1.6 Gti Engine Tuning

[Matt Holley 11]

Hello

 

I am trying to find out some good ways of getting some good power out of a 1.6 xu engine on a budget,(when I say budget I don't mean £2.50 I just don't want to spend £££s), I've done alot of searching but can't find anything from anyone that has done it with proven results just alot of ''to make it faster you need tuition and suspension''.

 

I've decided to enter sprints with it so had to change from the gti6 it had before and want to enter the 1400 - 1800cc mod prod class, I'd thought about using an MI16 but this would put me in 1800 - 2600cc class and that has some serious kit in it so want to avoid it.

 

Basically I've thought I would put a 1.6 in, bolts some carbs on ( I know this won't go down well but I have someone local that could set it up) and would want to up the compression and add a cam, I saw on an old thread you could use pistons out of another xu engine but didn't see what one, I would also like some thoughts on what cam to use.

 

Does the 1.6 suffer oil surge?

 

Any opinions would be good.

 

Thanks

[Anthony 1,000]

What are the rules for the class you're entering with regards to engines?

 

Can you use an XU7JP4 (1.8 16v) alloy block bottom end as a starting point, as that would be a good place to start for a sub-1800cc XU build IMO. I'm guessing that if you could have used an Mi16 then there should be no reason you can't use an XU7.

 

8v head will bolt straight on and gives a compression hike over a 8v bottom end if you need to stay 8v head for the class, or you can use a later 16v head.

[Matt Holley 11]

What are the rules for the class you're entering with regards to engines?

 

Can you use an XU7JP4 (1.8 16v) alloy block bottom end as a starting point, as that would be a good place to start for a sub-1800cc XU build IMO. I'm guessing that if you could have used an Mi16 then there should be no reason you can't use an XU7.

 

8v head will bolt straight on and gives a compression hike over a 8v bottom end if you need to stay 8v head for the class, or you can use a later 16v head.

 

I would say no to XU7 but who knows, I was speaking to the guys running the last sprint about using my 205 and he said at the time people fit MI16s and get away with it as it's just an easier way of fitting a 16v head to an 8v Heads are free! Do you know if you can take the 1.8 bits out and fit them into the 1.6 block and does it give the same compression hike?

 

The rules state that the block must be externally identifiable as one fitted to the original car.

[Anthony 1,000]

I'd argue that an XU7 bottom end is no more bending the rules than an Mi16 is - both are different externally to 8v blocks, but not dramatically so.

 

The parts are interchangeable between the two blocks, so you could fit all the XU7 internals into an 8v block without any issue that I'm aware of, but using XU7 or Mi16 block will be far easier if you're wanting to use a 16v head as the 8v upper engine mount I can't see fitting otherwise.

 

I was in the process of doing an XU7JP4 bottom end with XU10J4R head and GTi-6 cams/manifolds at one point, which I would have said would be a good engine for your class - subject to being happy bending the rules slightly on the bottom end which, as you say, people do even if strictly speaking they probably shouldn't. 28CRAIG on here has a similar engine using a GTi-6 head (which I felt the ports were probably too big on, hence using the non-RS head on mine) and that made 160hp coupled with a DTA (and with a distinctly dubious map!)

[Matt Holley 11]

It's difficult to judge on the future, I'd rather be on the right side of the rules.

 

I'd not thought about using the xu7 bottom with XU10J4R head though, I've got some gti6 cams, I would have to go down the full managment route for that though which hikes the cost up.

Edited September 22, 2011 by matt holley

[Baz 421]

This are the problems we face these days using 205's in competition as their engines are so off the pace in standard format.

 

 

Is this regardless of 'road' or modified class though Matt?

 

In the road classes over this side we have to retain the standard head although modified classes; as you say 'block must be externally identifiable as standard' which is usually very loosely adhered to, but mainly because not everyone knows what's what for different cars!

 

If the head's free then i'd be thinking about what Anthony's suggested as that's what i've even thought about even with our 1600-2000cc class breaks, giving you somewhere around a 1760cc 16v, just below the 1.8 margin and still usable over this way!. (Stupid having differing class breaks around the country if you ask me anyway!)

 

 

As it happens, i've been looking at building a diesel block'd 16v engine to bend the rules a little in mod.prod.

[Matt Holley 11]

This are the problems we face these days using 205's in competition as their engines are so off the pace in standard format.

 

 

Is this regardless of 'road' or modified class though Matt?

 

In the road classes over this side we have to retain the standard head although modified classes; as you say 'block must be externally identifiable as standard' which is usually very loosely adhered to, but mainly because not everyone knows what's what for different cars!

 

If the head's free then i'd be thinking about what Anthony's suggested as that's what i've even thought about even with our 1600-2000cc class breaks, giving you somewhere around a 1760cc 16v, just below the 1.8 margin and still usable over this way!. (Stupid having differing class breaks around the country if you ask me anyway!)

 

 

As it happens, i've been looking at building a diesel block'd 16v engine to bend the rules a little in mod.prod.

 

It would be modified production for the 205 although I ran the wifes standardish 106 gti in road class and really enjoyed it, wouldn't be able to get the trim back in the 205 for that though I wouldn't have thought.

 

I know of a 205 using a diesel block and it's very quick and you can tell when its out on circuit just by the sound of it.

 

It does seem silly to have differant class size accross the country.

 

What classes and engines have you used in sprints Baz?

Edited September 22, 2011 by matt holley

[Anulfo 22]

What are the rules for the class you're entering with regards to engines?

 

Can you use an XU7JP4 (1.8 16v) alloy block bottom end as a starting point, as that would be a good place to start for a sub-1800cc XU build IMO. I'm guessing that if you could have used an Mi16 then there should be no reason you can't use an XU7.

 

8v head will bolt straight on and gives a compression hike over a 8v bottom end if you need to stay 8v head for the class, or you can use a later 16v head.

 

So what would need to be done to make an original mi 16 fit into a sub 1800cc category??Im going by the understanding that in fully modded class heads are free so the mi 16 set up would make logical sense??