Kiwi scratchbuilt

[Russ Noble]

Thanks for the support guys.

In truth, Lim did actually make that offer, but we were trying to make light of a frustrating situation, and the prospect of yet more remedial work. Frustrating because the car has missed yet another race meeting.

Also embarrassing for me because we have to pre-enter, you just can't turn up and race, so my name has been in the program at every meeting this year but I haven't fronted, and every time its for a different reason.

There are no excuses in racing, you line up on the grid, you do the business and thats it. "When the flag drops the bullshit stops" Unfortunately I'm having trouble getting past the bullshit stage.....

I went out to the track yesterday and withdrew my entry and talked to a few of the guys and watched some of the racing and fielded all the inevitable questions....

The problem this time was we couldn't crank up oil pressure in the motor before startup. Spent about four hours doing checks, removing hoses left right and centre, tried refitting the old filter, screwing the relief valve up solid, tried everything external we could think of until about 1am when it became obvious that it was an internal engine problem, and that we had run out of time, since removing the motor is a bit of a mission as working space is so tight. Oh for a nice simple road car!

Nothing has changed in the oiling system since the motor was last running. Or perhaps I should say, neither I, Lim, nor Leon have changed anything! I have my suspicions about the cause, which if I am correct is a simple fix. However I am not going to apportion blame until I have stripped the motor and verified the cause.

So today while the other guys are going to be out there racing (it was a two day meeting) I am going to be pulling and stripping the motor.

 

[Leon]

Hi Russ, I was thinking of making some wise crack about fitting Duze fastners or quick release pins on the engine mounts and sump bolts, but that just the Chevy vs Ford thing coming out in me and thats a bit harsh and probably not very constructive.
But the truth is a feel for you mate and I know how frustrating it is, you just have to keep at it and keep smiling the prize is worth the struggle and everyone here is rooting for you.
We all look forward to better news in your next post's
Cheers Leonmac.

 

[Kevin Box]

Russ

You've been awful quiet for a couple of days
Hows the SBF
What was your oil problem ???/

regards KB

 

[Maurice Butler]

There's racing at Timaru this weekend - Russ was entered so he may still have his head stuck in the car somewhere

 

[Lim]

Russ

You've been awful quiet for a couple of days
Hows the SBF
What was your oil problem ???/

regards KB

Kevin,
Russ's computer was down. Just got back from Timaru, Russ's car running well today:thumbsup:. Will be going to Timaru again tomorrow morning.

LIM

 

[Ian Anderson]

Kevin,
Russ's computer was down. Just got back from Timaru, Russ's car running well today:thumbsup:. Will be going to Timaru again tomorrow morning.

LIM

Well if it's a race weekend and something is broken - better it is a computer than the car

Good luck over theweekend

Ian

 

[Kevin Box]

Russ & Lim

Sounds great

Best of luck

KB

 

[Russ Noble]

I have my suspicions about the cause, which if I am correct is a simple fix. However I am not going to apportion blame until I have stripped the motor and verified the cause.

So today while the other guys are going to be out there racing (it was a two day meeting) I am going to be pulling and stripping the motor.

So I did, and what I expected to find was a, or some, missing oil gallery bung/s which I thought the engine reconditioners must have removed when cleaning the block and omitted to replace at least one. And at the time I never actually conciously checked that they were in fact all there, since it didn't occur to me at the time that they might have been removed, but I would have thought I would have noticed if any weren't in place.

However, on stripping the motor everything checked out fine. So reassemble the motor and remove the entire oil system from the car. Tank, filter, cooler and lines and hook up to the motor on the work bench. Then prime with an electric drill and voila! pressure registers on the mechanical gauge we had tapped into the system. Yes boys and girls, after all that there was nothing wrong with the basics, what we had in fact was a gauge related problem! Traced to an open circuit between the sender and the gauge. Bugger!

A weeks work for nothing, worst of all we could have been racing on the day I was pulling the motor out!

I have lost count of the number of times over the years I have clutched at straws by saying 'check the gauge, it could be the gauge' when in fact it usually turned out that the motor was well and truly poked and it seldom was the gauge. . . . . .

Anyway got the motor back in and fired up all OK by Thursday night, thanks to lots of help from Lim and Leon, and I was able to get loaded up ready for a 6am departure Friday morning to take advantage of the Friday test sessions at Levels.

Will post a report on Levels on my Racetrack thread http://www.gt40s.com/forum/race-track/30372-scratchbuilt-kiwi-40-goes-racing.html shortly. Suffice to say it was a successful meeting with no major gremlins or damage, and a lucky podium as well.

 

[John]

Russ congrats mate, to get through a meeting without mishap is one thing, to stand on the podium anywhere is bloody wonderfull, Aislabie will be envious, lol
cheers John

 

Excellent news Russ!

 

[Leon]

Bloody good news mate. As I said, "The struggle is worth the prize" and a podium finish with so much more R&D to go you should have a real winner when fully soughted

Cheers Leonmac

 

[Trevor Booth]

Russ, throw away the electric pressure gauge.
use an old fashioned mechanical gauge and run a 1/4 or 5/16 pressure line in the car reducing down to the normal 1/8 pressure gauge line at the inside kick panel.

you can see in the photo there is also the oil pressure switch for the fuel pumps
The 'T' piece is a brake pipe union typically found on the english cars for the brake light switch. you can also see the rubber hose coming from the engine

 

[Russ Noble]

I think you're right Trevor. Again!

The irony of it is I have some 'idiot lights' that I have been meaning to fit to the top of the dash for water temp and oil pressure. Unfortunately there have been/are more pressing priorities! Had I had them in, the light would have been extinguished when the pressure came up and alerted me to the gauge problem!

The warning lights will be a winter project now, I really need them as insurance. On the track I find myself pretty busy in the cockpit, the corners loom up very fast. I only get the chance to glance at the gauges once a lap if I'm lucky, and not at all if I'm dicing closely with someone. Controlling this beast is currently taking all of my attention and there is not much time left over for the niceties of monitoring the mechanicals. Maybe with increasing familiarity of the car's characteristics I will be able to more actively observe all the other peripheral stuff....Really at present, it is only when I percieve a possible problem that my attention is drawn more to the gauges.

 

[Russ Noble]

The last couple of weeks I have been checking over the car, making sure everything is right. There are four race meetings on consecutive weekends starting tomorrow so a fairly hectic schedule but they are only one day meetings.

I found some loose CV bolts despite the fact that they had been well tightened and loctited. Something to keep a close eye on..... I also fitted new brake pads and started work making a housing for the bypass thermostat. My engine temps are still too low and tomorrow I am going to try running with no restrictors in the bypass.

Before the last race meeting I put some temperature paint on the pads and discs and they are running miles colder than anticipated so I have gone to much softer pads which should improve the feel and the performance. Rather ironical that my TR7V8 suffered from excessivey high brake and engine temps and now the GT40 is the exact opposite.....Still, I did design it to be a bit that way after the issues with the TR7! I guess it's a good problem to have, just means that I obviously have excessive weight in my cooling and brake systems :thumbsdown:

Anyway, it's all loaded up and sitting on the trailer ready for an earlyish start in the morning. Will post the days exploits on my Kiwi 40 racetrack thread

 

[Dave Deerson]

On my 930 I ended up drilling for safety wire, same problem as you. I know I torqued the bolts with a torque wrench, but after a weekend of track use I would find them almost finger tight!!

 

[Russ Noble]

Well the racing season is over and the last nine months have been a pretty frenetic time of prepare, repair, and alter setup.

Now I have until the first club meeting of the new season, 1st August, to make a whole raft of improvements, some minor, some major, that will lead to better lap times.

I have slowly come to the realisation that my wide historic race rubber despite it's width is not a patch on (smaller) modern tyres, compounds and constructions. The car is quick enough when racing with the Classics but I find I am doing a lot of non-classic races and the lack of grip has made life difficult at times. This same lack of grip may well partly explain why the brakes are running so cold also.

So, the first and easiest and cheapest major improvement,will come from a set of freebie (coz there's no market for them) F5000 Avon slicks that I have scored. They have only done a couple of sprint races and have heaps of life left in them yet. Its not going to worry me that having been heat cycled they could be half a second slower than new ones. I was extremely fortunate to find some 15" fronts as they were only used on the earlier less competitive cars and I didn't expect any of those guys to be spending the sort of money it takes to throw a new set on every meeting! Major bonus, just hope I can find some more of those fronts! Rears are not a problem, there's heaps all over the place. I expect the slicks to go a long way to solving the grip problem and further improve lap times. I took some photos today but need new batteries before I can get them out of the camera. Tomorrow.

Unfortunately, but no doubt it is a good thing, the Avons are quite a bit wider across the tread than my old Dunlops so thats going to entail reworking the flares for tyre clearance, then repaint etc. Then we'll have to go about dialling the suspension in again to suit them.

The other main upgrade I hope to do is regear the trans. Third gear is fine but I want to use my second as a first, this entails a bit of machine work, and I want to get another second gear with a ratio in between that old second and third. I also want to fit a shorter fourth. I'm hoping I can find the additional ratios somewhere second hand. I want something about 1.04 (26/27) for second and something in the range of 0.71 (31/22) to 0.76 (30/23) for fourth. That'll make it easier to drive and a wee bit quicker too.

Then there are about a dozen smaller improvements to do, more details as I embark on them.

And lastly, but probably not before the August meeting, some decent aero improvements in the form of a rear wing and diffuser, front splitter etc. These are more likely to be improvements that will occur as the season progresses since there will be a quite a bit of work in them and I will also have to do some research in the vain hope that I might understand what I am doing!

So that's it, winters on the way, plenty to do and its time to hunt out the workshop heater!

 

[Woody]

Hi Russ
I have really been inspired by your build thread, keep up the good work. I am glad you have had a chalenging but enjoyable season on the track.
Keep us posted on your trans build, I'm interested, do you have a local supplier for your second hand gears or do you go state side?

 

[Trevor Booth]

Russ,
there is more to slicks than just changing from treaded tyres,

If you were using dunlop treaded tyres the word dunlop in the dictionary = no grip.

Avon treaded are another story they have some very nice compounds

How hot were your tyres getting ? Do you really need tyres that wide ?

Cold slicks are not my idea of fun.

 

[Russ Noble]

Trevor,

Thanks for the comments.

I don't have the temperature data with me at present but I'm pretty sure the Dunlops were up to temp. For most of the warm up lap it would break into wheelspin when it came on the cam in 2nd gear. That doesn't happen once they get some heat in them and never in a race. I'm pretty aggressive with throttle and brakes on the warm up lap. In the races I tend to push it pretty hard and it is slipping and sliding all over the place and there is ocasional lockup under braking so I think the tyres will be hot and working to their max. It's just that its a very low max :thumbsdown:

As a reference point to how much work the tyres are doing, I am around 5 seconds a lap quicker on those Dunlops than a visiting race prepped GT40 was on slicks last year. My lap times are very similar to Jack Ondracks TVR Tuscan and this is a well sorted and well driven car on DOT Hoosiers and usually clears out from the field. It is usually the car to beat in the SFOS rounds.

I honestly think Avon slicks cold will have more grip than treaded Dunlops hot! epper:

Will the Avons be too wide to get up to temperature? I doubt it, I'm probably carrying 200kg more than a F5000, the tyres are protected from the cooling airstream, and I've probably got not a lot less torque/power being transmitted through them. No aero yet so the F5000s will have their tyres doing more work in that respect. But aero is planned, as soon as I get time to do it! However as another indicator I am about 10 sec/lap slower than a midfield F5000 so maybe the tyres wont be working hard enough? Nevertheless, just thinking about it, this is essentially with a 2 speed box, don't use first and only get 4th for a few seconds on the main straight. I think the regear will help, but not as much as the slicks!

As a matter of interest, the Avons are A11 compound because that was what I could get for nothing at the time. The other compound that could be available is A15. Which do you think would be best?

Pete, no supplier lined up yet. I'm hoping to get something secondhand out of the States and have several feelers out, but in case I can't I'm waiting on Albins to get back to me about cost and availability. I will put off buying new until the very last minute in the hope that something used will turn up. It's only a stop gap for this season as I want to go dogbox for the following one. I had wanted the dogbox now but funds are a little low, so it'll have to wait a year...

 

[Keith]

Hi Russ, I ran A11's on the Penske and they really depended on a good track temp. These were originally designed for endurance racing (or so I was informed) and F1 type single seaters and I calculated the weight difference between a typical prototype and my car and reckoned as I was a lot heavier these tyres would be ideal, plus they were cheap, but I really wanted them to last a season. However, on cold days (most were!) there was minimal real grip even at very low psi and I reckon they would have lasted probably 2 seasons running a full series.

My friends Pontiac on the other hand had some ex F1 Goodyear fronts and they would give you 1/3rd degree burns after a few laps with about 2 tons of gravel sticking to them, whereas mine were always as clean as a whistle. Those Goodyears were phenomenal.. If it wasn't for the fact that I was running about 200 hp more than him and a 'rock crusher' box with a very stiff tube chassis, he would have been close to beating me so good were those tyres. However, they were never available consistently enough and probably needed 2 sets per season.

The A15 I think would be a bit soft for a whole season for a powerful car like yours, but ideal for hillclimbing. They come up to temp really quickly and from memory are quite good on slightly damp tracks.

I would stick with the 11's and get the suspension working optimally to get as much heat in the tyre as possible.