Trying to cool my 59 on hot summer days

[Thomas H.]

Re: Trying to cool my 59 on hot summer days

How bout cooling passages in block?

As a point of reference, my 60 is a base 230hp car (stock rebuild 283 0.030 over) with a factory cooling setup (Dewitts radiator though) and it might get to 190-200 max sitting in traffic on a hot day. I did have a problem with high temps while cruising at highway speeds, but traced that to a bad vac adv unit.

Tom

[Bob S.]

Re: Trying to cool my 59 on hot summer days

William, What does opening the block drains prior to coolant fill do? (Obviously I have not done that) I am more and more thinking it is something internal. Good timing at idle (the problem is at idle), new radiator, new water pump, 3 different thermostats (all 180*), no butterfly in the heat riser. I hate to say it but I may need to remove the heads to check for correct gaskets (possible blocked passage). Engine was overhauled just prior the me acquiring the car and this has been going on since I first started it.

[Duke W.]

Re: Trying to cool my 59 on hot summer days

Duke,



The VAC on the car at idle is 15 inches. As stated, with VAC disconnected the timing is set at 4*. When VAC is re-connected to the vacuum advance the timing goes to 22*.

The first sentence makes no sense. VAC means vacuum advance control - the GM name for this part. Are you saying idle vacuum is 15" Hg? At what RPM?

In my previous post I said:

"Look up the design data in the AMA specs, post it and compare. There may be a a problem with the centrifugal."

This has yet to be addressed?

I also asked: "What's the number on the VAC?", which has also yet to be answered.

Duke

[Bob S.]

Re: Trying to cool my 59 on hot summer days

Duke, I apologize. It has been 50 years since I worked on a 50's era car. I have been raising a family, flying airplanes and managing a fairly large corporate flight department. I am not up on the vintage car acronyms.

I have a 1959 Corvette with a 283/230hp engine with a fresh overhaul (less than 2,000mi). I have a problem of the car overheating while at idle (long traffic lights, restaurant drive thru) when the ambient temperature is mid 90's or above. There is no problem while driving whether at 40 mph on city streets or 70 mph on interstate highways.
At an idle speed of 500 RPM the timing without vacuum attached is 4*BTDC, with vacuum is 22* BTDC (vacuum at idle is 15"), new radiator, new water pump, no heater, tried 3 different thermostats, no butterfly in the heat riser, 50/50 mix of Zerex G-05 antifreeze color still looks good (has been replaced once due to a different issue). When I took off the standard 4 blade fan and installed a 5 blade flex fan it helped but did no solve the problem.

I am at the point now where "shade tree" logic says I need to look internal. Since I did not personally assemble the engine I cannot vouch for the head gaskets not blocking water passages. I have changed the intake manifold gaskets to block off the heat riser.

Can someone give me another place to look internal?

[Terry D.]

Re: Trying to cool my 59 on hot summer days

Bob
You still have not told us the number of the VAC. If it is the wrong one for that motor it might be pulling too much causing too much timing causing overheating!

[Bob S.]

Re: Trying to cool my 59 on hot summer days

I think this is what you are wanting. The number is 163. The number under the XXX is 236.DSC00231.jpg

[Loren L.]

Re: Trying to cool my 59 on hot summer days

Fan on backwards?

[Bob S.]

Re: Trying to cool my 59 on hot summer days

No, but thanks. That would have been real embarrassing.

[Leif A.]

Re: Trying to cool my 59 on hot summer days

Bob,
If that is actually a 236 vacuum advance unit, then it is too aggressive for your engine. That would equate to a current B28 which was originally used on the L79 engines but, in actuality, is too aggressive even for that engine. Check with your local parts store for either a B20 or B26 vacuum advance unit (part #VC1765). This could very well be causing your idling overheating issue.

[Bob S.]

Re: Trying to cool my 59 on hot summer days

Thanks Leif. The 236 has been Xed out and 163 stamped above it. Does that change anything?

This will be an inexpensive and easy change to make. Leaving town this afternoon but will try this Monday.

[Leif A.]

Re: Trying to cool my 59 on hot summer days

Hopefully Duke will chime in on the #163...I have no idea. Anthing that's a re-stamp is troubling to me...no sure what you're getting. But, the NAPA VC1765 is a $20 unit that you can install in about 15 minutes. You might want to bring you MityVac with you to the parts store and check the new unit before buying to be sure the plunger is "all in" at around 12"Hg.
Additionally, have you checked your fan clutch. I had similar hot idle problems and one of my issues was a bad fan clutch that looked good but wasn't. Replaced with a fan clutch from K&B that is fully engaged at 160 degrees.

[Bob S.]

Re: Trying to cool my 59 on hot summer days

I just looked in the 1958-60 Corvette Restoration Handbook. They show the original distributor vacuum advance. It has MS which is a manufacturer's designation and 16 is the vacuum rating in pounds. Mine has both of these. The 163 is a derivative of part number 1116163. It appears mine is correct. Just don't know about the X out.

[Leif A.]

Re: Trying to cool my 59 on hot summer days

Bob,
It's not "16 pounds"...it would be 16" of mercury. And, if that's what the designation actually means on your current unit it does not fulfill the 2" rule. Your vacuum canister needs to be all in 2" LESS than your manifold vacuum. You stated early on that your manifold vacuum at 500RPM was 15". If that is the case, then your vacuum canister needs to be fully engaged, at idle, at no more than 13". Duke is the guru when it comes to this stuff and I hope he chimes back in. He sure straightened me out on this.

[Jim D.]

Re: Trying to cool my 59 on hot summer days

I just looked in the 1958-60 Corvette Restoration Handbook. They show the original distributor vacuum advance. It has MS which is a manufacturer's designation and 16 is the vacuum rating in pounds. Mine has both of these. The 163 is a derivative of part number 1116163. It appears mine is correct. Just don't know about the X out.

The 16 is the number of degrees of advance that unit gives when fully activated (full vacuum).

[Bob S.]

Re: Trying to cool my 59 on hot summer days

Mine may be a little high then. I am getting 18* advance at idle. (Sorry about "pounds". I was copying from the handbook and it has the error.)

Is 22* advance to high at idle and will this cause the heat problem.