Running too warm at sustained high speeds

[Jim_Gruber]

Bugsy my '68 Sprite with a BE Bonnet and a '66 1098 has an issue with cooling during sustained high speeds i.e. Expressway Speeds. Around town temps great at N or slightly below N on gauge. Get out on the expressway and temps quickly climb close to overheating but not quite there. Hit the exit rap and within 30-35 seconds temps drop right back down to normal range. I've been toying with the Geo Metro Radiator and can find a 3 row new Metro Radiator that is smaller I believe than a Spridget Radiator @ 12 3/4 x 12 3/4 and only 1 1/2" thick. Add a 10" fan and away you go.

However before I go that route, someone metioned retarding the timing slightly might help. Bugsy runs great, starts almost too quickly, plenty of pep and power. Are we talking a couple of clicks on the dizzy adjustment wheel or time to get out the timing light and crawl under the car. Manual says
"turning the nut clockwise retards and anticlockwise advances the ignition. Each graduation on the adjusting spindle barrel represents approximately 5 degrees timing movement and is equal to 55 clicks on the knurled adjustment nut."

My thought is 10 clicks Clockwise will give me 1 Degree less advance. Might also help the dieseling I'm getting now when I shut off Bugsy even though I'm runing premium 93 octane. Wish I could still get Sunoco 240, 94 Octane around here.

Retard timing 1 degree, go for high speed run and see if it helps with overheating issue? Still an issue go for another 1 degree and if overheating still there consider the MEtro Radiator Solution. Any consensus on my plan?

 

[jlaird]

Sounds like a plan Jim. Worst case you have to change it back.

 

[regularman]

Jim, are your sure your gauge is accurate? You could always pull out the bulb from the head and put it in some boiling water and see what it reads.

 

[aeronca65t]

Check your lower hose. This hose is under suction, and an older, "soft" hose will collapse at higher RPM, causing overheating (some lower hoses have a spring in them to prevent this).

Rev your engine while looking at the lower hose and see if it is sucking closed.

One of the guys I race with has a Metro rdiator....seems to work well.

 

[Jim_Gruber]

Those lower hoses definitely have a kink in them. I'm not at all happy weith the lower hose and that could be causing my issue. Since I have a 1098 with a crossflow radiator, I use a 1275 thermostat housing that still leaves the upper hose in a really tight bend. Resorted to using a copper 45 degree elbow and a couple of clamps to take the kink and narrowing out of the hose.

I'll need to look at the lower hose. Anyone got a part # from a source other than MOSS or VB that will work for a lower hose.

 

[Jim_Gruber]

Those lower hoses definitely have a kink in them. I'm not at all happy weith the lower hose and that could be causing my issue. Since I have a 1098 with a crossflow radiator, I use a 1275 thermostat housing that still leaves the upper hose in a really tight bend. Resorted to using a copper 45 degree elbow and a couple of clamps to take the kink and narrowing out of the hose.

I'll need to look at the lower hose. Anyone got a part # from a source other than MOSS or VB that will work for a lower hose.