Original, untouched 200 log head is off the block

Grandmas6

Grandmas6

Active member
Hi everyone,

I used to be on here a bit YEARS ago when I was talking about doing the Arning Drop. That turned out well.

Here's the background: I have a 1966 Mustang with an unmodified, all original 200. It's got 112,000 miles. Block has never been out of the car. Head has never been off of block. I drive it 2,000 miles a year, using valve lubrication additive. Lately, it's developed a miss when cold. Also, in removing the exhaust manifold to install an exhaust gasket, I broke off two bolts. I was doing well to only break off two exhaust bolts. :)

So I removed the head yesterday.

Here's the question: In addition to getting those broken bolts removed, what else do I need to do to the head so I can burn unleaded? What other easy and cheap things can I do to the head to lift performance a little bit?

Thanks a bunch. I know this answer is on here but the search function gives me way too much info.

Dave
 
I would say the easier ones would be to go with some higher ratio rockers and upgrade to a 2 bbl would wake things up a bit. Some argue whether or not hardened seats are necessary. If it's not driven excessively hard and the seats are in good shape you should be ok. But if you do get hardened seats installed you might as well go for the larger valves. Since the cam is still original the springs probably don't need to be upgraded so stock replacements are probably sufficient.

Other things to think about are a new timing chain, balancer, update the distributor (wires and plugs too), and advance the timing. If you pull the carb for a 2bbl, you'll need to replace the dizzy anyway. These are all the pieces of advice that I've been given on this forum wrt. an engine refresh that doesn't really touch the bottom end.

As far as the dizzy goes, I'm supposed to be getting my new HEI style distributor delivered today. Got it off of ebay from Riverside Performance. Otherwise I've been running a '70 distributor with Pertronix for the past 15 yrs without a hiccup but I think that upgrade won't be any cheaper than what I got my HEI setup for. I got the wires from Mike at ClassicInlines. CI also has some options on the adjustable valve train, depending on what your budget is.

I'm sure some other folks here with more experience have some additional/better advice as well.
 
I'm not sure on the guides. I suppose that if your existing valves are straight and the stems mic out evenly and are within tolerance to original spec, they should be perfectly fine. Maybe check the top and bottom of the guides for flaring but I've not heard of too many issues with them. Unless a valve got stuck at some point or run dry, I would expect the guides to be in working order.
 
Thanks! But they aren't subject to the degradation the seats are when running unleaded fuel? I had assumed they would be.
 
I had hardened valve seat inserts installed with my rebuilt engine. Original 'hardened seats' are flame hardened, no more than heat tempering of the head material.

And yes, the valve seats need to be hardened. A couple years ago, my son got a rebuilt 350 from ATK without hardened seats and the valve seats retreated maybe 3/16" in just a couple months.
 
You'll have to mill the head to compensate for the thicker replacement head gasket if you want to maintain the compression ratio.
The original metal head gasket was only 0.025 compressed, while the newer ones are up to 0.053 thick.
 
Dan,

I am sorry to hear that. Doesn't anybody sell the exact right head gasket? The one that was on there lasted until now.

Dave
 
The thinnest I've seen available new is 0.050". So you'll def want to shave the head in order to maintain CR. The amount will depend on how large the chambers are. Stock casting is supposed to be in the 51-53 cc range, according to the info I found on CI website.
 
Grandmas6":r3a9j9ti said:
Thanks! But they aren't subject to the degradation the seats are when running unleaded fuel? I had assumed they would be.
Click to expand...

I had two different early model heads wipeout the exhaust guides back when they changed over to unleaded only fuels. X2 I also believe the hardened exhaust seats are the main thing you would need to fix, but if your guides are loose replace them or use liners, your other choice would be to use a later model head that was designed for unleaded fuel. Good luck
 
The Victor Reinz is .045 compressed. While you're in there, I'd measure the deck height from the #1 piston @ TDC and cc your heads combustion chambers. Since you're going to have to mill anyway, you may as well bring the compression to 9:1 if need be.
 
I wouldn't rule out the possibillity of aquiring a late model head. I got mine for 150 at a pick n pull. Larger valves and hardened seats. Performance is wayy better than the stock head on the early sixes. That's only if your budget allows it though.
 
Been a long time since we last heard from you!

One of the things that can contribute to an intermittent miss at idle is the quality of the spark. Even a well tuned point triggered ignition will not be able to handle the uneven fuel distribution that's inherent to the log intake. I'd consider adding a Pertronix or a Duraspark or maybe even an MSD triggered from the points.

Since you have the head off, get hardened exhaust seats installed. Then for a little boost, have the head milled .050". That will make up for the gasket and bump the CR just a touch.
 
Jack,

That's the kind of advice I'm looking for! I just want to keep it running well and dependably without doing much to it. To tell you the truth, I bought another project car and really started in working on it. It's a 1978 Fiat X1/9. Might be heresy to mention something like that around here! However, it's a super-interesting car and a really clever design. It's rusty as hell, yes, but I said I wanted a project, didn't I? :)

Thanks for everybody's help.

Dave
 
Typically, the guys here like to build their own non-Ford scooters. Jack, for instance, and Frenchtown Flyer. They get a look they like and weld them up for fun. Jack's got a tube frame roadster and FTF is hand-forming a Duesenberg.

You could get an English wheel and a roll of steel. Who knows what might come out. Something like a Sunbeam, for instance.
 
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