Xmt - Sarty's Xsara GTI6 Turbo

[DrSarty 90 1 Cars]

OK and thanks; I'll give it a go (when I have more pictures). Shame you posted a pic of a 'dull' car.......

 

In the meantime - while Neo stops bullets in mid-air - can I field these main questions, some of which I asked you (Jackherer) earlier today by phone to the wider audience:

1) Exhaust ceramic coating or wrapping - worth it?

2) Turbo lagging jackets - worth it?

[petert 586]

Weird, my pics just go straight in. A straight drag and drop. When on the ipad I use "choose file".

 

1. I'm a great fan of ceramic coating. It drops the engine bay temps significantly and will keep your porno pipes looking young.

2. No idea

[Andy 105 1 Cars]

Great update Richard and ‘the Matrix’ is a class film !!

[Tom Rallye 3 1 Cars]

Great build!

On a side note, 18 inch also fit  (son's car): 

Edited August 18, 2018 by Tom Rallye

[wicked 103 3 Cars]

7 hours ago, DrSarty said:

 

1) Exhaust ceramic coating or wrapping - worth it?

2) Turbo lagging jackets - worth it?

If you have to work on it later on and need to touch wrap that has been baking for 3 years, you'll start to hate it...

Every time you touch it, it will release a cloud of fiber dust. It will itch the rest of your weekend.... 

 

But it does it's job...

Edited August 18, 2018 by wicked

[petert 586]

Rich, here is a site you'll find very useful.

http://www.turbofast.com.au/

Dave Walker put me in contact with Ray Hall many years ago. He's an absolute legend over here, although now retired.

[DrSarty 90 1 Cars]

Need to check I haven't missed something.

 

The DFW (Mi16 low comp) pistons PeterT sent me aren't a straight fit to the Mi16 rods. Did the DFW have different rods with a 'thinner' little end?

 

The XU7JP4 rods by comparison have the same little end as the Mi16 rods so it looks like the difference is definitely in the DFW piston.

 

I'll try to add some pics using my phone, which should show an 'X' on the piston crown (to prove they're DFW). You'll then see the thickness of the little end of the rod is much thicker than the space available in the piston.

 

If these were D6C/standard Mi pistons, (a) they'd have a 'Z' stamped on the crown, and (b) would fit the little end.

 

I'm hoping the answer is 'yes, DFW has different rods'. Then I need to know if I need to have the DFW pistons machined to fit the rod or vice versa or a mix of both?

[petert 586]

Something odd there. The only difference between an X and a Z piston is the compression height. The rods and pins are identical. It must be manufacturing tolerances. What are your measurements for the rods and pistons and I'll compare them to other X & Z pistons and rods I have here.

[DrSarty 90 1 Cars]

Mi rod little end about 3-4mm thicker overall.

 

XU7JP4 piston still with rod fitted compared to Mi rod.

 

Both pistons compared.

 

To my eye, the XU7JP4 and Mi rods are very similar, at least in terms of little end thickness, which means the difference is in the piston as stated; it might be just 2mm narrower, but 3-4mm overall extra width seems to be needed.

 

The only thing I can think of is that I've fished out 8v rods. But if 8v rods are the same as Mi rods, and also very similar to XU7JP4 rods, then it's definitely the pistons that are different.

Edited August 26, 2018 by DrSarty

[petert 586]

I just pulled apart two virgin X and Z piston/rod assemblies. This is the best I could measure given my arm is in a sling.

 

Z piston internal: 22.62mm

X piston internal: 22.62mm

 

Z rod external: 22.42mm (at its widest)

X rod external 22.47mm

 

For the Z rod, I say at its widest because it's actually tapered, down to 22.35mm. ie it was never ground flat. I'm measuring just under bush, rather than at the very top. The X rod is flat.

 

Disregarding the poor machining of the Z rod, both rods fit easily in either piston.

 

8V rods are thicker at 24.70mm.

Edited August 26, 2018 by petert

[DrSarty 90 1 Cars]

Your last comment I think covers it and is what dawned on me at the last minute. I either had a very odd set of DFW pistons or the rod was different.

 

It looks like I picked some 8v rods, which I'm going to guess are about 23.5 or perhaps 24mm little end thickness (?).

 

Thanks for checking Pete, and so quickly too. I'd have figured it out by trialling another rod, i.e. an Mi rod on Sunday morning.... at least when the sun rises.

 

P.S. I conclude from this that Mi rods are thinner than not only 8v rods but XU7JP4 rods. And I'm now also thinking that I chose the 8v rods because I'd read somewhere on here that they allegedly helped with the Mi16 crank bearing oil starvation issue, which I seem to remember has proven to be a myth. 

Edited August 26, 2018 by DrSarty

[petert 586]

Don't forget Mi16 rods are bushed, full floating. Where as 8V rods are pressed, with no bronze bush.

Edited August 26, 2018 by petert

[DrSarty 90 1 Cars]

Thanks again. Our post edits are overlapping which may look to readers like we're not paying attention to each other.

 

24.7mm for the 8v rods certainly explains it, but of course you added that dimension afterwards.

 

Can you please explain the bushed, floating and pressed thing please, and also whether the 8v rod might be a better choice, assuming it's feasible/OK to machine the DFW piston internal to accept the thicker rod?

 

*EDIT: Just found these. Seem simple enough explanations: http://www.pistonheads.com/gassing/topic.asp?h=0&f=23&t=864159

& https://youtu.be/7x4-EudnyJk

Edited August 26, 2018 by DrSarty

[petert 586]

I don't think you can bush an 8V rod to suit a 22mm pin. There isn't enough wall thickness left on the little end. I've got 8V rods here that have been bushed to suit a 20mm pin for an aftermarket piston however.

Edited August 26, 2018 by petert

[wicked 103 3 Cars]

Forget the 8v rods. Floating pins divide the friction over 2 'bearings', so it is less. The result will be that the piston tilts with less force and the crown will wear less..

[DrSarty 90 1 Cars]

I'm much clearer now on this and have learnt quite a bit.

 

On another subject: I took the under piston oil spray bars/jets from an Mi block I scrapped hoping to have them fitted to the XU7 block I'm using. Anyone see any potential challenges with this?

[Andy 105 1 Cars]

Going back to ceramic coating for your manifold. I got a quote from Zirotec this week to coat my Miles Horne Four branch manifold. With very awful tax, the basic , plain black coating comes in at a shade under £400 and if I want the ‘better ‘ coating that has a three year warranty and a choice of colours, over £500.  Gulp. I imagine yours would be a good deal more, given it’s size and complexity. However, the exhaust wrap one can buy , although it does work, is pretty nasty stuff and the stainless steel ties sometimes supplied are excellent at cutting ones fingers to shreds . Going back to Zircotec, to give them credit, I emailed them with my query and a photograph of my manifold, and they replied within 24 hours . What’s more, underbonnet temperature is an issue, particularly when stationary at lights on a hot day and, you having a turbo and all, will be even more of a concern. I am still in two minds about mine. It is a massive chunk of dosh but not a massive percentage of the total cost of the engine I am building, so got to keep some perspective. On the other hand, I do really need a new winter bike ............. ( Peter will understand ) 

[petert 586]

Any decent bike is 10x that anyway. I’d get the pipes done. Think of it as protecting your investment. Not just the pipes, but everything in the engine bay. It makes such a difference in my race car. I ran a non-coated down pipe recently and it burnt the firewall! The coated pipes haven’t done that in 12 years.

[woodymi16 24 2 Cars]

On 8/26/2018 at 9:53 AM, Andy said:

Going back to ceramic coating for your manifold. I got a quote from Zirotec this week to coat my Miles Horne Four branch manifold. With very awful tax, the basic , plain black coating comes in at a shade under £400 and if I want the ‘better ‘ coating that has a three year warranty and a choice of colours, over £500.  Gulp. I imagine yours would be a good deal more, given it’s size and complexity. However, the exhaust wrap one can buy , although it does work, is pretty nasty stuff and the stainless steel ties sometimes supplied are excellent at cutting ones fingers to shreds . Going back to Zircotec, to give them credit, I emailed them with my query and a photograph of my manifold, and they replied within 24 hours . What’s more, underbonnet temperature is an issue, particularly when stationary at lights on a hot day and, you having a turbo and all, will be even more of a concern. I am still in two minds about mine. It is a massive chunk of dosh but not a massive percentage of the total cost of the engine I am building, so got to keep some perspective. On the other hand, I do really need a new winter bike ............. ( Peter will understand ) 

I would give https://www.hccoatings.co.uk/contact a call, I had my Pugracing manifold coated and it was less than £400

[Andy 105 1 Cars]

On 8/27/2018 at 4:03 AM, petert said:

Any decent bike is 10x that anyway. I’d get the pipes done. Think of it as protecting your investment. Not just the pipes, but everything in the engine bay. It makes such a difference in my race car. I ran a non-coated down pipe recently and it burnt the firewall! The coated pipes haven’t done that in 12 years.

Manifold dispatched for coating .

[petert 586]

@DrSarty are you planning to run open boost, or closed loop boost control?

[wicked 103 3 Cars]

On a build like this; why would you consider even open loop boost control?

Edited September 12, 2018 by wicked

[opticaltrigger 52]

2 hours ago, wicked said:

On a build like this; why would you consider even open loop boost control?

Absolutely agree with Wicked. I think closed loop for sure guy's unless I'm missing something,that is.

Excellent thread though, all this. 

 

All the best

O.T.

 

[DrSarty 90 1 Cars]

Yet more (advice) I have to understand!

 

I'm moving house currently hence the apparent delay in progress. In fact I've moved to Beverley (near Hull), so would appreciate any recommendations for engine builders. I also need my GTI6 calipers stripped, cleaned and refurbed. And a 'friendly' MoT guy (or woman I suppose) wouldn't go a miss!

 

My new house has a potting shed, with a lovely, angled glass bit on the side, i.e. a typical shed but with a glass lean-to on 1 side and a big, well-lit and warm work surface. It has power and fits my engine stand. This is XU-hybrid-HQ!

 

The double garage (standalone and with electric roller door!) will have the Xsara and 205 in it this weekend, as it's the big move.

 

I've convinced myself to get the turbo pipework ceramic coated. I've also received a new lower rad to engine block hose (as the old and new rad has a metal hose fitting and clip) and a rising-rate FPR.

 

This advice reminds me I need a boost controller, but would someone please explain?

[petert 586]

I'm not sure how well you can do closed loop boost control with your current waste gate arrangement. I thought you'd need a wastegate with two ports and a solenoid (which your ECU controls) as per the pic to get full control. Here's a video which explains the benefits: