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Joined: 2009/4/16 10:37
From Cape Town, South Africa
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What a busy few weeks getting the Ute in order. On Saturday we have another gymkhana. Hope everything will be 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, all machining and balancing for R350 bucks (53 AUD, is this a lot) in SA currency it is cheap.
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 waterpump 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 traveling 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. Grinded 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 will not help.
Thanks a lot to all that helped and gave advice.
Posted on: 2009/6/4 8:41
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