I am trying to ***ist my 85-year-old friend who does not own a computer or cell phone. We have just reinstalled his original flathead motor. It is equipped with Fenton heads running 8.8 compression and a Potvin 3/8 cam. The Pertronics equipped distributer has mechanical advance without vacuum advance. The motor runs hot running around town. Currently the timing is 12.5deg. at 900 rpm at idle. My limited research indicates retarding the distributer for more effective cooling. The mechanic who set says leave it alone. Before we start to play with it. I thought I might put it before people with more knowledge than me.
Usually, retarding the timing will cause more heat. Does it puke fluid? Have you checked the temp with a different gauge to verify?
It idles fine it overheats at road speeds. Car is equipped with new radiator electric fan and waterless coolant. Fan seems to perform normally with no boil over. All temps have been verified with a digital Infared meter.
What is the temp at road speeds? If it's not puking fluid, it's not too hot. New engines will run a bit hotter until break in...could be nothing...? Huh?
Stock initial timing on '49-'53 Ford/Merc flathheads is 2 degrees BTDC with pointer aligned at the pulley groove. This can usually be increased two or more degrees, but total timing should 24-26 degrees all in around 2500 rpm for a modified engine. I would first get the timing straightened out and see any effect on cooling, as 12.5 degrees @ 900 is excessive, imo.
No vacuum on the street? You need to find out what the advance curve is on the DIST and go from there. Stock timing setting(s) are for the OEM LOAD-O-MATIC system.
A lot of the aftermarket distributors come with an SBC timing curve which has too much advance (36 degrees) for a flathead, which needs only 22-24 degrees all in. I had the exact same problem with an MSD distributor on a 276" flathead in a '36 3-window I had. Get an advance timing light (or find someone with distributor set up machine) and find out what you have for a timing curve. Start out with factory timing and make sure there's not too much advance. I have about the same engine ('51 Merc with Edmunds heads and a mechanical Mallory) and the stock advance is fine. Oh yeah; have your friend fire his mechanic. He seems to be living in an OHV world, which doesn't work for flatheads. They are a different beast. BTW, total advance is important, since that is where the car runs most of the time. Verifying the initial timing at idle is not sufficient.
My 41 with 8cm merc motor is locked at 20 degrees at Idle and doesn't move.starts great and goes great. Just my experiences
While I initially was surprised by this statement, it's probably right. 20 degrees advanced is about where a flathead likes to run most of the time, so if the car starts OK, you can probably get by with this (although the total advance seems a little short). I have to ask; what do you have for your starting system? 6 or 12 volt? Aftermarket starter? Cir***stances matter, and what works for you might not work for the vehicle referenced by th O/P. If you ever get he time, you should try installing a distributor with a working advance mechanism. You may have to re-define "starts great and goes great". Not to mention better fuel economy.
I've got a 12 V system and a stock starter. I've got the factory loadomatic distributor but locked it out so I can't move. I do have a Bubba's Chevrolet Converted points distributor with vacuum and mechanical Advance that I'll be putting in to toy with.
The 12 volts probably helps spin it over; once it's started, the 20 degrees is close enough. I don't think I could get by trying to start it at 31 degrees this morning here in Minnesota. I noticed my 13 year old Optima struggled a little earlier today. I think you'll like the Bubba's unit.
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