Tag Archives: welding

A12GX Head – A14 Sub – Dual SU's – Lightened Flywheel

What a busy few weeks getting the Bakkie in order.

Just want to give all that provided me with tips and tricks some feedback.
Got the Datsun

Comps spec on the flywheel, took the flywheel and a new pressure plate to the dude that does my machining, he got it down to 5.78kg, he also balanced the flywheel and new pressure plate for me.
Installed the A12GX head with worked ports and valves.
Fitted a 4-1 branch manifold, already had a 50mm Stainless Free flow System
HS4 Dual SU Carburetors, intake manifold ports matched to head intake ports
Fitted a electric fan, switch comes on at 85degrees, removed mechanical fan on water pump
Had to purchase a new Temp Sensor, could not get the old one out of the A14 head.

Here comes the interesting bit, somewhere down the line, they changed the resistance on these sensors, from about 560ohm to about 360ohm at 16degrees.
This caused more than enough problems. All of a sudden the temp gauge needle climbed way more that it should.

We started it up, all was fine, no bolts, pistons or valves flew around, tuned the su’s. The electronic fan came on, everything working as it should.

Once on the road it was a different story, torque there is a lot of, it is clean, revs up nicely, pulls excellent from 2k rpm right thru to the limiter (currently at 7k rpm), there is not even signs that you are about to hit the limiter, this means all is working together, producing nice bottom down torque and decent top end power.

Then, all of a sudden the motor gets hot. After a day or two and enough swear words to make a sailor look like a beginner. We figured it out. Once on the road there is enough air travelling over the switch to cool it down and not switch the fan on. This caused me more time under the bonnet than needed.

Obviously if the water gets way to hot, pressure builds

and want to escape somewhere, the place it picked was between cylinder 3 and 4 at the water ports on the intake manifold gasket. After taking it apart, I also noticed that the one exhaust manifold washer was pressing against a piece of welding on the branch. Smoothed it down, reassembled the lot. Also re-fitted the old mechanical fan on the water pump to be on the safe side.

Took it for a drive, no issues what so ever anymore, the fan doesn’t even switch on after some heavy spinning and gymkhana practice.

Saturday we have our next race meeting and look forward to the added power and overall better A14-A12 inbreed.
Just hope I will be able to keep the wheel spin to a minimum, we are expecting rain also, and that sure as hell wil not help.

Thanks a lot to all that helped and gave advice. Special thanks to Einstein(My Brother), My Father and Ruan.

Feedback: Datsun Rear Suspension Stiffening Experiment

This worked well, but on a rear wheel drive Gymkhana vehicle you need as much possible travel

on the rear wheel as possible and a progressive suspension, all or nothing doesn’t work as you start unload the inner wheel when cornering hard. We tested a

ll possible settings this weekend on the 22nd Casino Mykonos Langebaan Gymkhana.

It helps for rear end stiffening, but sure as hell not for traction, body roll is a lot more in control, but in our case we need some to keep the wheels to the ground.

The one thing that we did learn from this experiment

for gymkhana setup, the front of a rear wheel drive vehicle should be hard and the back soft or to an extend that excessive body roll starts creeping in.

On another note, never never ever and a day, weld anything to tempered steel like leaf springs, due to this experiment, I broke my left leaf and must replace both now to get rid of this upper leafs with the welded parts to it.

Will be using this as a opportunity to rebuild the rear leaf assembly to get rid of some excessive body roll that is impacting front end roll. All of this is part of the bigger picture.