[Roadsters] 1964 SPL310 vapor locking solved

[Charles Hubbard]

I finally fixed the problem with my fresh 1964 Datsun SPL310 overheating and vapor locking.  Some of you may recall that I recently completed the driver restoration.  It only took 15 years of persistent procrastination.  I started driving around town in spurts but noticed that after about 20 minutes of steady driving, my temperature gauge would climb to about 210-230F.  The motor would start coughing, backfiring and bogging down when I hit the gas. At first, I chalked it up to the motor running too hot. I then began to wonder if I had a blown head gasket.  My motor as about 100 miles on it,  a 3-row radiator and a high-temp fan pulley.  I recently converted the cooling system to a pressurized system so the coolant would stop dumping on the ground every time I topped it.  After purchasing an infrared thermometer, I conclude the car was actually running at about 180-190 degrees and that the stupid design of having the exhaust manifold next to the temperature sender was cooking my after-market gauge sender and giving off false readings.  It just so happens that having a steel fuel line routed right next to a hot motor up the front of the timing cover, then bolted to the steaming hot thermostat housing and over the top of the scorching intake manifold might be a bad design.  GO FIGURE!  Well, I took a 4ft heater hose, slit it all the way down the center and used steel tie wraps to insulate the entire fuel line.  I then took it out on a 1 hour ride down the highway at 70+ MPH and no more vapor lock.  Six bucks worth of rubber hose solved a problem that had me scratching my head.  I have had this car since 1982, so let's say a was a little slow on the uptake.  In any case, if you know someone out there that could use this bit of advice, feel free to pass it on.

ALSO  ==>  Thanks to Dean at Datsun Parts and other local roadster enthusiasts for helping me diagnose and resolve this issue.   I especially want to thank Tim Corcoran for giving me many rare 1500 parts from his personal stash to help me get this car off the blocks and back on the road just in time for Spring.  Tim has been more than a little helpful.  Whoo Hoo!  Life is good.

Respectfully,

Charlie Hubbard
Flower Mound, TX
1964 Datsun SPL310 Fairlady

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