1970 GTO V3

[andrewb70]

Today I had the opportunity to go work i the garage. I decided to tackle the intake manifold assembly and final installation.

The first step was to install the o-ring that seals the base with the intercooler. It is a single viton string that gets inserted into the machined groove, the ends are butted together, trimmed flush, and the a drop of super glue is used to hold it together.



The intercooler is bolted into place.



Followed by the lid.



I also installed the all of the fuel injectors and rails. I used the rail brackets that came with the intake manifold, but I replaced all the hardware with ARP stainless fasters. I really like this combination of black and silver against the bronze intake manifold.



I took the masking take off the heads and cleaned everything with acetone.



Then I installed the intake manifold assembly on the engine. The intake manifold has o-rings that seal it against the heads. I also lubricated the mating surface so the intake can easily slide around and find a happy spot as it is being torqued down.



I used these stainless p-clamps for the oil feed line, again with the ARP bolts. Vic added these holes to the intake manifold months ago.



Here is a broader view that shows all the details of the stainless hardware, with black, against the bronze intake, with a pop of red on the valve covers to keep it interesting.



Slowly, but surely...

Andrew

[syborg tt]

Dang does that look nice.

Looking forward to more posts

[andrewb70]

Progress has stalled a bit on the GTO, although I managed to take an interesting and useful detour. I was working with a local customer a couple of weeks ago and I noticed that his 5.4L Mustang GT500 engine had a very interesting looking sensor on the fuel rail. After some digging around I figured out that it is Bosch 0 261 230 093. What caught my eye is that one side of the sensor was in the rail while the other side had a vacuum nipple on it.

As I suspected this is a differential pressure (Delta P) sensor. It outputs the difference between rail pressure and manifold pressure (positive or negative).

You may wonder why we should care. I am glad you asked, because differential fuel pressure is actually what we really care about, not rail pressure. Another way to think of the differential pressure is the pressure across the injector discharge. Let's do an example:

Let's say you have a fuel system that is set to 60psi at the rail and there is no vacuum or boost reference on the regulator, or the regulator is not adjustable. This is a fairly common scenario with a LS swap, simple in-tank pump, and a Corvette style regulator. Let's also say that you have a moderate performance cam and the engine idle around 50kPa, which is about 15in/Hg, which is also about -7psi. Note that the units are all different, but they are describing the same thing, which is the amount of vacuum in the intake manifold when the engine is running.

In this scenario the rail pressure doesn't change, but what happens to the pressure across the injector discharge when the engine is running? Because of the vacuum that is generated by the engine, the differential pressure across the injectors is actually 67psi. In other words, the injectors act as if they flowed more. That is exactly what this sensor will read, because it measures differential pressure directly.

Consider a different scenario. Turbocharged engine, adjustable regulator with a vacuum line hooked up to it. Let's assume the same base pressure of 60psi. When the engine is running under the same conditions, a normal pressure sensor would show 53psi at the rail, but this sensor will still read true differential pressure, which in this case is 60psi. Take the same scenario under boost. Engine is making 10psi, rail pressure sensor will be reading 70psi, and this sensor will still read 60psi. The purpose of having a vacuum/boost referenced fuel system is in fact to maintain consistent differential fuel pressure.

This is a fun topic and if anyone has any questions, please post them.

Here is sensor mount that Vic machined.











It attaches right to the back of the rail with the AN-6 female to female union.



The eagle eyed will notice that it is mounted to the Cougar. I am using the Cougar to do the testing for the sensor.

Andrew

[andrewb70]

Progress on the GTO is a little slow, but moving along. I need to thank my friends at The DriveShaft Shop for making me a bullet proof, dual CV, carbon fiber driveshaft.



Here you can see the details of the 108mm non plunging CV and the carbon fiber tube.



This is their new design 8 bolt non-plunging CV. These are used on the Nissan GTR 2500+hp driveshafts. Good enough for this pile...



Here you can see how it fits between the exhaust. There is plenty of clearance, so heat should not be a concern. Besides, there is a constant stream of air passing under the car while it is moving, which cools the exhaust.



Plenty of stick-out for any little movement from the rear end articulation and deflection.



Andrew

[waynieZ]

It looks good Andrew! The intake look good on there.

[syborg tt]

Some very nice progress and I love reading your post as I feel like I’m back in school.

However, this time I’m really excited about going to class.


Sent from my iPhone using Taptalk

[ProTouring442]

Originally Posted by andrewb70

Progress on the GTO is a little slow, but moving along. I need to thank my friends at The DriveShaft Shop for making me a bullet proof, dual CV, carbon fiber driveshaft.

This is their new design 8 bolt non-plunging CV. These are used on the Nissan GTR 2500+hp driveshafts. Good enough for this pile...

Here you can see how it fits between the exhaust. There is plenty of clearance, so heat should not be a concern. Besides, there is a constant stream of air passing under the car while it is moving, which cools the exhaust.

Plenty of stick-out for any little movement from the rear end articulation and deflection.

Andrew

Hopefully you have better luck with The Driveshaft Shop than we did.

[cpd004]

Originally Posted by ProTouring442

Hopefully you have better luck with The Driveshaft Shop than we did.

Failure? What type of shaft did you use?

[ProTouring442]

Originally Posted by cpd004

Failure? What type of shaft did you use?

Poor customer service. Huge lead time, then they made the driveshaft too long. After that, they then refused to do anything to expedite the replacement shaft (the error was on their part). Gave me tons of attitude.

[andrewb70]

Originally Posted by ProTouring442

Hopefully you have better luck with The Driveshaft Shop than we did.

I have been using their products for over 10 years on numerous projects.

Andrew