Thanks for the input.
I am now certain my overheat issues were caused by the very retarded timing and super slow curve.
The cooling issues just get better and better the more timing I put into this engine.

I will be tuning to run pump premium, non-oxy gas, so I can reliably get gas wherever I am driving rather than being limited to a driving range of 1/2 a fuel tank so I can get to my barrel of race fuel.

I am curious what others have found to be a good timing curve, especially in the 2,200-3,100 rpm range where I am cruising down the highway.

Good day everyone.
I am working on a 1967 427 street cobra and I am having a brain fart remembering the 427 timing marker meanings.
This engine has the calibrated tab/pointer with no indications on any portion of the balancer and just two indents on the outer lip of the single pulley.

I seem to remember the first mark is initial timing setting and the second mark is the total timing mark...but I am not certain. I checked my 1966 shop manual and it does not directly address this timing set up other than to mention setting it at 8 BTDC initial. The manual has images and directions for many 1966 options, just not this timing marker set up.

My main goal is I am trying to figure out a slow overheating issue and I am discovering things as I go.

The internals of this 427 are unknown to me, but I suspect it is 1967 stock with the exception of a Pertronix in the distributor.
It starts and runs well enough, idles fine with what sounds like a stockish cam, but it has a slight surge at steady cruise and eventually loses control of the coolant temps if the ambient temps are above 80*F. and the cruise speed are below 40 mph.

I was looking to see if the timing curve was bouncing at the lower cruise rpms, causing the surge. When I tried to verify timing I discovered the curve is quite slow, and not all in until about 4,400 rpm...which seems very high for this vehicle.

My theory is the carb is running a little bit lean causing the cruise surge (because the timing curve, although very slow, is very steady across the rpm range) and the timing is good at idle, but runs retarded through the 2,200-5,000 rpm range due to the slow, tight curve, thus causing the slow overheat condition.

Today I will verify TDC to see if the markers have slipped...which I kind of think they have, but I will verify.

Just to give some info about what I have verified.
The carb is a Holley LIST 3255 (C5AF-9510-BE) which was redone and looks perfect, but I have not verified any internals. I have only snugged up a few things to stop weeping fuel.
I have vacuum gauge tuned the idle screws, which are currently 1-1/4 turns out, and the engine likes it there.
I have played with the inital timing by finding the range between where the engine is hard to start (cranks hard when hot) and where it is lazy to start. Currently initial is set higher than stock and it is ever so slightly hard to crank when fully warm, but the total is 37* at 4,300 rpm.

I installed a 180* T-stat thinking the 160* that was in there may be holding open and not allowing the radiator enough time to cool effectively. This helped, but did not cure the heating issue.
I can see the waterpump is moving the coolant a good amount through the expansion tank.
All the cooling system components look to be in great condition and hould be up to this task with ease

Do I have the timing markers correct? (one is initial, the other is total?)
Am I on a good track to finding the overheat issue? (likely due to slow timing curve)
Any ideas are appreciated.
Thanks and have a great day.

I will be making a temporary tailpipe mounted O2 sensor holder and am wondering how deep into the end of the temp pipe does the sensor need to be?
1", 2", 3"? I don't know.

This sensor hook up will basically be a smaller section of pipe that slips inside of the existing tail pipe, with an O2 bung welded to it for mounting the O2 sensor.

How much extra pipe should I have to keep any unwanted air from screwing up what the sensor is reading?

Thank you for the replys so far.
I appreciate the perspective.

Today I encountered a situation and I would like your perspective please.
There is a business located about 5 miles from my house called MAPerfromance (Modern Automotive Performance)
https://www.maperformance.com/

They are listed as a distributor of Innovate Tech products and I am going to purchase a new LM2 Kit.
I had some work that had me driving by today so I stopped in to make a purchase...they have the LM2 listed as "in stock"....Great, I'll be using this tonight for some tuning.

I pull up, get out, and find the doors posted with all kinds of "not open for walk in businees due to COVID19" stuff.....
It just so happens two employees are pulling up as I am pulling on the doors...they must have been returning from lunch I would guess.

One of them asks what I want, nicely mind you, and I state I am here to purchase an Innovate LM2 Kit.
He goes into a speech about how they are not open to the public because of COVID restrictions and then explains how I can go home, call in on the phone, or go online and place my order, then come back and pick up my order at the rear shipping door.

I'll admit, this rubbed me the wrong way.
The COVID restrictions have been lifted a while ago around here.
The idea that you would tell a customer to go home, place an order, then return to pick up said order, seems stupid in my eyes...especially when said customer stated they were going to purchase items, not just look around.

I would like your take on this situation to help me form a better picture of what is happening...because at the moment I seem unable to form a nice result in my mind.
Thanks, and have a great day.

Do these cars have belly pans or such and are the alignment specs different or such ??

Was curious as my 65 F100 at 100 mph sounds like its bein beat by the wind  .. ya can feel it as well
Yes, most cars going over 150mph get fitted with some kind of air under the car mitigation system because the lift become quite noticeable.
Even a front air splitter makes a big difference because it keep a lot of air from going under the car.

I have had my 1966 Sunbeam Tiger up to a calculated 157...the speedo ends at a calibrated 140. At about 130 I notice a bit of lightness in the steering wheel but things feel pretty good.
At 140 the steering lightness becomes noticeable and is attention getting and the car starts to stand up a bit.
At 150 all of that is multiplied and all aspirations of calm and ease leave because you know you are past the limits of aerodynamic stability.
157 is all the faster I dared go on that run, and to be honest, if there was a hump/wave in the road I probably would have crashed in some manner.

This Tiger has no body modifications so there was a lot of undercar air pushing up, as well as air over the car lift going on.




Ricky.

A very nice, stock, 27,000 mile 1974 Bronco sold for $110,000 today on Bring a Trailer.

Didn't watch it back when, still don't.  Over glorified drama queens.  I get it, it's about what the directors want, but still.  I have no need for it.

I do watch a few channels on youtube, like 1320 Videos.  They actually go out to places and video more realistic "street racing".  They don't do "director installed drama".  Just talk to racers and show racing.   Much more down to earth true "reality".  Street Racing Channel is another I watch.  They are just south of me and show a lot of racing footage from them going to places and racing.  The shop I use built the motor for "Molly's" mustang.

Two of the Street outlaws came to local track a couple years ago.  I went down to watch some of the local buddies run in this circus show.  The two TV show cars just sat there all day on jackstands while the locals made test passes.  I did see one of the "drama cars" literally just drive down the track.  OH YEA....exciting.    It just proved that they will never get a 2000+ hp "pro mod" car down Magnolia drag strip!  I left before any of the actual racing started.

The fake drama is what really drives me away from this show.
For instance, the new format of "America's List" imposes all these convoluted "rules" about how you can be called out, or how you can call someone out.

They kept going on and on about how much trouble this will cause, how difficult it is to understand and navigate, and how the OKC guys know how to run the list giving them an advantage.....Really?
Your premise for racing drama is to build a specifically convoluted, hard to understand, set of rules regarding how you will get your next race?

What was is wrong and hard about asking the next guy in line for a race?

They even went so far as to have "JJ Da Boss" and "Preacious" run away from the track, into the woods, trying to hide from Mike Murillo's call out to JJ. The funny part is JJ and Precious literally fell into the construction ditch during this drama BS session.
While I do not like to see people get hurt, there is a bit of ironic justice to being honestly hurt while trying to play out fake drama.

I will say they did NOT have any of the fake, almost fight, BS drama last night...and for that I am very grateful.
This tough guy act, as begun with the Fast and the Furious, has really changed the street racing scene around here.

While there always seems to be at least one punchy person in the crowd, it was NOT the norm around here for a long, long time.
Plans are made for the place to race.
Make your way to the spot...shaking the trouble makers if you can.
Talk, BS, catch up, figure out the races...race, rinse, repeat.

Then The Fast and Furious movie came out and suddenly EVERYONE is a tough guy.
NOBODY races for anything less than $1,000...even in their 17.50 stock Civic with a fart can.
The endless bitching, bad mouthing, nonsense talk and posturing prior to ANY race.
The self important "racers" prancing and parading around as if they are the reason everyone is there tonight.....like Street Outlaws showcases most of the time.

As much as I did not like last nights show, for many detailed reasons, I was very happy to see they did not interject any of the fighty, tough guy, BS.

While this show has not been about pure street racing in a long, long time...or maybe even ever, in it's current guise it is really a sanctioned Pro Mod drag race taking place on a "street" only by the purest definition of the word street.
Pretty soon you will see sponsor logos on the road surface, the back of city street signs, and strategically placed billboards that just happen to be in the camera shot in the background.

Anyway, thanks for the replys so far.
I am not searching for any specific answer.
I just want to hear your reasons for liking, or disliking, the show.