Sunday, February 20, 2022

A Quick List of Projects

Quite a bit of time has passed since I've done any work to the Mustang or driven it for that matter.  I checked into the price to paint the Mustang at a local, high end restoration shop and was told $20-$25k.  The wait to even start was 1.5 years.  This was not the best news and I've been debating what to do with the car since.  It is more than I expected and I'm not really sure if it is worth it.  I tell my self that the paint and exterior condition is why I don't drive it but I'm not so certain.  

There are a few small annoyances that I want to fix on the car.  They are things I have put off for a while and should be done if I decide to paint it or not.  These include:

1) Transmission Leak - The transmission leaks a fair amount.  I believe it leaks from the drain plug because I did not put any sealant on it.  That said, I think I will also replace the tail shaft seal with a new one while on the fluid is drained out.

2) Master Cylinder Leak - The master cylinder is a Raybestos for a 1974 Maverick because it fits and has a 15/16" bore.  The problem is the lid leaks and I don't see a way to fix it.  The leak strips all the paint off the steering column inside the engine bay and perhaps more.  I need a good master cylinder.

3) Parking Brake - The parking brake stopped working quite some time ago.  I believe there is something wrong with the pulley or wire connection inside the car that activates the rest of the system under the car.  It stopped working and I've not even looked so I'll need to start there.

4) Rattles - There are many rattles on the car including the rear bumper for starters.  I'd like to make the rattles go away so that it does not sound like a box of bolts rolling down the road.

5) Windshield Leak - I still have not addressed this since the road trip a few years ago.  I questioned waiting for the paint job but with a 1.5 year wait for paint, I might as well do it if I'm going to drive it anywhere.

6) Rear Suspension - The rear leaf springs are just too stiff.  I hate to just go buying more leaf springs but don't believe there is another way to fix it.  I'm going to need to think on this one a bit more before buying anything but I need a solution.

7) Clutch Squeak - The clutch spring squeaks and makes noise when the clutch pedal is pressed.  I'm not sure I need the spring anymore.  I'm going to look into it and might convert to a roller bearing bushing on the clutch and brake pedal assembly.

Saturday, February 12, 2022

Considering Compression Ratios

I continue to consider different ways of making the Mustang faster.  The challenge is that any performance improvement at this point involves replacing a relatively new part I installed with something better.  The gains are smaller without considering a larger engine.

If I went to a larger engine like a 347 or 363, I would need different heads that would work with a roller camshaft.  Bigger heads would have some form of improvement now so they would work for either option.  While I don't know that they offer a great deal of improvement in my current setup, I'm considering it and wanted to collect all the details I have on what different heads would do to my current compression ratio and if I switched to a larger engine later.

Looking through my original posts, I found the following detail on the original engine configuration.  If I plug it into an online calculator, the compression ratio is only 8.13 which does not seem right compared to the stock specs published online (9:1+):
    Cylinder Size: 4.040 x 2.87
    Deck Height: 7.365cc (.035" In Bore x 4.040 Bore))
    Gasket: 10.16cc (.047 x 4.10" Bore) (Fel-Pro 8548PT-2)
    Piston: 12cc Dish (Keith Black Silv-O-Lite 1157)
    CR 8.13 (w 55cc heads)

If I calculate where I am after the rebuild, the compression ratio is at 8.86 which is rather low.  I thought it was a little over 9:1 for some reason but don't see where my measurements are off.

    Cylinder Size: 4.040 x 2.87
    Deck Height: 0 (Zero Decked)
    Gasket: 10.16cc (.047 x 4.10" Bore) (Fel-Pro 9333PT1)
    Piston: 6.5cc (Keith Black KB115)
    CR 8.864 (w 60cc heads)    

The Summit website states that the compression ratio of the Dart 347 small block is 10:1 with a 58cc head.  The Summit site does not include a compression ratio spec for the Dart 363 but it does indicate the pistions are Mahl 93024485 with a 6.5 cc dish which would put the compression ratio at 10.7:1 with a 60cc head and 11:1 with a 58 cc head.  

The FelPro 10112 head gasket which compresses to .039.  The cc of the current FelPro 933PT1 is 10.169cc and the 10112 is 8.438 cc.  This has almost the same effect as dropping the head cc to 58.  This still only puts me at a 9.045:1 with the current setup.

If I use the FelPro 10112 and start to mill the head, I see the following impacts on the current setup:
58 cc = 9.266:1
56 cc = 9.5:1

According to a MotorTrend article I read, a change in 1 compression ratio is about a 3% change in power.  https://www.motortrend.com/news/0311em-power-squeeze/

My thought is that this really isn't worth the trouble.  I don't think the head would flow that much better and the compression ratio benefit is minimal.  The real difference is that I could have more than .550 lift and would be able to rev beyond 5500 rpm.