Garrett GT20 Project

[Grant]

I wouldn't have said that template was particularly accurate. Don't forget when working with anything exhaust related you want to work to as smaller tolerances as possible to avoid leaks. Do you not have a scalpel or similar you can use to cut the holes out? It looks as if you have jabbed holes with a pencil.

[306Puggy]

No I don't have a scalpel, but I had an attempt with a stanley blade:

It is a lot better but I can't get the bits of fluff off. I tried using the drill bit to clean them off which worked a bit but not a lot. It is difficult to gauge for me whether this template is accurate enough or not, what do you think?

[Grant]

That looks considerably better. See how you can now clearly see the circumference of the holes, so you have a better chance of drilling them in the right places?
Crack on with that, it looks to be a good template.

---

Havn't been asked to go on strike lately have you by any chance?

[Dave]

Looking good, for that sort of stuff, you can always make your holes slightly bigger so you have abit of tolerance incase your hole spacing isn't entirely accurate (which it wont be if your using from cardboard templates). I might have missed this in the thread previously, but what are you going to do about the actutor and clocking the compressor?, 'cos this is gonna be a major issue even for someone with a welder, a bracket will need to be made, and fitted so it doesnt foul, and where your actuator will then sit, is exactly where your turbo outlet for your intercooler is. You could possibly bend the actuator rod and have it behind the compressor which would work, and then get someone to just simply tack it in place on something steel, this would be the option I would go for.

[306Puggy]

That looks considerably better. See how you can now clearly see the circumference of the holes, so you have a better chance of drilling them in the right places?
Crack on with that, it looks to be a good template.

---

Havn't been asked to go on strike lately have you by any chance?

Thanks for the input. Yeah, I can definitely see how this will allow me to outline the holes more accurately.

Not sure what you mean regarding going on strike? As in, banned from the forum? Or are you making a joke about my project that I don't get? Sorry but it has fallen flat if so

But yeah, thanks for suggesting to use something sharp to cut the holes out I don't think of these obvious things most of the time!

Looking good, for that sort of stuff, you can always make your holes slightly bigger so you have abit of tolerance incase your hole spacing isn't entirely accurate (which it wont be if your using from cardboard templates). I might have missed this in the thread previously, but what are you going to do about the actutor and clocking the compressor?, 'cos this is gonna be a major issue even for someone with a welder, a bracket will need to be made, and fitted so it doesnt foul, and where your actuator will then sit, is exactly where your turbo outlet for your intercooler is. You could possibly bend the actuator rod and have it behind the compressor which would work, and then get someone to just simply tack it in place on something steel, this would be the option I would go for.

You mention that cardboard templates aren't that accurate, what other methods are there? That someone with limited tools/budget can do ofcourse. And regarding making the holes bigger, I am glad you said that because I was wondering if that would cause a problem if they were slightly bigger but I guess not since you have said it's okay

Was clocking the compressor part of the problem you are mentioning? I found a clocking video on Youtube, the guy said it is a really easy part of the setup. I could take the actuator off and clock the compressor housing with the actuator out of the way, if the actuator's position causes an issue.

I have no idea what to do about the actuator's location I just realised today actually that it is on the front of this unit and the 306 standard turbos have them on the bottom. If you say a given method is the best then that is what I will do, hopefully once I get this together I can then sort the actuator. Luckily I found somewhere a couple years ago that will actually weld (seems to be rare at garages these days).

Right, the next step is going to be to start drilling holes. I have read several methods and I'm not sure which one to use:

method 1: Use a punch to mark the centre of the hole by eye and then use the drill bit that you want for the size of the hole straight off.

method 2: Use a small drill bit to start with and then work up through sizes without using a punch to mark the center of the hole.

method 3: Use a tap to mark the centre of the hole, drill a pilot hole with a small drill but then use the full sized drill bit you want to for the hole.

Method 1 seems to make the most sense to me, I can't see why I would need to do the other bits for this sort of thing. But feel free to correct me.

Also I am going to have to get the adapter plate cut slightly at the top because the turbo actuator arm coupling catches on it which means I can't lay the turbo flat on the plate at the moment. Will a hack saw cut mild steel? Or is that a dumb question?

[cwspellowe]

Just to clear up the misinformation, ive bolted my gt2056 directly to the manifold, and used a 10mm adapter plate with a tight radius 90 degree 2.5'' elbow..

[306Puggy]

I think it must have been ricky who used the 6mm adapter plate then. Also, how straight does the template have to be? I have done it by eye and it looks straight, but is there a way to measure it? I don't want to drill the holes and then find when I come to bolt up the turbo that it is on the piss.

[cwspellowe]

Well.. if you're using an 8.5mm drill bit, you have to be within 0.5mm tolerance for the bolt holes lining up.

Stick the steel on the flange and mark the steel itself, no need for the cardboard as it's asking for a sloppy fit.

[Poodle]

Use the cardboard as your template, so score round it onto the steel and mark out where the holes should be. Centre punch and drill one hole (if I was you i'd start with the one that'd be most innaccesible when it is bolted up), bolt that up and align the rest of the marked area as best you can. Now make any adjustments required to the marked area, centre punch the other two holes and unbolt it again. Now you can drill the other two holes and know it will all line up.

[Stephen]

Do you work for aldi or something?

[samass]

What i did was drill one hole roughly in the right are on the plate, then bolt the turbo down to it, and clamp it down really tight so it won't move. Then I used a drill bit that was a tight fit in the holes to make my centre marks for the other holes, removes the turbo and finished drilling the holes. Do one at a time tho, and then bolt two down, clamp and mark, and then drill the final hole, that way, you shouldn't be able to cock it up

[Grant]

That looks considerably better. See how you can now clearly see the circumference of the holes, so you have a better chance of drilling them in the right places?
Crack on with that, it looks to be a good template.

---

Havn't been asked to go on strike lately have you by any chance?

Thanks for the input. Yeah, I can definitely see how this will allow me to outline the holes more accurately.

Not sure what you mean regarding going on strike? As in, banned from the forum? Or are you making a joke about my project that I don't get? Sorry but it has fallen flat if so

But yeah, thanks for suggesting to use something sharp to cut the holes out I don't think of these obvious things most of the time!

I noticed your CWU letter in the background that is all. It says 'VOTE', and as I have been presented with the fact that I may be going on strike soon, I was wondering if we were in the same line of business.

[Dum-Dum]

What samass said at the top of the page sounds like a good idea.

Im worried that 6mm might not be thick enough and it definitely dosent give you the option to countersink holes.

8.5mm is the hole size you'd want for 8mm to give some room for error/expansion.

I'll write a better reply when im back in civilisation.

[306Puggy]

That looks considerably better. See how you can now clearly see the circumference of the holes, so you have a better chance of drilling them in the right places?
Crack on with that, it looks to be a good template.

---

Havn't been asked to go on strike lately have you by any chance?

Thanks for the input. Yeah, I can definitely see how this will allow me to outline the holes more accurately.

Not sure what you mean regarding going on strike? As in, banned from the forum? Or are you making a joke about my project that I don't get? Sorry but it has fallen flat if so

But yeah, thanks for suggesting to use something sharp to cut the holes out I don't think of these obvious things most of the time!

I noticed your CWU letter in the background that is all. It says 'VOTE', and as I have been presented with the fact that I may be going on strike soon, I was wondering if we were in the same line of business.

Oh, no, heh. I'm only on a 5 hour 3 month contract but I have been working full time due to overtime recently, no way I'm gonna go on strike! The only reason I have been able to undertake this project is because of that job!

What i did was drill one hole roughly in the right are on the plate, then bolt the turbo down to it, and clamp it down really tight so it won't move. Then I used a drill bit that was a tight fit in the holes to make my centre marks for the other holes, removes the turbo and finished drilling the holes. Do one at a time tho, and then bolt two down, clamp and mark, and then drill the final hole, that way, you shouldn't be able to cock it up

Oh I get you I think. So you use a drill bit that is a tight fit in the hole so that it doesn't leave any room for movement and then tap it with a hammer like a punch to mark out the hole? Really good idea! That way it will be bang on in the center.

And then doing it one by one means that you can check as you go along because you are bolting it down as you go. Yeah, that makes sense.

This arm for the wastegate is stopping me from laying the turbocharger down completely straight:




I will have to get the steel plate cut down by someone to accomodate the wastegate arm, unless I can cut it with a hacksaw? It's only a few CM off the top of the plate that needs removing.

What samass said at the top of the page sounds like a good idea.

Im worried that 6mm might not be thick enough and it definitely dosent give you the option to countersink holes.

8.5mm is the hole size you'd want for 8mm to give some room for error/expansion.

I'll write a better reply when im back in civilisation.

Yes, I certainly don't have the option to countersink any holes. I don't know whether it will cause any issues except for that though. Hurry up and get back to civilisation please

One thing I can get on with now is plotting the manifold holes on the other side of the adapter plate. I have thought of a more accurate method. I am gonna lay the manifold on the plate and then use spray primer to spray through the bolt holes which should give me perfect circular marks for where I need to drill and then I can use Samass's method to mark out the center through the manifold holes as well. Then I just need to wait until my 10mm drill bit gets here!

[Stephen]

You could cut it with a hacksaw, would probably take about 20 days though

[306Puggy]

Heh, yes, as I have found this morning!



Half an hour of constant sawing later, it was done:



I can now lay the turbo flange flat on the plate without the actuator arm catching on the top. I may have to take slightly more off to allow the arm to move but for now I am happy that I can plot the holes for drilling.

Just one last thing before drilling that I need (apart from waiting for my drill bits to arrive) I need to know what sized hole I should be cutting in the adapter plate because the manifold hole is bigger than the turbo flange hole.

And, also, how should I make sure the hole is gonna line up with the hole on the flange? Or should I drill the main hole for the manifold or exhaust flange and then line up the other side respective to that? Thanks.

[samass]

Don't use the drill bit as a centre punch, it'll ruin the bit. Put it in a drill and start to drill a bit of a hole to make a small divit to then drill the hole all the way through

[306Puggy]

Oh yeah, that sounds easy enough. Thanks for clarifying that! Just gotta wait for my drill bits to turn up tommorrow or tuesday! Planning to drill the manifold holes and hole and then plot the exhaust flange holes on the opposite side in relation to that.

[306Puggy]

Just looking at the manifold and adapter plate now, I think the only option for the turbo flange to adapter plate bolts is to tap the holes for the turbo flange in the adapter plate and then drill holes (and possibly tap) in the manifold to give the rest of the thread of the bolts room to go through. All together that would give me about 20mm of threaded hole for the turbo flange bolts assuming I leave 1mm to stop going through into the actual manifold area. And this turbo does feel hefty and the bolts are not very big

Ideally I should get a thicker plate and get some countersink bolts but I don't want to waste this adapter plate that I have got ready. The main question is then, would 20mm of thread be enough to hold the turbo on with 3 bolts?

Edit: Just found this thread:
http://306oc.co.uk/forum/thread-2611.htm...er%2Bplate

Ruan says that 6mm plate should be okay to countersink bolts in. So now it is a question of which is better? Trying to countersink the bolts or drilling and threading?

Edit: Just realised I won't be able to countersink the bolts and then do them up! If the bolt head is going to be against the manifold mating surface, how am I gonna get an allen key/torx bit into the bolt head!? I won't be able to, that's how! Back to the original plan then. Actually I could get them welded and then they would be studs. Yeah, that sounds like the best solution.

[Dum-Dum]

You can buy allen or torx head bolts / set screws. Screw fix and halfords do them.

[306Puggy]

Yeah but I won't be able to get to the head of the bolt you see. So getting them made into studs is the only option.

[306Puggy]

Right, mammoth update, made some good progress today and taken a lot of photos! Was a bit nervous with the drill to begin with, my hands were shaking after making the first hole! And it certainly wasn't easy either. I had been trying with the holesaw for half an hour before I realised the drill was on reverse! I just assumed it was "rightly tightly, lefty loosely" like with screws but I guess not.

Once over the beginner errors I was able to make some progress. I decided I would drill the main exhaust hole in the adapter plate first and then plot the bolt holes in relation to that so that it would line up well. I had marked out a rough circle (using spray primer through a rough template of the mani mating surface) but I needed to find the center of it to begin drilling in the right place.

A quick Google search (actually it was a comment on a Youtube video of a less good way) revealed this nifty way:

Draw a square around the circle that is the same width and height and then draw two lines diagonally from one corner of the square to the other. Where the two lines crossover is the center of the circle. Below you can see the method in use:





If you look closely you can just about make out the scoring of a square, the diagonal lines are easier to see.

After half an hour of drilling with the drill in reverse and wondering why it wouldn't go through, I switched the drill to the forward setting and not soon after the arbor bit got through the metal and the holesaw started to bite, the arbor's bit snapped! Causing me to momentarily lose control of the drill and the holesaw to make this lovely pattern in the plate:



Luckily, there was enough of a groove in the metal for me to carry on with the holesaw without the guidance of the arbor bit digging into the metal.

Thought "right, that's going back to B&Q"!:



Sorry about the picture quality.

Once the hole was done I lined it up with the exhaust manifold and clamped the manifold to the plate:



Then with the manifold clamped to the metal plate I clamped the mani and plate to the bench



Yes, that is 3 clamps you see in that picture

Next thing to do was to use Samass's method to plot the bolt holes:



All holes done, plate on manifold (edit: this was after I had drilled the exhaust flange holes):




The next stage was to drill the bolt holes for the turbocharger exhaust flange.

I clamped the unit on the bottom bolt hole and then drilled the two top holes first:



Then I bolted them up to mark the hole for the bottom bolt:



This is a mockup of how I want the studs coming through:



That is upside down by the way, I haven't drilled the holes wrong.

And this is why I need to countersink the turbo bolts and make them into studs:





And this is eventually how it will look on the adapter plate when the studs are made up:



Right, that is all the fabrication documented thus far. On Thursday I am going to go to my welding guy and ask him to countersink the bolts and weld the heads into the countersunk metal to make the studs. The bolts I will be using are these screws:



They are M8 30mm long with a countersunk head.

I decided to get my welding guy to do the countersinking because I tried B&Q, Homebase, Toolstation and screwfix for metal countersinking bits for M8 bolts but they didn't have any/didn't have any knowledge of what the hell I was on about. Eventually found some in Wickes but at £10 pound a pop and not being sure which size I needed I decided it would be better just to get my welding guy to do it instead.

Oh yeah, the drill bits off eGay were utter crap. I thought I got a bargain but when they arrived they were "Tool Zone" in a shitty plastic case, the 8.5mm one went blunt after 2 holes! Luckily I had ordered a decent 8.5mm drill bit as well before I ordered the Tool Zone set.

If anyone sees any problems please say, I won't be offended, this is my first go at this kind of thing anyway. Oh yeah and as you might guess I wrote this all up in notepad as I pre anticipated internet explorer failing (which it did about halfway through me writing this on notepad).

Once I have the adapter plate made up I need to do the following:

Clock the turbo (easiest bit)
blank off recirculation valve
Sort out actuator mounting
Drill adapter plate for exhaust elbow
Get custom exhaust elbow madeup and welded to exhaust adapter plate
Get flange welded onto exhaust elbow
Drill and tap hole in mani for EGT gauge

Right, I think that's about it! May edit this with bits I forgot if there are any.

[martyn92]

Where the bolts stick out and get in the way you can just make a thread in the plate and bolt it from the other side.
Good work though!

[Dum-Dum]

How deep is the head of the countersunk bolt (between its flat and the start of the thread) and whats the diameter of the thread

Finally whats the angle of your countersunk head and whats the angle of the tip of your largest drill bit (see where im going with this)


Looks like cracking work mate, well done.

[306Puggy]

Where the bolts stick out and get in the way you can just make a thread in the plate and bolt it from the other side.
Good work though!

If I did that then the thread of the bolts would poke through though wouldn't it? Unless I have misundersood. Maybe a paint diagram would help.

How deep is the head of the countersunk bolt (between its flat and the start of the thread) and whats the diameter of the thread

Finally whats the angle of your countersunk head and whats the angle of the tip of your largest drill bit (see where im going with this)


Looks like cracking work mate, well done.

Bolt head is 4mm deep thread is M8. Not sure how to work out the angle though?

I guess you are getting at using a standard drill bit to countersink it? I did notice the holes that the drill bits were making before going through looked quite a lot like countersunk holes.

One of my concerns about this adaptation is how are those 3 M8 bolts on the turbo flange supposed to support the weight of the whole turbo hanging off the manifold? I think this turbo was designed for quite a different fitting than on a 306 because it looks quite precarious with just 3 bolts on the flange.

Maybe a simple bracket which bolts to the top mani bolt and then welded to the compressor housing might help?

[cwspellowe]

Er, why would the bolts not suffice? Do you have any idea of the clamping force you can get from three M8 bolts?

The weight of that turbo, one bolt alone would hold it. It just wouldn't stay in place for long

[Stephen]

Nice work mate. Interesting to read

[306Puggy]

Er, why would the bolts not suffice? Do you have any idea of the clamping force you can get from three M8 bolts?

The weight of that turbo, one bolt alone would hold it. It just wouldn't stay in place for long

I don't know why they wouldn't suffice, it was just a feeling. Not necessarily the bolts but the fact that they are all on a small flange supporting a much bigger "mass" if that makes sense. The standard K14 setup has much more evenly distributed fastening points.

Nice work mate. Interesting to read

Heh, thanks, I'm trying to be as detailed as possible to give people an idea of how to do it. If it turns out okay I might make a guide.

[Grant]

Those bolts will be fine, just get a nice bit of threadlock on there

[martyn92]

Where the bolts stick out and get in the way you can just make a thread in the plate and bolt it from the other side.
Good work though!

If I did that then the thread of the bolts would poke through though wouldn't it? Unless I have misundersood. Maybe a paint diagram would help.

Yeah but you can trim the bolts so they dont end up coming out the other side and stop inside the plate

Either way countersunk bolts could work