Ok, here is what I have. I have 289 mustang that over heats. I have tried a new thermostat, new water pump, trans is full, brakes arent dragging, 4 core radiator, new temporary temp guage, temp guage sending unit is in right spot on intake manifold as well as new, new carb, had exhaust checked and is clear, have good compression, no exhaust leaks, no intake leaks, no exhaust in antifreeze, and no antifreeze in oil. I just shelled out and pulled my heads to have them re machined at a reputable shop, they were shot peened, de-carboned, and pressure tested, and re surfaced. I thought for sure that would solve my problem with new head gaskets and freshened up heads but no dice. Head gaskets are installed correctly, as well as heads torqued to 70ft pounds. I am running out of things to try on this piece of S*%$. When I start the car it runs fine and warms up to about 185-190 and at idle could probably do that all day long. When I drive it around town cruising anytihng above 50mph for a long period of time "7 minutes" the car will move up to 210 and will go on, so I shut it down and offcourse once i shut it down it jumps to 240 or so, so i let it cool off. Now the only thing i can think of is ignition/timing. My timing is hard to check because I cant find any literature on my timing markings. They are 1.0, 2.0, and 3.0 and with the motor idling at 550 and the vacume line plugged the car idles its best between the 2.0 and 3.0. Now I am curious as to what the heck those numbers mean. 10 degrees. 20 degrees? My question is what the hell could be causing my car to over heat? I am considering pulling my distributor and replacing it, to rule that out. Any advice on solving my problem? Also anyone familiar with those timing marks my car runs great at around 2.0 and gets slightly better as i move to 3.0 is this ok, everyone tells me 8 to 10 degrees at idle but since i have no idea what my timing marks mean that is hard to achieve. Sorry for the lengthy post but this overheating problem is getting old as hell, and I am sick of dumping money on overheating problems. Thanks Again.
over heating mustang, who knows SBFORDS
- Thread starter phinkel26
- Start date
phinkel26 said:yea, i tried that already, I am running a flex fan with the long spacer so I am like a half inch from the radiator and I am running the big shroud. It sucks I cant drive the mustang.
I am not sure if this will help. My mechanic prefers not to use a timing light to do the final timing adjustment. Instead he uses a vacuum gage that he connects to the vacuum tree at the rear of the intake manifold. If your engine is in very good condition, it should read a steady 20, for a 302 engine, for the best performance on the engine timing. a bigger cam will reduce this reading. My Crane cam has a .484 lift and my best performance on timing is a reading of 17 on the vacuum gage. I have no engine knock or overheating at this reading. Use a vacuum gage and see what reading you are getting. you can also use the vacuum gage to detect other possible problems. A good Ford manuel will show how to use the gage for timing and detecting other possible problems. The mechanic I use has over 40 years of experience and has told me that he has found too many engines with the timing marks off and for this reason he does not trust using timing marks without doing a final vacuum check. If your timing is off, it can cause overheating. It seems that you have done everything else to correct the problem. I hope your engine has not been bored out to much and has thin walls.
68 dailydriver
6Stang7
New Member
What is the condition of the carb? When was it adjusted last? If you're running too lean of a mixture, your engine will run hotter.
-Shaun
-Shaun
mfp4073
Founding Member
phinkel26 said:
Ok, heres a little info on some problems I was having.....not specifically the same kind, but somewhat. I was running hot and having preignition at the track. Sitting in the staging lanes it would climb in temp a little. Now the car ran fine around town, and would run fine, except under full throttle and about 3/4 of the way down the 3/4 mile. Now part of my problem came from the fact that somehow I had installed a 190 degree thermostate in it (I am still trying to figure out how I did it and can only think that I got the wrong part in the wrong box at some point). Still had some problems with preigntion and went to a higher octane gas. That fixed me up. Once again, was showing no signs of problems or power loss under normal driving and would only get a little hot before the thermostate change. What I am getting at is that you may be leaning out and having some preignition that is not audible to the ear. I LOVE HOLLEYS...but also beleive that they suck out of the box and have to be tuned...and that is sometimes like voodoo. Have you had the problem the entire time you have had the carb? Also, you may have had more than one problem...one may have been solved but another may still be present or been created. As I fought this myself (and that I have a big box of jets layin here) I would richen it up a bunch and see if that changes it.. do you know what jets you are running?
phinkel26 said:
Yes, they mean 10, 20 and 30 degrees BTC. Those are the typical timing marks for 289 & 302 V8's. If your car runs the best between 20 & 30 then that means you are running 25 degrees BTC and that is way too much, stock specs are 6 degrees BTC. My guess is your overheating issues are due to your timing, get a timing light on it and set it back to 6 degrees and see if that solves it, thats what i would do. Let us know how it goes.
His timing should be at around 10-12 BTDC degrees, the stock 6 degrees just plain sucks for performance. I would get the timing issue worked out before moving on with the running warm issue, 210 degrees isn't hot, just a little warm. And it jumping up to 240 when he shuts it down is normal. It should coem right back down when it's fired up again though.
67coupestang
Founding Member
- May 31, 2002
- 509
- 2
- 19
i'd be willing to bet the holley is running lean at off-idle and your ignition is to advanced...
Ok, thanks I will definately give that one a try. Now let me clarify and ask this. when I turn the distributor to lower my timing towards the 10 degree area it will run lke complete crap and die on me unless i nurse it by giving it gas. Why is this happening? It sounds and runs so nice between 20 and 30 degrees? The question is, on hydraulic lifters could it be that my valves were set to what my timing was therefore I cant achieve the 10 degree area? Or should I set it at the 10 degrees make the motor run like crap and then go and reset my valves? I hope that is understandable. Thanks.
Ok but can somone answer this:, my timing was and is now close to 20 degrees when I adjusted the valves and sounds good. Now when I play with the timing and try to turn it back to 10 degrees the car will run like complete crap and hardely idle if anything. Now could it be also that my valves need to be set with the ignition timing set at 10 degrees, or does that not matter that when i adjusted the valves my timing was at 20ish degrees? Also does anyone have any good webpage addresses on mixture adjustments on holley 650 carbs.
You have hook it straight to the manifold. You have to to have manifold vaccum. If you can't, then hook it to the carb, where you have the spark advance hook up. Yes, you want to get the most vaccum with it in drive. It needs a load. If it over heats while driving I would not worry too much about the idle mixture as much as your intermidiate circuit. After your car is warmed up, Rev it to 3k. Pour " A LITTLE WATER " down the carb to clean the plugs. They will look brand new again. Take it for another drive, when it starts to overheat, pull over and look at the plugs. Look for ash, white ground straps or electrodes, or chipped porcelain(detonation). Then post results.
Pakrat
Founding Member
First off, you are assuming that your timing marks are lined up correctly and that what you say is 10 or 20 is actually 10 or 20. As mentioned above, many cars tend to be off at this stage in their life. I agree the stock 6 is way too low, and generally that 12 is more suitable, but every engine is different, even the same size and set up could like different timing for a variety of reasons. If what you read as 20 - 30 was too much, I would believe that you would actually be hearing some pinging as a warning sign. As also mentioned, you can use the vaccumm for timing, but everyone is assuming I believe that you have a vaccumm advance distributor. I personally have a mechanical one now, so my vac lines are plugged. I have learned from others that another proven menthod is simply advancing your timing until it pings and then backing off until it stops. Regardless of where it reads, that should be the setting that your car likes most and runs best at. If your holley was fresh out of the box, then you really should adjust the idle first though before you proceed with timing experiments.
One other thing, after your pretty sure, that you have the timing pretty close to correct, and the vacuum looks good; if its still running hot try one more thing. Buy another thermostat from a different supplier and try that. I had the same problem with my 65, had replaced everything and got nowhere. It turned out that the new thermostat was also bad. It must have been a bad batch. Don't buy the cheapest one either.
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