Overheating issue

+1 on the Trick-Flo heads.

 

Alright, guys. Just ran a engine block test and everything is fine there. The color stayed a solid blue and didn't even try to change to the greenish or yellow. The only thing left that it could be is a blockage in the engine at this point I believe. Anybody have a good chemical flush or trick to maybe break down some junk that might be causing a blockage. The problem with the heads is being a 20 year old kid in school spending 600-700 on heads isn't exactly the most practical at the moment. LOL

 

I always use bars Radiator flush and have good luck with it, but I have never had a real problem with blockage, just getting general gunk out of the system. I think it would clear a blockage though.

 

the thing about breaking up a blockage is...it will stop up radiator and heater core...

 

X2!

With as many times as its over heated I'd go get a junkyard engine from an exploder (with gt40 heads). Buy a 50oz flex plate, swap your intake oil pan/pick up, headers and timing cover and let her eat.

 

My heater core is bypassed at the moment so the heater core is out of question. I'm really only worried about getting it to stop overheating at the moment then the modifications can come later.

 

are you running a 50/50 mix for your coolant and a hole in the tee stat?

 

Not trying to imply that you don't know what you're doing here.. but if I had a nickle for every time I've heard this same thing. Assumption is the mother of many errors and much tail chasing. As you get older and wiser, you'll learn that tossing parts at a problem can get you nowhere fast. Back to the basics and start from the beginning. Regardless of what has worked and where you think things may still be set from the past.. always best to check and reconfirm the tune.

And as far as manifold vacuum goes.. it is THE best indicator of an engines state of tune during idle and part throttle conditions. The higher it is.. the better the engine will run and make the most of it's fuel supply. To do it right, you'll need an adjustable vac pot(which many Fords already have in place).

So here are some basic questions to hopefully help you through such a frustrating and costly experience.

Is the engine building pressure in the cooling system/pushing coolant BEFORE it even gets hot?

Hose still collapsing?

What is the initial timing and it's associated idle vacuum reading? Stock/ish cam?

Distributors vac advance can hooked to ported or full manifold vacuum source? Maybe you inadvertently swapped it from full vac to timed vac source? Though full manifold sourcing may cause a lean cruise condition at very low throttle openings(before the ported would normally come into play) if the unit was originally calibrated for ported(which is highly likely since they came that way from the factory).. it will rarely ever make an engine run worse at idle speeds. If the engine likes it.. the idle rpm will rise and you'll need to readjust it back down and reset the idle mixture screws.

Check coil/spark strength? Just like a bad tune.. weak spark can cause an overly rich condition at idle even without the tell-tale spark/cylinder miss. The next question is usually a very good indicator of this.

Is the manifold/header getting pretty hot/hotter than normal BEFORE the engine starts overheating?

Can you power test it before it pushes coolant or overheats?.. runs the same(similar throttle response) or down on power at all?

Maybe your timing chain jumped a tooth?

Did you pull the distributor/reinstall a tooth off?

How long has it been since the carb was adjusted/cleaned/rebuilt? Although they'll usually cause a misfire.. lean outs can heat things up in a hurry too.

Just a few things to think about and always best to get back to the basics by confirming and/or establishing proper baselines to work from.

 

Back in the day of regular junk yard engine swapping, I'd always knock out all the freeze plugs and give block a good douching before install... Sometimes there would be one or two inches of crud in the bottom of water jacket... Of course this is a bit tough to do with engine installed, still it's at least possible to access one or two on each side of block...

Point is, if you can't find other problems it's at least cheap to check...

 

good advice here. and crud can develop over time. I sunk a new radiator with crap trapped in a block once. what I do now is drain the coolant, than do a 'marine' flush. this is crude and messy but works. I pull the thermostat out, reassemble, and when the motor is COLD I hook up a garden hose and leave one end of a heater hose off and low. I runt he car with the hose wide ass open and the flow usually flushes the sediment out within half an hour. I vary engine speed. the motor doesn't really ever really warm up the coolant, but it wont overheat either and its a total loss system like old marine motors. (sort of). you get the point. do this until it flows clean. worked for me in the past. the 250-6 I have was pretty nasty and I flush it like this each year and its stayed flowing nice. (sat previously for 20+ yrs so you can imagine the crap that was in there)

 

Not to say crud doesn't have an impact on cooling efficiency.. but I've had short and 3/4 grout filled short blocks that don't act up like this motor is. It's one thing when the crud is accumulated on top of a crappy tuneup, used up parts, and partially blocked radiator.. but this thing shouldn't be in that cumulative problem child category in the least.

Will be interesting to see what the OP has to say about some of the questions asked above.

 

Yes. I was running 50-50 but after I drained it I just used water as I didn't want to waste money on coolant. I haven't had a thermostat in the car since I took it out trying to diagnose the problem.

 

I know what you mean. All I am saying is that I'm 90% positive that it is not a tuning issue. I know I may be 20 years old and still young and dumb but this isn't my first rodeo. If it was a tuning issues that would cause overheating than I would most likely have a issue with the car starting hard or diesleing on shut off. I also find it hard to believe that a tuning issue would cause a car to climb past 240 degrees without having massive tuning issues, which I don't. Now I'll answer the questions.

Manifold vacuum is in the normal range according to my gauge. I found a little leak coming from the carb and fixed it and it's now fine.

The engine doesn't seem to build pressure right off the bat but it does seem to build faster than it should..

Hose is not collapsing.

Timing is fine around 10-11 initial. It's got a decent cam but nothing crazy.

Vacuum advanced is fine and ported extaly where it needs to be.

The coil strength is nice and strong. New coil, plugs and wires. After a power run the plugs look nice and clean. Nice caramel color to them. Another reason I don't think it's a tuning issue.

The headers seem to get warm like they usually would. They get pretty warm after a minute.

The car still runs as it usually does. Has no problem breaking the tires loose going into second.

Highly doubt it jumped a tooth as it runs perfectly fine.

Never pulled the dizzy or messed with timing after the first headgasket install a year or two ago.

Carb was rebuilt the same time I did the headgaskets the first time. A year or two ago.

The car runs way to well for it to be a tuning issue in my opinion but at this point I'm open to anything. I did the block test a second time with an even better tester and the color stayed blue. I made sure the dye was good by sucking some of the air up from my exhaust. I'm going to try and flush the system tomorrow and we will see from there. Like I said the car never gave me problems till now and I haven't changed a thing tuning wise.

 

Why not have the entire cooling system power flushed by a reputable shop? How about these guys? Might want to give them a call and just discuss the issue.

http://www.sunriseautomotiveservice.com/

 

ok.. sounds like you've got some bigger issues going on here. It might sound a bit gruff to say but I mean no offense and typically just shoot from the hip in an effort to save people I care enough to try and help more time and hassles. No hidden tones, no holier than thou attitude, simply spending my time to try and help and calling it the way I see it. Not nearly my first rodeo building and tuning engines either.

First off.. a motor is VERY forgiving. There's some science involved.. but it sure ain't rocket science and no degrees required either. They can puke water, oil, gas, run on 5 cylinders, etc, etc.. and STILL get you around semi-reliably if you have all those backup fluids and funnels sitting in the trunk to keep you from burning it up completely. Hell.. run it down to a single quart in the pan and it'll still run for a long time on that minuscule amount of jet black syrup. Many of us have driven a few and seen countless hundreds of others that seemingly defy the laws of physics as their owners keep driving them into the ground month after month. That being said.. and as mentioned before, even if you have some crud filling the entire lower half of the block(again.. some guys do that on purpose with engine grout) it's highly doubtful that a brand spanking new radiator would suddenly plug up completely and give the same exact issue as if you had done nothing to fix the issue. No way no how will an engine quickly go to 240 with the newer components you have installed.. UNLESS.. there is some other underlying issue that's causing it to do so. Water pump spins and circulates water/coolant though the block, heads, manifold and out through the radiator. Doesn't need to be even close to perfect to keep an engine from shooting up to 240 in short order. It seems MUCH more likely that you're missing a head gasket leak(likely from a warped head/s if the new gaskets did not cure the issue), cracked head(could even be in the exhaust port which the exhaust systems pressure would not be high enough to contaminate the testers reading from any intake vacuum source), have them reversed(or maybe even the intake gaskets are wrong style/reversed). Takes a severely plugged system to do what you're describing here.

My last bit of long winded advice is this.

Lose the fancy high-tech tester and do a simple pressure check at the filler neck. Many big-chain auto parts stores rent loan them out for free these days. There are many locations for compression to enter the cooling system and not all of them will have spent exhaust gasses present. A simple cooling system pressure checker doesn't care about gasses.. only the integrity of the cooling systems sealing points. The KISS rule applies here in spades.

You didn't say anything about numbers for vacuum readings and "normal" is usually ALWAYS lower then the engine would prefer. No manufacturer wants to put timing into an engine that results in smaller margins for people who don;t rightfully and religiously maintain their cars engines. Plus, even before catalytic converters where a major concern, none wanted to tune their engines in a way that NOx starts going through the roof due to higher amounts of spark advance. Funny as it sounds, they'd rather you contaminate your oil more quickly(which pistons, rings and cylinder bores really hate) and send more raw fuel out the tailpipe than drive up the NOx readings with heavier timing advance. It's the old monkey see monkey do thing and gets perpetuated. I know this to be fact and have proven it to many over the years. Even guys around here have cured overheating issues like yours by doing nothing more than optimizing their initial timing and changing over to a full manifold source for their vac advance pots. And some of those fixes came AFTER throwing many of the same parts as you have at a nearly identical "overheating" situation.

Timing advance. You seem as though you may be resistant to the idea of what an engine truly needs for spark advance at idle, especially with a bigger than stock camshaft, but I will spend some time to try and edumacate you a bit more. This engine, almost ANY engine despite some of the newer combustion chamber efficiency increases(look at the timing tables of an EFI engine and you will see upwards of 50° or even more), wants/needs/MUST HAVE much additional advance due to the very slow and sluggish low density mixture speeds at low idle/induction/piston speeds. Add bigger smog style chambers, thick/oversized head gaskets(let me guess.. 4.100 bore gaskets?.. YUCK), lack of sufficient squish pads(smog heads), too much deck height, and then top it off with a bigger than stock cam that makes the incoming mixture even lazier and what do you get? INCREASED TIMING LEAD REQUIREMENTS AT IDLE AND PART THROTTLE. In fact, IF you are running the distributors vac advance pot from a ported source?(and seems probably since you didn't define that fact).. I would go so far as to put money where my mouth is that this motor has far less timing and manifold vacuum than is optimal. Should it start overheating now when it didn't prior?.. no way. BUT.. tunes don't stay identical over time as components wear out and electrical parts build continually build resistance either. You have absolutely nothing to lose and everything to gain by simply swapping that little hose over to a full manifold vacuum source. It may not fix this issue but troubleshooting rarely gets easier than that simple task. Spark lead will go into the low 30's, idle speed will increase(again, you'll need to adjust idle stop and mixture screws to dial it back in), manifold vacuum will go up, EGT's will go down along with their related coolant temps. Manifold vacuum on a semi-healthy engine(which seems somewhat debatable here) with mild cam should be AT LEAST 17-18 inches. With fine tuning of both ignition and fuel curves it is possible to reach upwards of 20 inches or slightly better even with a mild cam. As some members I have helped around here will attest to.. the difference in how an engine runs, and the reduction of heat it puts into the cooling system can be startling to say the least. Throttle response and mileage gains are a certainty as well.

My main point is this. If you're logic is not sussing out the issue and you've thrown everything but the kitchen sink at the problem?.. change your logic. Or another way. If the result doesn't match the theory?.. keep changing the theory until the results line up. Preconceived notions will often get you nowhere if you hang to them too tightly. Wipe the chalkboard clean and start over based on the physics alone. Good luck and hopefully something within all this babbling can help you figure it out.