Turbo Exhaust inlet manifold - part one

30th Nov 2007.
This was the first attempt , the second was no nearer. It was time to change the company i was using to make it. Stainless is obviously slippery to weld.

After getting a few quotes for the fabrication of this item I unfortunately went with the company that I thought would be the best and not based on cost of the manifold being made. This unfortunately was to be not a good idea as for the first time I had had something fabricated externally the company produced a piece of work which was unsatisfactory and not of good workmanship. As you can see from the picture the manifold was not vertical with the garret manifold not horizontal either. The second attempt when returning the manifold to the fist company produced not much better results. The manifold still placed the Garret about 20-25 degrees out and the horizontal measurement of the top of the garret flange did not read on my gauge. The Triangular flange had been skewed when it was welded to the pipe and was not horizontal with the tube. The finish was still no better.

Fortunately I am in the lucky position of having another company nearby Philcox's of Catsfield. Look them up on yell.co.uk, I am sure you'll be happy. They where more than happy to take the flange of from the inlet manifold and fabricate a new one that was going to be welded properly to the tubing. They also offered solution for the missing studs in the turbo flange they offered to weld in 10mm studs. I would need to return to pick up the manifold in two pieces to mark the upright position of the top flange.

I asked if I could have the triangular manifold cut of having to have it shortened by an inch and the 10mm studs inserted. When I asked if they would keep the old flange for me. I was asked if I wanted it for sentimental reasons, I said no , he asked if I was going to send it to the first company as a memento or a Christmas present. I conceded that it would make a novel Christmas present as a desk pen holder, LOL .

Garret Turbo Exhaust

14th November 2007
My Cosworth Turbo 2WD Stainless front section finally turned up much to the embarrassment of the postman trying to get this through the letter box to no avail.

I was very pleased with this item as I picked it up from eBay and to be honest this item was possibly the cheapest part I have purchased.

The exhaust I was planning would only need the front end of this exhaust section. When choosing your exhaust it is important to ensure that it comes from the car that the turbo came from. The reason for this is that the Garrett T3 unit comes with an assortment of different exhaust turbine sections to fit different exhaust.

I took the exhaust to a friends workshop to get it cut as cutting exhaust tubing to leave a square edge is notoriously difficult. My friend had a bench with a motorised hack saw that could hold the exhaust squarely in to cut it. I tried to use cleaning compounds to clean up the exhaust , but nothing seemed to budge the grime.

Luckily I had found a metal surface specialist company that would clean the exhaust with a glass bead blasting system, and would be able to then clean and polish the exhaust to a high luster. The results speak for themselves.

The turbo unit was nearly ready to go on the car. I only needed a few items left to get the lambda sensor, which was a V90HF9F472AA Cosworth Sapphire 4x4 Lambda Sensor these usually go for about £50 and I was hoping I could find one through an auction service cheaper. I would also need to purchase an induction kit for the turbo that would also required to be fitted with an air flow mass meter. Both of these senders would be needed for the Megasquirt ignition system that I still needed to source and build.

The next item that I needed to manufacture was the stainless steel section that would attach the Garret Turbo to my ceramic exhaust. I have been told this has to be stainless due to the high temperatures reached in the turbo. I had purchased a Turbo installation kit which contained studs and gaskets for the T3. I needed to locate the triangular 60mm gasket to join the exhaust. My plan was to make a u shape that would have to manifolds on each end. This would put the turbo up above and behind the exhaust in the same orientation that it came out of the Cosworth. I would need to find a company that would mill the flanges and be able to stainless steel weld them onto the manifolds. I had contacted one company and they had quoted me around £100.00 to build the adapter from scratch . The cost of this manufacture was high as the current stainless steel prices were very high making fabrication costs dear.

Christmas was coming at full speed and I was not sure whether I could spare this money before Christmas.

Turbo Spooling

11th November 2007.
After a mournful start to the day and a number of interesting thoughts conjured up by the bishop of our church , whilst visiting with my daughter who is in Rainbows. I ventured back to the garage.

I noticed that the actuator valve was not closing entirely and remembered reading an article on the Internet which suggested winding back the actuator arm turnbuckle five turns to obtain the best boost with the Collins actuator and to ensure that the valve was clamped shut. I had not yet managed to acquire the silicon hose to connect the actuator to the compressor housing nor had I managed to buy the correct turbo housing brass tail which was a T piece allowing a boost gauge to be fitted.

Whilst in the garage I decided to see if the Turbo would spool up If I held the turbo inlet to the exhaust. I wanted to see if the turbine would spool up before I released the funds to build the stainless exhaust to turbo manifold as this was going to be fabricated by a company that could fabricate, weld and mill stainless.

I started the engine and held the turbo flange against the exhaust flume. At tick over nothing moved. I reved the engine and watched to see if the compressor turbine spun up. It spun up very easily. I quickly removed the turbo from the exhaust flow as I had not plumbed the oil feed or the oil return to keep the bearings lubricated.

This was a major part of the testing for the turbo as I was unsure that the RS Cosworth T3 could be driven by the 1641 lump. I had intentionally chosen a small compressor to allow it to spool up at low reves.

The next phase was to have the stainless exhaust union made to allow the turbo unit to be bolted to the exhaust.

I had purchased a T piece for the oil supply from the pressure gauge output although I would have to get taps and dies to re-thread this to 10mm 1.0mm pitch as I had bought a T piece with 1/8 bsp on each thread.

I also had just purchased a stainless exhaust from a cosworth 4x4 that i was intending to shorten an re-bend to create a screamer type pipe with a park arrestor on it. I would have to receive the exhaust before I new for sure what size pipework it used as I was not sure if it was 2" or 3" pipe.

Christmas was approaching at great speed and I was going to concerate on my family christmas for the next couple of weeks or months.

Hopefully some of the new parts I have ordered would turn up and the exhaust manfold would be made and delivered.

Fitting a Collins Turbo Actuator

10th November 2007
Whilst acquiring bits for the turbo accessory bits i needed I acquired a Collins Group A -31 Actuator which was supposed to be compatible with my T3 Turbo which came from a Ford Cosworth lump.

I soon realised that my actuator had a straight arm. This was annoying, as my bracket that came with my turbo positioned the actuator too high and looked as if it required an arm with a bend in it. This was particularly odd as it was sold with a straight arm actuator fitted. I now believe the reason this worked before was that the compressor output on the side of the turbo must have been directed in another direction. Additionally you will notice that the actuator was second hand and someone has welded the nut onto the thread. This is supposed to be a locking nut so I could not imagine why this had been done. It was lucky I had a nut splitter. This made short work of the nut and it came off easily, otherwise I would have to locate a replacement.

I decided that as the turbo components where able to get very hot that I would use stainless steel sheet to make the bracket. Luckily I have a scrap merchant that i have used for some years who is happy to sell me scrap stainless steel. Firstly I removed one of the compressor securing plates and drew around it on a piece of card. I left a large area of card on the opposite side of this so that i could shape it into a bracket. I bolted on the card board and set the actuator where i wanted it to go. I bent the card back so that i could mark the position of the bolts that protrude from the actuator. This gave me a rough template for the compressor housing bolts and their relation to the actuator mountings. From this I was able to use the old bracket to transfer the other holes that the actuator uses.

I was then able to draw around the holes to make a bracket shape. This was the stuck onto the stainless with paper glue.The holes could then be drilled in the stainless where they where marked on the paper template. Drilling this required a very slow drill speed as it is easy to break,blunt or snap a drill bit when drilling stainless. I am pleased to say that my Starrett 3/4" hole saw and arbour drilled through the stainless also without any sign of problems.

The next job was to start cutting the the bracket out by cutting around the paper template. I used an angle grinder for this although a plasma cutter would have been faster. You must remember to keep the template wet otherwise it will burn from the heat of the cutting process.

Once the template had been roughly cut around I used a clamp and a large 4x4 post to clamp it to so that it could be worked on. The metal was soon removed from around the template by filing it away with a coarse metal work file. Once the bracket had been cleaned up it could be bent to shape. This required a large vice and a larger hammer. Bending metal always leaves small marks on the metal and I used a sanding disc in the angle grinder to clean them off. Warning Don't pick the bracket up after sanding, It gets very hot.

The bracket was fitted to the turbo to see if the angles to which the bracket had been bent where suitable for the actuator to fit and reach the waste gate crank without bending the arm in the actuator head. The first trial showed that the bracket was still about 10 degrees out.

Once the bracket had been re-bent it was fitted onto the turbo to check everything fitted OK. The sanding process leaves striation lines on the surface of the stainless. I used some copper saucepan base cleaner to remove this giving a better finish to the metal work.

The Actuator fitted onto the turbo quite nicely and when making the bracket I had made sure that the bracket would not foul anything else. Especially as the oil return was quite close to the bracket.

You can see in the picture above I have replaced the compressor bolts with Allen bolts and sealed the water unions with 18mm x1.5mm pitch Allen grub screws.

Garrett Turbo T3 assembly.

4th October 2007
When you buy a turbo unit second hand with the intention of using it for a project you are very lucky if you get one in good condition. Usually as we have already seen you have to purchase a tturbo repair kit and fit this to the turbo to make it functional. In addition to this there is also a large amount of extra componants that you need to put onto the unit to get it to function. This is something most suppliers neglect as they could normally assume that you are just replacing a unit with another. Normally you can bolt on your old fittings so this is not a problem. In my case I have to locate new parts: Lamda Sensor; Air Mass Flow Sensor; actuator and water union block off bolts.

Generally most of these componants are readily available and are easily found on eBay or similar auction house.

I located bolts to seal up the water unions after a days worth of surfing . Made from stainless these are quite an expensive item to purchase.

http://www.a2stainless.co.uk/M18-x-1-50-x-12mm-Pipe-Plug-DIN-908-A4-70_AICFP.aspx

INCORRECT "I also needed to aquire an 1/8^th inch connector with –4AN flange fitting to make up my oil feeds. "