1968 still overheating

[green56]

Hay everone i am still having trouble with overheating i replaced these items 3pass hi Eff rad 7 blade fan, shroud, waterpump,and changed timing.I bought a set of heads off the internet they were from 67-68 mustang do you think if i changed heads it might be better checked temp after running for awhile it gos up to 202 we tested with the electronic meter held against the hose to get the temp.would like to drive the car this summer. The heads that are on now were of a 66they were boiled out and rebuilt THANKS TOM FROM WISCONSIN

 

[Mosesatm]

How old is the block? Might the water passages be all crusted up and restricted?

 

[nfrntau]

Failing everything else, you might check that you have the correct head gaskets and that the water ports are not blocked by the gasket

 

[J.Bart]

what is the bore of the engine?
are there any bubbles in the radiator with the engine running, bad head gasket?
have you looked at the plugs? maybe the engine is running lean?

 

[green56]

over heaTING

The engine was pulled boiled out and rebuilt did not bore out the cyclinder walls org engine needed new crank. The heads were used and rebuilt also boiled out. Head gaskets hAVE the tabs in front. put in a new cam Do you think i should pull the engine or just the heads and take a look to see if i can find something. Radiator is ok removed cap looked in side no bubbles thermostat is ok watch it open and close. Did not look at plugs can not work on car the temp is -8 % wind chill is -16 so a little cold

 

[J.Bart]

can you test temp. of water going into the engine also, to see the differential before and after the radiator?
also, how long does it take to get to temp. at idle?
or do you have that info already?

 

[green56]

overheating

sorry i will have to wait until the temp gets warmer out side or if i get voted in to put car in the new car auto show have to wait

 

[J.Bart]

i'm leaning towards Gremlin's being your problem.

 

[robert campbell]

Tom,
Still think your problem is timing. You mentioned you changed/checked timing. Can you tell what you tried?

Unhook all vacuum hoses from the distributor and plug any that make the idle pick up. Spin that bad boy to about 12 degrees BTDC. Not to be insulting but it is critical to know the difference between BTDC and ATDC. Looking at he timing marks on a running engine, BTDC is below the pointer.

One thing we have not discussed is the condition of your vibration damper. On rare occasions they can slip and the marks are no longer valid. To check this crudely, take the number one plug out and use a plastic straw and stick it in the spark plug hole and rotate the engine until you see the rotor pointing at the number one wire on the distributer cap. Then gently rock back and forth until you feel you have the piston as high as it will go. Easiest with two people. Get as good as you can and then look at the TDC mark in relationship to the pointer. They should be very close

This will say a lot about the engine. I hate to ask this question, but are you confident in the timing mark alignment between the timing gears at installation? One tooth off will create all sorts of problems.

If the timing mark check is good, and the timing gears are you should be able to twist the distributor from TDC to 6 and then to 8 and then to 12 degrees and each time the engine should speed up and run “freer”.

Did you check the thermostat on the the stove with a candy thermometer to ensure it opens art the correct temp. and easy check.

But at a true 12 degrees BTDC, that engine should idle fine and not heat up. If we can fix that first then we will go into detail about how to set it up not to overheat when driving.

I talk much faster than I type. Call me between 9:00 a.m and 8:00 p.m. anytime. (360) 377-5164.

Rob

 

[Powell]

Rob,

Great information for Tom.
One of the things I hope is that members here never get "insulted" when the"MASTERS" like yourself ask questions about where they are at and their skill/knowledge level.

I have a fun story about my GT/CS and similar situation. My brother-in-law is a rather famous motor builder for the sprint car circuit in california. After I purchased my car and had it for a couple of years I knew it needed a tune-up, having mentioned that to him there was no way he wasn't going to get involved. Once I had all the parts I took everything to him, and we proceded to replace all the common tune-up parts.

Now it was time to start it up and time the ignition. What a situation, as I started the engine he hooked up the timing light and began to turn the distributor. It was so far off that he said there are no marks on the harmonic balancer, so he just started working off a white mark on it. Would not run at all. We were about to go about ROB's TDC # 1 piston when my autoshop 1 kicked in.... He has been working on chevy engines too long to remember where #1 is on the FORD.

Anyway we all need a lesson now and then to make sure we are all on the same page!

Ralph

 

[robert campbell]

Sometimes I feel like the "master of disaster" when I work on my stuff!

 

[rvrtrash]

I'm just getting in to this discussion, so bear with me. I went back and checked your older post and noticed that you said the water in the radiator was moving back and forth when it was cool. That concerns me. The water shouldn't flow until the thermostat opens when it gets hot. It suggests a problem with the thermostat. I've had brand new thermostats that haven't worked. I would recheck it, by boiling as previously suggested. If it's opening to soon, that wouldn't lead to overheating, but who knows what's going on with it if it's not working correctly. At this point you need to eliminate problems as you find them. I also want to echo the thoughts on your cam gear and the harmonic balancer. I've had a couple of balancers that the outer ring had moved due to age of the rubber insulator, and my stock one on the CS actually blew up last year. For the cam gear, the easiest way is to pull the valve cover and look at the valve position while you find TDC on the number one piston, but you really have to be paying attention. The best was is to pull the timing cover and recheck it. Did you use a cam gear that has different advance settings and possibly use one that isn't right for your engine?

Steve

 

[robert campbell]

A thermostat stuck open can actually let the water flow to "fast" through the radiator. The water does not get enough "time" to remove heat as it goes through. I also have had defective "brand new" thermostats. I used to work in a radiator shop re-coring radiators and heaters. We never installed a thermostat until we verified its operation. Early on we learned this the hard way.....

 

[green56]

Radiator cap

installed a radiator cap with a thermostat built in it is 16lb cap will i hjave any problems with the 16lb cap also put a fan in front of radiator it seems to help but just installed new cap ??? thanks

 

[franklinair]

A 16lb cap should be OK (assuming the radiator & hoses are OK). I also use a radiator cap with the thermometer built in. I like it as a cross check to the dash temp gage.
Rerevious inputs, have you verified;
Timing 10 to 12 degrees BTDC (advanced)?
Thermostat opening (observed in boiling water w/thermometer)? As an aside, I always drill a 1/8" hole in the thermostat flange to assure a minute amount of bypass.

Neil

 

[green56]

thermostat cap

Neal i checked with the temp dial on dash and it was pretty close i also add a fan in front of rad that i have set at 180 the timming is set 8 know i have trouble with carb it wants to chock out when you step on the gas so i will replace the acelarator pump every thing has been done?

 

[CougarCJ]

Get your air/fuel ratio corrected next.

 

[green56]

radiator cap

can some one tell me how do you set up for air/fuel ratio and what should it be set at

 

[franklinair]

Do you have a vacuum gage to connect to the intake manifold? Or do you want to set it by feel/listening? (Rob can do this with his eyes closed:smile

Neil

 

[robert campbell]

lots of good information here!

http://californiaspecial.com/forums/showthread.php?t=5039&highlight=idle+mixture