ACHIEVED IDLE

June 30, 2007
by: jovial_cynic

Here's the first video of my 510 actually running with the SU carbs.

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It's got quite a bit to go before it's done -- the engine is still backfiring like crazy, and the radiator has a small leak, and there's a little bit of an oil leak on the front cover. I also need to get the throttle linkage hooked up, which will require fabbing up some new parts.

Anyhow, good stuff. It's running, and it feels like the engine is comfortable revving pretty high. I'll have to watch the timing, though -- running as far as advance as it was today, I was pushing 230 degrees, which is pretty close to head-warping temperature...

np category: 510
tags: 510

COMMENTS for ACHIEVED IDLE

datzenmike said:
I don't feel that the ignition advance and overheating are related. A lean mixture will make it run hotter but not that hot. A rad leak (unpressurized) will also cause it to run hotter. You have to fix the rad anyway, is there a fan shroud on the rad? Is it a clutch fan water pump, if so the blades should feel firm when turning by hand. Sometimes the silicone liquid coupling leaks out and the blades don't spin enough to move the air properly. Is the thermostat working, don't assume switch if there is any doubt. Is the rad core clean inside?
June 30, 2007

jovial_cynic said:
There is a fan shroud, and the fan is entirely belt driven.

I believe I put a new thermostat in, but it's a cheap enough part to just throw another one on, just in case. The radiator is fairly clean inside... there was a mild hint of rust in it, but I've flushed it out a few times before I used it.

I just read on this site that the lack of pressure on the radiator is a likely culprit. Specifically:

A failed pressure seal will allow the coolant to boil at a lower temperature, and coolant will be able to travel freely to the expansion reservoir. This will cause localized hot-spots inside the engine, which can lead to premature head warpage, and may hasten head gasket failure. It will also cause the rad coolant level to be low, just like a failed head gasket.

I wasn't aware that the coolant system was under enough pressure to create a difference in coolant boiling point...
June 30, 2007