New Intake Manifold - Painting and Clean-Up

Today I spent a little time cleaning up and preparing to install the intake manifold.  I'd go ahead and install it but I decided to use a Fel-Pro 1250S gaseket which is metal lined instead.  It will take a few days to get here but it is added insurance so that I don't have the same problem with the gasket as last time.

I painted the timing cover and water pump were the leaky thermostat housing discolored it over the past couple of years.  This took some time as I had to remove quite a bit and then use some strips of tape to cover bolts and pieces of plastic to protect everything from overspray.  The job took a bit but the engine looks good again.  

New Intake Manifold - Installation Discovery

I'm working a small amount on the intake installation in the evenings.  I work for a bit and then take a break for the evening as it is rather hot in the garage and I'm in no hurry to get the job done.  

While working on the car last night, I took a picture if the engine before removing the intake.  I've become familiar with seeing the blue intake on top from when I painted it years ago.  I expect it will look quite a bit better with the bare aluminum intake.  

Once I removed the intake, I found the gasket was in horrible condition.  There are two cylinders (#6 and #2) where the intake gasket cracked and caused very clear leaks to the top side of the motor.  There are several cylinders (#3, 5, 6, and 7) with leaks to the interior of the engine.  The intake slid over so that it actually blocked the ports on cylinder 6 and 7 to a degree. 

I'm quite shocked at the condition of the intake manifold.  The front two bolts felt a little lose when removing them but the rest did not seem too loose.  The center bolts were tight but they did not feel over torqued.  I'm not sure what caused this to occur and how long it has been this bad.

I'm a bit concerned about the situation as I purchased the same FelPro 1250 gasket for the new intake.  I remember installing the intake last time and I was incredibly meticulous about every task of installing the components as I wanted it perfect.  The following picture is from the install and shows the gasket adhesive, rtv around the intake ports, and everything looks perfect.  I can only assume bolts came loose over time or were not torqued properly and slowly the gasket deformed.

This explains the difficulty I have experienced when trying to tune the carburetor.  I would reject the carburetor and it would seem better but then be lean again over time.  This is concerning as I was likely making certain cylinders incredibly rich so the O2 reading averaged out properly while certain cylinders were very lean.

The second item this explains is the burning of oil.  I thought the engine was picking it up through the PCV valve.  I did not expect a leak between the lifter valley and intake to be the cause.  It is most certainly the main cause of the problem.

Lastly, I noticed before when performing a compression check that cylinder 3 and 7 had strange looking spark plugs.  I think those two were lean from breaks in the intake manifold.  Looking back at the pictures, cylinder 5 was also darker than the rest and that is likely from oil entering that cylinder because the gasket is all deformed. 

I'll be happy to get this job done and see how the engine runs.  I'm curious if I will notice any improvement in the performance.

New Intake Manifold - Edlebrock RPM Air Gap

There are numerous items which still need work on the Mustang.  One would think I would continue to work on untouched areas to finish up the restoration.  Instead, I replace gears I installed a short time ago and am now going to replace a perfectly good intake.

The existing intake is a Weiand Stealth (#8020WND) which I installed in 2009 with my Holley Street Avenger carburetor.  While there are no issues with the intake, I'd like to switch over to an Edelbrock RPM Air Gap intake.  I don't expect much if any improvement in performance but want to switch for appearance reasons and to have the carburetor run a little cooler.

On Sunday evening, I purchased an Edelbrock RPM Air Gap intake (#7521), Scott Drake aluminum thermostat housing (#SDK-C5OE-8592-A), a set of FelPro intake gaskets (#1250), and a FelPro 35067 thermostat gasket.  In normal fashion, Summit sent them to me in record time.

I drove the car this evening to take a picture with my son and the 2006 Mustang he just purchased.  I've been wanting to take the picture with him since we purchased it about three weeks ago and just now found the opportunity.  Now I can pull the intake and swap it without worrying about taking the car out of commission for a few days or longer if I choose.

Rear Gear Ratio Upgrade - Part Two

The shop installed the new set of Motive 3.80 gears in my differential in just a few hours.  The gear pattern paint looks good from my limited experience of having one other gear set done.

My schedule has been very busy lately so the assembled carrier on the garage floor for a few weeks before I installed it this weekend.  I cleaned it some and put a few light coats of the original paint back on the carrier to cover some scratches left from the machine shop.

The carrier is very heavy and it took a few times of lifting it before I was able to get it up and into place with the exhaust still installed.  I used a new Fel-Pro gasket with a light layer of RTV.  Additionally, I used a new set of copper washers and locking nuts.  I was not as meticulous as in the past with cleaning up everything after the install (brakes, driveshaft, etc) but the job is done.

I sold the old set of 3.25 gears on eBay which paid for the installation of the new gears.  No reason the have the 3.25 laying around as I do not expect to switch back.

Rear Gear Ratio Upgrade - Part One

In June, I purchased a Motive 3.80 rear gear set which has been waiting on my workbench for months now.  Randomly, I decided today would be the day I start the installation process. 

I decided to tackle the project now as I have a few hours in the morning tomorrow before I need to catch a flight for work.  It is one of the few weekdays in which I have time to drive over to drop off the parts for installation.  Additionally, I'll make it back from the trip just early enough on Wednesday to pick up the parts during the work day.  In that regard, the timing is really good.

The task of removing the rear carrier is not very hard and does not take a great deal of time.  However, it is a rather messy job and don't particularly like the smell of rear gear oil.  I made quick work of it and within an hour or so had the carrier laying on the garage floor.

The new gears are part number F880380.  I also purchased a new Fel-Pro gasket for the carrier.  I did not buy new bearings as the ones which are in the carrier were just installed with the 3.25 gears not long ago.  I'm going back to the same shop so I hope they don't give me any trouble.  I doubt they will as they wouldn't warranty the work as it was done using my parts and I expect this time will be no different.