Large Log Head Swap

Just_Fare

Active member
Recently I had a head swap done on my 1966 Fairlane. I got a mid 1970s large log done up at a local machine shop and had a competent mechanic install it with the original Autolite 1100 using an adaptor plate from Vintage Inlines. The engine runs well and has moderate performance improvements. However, it is pretty hard to get started for the first time each day and any time it sits for over 8 hours, like when I'm at work. It has to crank over quite a lot before firing to life. Before the head swap it started up instantly, every time. Any ideas on what might be the problem? I have a new fuel pump, fuel filter, spark plugs, wires, HEI distributor, all of which were installed before the head swap. I like to change one thing at a time to isolate changes.

Thanks for your input,

Chris
 
new fuel pump, fuel filter, spark plugs, wires, HEI distributor

New build and a new component may have crib death - sounds fuel related. Choke? - carb problem?

Start simple, when it's been sitting, remove the air cleaner and give it a squirt of fuel or starter fluid. IF it fires and dies, problem is related to the fuel system. (Use a small amount of fuel only to test).

haev fun
 
This may seem trivial...but how many pumps on the accelerator pedal do you give it before a cold start?
 
First thing I'd do is check the choke like powerband mentioned. I had similar problems with my Mustang that turned out to be the choke not working.
 
I have the same problem with my 65 200, rebuilt 1100 carb. I can not get it started unless I use starting fluid, it is ok for driving, let it sit for a few hours and starting fluid all over again. I am ready for a change, any one have good luck with the Chinese Carters, installing and tuning?
 
What is the compression with the new head ,is it lower or the same? It may want more initial timing.
Also thinking carb, choke.
Good luck.
 
That would be very frustrating.
So you used a later large log head and the same carb and still experienced a noticeable power increase? Ford should have figured that one out earlier!
 
Thanks for all the input. I just finished my primary employment for the season (I pack full time work hours into a 7 month season) so I can now set to sorting this all out.

It sounds and feels to me like a carb issue as it also doesn't go into fast idle right away either. Usually after it starts it takes about 25 seconds or so to get into fast idle. However, what's weird is the carb hasn't changed at all, I changed the cylinder head only.

I do fear that the compression might be low and I do plan to have that tested soon. I told the machine shop what needed to be done and sent them an email with a link to the archived Classic Inlines site on the topic. However, the head of the shop is a gruff man of few words and I never did find out for certain how much he actually had milled off. I hope not to have to get it re-milled, but I suppose that is a possibility.

I guess if it does have to be milled again that would be a good time to upgrade the cam, right? Or is it possible to replace the cam and timing chain without removing the head? Excuse my ignorance. I tend not to take things apart if I don't know if I can put them back together, especially on my daily driver.
 
Hi, as mentioned, it sounds like the choke is not fully closing. Can you check it your self?
When the engine is cold, remove the air cleaner and open the throttle all the way. The choke should snap closed. Press it with your finger and it should return to the closed position.
The adjustment is made by loosening the three small screws holding the choke thermostat spring, and gently turning the black housing. Sometimes the housing shows a rich and lean arrow. I would think you need the rich ( tighter) setting. Good luck
 
As to your question on changing out the cam if you needed to pull the head. Yes that would be the time to also change the cam, lifters, and timing chain. The way these small six'es are made its imposable to pull the lifters out to change out the cam with the head on. Also with the head off you could then CC your combustion chambers to verafy your real compression ratio. If you happen to have the use of a compression tester you chould check your cranking compression too before disassembly this can give you a rough idea of your compression ratio too. Good luck :nod:
 
It's been awhile for me to write back with an update on my cylinder head woes, sorry folks. Thanks for all the advice and encouragement. I'm fairly confident that my problems are due to the old carb on the car and was hoping to write back with a follow up when the carb was swapped for a rebuilt one. Things tend to take a long time to happen on the small island that I live on. The guy who is allegedly rebuilding my carb (rumoured to be the only person on the Island who still rebuilds carbs) has still not finished the job some 7 weeks later. Similarly the carb spacer I bought has yet to arrive. I still have faith in the our postal system. Sometimes they use one-legged mules and sometimes stuff gets held up at the border for ever it seems. I will be putting the Fairlane into winter storage in the next few days so no more work will be done until the spring.

In the meantime I still have the original small log from the car in my basement and was wondering if it's worth keeping at all. I have a friend who is a machinist who graduated college for her trade a few short years ago and is eager for a project. She could rebuild the head and convert it to 2V but I just don't know if she / I could recoup any value from it. I want to stick with my large log head and probably stay with 1V carb for this particular car. I don't know anyone near where I live who runs an inline 6 and likely anyone who does would either swap out for V8 or keep it stock, not bothering to mod it for performance or economy.

Hopefully some of you might have advice. Should I scrap the old head or pay for it to be machined? If I get it machined I don't know if I'll ever have any use for it and have doubts as to whether I could sell it. It doesn't feel right to scrap a potentially useful thing yet my basement already has to many projects and things lying about taking up space.

Thanks in advance,

Chris
 
2Bbl adapters on large log heads have been successful mods for project sixes without the direct mount conversion. Direct mount may be an optimal setup but don't discount the added options with a 2bbl adapter and large intake head.





It doesn't feel right to scrap a potentially useful thing yet my basement already has to many projects and things lying about taking up space.
... the continuing dilemma for most of us , I gave away an early log head but still have a few later stashed. thanks to E-Bay, CL, etc, the need for a large inventory of archaic parts is diminished, but for a few bucks - - I'd rather keep it ... -
my stuff is 'put away ' til warmer weather and even the shop is fairly cold right now and saved for have to work instead of should do . I try to spend on the things needed to drive the car, and mothball or pay forward the parts you don't need to go down the road.

have fun




 
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