually and SU, you remember) then it may show the SU is at fault. Webers are not supposed to be as good at low speed torque.

However, it was choked and jetted for a Mini so the primary choke was just 23mm, which to my mind would allow gentle acceleration at small throttle openings.

Fitting it wasn't exactly easy as the stud spacings are different. I didn't want to alter the Suzuki manifold as I may want to refit the SU. I made a plate to fit which bolted at one end and clamped at the other. It sounds a bit Heath Robinson, but works very well.

Of course the new carb points directly upwards so a bit of my new bonnet bulge had to go to allow the bonnet to close.

Trying it in the drive showed that the progression from idle to power was much smoother. But I was still having problems with the miss-firing and at idle the plugs were sooting up. I tried changing the idle jets for smaller ones but that only partially worked and led to a less smooth transition.

Sooty Plug

It was whilst laying in bed one morning pondering on the meaning of life that it struck me.
Stupid really.
I had been obsessing about the mixture and tickover and ignoring the facts.
Clean plugs runs OK. Run for a while and they soot up then it doesn't run well.
What else could cause them to soot up?
A miss-fire. The miss-fire is causing the problem, it's not a symptom.

Coil Buggered

I tested the coil with my multi-meter and it was way below spec. I don't even know if it's the right coil for the ignition pack. Information is so hard to get on old ignition systems, although I do have a Haynes manual that gives the resistance specs for the coil. On-line resources fail to recognise that the 1989 Vitara has an old-fashioned oil filled coil.

I sourced a new Lucas coil from Powerspark in Birmingham. They helpfully suggested that as the data they have doesn't offer this type of coil for this engine I would be safer with the Lucas coil for manufacturer-fitted electronic ignitions as it was within the specs from my Haynes manual. They did a cheaper Own-Brand coil but thought the Lucas one would be safer.

It arrived next day and I fitted it. I ran the car for a few minutes and drove it up and down the drive. It seems better and when I pulled a plug it was not as blackened (just a bit darker than I would like).
I also found the source of the water leak which was (rather strangely) a sender unit in the manifold which I don't use, but is still there to block the threaded hole. Which it wasn't doing! I've tried it with some PTFE tape on the threads. If that doesn't work it's alloy welding I'm afraid.

Just a week to go before the next event, so I need to get the car up to my friend's farm for a run around for an hour or so.

More Modifications. Major Step Backwards.

October 8th 2013

So, I took the car to my friends's farm and ran around for an hour or do. Eventually got the Weber to run pretty well and we got up every gradient we tried (funny how you can do that, unless it's actually on a Hill in competition).
However the main problem with using a Weber became obvious.
If you climb a very steep hill the carb (as well as the car) tilts and the fuel level in the carb become low at the front and deep at the back. That's where the emulsion tube is. That's the pipe through which all the fuel going to the jets passes and if it's too deep it over-richens the mixture, Badly.

So, in summary, It's great except when you go up a steep hill.

Eeeek! Not much good then, as the premise is that we climb steep hills.


Back to the beginning, At home I ripped off the Weber and refitted the SU lookey-likey. The thing I now needed to do was develop a better progressive throttle linkage to give me much more low-speed control.

Whilst laying in bed I dreamed up a two lever, two-stage mechanism. Whilst I could see it working in my mind's-eye I had to work out how that was happening. It didn't take long to make. The rods are old wheel spokes. I had to make a new bracket to hold it all together. Tried it out and "Wow" it works.

OK. So just how does it work? The cable pulls the top-hung lever. That pulls both rods, but the top one is the first to pull on the throttle lever (on the right). As the top-hung lever moves the bottom rod takes over and whips the throttle lever over. So we have slow first stage and quick second stage. Ideal.

I hope that explains it.

Of course I now have a Weber-shaped hole in the bonnet. I have some red gaffer tape which is an excellent match for the car colour so that is what I stuck over the hole. Didn't look too bad, actually.



On to the next event. The site near to Sedbergh is amongst the trees with no respite from the steep terrain so that even getting between Hills (the term for each test) is a trial in itself. The only way to get from Hill 4 to Hill 5 is to wait until no-one is running on Hill 3 and go up the track that is part of that test. Ian suggested a bottle of wine for just reaching the start of the Hills. No-one responded.

The new throttle mechanism worked well with regard to progressive control.

As things heated up the top rod became a bit sticky in the hole I had made. Although I had elongated the hole to allow for the change of angle of the lever it was still binding a touch. I need to relieve that hole and possibly fit a small spring to ensure the lever returns to the throttle stop point. Or, I may alter the main throttle return springs to give more pull, but that will effect full throttle resistance as well.
I made a water jacket for the manifold to help with possible icing-up problems, but haven't plumbed it in yet.

The main problem was the faster tickover caused by the rod binding, but that also hid a developing air leak on the carb manifold. This may have exacerbated the overheating. It was easily solved by nipping up the bolts up a touch. I have used a paper gasket, but may get an "O" ring mount so that sealing is easier to achieve.
The overheating was par for the trials site, which is very steep, so even running between Hills doesn't give any respite to the motor.

I was quite surprised that 3 people came up to me during the day and said they had been following the progress of the throttle saga on my Youtube channel. 

Frightening. I have stalkers

The starter motor stopped working. I initially thought it had jammed, as I heard a clunk. But Ian pointed out there was noise noise at all when I pressed the starter button so it looked to be electrical. The problem occurred quite high up on the site so we could start by bumping off down hill. However it meant that we couldn't really afford to switch the engine off, but we needed to to let it cool between Hills. Bit of a bind really.
After Ian fell and hurt his knee whilst pushing the car, a picture taken by Glen shows that he has developed a death-stare (which I cannot see as I am concentrating on other things). 

At least he has a new red hat (he lost the old one last time). Happily, he fell face forward. If that is the correct sentiment.

  We eventually found that the undergrowth had pulled the solenoid wire off. I say eventually because it wasn't visible except from below and crawling about in mud isn't high on my priority list for a Sunday afternoon. We'd checked all the other wires as far back as the starter button.

The actual driving was a mixed bag. Some hills were a disaster with uphill, left turns proving difficult. Some hills were great and we scored 2s, 1s and a clear (12 is bad, 0 is good).
Observations from marshals led us to suspect the left rear brake isn't working properly. I'd just checked the brakes and put new pads in. This could be part of the problem as you don't get the chance to bed them in like you would on a road car. Someone suggested jacking the car up and running in gear with the brakes dragging to wear down any high spots. Seems a cheap and possibly successful way to bed them in.
We made better progress thereafter by treating the left fiddle-brake-turns as a do-or-die, pull as hard-as-humanly-possible event. 
 I'd already decided that we may try alternative methods on subsequent runs to try and get the best technique. The trouble with this is that by definition some runs won't be as good as others. Still, that's how you learn. I'm thinking that I am still used to the under-powered Imp engine so when we have grip I make the most of it and probably end up going too fast. I also think that I need to get the hang of easing out of the throttle for awkward surfaces to avoid losing grip.
However we did better than we usually do, especially in getting past the bottom of the hills. 

Next post will be about some detail work on the brakes and inlet manifold.