Two new racecars in NZ

What would the valve pcket depth be with lift from a standard G camshaft? With the turbo I'll need to do a little pocketing on the flat top pistons to just clear the valves.
If I measured correctly it's about 2mm pockets?
 
Hi TLJakes,
The depths of the pockets vary because I mainly use them to get a "fine tune" of the compression ratio. Depending on the bore size, how much the head has been skimmed etc, that will determine the depth I cut them. My race car is running 12.5:1 CR and I made the cuts on mine 4mm on the exhaust valve and 3mm on the intakes. That is measured from when the milling bit touches the dome.
A different head will have different depths. After I have finished the cuts I will do a dry assembly and then check the piston to valve clearance. They normally work out OK so I would guess a 3mm cut will be sufficient. Because I have my own way of adjusting the cam timing like the vernier gears on OHC motors (see the extra cover on the cam chain cover in the previous thread, "radiator to the front") I do not make use of the keyway so I cannot tell you what it should be because that changes the valve/piston clearances a lot as well.
I treat each engine I build as an individual then I know all should be OK.
Regards,
Frans.
 
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Time for report back.

We had the warmest day ever here in NZ. It felt like 48……not quite but very hot. Normally good times and lap records doesn’t happen on hot days.

My best time was the same as before but then as I have said, it wasn’t a good move to do the engine in such a short time so I left the timing and rev limiter where they were before. My excuse is that I was running the engine in. With the same available revs I could not improve on times.

The events turned out to be normal until the last race in the afternoon when too many close shaves happened. I hope to put it on YouTube. My brakes failed on a few occasions and the pedal went low on another few occasions and all this happened at different places and times. Bad experiences. I have discussed this with Ross and he persuaded me to go with the 16TS brakes. So I will start a.s.a.p. with milling the ally brackets out of a solid piece of High Tensile aluminium. I have discussed this with a Rep in alloys and he advised me to use 6082 unless someone can advise me on something else. I will also drain the system and start using competition brake fluid. Up to now I was running on Dot 4 and that is obviously not good enough. I must say that the original R8 brakes are doing an excellent job and the fact that they failed is my fault using cheap No Name Brand Dot 4 Fluid. By changing to the TS brakes I will only gain by having a better selection of disc pads. I hear they say it is a better all-round mod.

Highlites: The car didn’t overheat and the engines sounds OK.

Lowlites: Brake fail, couldn’t improve on my times, couldn’t catch that darned Escort, I had 3 near hits with other competitors, bent one rim and wheel alignment out after evasive action on the last lap of the last race.

Regards,
Frans
 
Hi Frans Sounds as if things became quite hairy by times! Trying to use brakes and having suddenly none can become scary. I found that happening on the rear breakes of my Suzuki TL but it's due to the rear reservior being too close to the exhaust which then makes the brake fluid too hot.
Would the 16TS brakes fit direktly onto the R8 disks? What pads do you then use on the calipers and are they still available?
 
Hi Frans,

I'm guessing you have competition pads in your 8 ? If so, where can you buy them ? Have you fitted a remote booster to yours ? I can't imagine racing my 10 with it's standard brakes - they're pretty ordinary :confused:
 
Tljakes said:
Would the 16TS brakes fit direktly onto the R8 disks? What pads do you then use on the calipers and are they still available?
Click to expand...

No, we can't be that lucky! There is a bracket to be made and some milling to be done on the 16TS disc rotors. Then you can use Mazda RX7 pads.

Frans
 
Thanks Frans,

Then Golf calipers with Opel disks still sounds like a good option. Just the mounting plate to be made and the 3 holes to be drilled on the rotors to be fitted on the renault then.
 
J-man said:
Hi Frans,

I'm guessing you have competition pads in your 8 ? If so, where can you buy them ? Have you fitted a remote booster to yours ? I can't imagine racing my 10 with it's standard brakes - they're pretty ordinary :confused:
Click to expand...

Hi J-man,
No, I have normal street pads in the race car, that is why I need to replace them after only 16 laps. Can't buy them but you can have a race compound put on if you supply the correct backing plates. I do not have a booster at all and I like it that way because the brakes are very good and you can slam your foot down on the pedal as hard as you wish. The car stop very well and you don't get your wheels to lockup. Just another thing you don't have to worry about.
I will do my next race again with the standard brakes but I will change to racing fluid. I don't think I will be ready with the 16TS conversion.
I have never complained about the brakes, only about changing the pads every 2 heats and on Sunday the heat got to the fluid and caused the failure.
Make sure you have your discs skimmed with new pads and you'll be OK. I can't complain, Johan doesn't complain, and Ross never complained.

Frans
 
two new race cars in N Z

SOME THINGS TO LOOK OUT FOR ON R8 R10 BRAKE FAILURE
As frans said brake fluid with a high BOILING POINT
Rear drive shaft bearings which are worn kick the pads and pistons back into the caliper housing and with the next brake application you have to take up all the displacement hence the feeling ooops no brakes.
At this stage pumping the brakes 2 to 3 times does the trick but no time for this when you are racing.
Meca parts sell a mintex racing pad which fits the standard caliper. It works well but be carefull it needs warming up.
Jimmy
 
two new race cars in N Z

I forgot
braking has a lot if not everything to do with getting rid of heat. SO you need metal [brake disks] with some meat as thick as you can to a point then you need ventilation when the metal becomes too thick.
the metal will absorb and let the heat free to the atmosphere.
Meca Parts sell a set for about 150 to 200 NZ$ and they are 8mm thick and appear to have a bit more carbon than the origional STEEL ones Renault fitted to their cars.
sorry I am not a MECA PARTS rep but these things work
 
Frans said:
Hi J-Man
Make sure you have your discs skimmed with new pads and you'll be OK. I can't complain, Johan doesn't complain, and Ross never complained.

Frans
Click to expand...

Thanks Frans,
I think that's my main problem then, my rotors have a dodgy surface on them from the car being in hibernation sitting for 7 years some of that out in the weather with just a cover over it plus they're under size as well. Looks like some new standard pads & rotors should be fine for my car then (it's definitely no race car). I was thinking I'd need to do a conversion so thanks Frans you've saved me the worry !
 
Hi Frans,

So i just chuck out the brake booster then and run directly from the cylinder directly connected to the brakes?

If it can work it seems like a plan!
 
two new race cars in n z

allow me to jump in Frans.A car designed to run with a booster normally uses a lager bore master cyl ,like the G uses a 22mm bore.The bigger bore is used to take up the increased volume needed in the booster and the booster then has a boost multiplication based on amongst others the diaphragm size of the booster.This gives you the feel of vauum assisted brakes.
On a G if you bypass the booster your brake pedal will be soft and to counteract that you have to change back to a 19mm master cyl to get the sharpness high pressure back.So bypassing is not the solution.

jimmy
jimmy
 
A good read and loved the videos, that track looks sensational, I will be visiting NZ in January so looking forward to see it after 26 yrs away. Seem to have much more interesting cars in races there, for me anyway.
 
Update time.

Hi All,
Me and Johan had another huge race event this weekend over both days at the Taupo Track.

It was my 1st time on this track layout which was the longest track at Taupo.

http://www.tauporacetrack.co.nz/default.asp?sid=9&cid=16&aid= It was quite a busy layout with 14 turns per lap. I had 4 laps practicing with a lap time of 2 mins 2 secs and my fastest time went down to 1 min 59secs. The racing was good with some very tricky corners. Turns 2,3&4 throws the car's balancing around so much that if 1 of the turns is not taken right then you have a huge problem at the next turn. Turn 9 is fast and the gearing is of such that it is too fast for 3rd but too slow for 4th. Turn 11 is another tricky one that actually becomes tighter as you exit the turn and I ate dust there on a few occasions. There is a flexible marker to mark the end of the ripple strip that I hit twice. But both marks will buff out:headbang:. Turn 12 was good for overtaking if you out brake the other guy.

I have some footage from the incar camera and will upload it to Youtube. That was of our 1st race.

The double rings that I mentioned earlier on doesn't work. That is the thinner rings with a spacer. We have a huge oil consumption complete with blue smoke and a lot of blow by. So much that the breather bottle of 1L runs over after 8 laps. I can only think that this method works on street cars and not on racing cars because my stock G runs fine on the ring+spacer method and so does HarryA's R10 with the G motor.

Back to the drawing board. If I want thinner rings then I will have to look out for other car's pistons that can be made to fit. For the next event I will go back to the thicker rings and re-evaluate my priorities.

I will post a link when it is on Youtube.

Regards
Frans.
 
YouTube clip

Hi all,
I have uploaded another You Tube clip for you to see.
this is from Saturday afternoon and as I had only 4 laps practicing you might note that I tried a few different gears and different lines because I didn't know the track yet.(good excuse!) I have edited the video to show only the 1st 4-5 laps. Were the video ends is how the race continued and became boring. That is how we finished. The Torana that I took down the straight is a 6 cylinder one.
I have a lot of respect for the Fiat 128 that overtook me. It is very quick and the owner is a good driver as well, he did a lot of Go-Kart racing. The engine started life as 1500 SOHC out of a X19 and was developed from there.

http://www.youtube.com/watch?v=B5oaaIOgkus

Regards,
Frans.
 
Great to see

Rocketship off the start line! Yes, the gearbox change you were talking about is needed, revlimiter in top and gearchanges midcorner...
Yeeha
 
Hi Frans

Was good to meet you in Aulkland and if we had more time would have been at the track but the one day we had in Taupo was spent going to Rotorua.
So impressed with all the race cars we saw on the road back to Taupo on Sunday. Such cars we do not see in WA unfortunately. The racing scene looks very well supported in NZ with Hampden Park being used as we drove passed and the Taupo one, I wil look at the videos when back on a fast connection.
 
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