My 200 w/AC overheats what about fitting a 390 radiator?

I have a 67 Mustang w/AC that overheats w/o the AC running. I have tried an AL rad for a six but overheats w/AC running. I want overkill cooling so I know a 390 will work but getting it to fit is another new set of issue. The hoses for example, there is a size change between the outlet pipe on the rad going back into the engine and hose length could be different as the inlet and outlet pipes are probably different from the original six. Then there is the main problem, is the radiator support for a 200 six going to accommodate a 390 radiator w/o cutting into the radiator support? Anyone done this that can give me some detailed advise?

I'm no expert on fitting a larger radiator but it would seem that maybe you have another cooling problem if even an upgraded aluminum radiator can't handle the job? Do you live in a really hot climate? Also I have heard timing issues and running lean can cause overheating problems.

The 390 Rad fits without cutting , BUT , it takes different mounts , The inlets and outlets are also very large in comparison to a 200 6 ( I own a original S code( 390) 68 Mustang the upper is on the pass side lower on drivers , It uses a saddle mount with a clamp on top ( I have for sale by the way ) the outlet and inlets can me adapted down , the easy way is by using the summit racing rad hose kit ( cut to fit stainless ) its very nice, durable and also helps with cooling , pm if your interested

I doubt that a larger rad would solve the problem.
What about the heater core? Could it be gunked up and restricted?
You'd be amazed at how much rust can accumulate in the head itself.
There are plenty of folks here that don't have heat problems with stock parts.
Has it ever boiled over?

Without a doubt, the radiator is NOT the problem. Does it overheat around town or during freeway driving?

Do the easy stuff first, time your engine correctly, both initial and full advance.
Water flush the entire block and radiator, open every orfice; flush and back-flush until clear.
Don't gamble with your stat and cap, they are cheap and easy to replace, do so.

8) i also agree that you dont have a radiator problem. a stuck thermostat, or no thermostat, ignition timing too far retarded, an excessively lean fuel mixture, a bad head gasket, rust and scale build up in the block, a bad fan clutch, no fan shroud, all can contribute to overheating.

I had the same problem with my car. My question is do you have a four blade fan or a six blade fan??
I had a three row rad and a four blade fan that would still run hot. I was tired of dealing with the a/c so I removed all of it and installed a six blade fan and now it runs much cooler and no problems.

Some things I've already done:
1-Flushed the system, i.e. block.
2-Started w/a new AL radiator, single row, worked okay (W/O AC ON) w/electric fan, then elec fan ate through the mount pads you place between the rad and the rad fins, and tore multiple holes in the AL RAD, due to vibration I'm sure.
3-got another original 6 cyl copper radiator larger than original NEW. This is the one now overheating while sitting in traffic in 85° weather, so CAL.
4-No rust build up in block or chips floating around in the cooling system, i.e. no blockage.
5-6 blade fan.
6-no shroud, I need one I know but don't know which ones will work?? (I ordered one from CJ Pony Parts & they never shipped it)
7- I installed the vintage air AC system last year and still can't use it.
8-Timing is correct but didn't check it a high RPM.
9-Mixture? Can't tell if its running too lean or not, ANY how to help here would be appreciated.
10- New water pump, new thermostat.
11-Petronics Elec ignition.
12-Engine needs a rebuild though, 10 mi/gal, blue smoke, oil fouled plugs. I sand blast the plugs every couple of months or so, etc.
My theory is to overkill w/cooling thus the 390 rad idea. I have not heard of anyone NOT having overheating issues with 6 w/AC, in fact I've never seen a six Mustang w/AC except mine. VERY frustrating.
Thanks very much for your thoughts but has anyone got a 200ci running cool with AC?

preston215":2bzwdlps said:

6-no shroud, I need one I know but don't know which ones will work?? (I ordered one from CJ Pony Parts & they never shipped it)

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8) i think this is you problem. if you live in the LA area, go to larrys tbird and mustang parts, they will have the shroud you need.

I too have basically your set-up, see my signature. I too have the overheat trouble, not boil over. And cannot figure it out. I'm of the mind now that my car runs in the low 200s and maybe it's normal for my set-up.?

I have become convinced that the 200 is just not capable of staying cool with an A/C condenser in front of it. No matter what is done.
Probably why we hardly ever, if ever at all we see them with A/C.

does it ever overheat while driving at moderate to high speeds? you only mentioned in traffic, so i'll assume thats the only time it happens. the lack of a fan shroud is a big deal - its why my F250 (300) would overheat so easily while fighting through the snow at near-zero speeds, but never while moving above 10mph.

I have rust cyclicles,,( chunks of rust coming outta my block,,engine hasn'nt been rebuilt yet) and had to make a home made filter from a spagetti strainer to keep from plugging up the RAD,,( 66 200 ci) I still need to get engine rebuilt,,but I know from the junk factor that if the garbadge showing up in the filter is still coming through after 4 years and a cooling fan doesn't keep it down that one of 2 things are happening based on my experience,, the Rad is plugged up somewhere or you got the rust cycles in the block hangings onto the heat,,just a bit of a wild idea

mv

I had overheating problems with my car until I fixed the slipped balancer. Timing was way off and ran hot. I have A/C and a copper radiator and have no overheating problems.
I would dig deeper into the timing issue. You may need to verify that the harmonic balancer has not slipped. If you set timing according to a balancer that has slipped, then your timing will not be correct. Pull the #1 spark plug and stick a long screw driver or stick in the hole. Use a wrench and turn the engine to TDC as indicated by the timing marks on the balancer and see if the screwdriver/ stick is at the top of the stroke. Pop the distributor cap and see if the rotor is pointing to / near the #1 spark plug wire terminal on the distributor cap.

You should not be having cooling issues with a new radiator. Wha do you have for a carburetor and distributor combination? Is the vacuum advance diaphram on your distributor in good shape and holding a vacuum. If not, the timing at idle and at low throttle cruise conditions will be retarded.
Doug

If you got a big block radiator handy go for it. It worked for me, but had one that I borrowed from another car. However, it would never warm up on the freeway on a cold day. But I agree with the others that there's something else that's wrong.

This problem has been a long lasting thorn in my side. I am really excited with all the responses I'm getting, this is a great forum, a big THANK YOU to everyone!

Addressing some questions folks have asked about.

The filly does not overheat while moving on the road only while sitting in dead traffic. BTW I have a calibrated temperature gauge mounted to read the actual °F, when running nominally (moving down the road) she sits right around 140-150°F. Now I've read 160° is ideal but that reads about 3/4 or a little higher on the Ford gauge. That makes me uneasy to see the needle riding so high but I've heard that's normal. So that begs the question; What is the actual ideal operating temp where the wear and tear on the engine is at a minimum?

Larry's Tbird doesn't not have a shroud for my application except for the V8 (non-390/200/250).

Doug
Do you mind if I ask where you live and how hot it gets? Do you have a stock rad? A shroud? I'm going to test for my balancer slipping tonight, that's something that never crossed my mind. Carb-I have an Autolite 1100, rebuilt about two years ago. My daughters school is only a mile away so she doesn't rack up the miles and its still in good shape. Yep, she drives it as a daily driver. 8) I have a stock distributor and the vacuum at idle is good...I think... at around 17 psi. I haven't tested the vacuum advance at cruising speed... maybe I should do that tonight too.

Johh
Can you tell me what radiator you used, was it from a 390 or? Did you use the hose kit from Summit Racing?

Hey senior LaGrasta, see you Tuesday afternoon at the car show!

cars of this time period usually had a 180* thermostat installed, so thats the "optimal" temp. later models used 195 and sometimes higher, as the higher temps have some advantages, so long as you keep it in moderation. getting above 230 is where you really have to start to worrying.

Thats strange that you say that the temperature is usually around 140 to 150 while driving, this is too cold, it should be around 180. I also know on my 65 falcon at least when its warmed up at 180 its about 1\4 of the way over, not even half. How hot is it getting when yous ay it overheats?

preston215":2srwbph7 said:

Hey senior LaGrasta, see you Tuesday afternoon at the car show!

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I'll be there by 6!

I live in Oklahoma and have also lived in W. Texas with the car, so it sees 100 deg plus. It is a stock radiator. However, I do not recall if it is 2 or 3 row. No shrouds, but I did put on a 5 or 6 blade fan with the AC (I forget).

Check the vacuum advance by disconnecting the vac line and sucking on it to see if the diaphram holds. With the engine off and the distributor cap off, you can check to see if the distributor plate rotates when vacuum is applied. With the engine running, the engine rpm's should increase when you suck on the vacuum line.

From the temps you are describing, what are you defining as hot or overheating? Are you boiling over? Is there really an overheating problem or are you just uncomfortable with the higher temps at idle?
I rebuilt my Pontiac last year with a new aluminum radiator and overdrive transmission that increases the load on the cooling system. The stock thermostat is something like 192 or 195 deg. That is the nominal temp that the T-stat starts to open. My temp does not level out until about 205 to 208 deg. T-stats fully open about 10 deg higher than the nominal rating.

Additional vacuum advance at idle can help raise the idle speed and reduce engine temp. Many of the vaccum canisters are adjustable with an allen wrench.
Doug