1.6 GT to 1.8 8v Conversion

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liam_0404
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1.6 GT to 1.8 8v Conversion

Postby liam_0404 » Tue Apr 18, 2017 8:36 am

Hello all,

My 1.6 GT needs a new cam belt and a new clutch. I have a friend who has a 1.8 8v that he only wants £100 for, so would it be worth dropping this in? I'm not sure what engine code it is but know it was going to go in his caddy. By the time I've taken the box off for the clutch and cambelt would it be worth just ripping it all out.
Do I need any specific items (fuel lines, loom) from the 1.8?

Or is it not worth it for the small gains.

Thanks all.


'88 Scirocco GT
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unknownmale
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Re: 1.6 GT to 1.8 8v Conversion

Postby unknownmale » Tue Apr 18, 2017 8:40 am

It's a pretty easy swap, all parts will swap over. If it's lower millage than you're 1.8 then go for it, but not a huge power gain.


- David

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Re: 1.6 GT to 1.8 8v Conversion

Postby mark1gls » Tue Apr 18, 2017 1:02 pm

What sort of mileage is the 1.8?

Cambelt and tensioner is 1 hour job costing £30 ish and I would recommend changing the cambelt on the 1.8 if its older than 6 years or 60,000 miles.
Depending on how you get the engine out of the car you may need to separate the engine and gearbox any way as it's easier that way, if you drop the engine on the floor and lift the car up then you don't need to split the engine and gearbox.

The only difference I can think of is the top radiator hose as on the 1.8 it's in a different place to the 1.6.

Both engine are 8 valve, is the 1.8 a fuel injection engine or carb?


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liam_0404
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Re: 1.6 GT to 1.8 8v Conversion

Postby liam_0404 » Tue Apr 18, 2017 1:20 pm

I'm waiting for some info on the 1.8
I heard the cambelt was "easy" to do anyway, as isn't the 1.6 non interference?
As the clutch is on it's way out is that an easy/expensive job to replace? I think the whole clutch kit is £70 so that plus a few bits and time. Plenty of room in the bay!
Just depends if I want to keep it original or not.
Liam.


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mr.brown
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Re: 1.6 GT to 1.8 8v Conversion

Postby mr.brown » Tue Apr 18, 2017 1:54 pm

Time/effort/expense is going to be a LOT more for the engine swap. Assuming it's the "easiest" option, i.e. an EX code 1.8 from a Scirocco you'd still have to do things like unbolt the exhaust, drain the coolant, undo all wiring and fuel lines. You then have the issue of the carb jetting being incorrect (assuming you're not getting the 1.8 carb). If you want to use your current gearbox then the clutch pressure plate has to get swapped too. Possibly more things that I've forgotten.

I'm not saying don't do it - as it's invaluable experience for future conversions ( :-D ) but the gain for all the extra work would be 15bhp in theory and more lower down torque.

Cambelt is fairly simple - especially if you use the Fuzz Townshend method from Car SOS - cut the old one in half LENGTHWAYS so you have a half-width belt on there - this retains the relative positions of the cam, crank and intermediate shafts. Slide on the new belt and cut off the remainder of the old one. Job done, no re-timing necessary!



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james butler
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Re: 1.6 GT to 1.8 8v Conversion

Postby james butler » Thu Apr 20, 2017 10:05 pm

one thing to consider is the 1.6 will run on pretty much any uk spec fuels
the 1.8 will prefer super unleaded only, unless you detune it to run on normal.
but the 1.8 is easy 90bhp and more torque so is a good way to go for £100


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mark1gls
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Re: 1.6 GT to 1.8 8v Conversion

Postby mark1gls » Thu Apr 20, 2017 11:14 pm

Do the carburettor cars still need super unleaded like the fuel injection cars then?


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DannyH
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Re: 1.6 GT to 1.8 8v Conversion

Postby DannyH » Fri Apr 21, 2017 1:17 am

I've had both carb and injection cars as daily drivers and it's nonsense to suggest that they need super unleaded!

the cars night be slightly more responsive using super but if it's not a sporty toy it's not necessary.


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the edmundator
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Re: 1.6 GT to 1.8 8v Conversion

Postby the edmundator » Fri Apr 21, 2017 8:50 am

It's not nonsense. VW put a sticker inside the fuel flap that tells you to run on 98 RON. That's what the timing is set up to work with best. It will still run ok on 95 RON, but not optimally (although in a 30 year old car a lot of things probably won't be optimal any more).


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unknownmale
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Re: 1.6 GT to 1.8 8v Conversion

Postby unknownmale » Fri Apr 21, 2017 9:31 am

I have a 1.8 carb and it's noticeably better running super.


- David

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Re: 1.6 GT to 1.8 8v Conversion

Postby essextom » Fri Apr 21, 2017 9:45 am

My 82 gti def needs super to run right, it's harder to start and doesn't run as well on the 95 stuff. My car could do with a good service though.



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james butler
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Re: 1.6 GT to 1.8 8v Conversion

Postby james butler » Fri Apr 21, 2017 5:32 pm

the edmundator wrote:It's not nonsense. VW put a sticker inside the fuel flap that tells you to run on 98 RON. That's what the timing is set up to work with best..

also has a lot to do with different compression ratios as the 1.8 has a higher compression ratio so needs a higher octane fuel to reduce knock


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Re: 1.6 GT to 1.8 8v Conversion

Postby DannyH » Fri Apr 21, 2017 5:57 pm

Never had a problem in over 150000 miles but not really looking for high performance?

As far as i'm aware you can't use the 2 interchangeably without altering the timing.

I would also imagine that most cars will have had the timing changed at some point to accommodate the lower octane perhaps the cars that struggle with it have not been altered?


Danny

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Re: 1.6 GT to 1.8 8v Conversion

Postby BlackGTX » Fri Apr 21, 2017 7:22 pm

tdc-1 will give you some of the surge back




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