|
Sponsored Links (Register now to hide all advertisements) |
|
|
Thread Tools | Display Modes |
07-10-2011, 04:56 PM | #1 |
Member
Join Date: Jul 2011
Location: Boston, Ma
Posts: 31
|
Flathead overheats 1 side
My 49 merc flathead overheats on 1 side. The left side runs 190 and the right side will get to 230 before I shut it down. These temps are with an ir termometer at the t-stat housings. These temps are taking just after a drive but they will be about the same at idle. The engine is stock , with duals. There are no thermostats, no resrictions in the exhaust (flapper valve moves but does not come into play with the duals) timing is correct, engine is not running lean, no combustion gas entering the cooling system, has new rebuilt high flow waterpumps, flushed the block with water with the heads and pumps off. In the block is a bit scaley. I am in the process of doing a vinergar flush. The radiator seems to flow ok a temp drop of about 50 degress top to bottom, but the bottom left is a little cooler than the rest of the radiator.
What do you think? Do I need to install the t-stats as a restictor? But it seems a bit odd its only one side? |
07-10-2011, 05:43 PM | #2 |
Senior Member
Join Date: May 2010
Location: Poulsbo, WA.
Posts: 356
|
Re: Flathead overheats 1 side
Have you checked the water passages in the block for sediment/foundry sand? Henry Ford was not too critical about getting all the foundry sand out of the blocks and over time it migrates to the back of the block. A long screwdriver could be used to check how deep each side is through the water jscket holes and compare from side to side. When my blocks were built, they were rolled back and forth on a sheet of plywood and prodded through the water jascket ports with a sharp pointed screwdriver. Prod and roll, prod and roll and the result was over a quart of old foundry sand fell out of each engine. Both of mine run 185 degree thermostats and hold that temp. despite long idling or highway driving. I did drill a couple of holes in the thermostate butterfly to allow any air to leave as it was being filled with 50/50 mix of water and antifreeze. I have checked the temps with a electonic thermomoter and both side run the same.
|
Sponsored Links (Register now to hide all advertisements) |
|
07-10-2011, 06:19 PM | #3 |
Senior Member
Join Date: Jun 2010
Location: San Antonio, Texas
Posts: 16,431
|
Re: Flathead overheats 1 side
The only common area to the two sides is the radiator. If you have a compression leak into the hot side or a sticky thermostat on that side, it will run hotter. I'd check the easiest thing first and go from there. Since you have no thermostat, I'd check the plugs for signs of water leak and do a compression check on that side first.
Kerby |
07-10-2011, 07:06 PM | #4 | |
Member
Join Date: Jul 2011
Location: Boston, Ma
Posts: 31
|
Re: Flathead overheats 1 side
Quote:
I believe I have covered everything I could think of. Maybe I will have some luck when I'm done with the vinegar flush |
|
07-10-2011, 09:03 PM | #5 |
Senior Member
Join Date: May 2010
Location: Cottageville, WV
Posts: 1,535
|
Re: Flathead overheats 1 side
Try disconnecting one spark plug wire at at time on the affected side and let it idle. Use your Infrared Thermometer to isolate the cylinder or cylinders that are overheating. This would be a start and a place to look closely at should you have to remove the head.
Shadetree
__________________
Son, you will never blow an engine up in high gear. |
07-10-2011, 09:34 PM | #6 |
Senior Member
Join Date: May 2010
Location: now Kuna, Idaho
Posts: 3,779
|
Re: Flathead overheats 1 side
Sponsored Links (Register now to hide all advertisements)
|
07-11-2011, 07:58 AM | #7 |
Senior Member
Join Date: May 2010
Location: nw SanAntonio, TX
Posts: 939
|
Re: Flathead overheats 1 side
"Allready checked for combustion leak on that side"
How do you check a side for a combustion leak? Only way I know is to do the check of your radiator water for combustion gases. If you detect the gases then it follows that may be the cause of your high temperature on that one side. I'm just asking because I would want to learn of any new test that might be out there. Also, may I suggest that you put your locale on your thread ID? It is nice to know how extreme hot running engines are given where they are located. In other words, driving your flathead here in S. Texas this summer and it getting hot is kinda expected. However, if you are driving it on the Oregon coast and it is getting hot, then you really have a problem. |
07-11-2011, 08:14 AM | #8 |
Senior Member
Join Date: May 2010
Location: on the Littlefield
Posts: 6,159
|
Re: Flathead overheats 1 side
I had an overheating problem with the 46 truck we used to go to Hershey and other flea markets in, , it was only on 1 side, after duals were installed, the problem turned out to be the muffler ---who would have thought a muffler for a mustang with a 302 wasn't flowing enough to handle 4 cyl of a flathead, installed another "stock type" muffler and no more problem.
|
07-11-2011, 08:50 AM | #9 |
Senior Member
Join Date: May 2010
Location: Michigan
Posts: 505
|
Re: Flathead overheats 1 side
Any chance you have a mis matched head gasket on that side and are blocking some of the water outlet or passages? Just a thought.
|
07-11-2011, 12:43 PM | #10 |
Senior Member
Join Date: May 2010
Location: Waddell, AZ
Posts: 2,540
|
Re: Flathead overheats 1 side
how's the waterpump on that side??...maybe belt slipping and not allowing it to turn as fast as other one??....maybe clogged passages in head??....you could check flow from both sides, i guess.....good luck...Mike
|
07-11-2011, 01:19 PM | #11 |
Senior Member
|
Re: Flathead overheats 1 side
Some very good suggestions here .A cylinder leak generly dumps water out the overflow . Something to try is to cross over the bottom radiator hoses ,get some Constantine hoses ,see if the problem swaps over .
|
07-11-2011, 02:54 PM | #12 | |
Senior Member
Join Date: May 2010
Location: Alabama
Posts: 3,260
|
Re: Flathead overheats 1 side
Quote:
|
|
07-11-2011, 03:23 PM | #13 |
Senior Member
Join Date: May 2010
Posts: 500
|
Re: Flathead overheats 1 side
Are you using an off set generator? On the side with the offset, there was little belt overlap with the water pump pulley, I could easily slip it even when the other side's water pump pulley was tight. I had a 20 degree difference in temperature. I made an idler pulley setup and the temps became the same.
|
07-11-2011, 05:27 PM | #14 |
Senior Member
Join Date: May 2010
Location: nw SanAntonio, TX
Posts: 939
|
Re: Flathead overheats 1 side
Thank's, Ken.
|
07-12-2011, 10:59 AM | #15 | ||
Senior Member
Join Date: May 2010
Location: 74FL
Posts: 323
|
Re: Flathead overheats 1 side
Quote:
Quote:
__________________
Daddy always said, "If yer gonna be dumb, you gotta be tough" and I'm one tough sumbitch! T5 Tech |
||
07-12-2011, 11:13 AM | #16 |
Senior Member
Join Date: May 2010
Location: Tyler,TX
Posts: 462
|
Re: Flathead overheats 1 side
Sometimes we get lucky here and this works: Pour a box of granulated Cascade in the radiator.The water will likely turn rusty.Drive it awhile and drain it.Many times this will work and nothing is cheaper.James
|
07-18-2011, 06:41 AM | #17 |
Senior Member
Join Date: May 2010
Location: Lithia, FL
Posts: 1,050
|
Re: Flathead overheats 1 side
I had the same problem on my 46 Coupe except it was the driver’s side running hotter. After having the radiator thoroughly cleaned, flushed and bent fits straightened (knock on wood), she has been running cool with even temperatures on both sides. I am convinced that 90% of overheating problems can be attributed to dirty radiators. Good luck. Steve
__________________
If it aint broke, don't fix it! |
|
|
Sponsored Links (Register now to hide all advertisements) |
|