1967 Mustang Coupe

[Rmoore45]

I figure I would start a general thread about my car vs. a bunch of individual threads.

I have a 1967 Mustang Coupe with a 289, automatic, power steering, power brakes (drums all around), classic auto air in dash A/C, black interior, and painted "Silver Smoke Grey".

The 289 has: bored 30 over, dual plane highrise aluminum intake (not sure of the manufacturer), hooker long tube headers, Edelbrock 600 cfm carb, some kind of cam (previous owner rebuilt engine), stock heads, aluminum water pump with 6 blade fan. The car originally had a 289 2V, automatic, power steering, and dual master cylinder drum brakes, black interior and was painted "Springtime yellow".

I'm in the process of gathering up parts for a T-5 conversion, I'm going with the mustang steve cable clutch setup and roller bearings. So far all I have is a '86 t-5 bell housing. I'm looking for a T-5 that can handle 300lbs of torque and a '67 mustang clutch pedal, I can fabricate a cross member.

Now onto the problems...
The main problem I'm having is the 289, I get 13 mpg (when I drive it carefully, 10 when I drive it normally) and it runs like crap, acceleration is is good but taking off normally sucks, it spits and sputters. I have cleaned the carb, replaced the distributor (still running points), coil, plugs, and spark plug wires (plugs and points were set according to specs).

It runs hot even with a 6 blade fan and fan shroud, hot meaning 195 while driving with the a/c on but quickly jumps to 210-225 when idling. These temps were taken from a Sunpro temp gauge.

Once its warmed up, if you kill it and let it set for 15-20 mins, it is very difficult to start. I have installed a fuel pressure regulator that is set to 6 psi, reset the floats in the carb, and installed a spacer between the carb and the intake to keep the carb cool and prevent boil over. None of this has fixed the problem.

Hopefully some other members have had problems like this before and can help me out.

Thanks, Ranger

 

[Fstbk]

Are you certain the water pump is set up for the correct rotation? If it is off of a 5.0 it is running backwards.

 

[horseballz]

Rmoore45,
Nice looking car & welcome to the forum. What is your ignition timing set at? Incorrect timing (too far advanced OR too far retarded) and/or improper advance curve can cause all/most of the issues you describe. What temp & brand thermostat are you using? 6-PSI might still be a little much for that carb, try 4-5-PSI.
HTH,
Gene

 

[Rmoore45]

Gene, thanks for the advice.
Fstbk-the water pump is the correct one. I just have a radiator that isn't meant for cars with a/c.

My timing is advanced 10 degrees from 6 degrees BTDC.I turned down the regulator to 4.5 psi, I did this by installing a fuel pressure gauge inline with the carb and turning down the regulator. While doing a test drive I stopped by O'Reillys and bought Royal Purple Purple Ice, I saw this on Horsepower and their results seemed promising. I let the car idle with a/c on and in park for 15 mins, it barely got up to 210 normally it would be up to 225. Temps were taken with a Sunpro mechanical temp gauge CP7983.

Another thing I'm having issues with is the PCV system, there is a lot of blow by coming from the breather cap on the driver side valve cover. The PCV hoses are not clogged and I replaced the PCV valve today. This has always been a problem but it would be nice to solve it for good as I'm tired of having smells in the car and the dipstick spewing oil if I drive on the freeway.

Tomorrow I will do a compression test, I'm afraid of what the results might be.

-Ranger

 

[65ShelbyClone]

Any idea how many miles are on the engine? Pushing oil out of the dipstick is usually an indication of significant blowby. The compression test is a good idea.

Sounds also like it may be running rich. I manage to average ~14mpg out of my '68 and it has a lot more engine plus a double pumper carb.

 

[robbz28]

GO ahead and install that points conversion, it is one of the single best bang for your buck additions you can do. I noticed a night and day difference in the throttle response on my 289, it was doing the same thing. Also, timing, jetting, get rid of that crappy 2 row radiator and get a 3 row copper or 2 row aluminum radiator and put in there and that should take care of your cooling problem.

 

[12sec67]

get rid of that crappy 2 row radiator and get a 3 row copper or 2 row aluminum radiator and put in there and that should take care of your cooling problem.

The above statement is correct!

the problem your having is once you stop moving forward your not getting much movement through the radiator to cool off the water/antifreeze. you need to upgrade to a larger aluminum radiator with at least 3 rows.

 

[1968-coupe]

Any idea how many miles are on the engine? Pushing oil out of the dipstick is usually an indication of significant blowby. The compression test is a good idea.

Sounds also like it may be running rich. I manage to average ~14mpg out of my '68 and it has a lot more engine plus a double pumper carb.

I had oil coming out of the dipstick on my 94 F150 with an EFI 302. Pulled the plugs, found oil on one. The rings were not sealing and compression was feeding down into the oil pan and having to go somewhere exited out the PCV valve and dipstick. Im afraid you have a bad ring. This would cause a rough start off. However my 302 still had nice acceleration even with only 7 cylinders.

 

[JonK]

If you open the cap to the rad. (cold of course) you can count the rows of tubes running front>back (2,3) in the top of the rad. if the fluid's clear or you may need to bleed a little off. I swapped out my stock nonAC 20" '67 rad. with a '68 AC 24" wide 3+ row from NPD. The '68 one comes with the correct right upper/lower hose inlet/outlet and fits your rad. opening with the spacer plates removed. I fabbed my own side mounts out of alum. flat stock as I didn't want to buy the up/low mounts for the '68 and like the cleaner look of no upper mount. I also liked the look of the bare top tank once i stripped it for repaint so I polished/clear coated it.

Have you tested the rad. cooolant to see what the AF ratio is?

What material is the spacer under the carb? Phenolic, wood or alum?
Jon

 

[Rmoore45]

The compression test was a bust... the threaded insert on the rubber hose got stuck in the spark plug hole Took an hour to get it out. Compression on #1 cylinder was 155 psi.

So an hour after getting the thing unstuck, I thought that cant happen again...yep the insert stuck in #2 cylinder as well Took longer to get that one out as its harder to get to, I thought I might have to remove the headers. I'm NOT going to be using that compression tester anymore.

I finally got the engine running better, I swapped out carbs for another 600 Edelbrock, this one is a little newer and I think I got it tuned better.

Timing needed to be retarded, not advanced, I moved it to 6 degrees and it was running pretty good. I think that I need to adjust the vacuum advance a little bit.

65ShelbyClone -I'm unsure of what the exact mileage is on the rebuild but it cant be over 15,000 miles.

I will probably get a Pertronix ignition, but which one should I get? I'm thinking about saving up and just buying the ignitor III and a flamethrower coil.

I'm working on getting a new radiator atm. My dad is going to check the local radiator shops for pricing otherwise I will order the champion cooling systems from MU, its only $20 more than the 3 core brass/copper one they have.

I pulled the plugs and found carbon/oil deposits on #8 spark plug, so when I get a better compression tester I will definitely check that cylinder. I modified the PCV valve so that it will suck up all the excess blow by.

I think the spacer is wood, it keeps the carb from getting too hot. I can touch the carb whereas the intake will be HOT.

-Ranger

 

[Twistt]

wow nice

 

[2+2GT]

Gene, thanks for the advice.
Fstbk-the water pump is the correct one. I just have a radiator that isn't meant for cars with a/c.

Actually, everybody had that radiator in 67. 390 cars were equipped with a 23" radiator, but everybody else got the 20". If you had AC, they added a 20" fan shroud and upgraded the fan.

The compression test was a bust... the threaded insert on the rubber hose got stuck in the spark plug hole Took an hour to get it out. Compression on #1 cylinder was 155 psi.

So an hour after getting the thing unstuck, I thought that cant happen again...yep the insert stuck in #2 cylinder as well Took longer to get that one out as its harder to get to, I thought I might have to remove the headers. I'm NOT going to be using that compression tester anymore.

You need this one. The hose has a threaded steel tip, with o-ring steel. I've used one like it for years, never got stuck:

 

[Rmoore45]

My uncle brought over a good compression tester. While I'm here I'm trying to find the timing specs for this engine, I cant seem to find a straight answer. Can someone enlighten me? What is the initial timing for a 289 4v?

Thanks, Ranger

 

[2+2GT]

6° BTDC

 

[Rmoore45]

6° BTDC

Thanks. That's what I set it at.

Aaaaaaaannnnnnndddddd the verdict iiiiisssss: LOW COMPRESSION
Here are the results of the compression test (psi)
#1-155
#2-160
#3-170
#4-155
#5-195(for some reason)
#6-160
#7-160
#8-60

Well that would explain the excessive blow by. We poured a little oil down the cylinder and got up to 90psi but it stopped climbing after that. We also checked the valves to make sure that they were fully closed, and they were (or appeared to be). Is there anything else this could be besides a bad ring? Head gasket maybe? Bad valve?

Thanks, Ranger

 

[2+2GT]

That high one is probably carbon build-up. The low one came up 30 psi, just from squirting in a little oil. Broken ring, etc., is prob'ly what you'll find. Well, it could be the head gasket, as a long shot. Either way, it'll have to come off, then you'll know.

 

[Rmoore45]

Ok now that I know its a bad ring, what should I do? Is it possible to buy rings for just that cylinder and put them in without having to replace anything else(besides a head and intake gasket)? I'm thinking all I would need to buy is one set of rings and a head gasket.

 

[2+2GT]

Typically, rings come in engine sets, not individual piston sets. But then, prices start at like $25, so it's not a budget-buster. I'd be more concerned about the condition of the pistons, etc. Certainly, if you put new rings in one cylinder, you should do them all. Let's see what you have, first. Even new pistons would only run $80.

 

[robbz28]

This would be a great opportunity to see exactly what you are working with....mic your cylinders and check your crankshaft journals. Hopefully that broken ring didn't score your cylinder wall (if that's the problem). You can get entire lower rebuild kits for really reasonable prices. If you do the work yourself it shouldn't be an expensive fix (if the block is OK to use).