ethynol 93 high test, Winter blend in summer

[TomJudd]

Filled up my 59 last week . I run 93 ethynol mix in summer cause I go through a tank a week. For winter storage only 91 non eth. with stabilizer.  After filling it and cruising, parked it for a half hour. (90 degree day) Hard restart and stumbled for a minute then cleared up. Turns out after inquiring at gas station that that were still selling their WINTER BLEND !! The price was same as 89 but thought it was some special. I went back and the guy was honest and said they reduced the price to sell off winter blend quick.  Lower vaporization temp, and guess what, more prone to vapor locking. TIP on all my regular driven Caddys I insulate the steel fuel lines with a split 3/8 fuel  hose. I also insulate the choke heat riser tube. May not look stock, but for driver cars who cares. Pull the hose wraps off for shows, or not.  I battled with vapor lock for two years with my 58. INSULATE

[TomJudd]

Annnnnd….. Don't neglect your exhaust manifold thermostatically controlled ? spring operated heat riser valve. This closes off all exhaust from that side, and routs the exhaust thru the intake manifold, under carb, for cold start and quick warm up. If this butterfly type valve sticks closed , and they commonly do, All ex runs through IM after up to temperature and WILL cause vapor locking/ boiling fuel in carb. Even more detrimental is engine internals (pistons/rings and valves will overheat and destroy your engine) generally the center two cylinders on either side. You may see your intake manifold paint whitened and paint burned off from this condition. Quick check, when at operating temp check for similar exhaust flow from tailpipes. Or on lift manually rotate valve. Should be checked annually at minimum. AND lubricated with copper type penetrating fluid. When they work ,all fine,when they are stuck ….DANGER !!! On my 58 it was sticky and didn't trust to operate correctly, I wired it in OPEN position. This valve generally only is needed in cold weather as engine comes up to temp. I usually let my classics run a minute or two anyway so not really needed. On my 59 I was installing a complete ex system, so it was easy to drop the riser /valve off the manifold studs and bring to work bench. I actually drilled the rivets out and removed the butterfly completely. Left shaft and coiled thermos spring. Looks stock.   Next tip to follow is regarding priming fuel system after weeks or months in storage.. Good day, time to take the QUEEN out and burn some rotted dinosaur guts!!!

[Cadman-iac]

Another thing that can be damaged by the heat riser valve sticking is the cam bearings if the issue is not caught quickly.
My 81 El Camino has (now its had) a valve that was controlled by a thermostatic control valve using vacuum to actually close it when cold. The  control valve stuck, the vacuum never released,  and I drove it quite a bit that way until it began to have overheat issues. When inspecting it i had the engine off, and of course no vacuum was keeping the valve closed at that point, making it unclear as to why it was overheating.
Long story short, after I replaced the engine I tore down the old one and discovered that the 3 center cam bearings had begun to deteriorate from the heat and downward pressure of the valve train.
This was a 350 Chevy, a very good design and very dependable engine. If it can happen to it, it's also possible that it can happen to an older design of Cadillac engine.
I realize that it is not common for this problem to progress this far, but it is possible. (Especially if you ignore the signs as I did initially).

Rick

[TJ Hopland]

When does your state normally come off the winter blend?  Even knowing that it does make you wonder how fast some stations turn over their supply under normal conditions.   This spring obviously has unique dynamics when it comes to fuel demand and usage.

I also wonder if stations have any ability to vary what they stock and how well they can estimate what demand will be.  By vary are the tanks set up so they can be partitioned so to speak so if mid grade becomes a big seller they can expand its capacity?  Or are they just stuck with whatever size tank and if it doesn't sell they have either an almost empty tank or a full tank of fuel going bad?  Do they have say a 500 gallon then a 1500 then a couple 2000 gallon tanks and a setup so they can configure any of them to be any type of product?   

[TomJudd]

Im Rochester ny, I was told the shift in blends was june 1 here. I think the Govt. weights and measures certify pumps only annually, with a volume and specific gravity check. I guess go to a busy station!!