General Help

[Anonymous]

Hello, I am new to Mustang's in general but I have a 66 Fastback with the 200 in it. I just finished taking off the head today so that I can redrill and thread the exhaust manifold bolt holes and also weld in the port divider. The car currently idles very rough but gets better as I accelerate. Cylider one seems like it is barely ever firing even with new plugs wires, distributor stuff. I can tell because the I can pull the wire and it has pretty much no effect on the engine running. Is this simply because of how horrible the fuel/air distribution is? or something else? What else can I do that would cost very little while I have the head off to help? Also I noticed the pushrod on the exhaust port is worn on the upper ball about 1/2 a mm or so because it seems the oiling hole was plugged (there is a little raised strip where the groove is). Could this cause a problem? Thanks for any help

 

[addo]

Wear on a specific part of the valvetrain is never good. The rough running is not to do with the design of your intake manifold; it's a function of either compression or valve operation.

The front cylinder wears the most, as it tends to run coolest. People who run without a thermostat, exacerbate this problem. Inspect the bore for signs of a lip or ridge near the top. Can you still see cross-hatching marks from bore honing?

Have a good look at the head itself for signs of valve recession into the chamber roof. If it's the original head there won't be any hardened seats. If everything looks OK check the seats, too. It's a good time to put new valve stem seals on - at less than a dollar each you can't gripe about cost.

Also while you're head off, check the markings for TDC on the balancer; if necessary make a new balancer mark.

Valve operation may be compromised by cam wear. The only real way to test this is dialling the cam lift for each lobe, to compare.

The final comments are more of a general flag - identify the head's year of manufacture and see if you can calculate the CC's. It may still need a light cut for the modern-style gaskets.

Regards, Adam.

 

[Anonymous]

So should I replace this pushrod? If so do I need to replace all of them?

 

[turbocharged66stang]

yes replace any damaged push rods and like addo said the head could be the problem i would have it looked at and if it needs repaired the put harden seats in it.

 

[JackFish]

Don't forget about the gasket "gotcha". Are you going to re-use the original steel shim head gasket, or a new composite?
The head should be milled to compensate for the extra thickness of the thicker gasket, or you will lose some compression.
Grind the valve guide bosses?
Install SI stainles steel valves @ 1.75in/1.50ex.

 

[CZLN6]

Howdy SLRacer:

And welcome to the inline adventure Forum.

The wear you indicated for the #1 cylinder exhaust pushrod indicates a lack of oil through the rocker shaft, and/or the oil holes in the rocker arm itself. You will need to replace any pushrods that do not have a round, shiney surface. There were some topics about a month ago about this very thing. Try doing a search.

As Adam pointed out, the #1 cylinder frequently shows the most wear because of its proximity to the water pump and fan. It is also the last cylinder to get oil to the valve train, on start up, and frequently the 1st rockers to plug up and stop oiling all together.

Basically, you will need to disassemble the rocker system to thoroughly clean the inside of the rocker shaft and the oil holes on each rocker arms. This is a cheap, but very necessary- messy job. A 3/32" drill bit will facilitate cleaning out the oil holes on each rocker arm.

I understand the need for economy (Necessity of poverity) but an investment in a quality valve job is one of the best performance values you will find. It should include a three angle valve job, back-cutting the intake valves, milling to true or to compensate for a modern composite head gasket. Along with installing the exhaust port divider you might wnat to consider boring the carb hole out to the later 1.75" diameter. This will depend on what your future plans are for intake upgrades.

Hardened valve seat inserts may be a necessary expense depending on your driving expectations for this engine.

The new valve stem seals, recommended by Adam, will be included in a valve job gasket set.

Enjoy the journey.

Adios, David

 

[Anonymous]

I also had to have the car running very rich in order to make it actually idle, and a rough idle at that. Would this suggest anything else I should look for with the head off?

 

[JackFish]

How's the carb? Does it need a rebuild?

 

[Anonymous]

I think it's fine. Im not too knowledgeable about carbs , what should I check to see if it is fine.

 

[JackFish]

PostPosted: Fri Sep 16, 2005 9:59 am Post subject: Reply with quote
Quote:
I went to the junkyard and bought duplicate carb for $15 and worked on that.

This is the best advice you'll ever get. Fool with the carb, push and pull the levers and screws and all. Watch what closes and what flaps open, how the pump works, where the float and the jets are. When you have a thorough understanding of how the thing works, then you can rebuild it and adjust it in place because now you know what everything is before you take a screwdriver to it AND you have something to comepare it to.

I would think it safe to assume it's got some gunk and crud (technical terms!) buildup, if it's never been done to your knowledge.
A few searches on this site will turn up lots of excellent info.
Here's a thread:
http://fordsix.com/forum/viewtopic.php? ... rb+rebuild