Inspiration

Time to share some inspiration I think. I've included a video from each of the 3 venues that make up the Championship to show folks just what the Polo will be getting used for.

Doune

Generally regarded as the scariest/fastest/craziest course of the year watch as Graeme Wight Jnr. threads his highly modied Imp up the hill in the video below:

If you want to see something totally unhinged watch as he then pilots his V10 single seater up the same skinny stretch of tarmac. This video is not speeded up:

Forrestburn

My favorite track as a spectator. Ballsy at the start then gets more and more technical as you go. Here we have Clark pedaling his BMW e30 318 to a class record followed by the Integra that normally sits on the trailer that was used to tow the Polo:

Fintray

Our local course and it's only 10 miles away. It's the shortest too comprising of only 3 bends. Don't let that fool you though the first one is a tricky double apex...or single apex...or triple...depends what you make of it! This course favours power and traction as you accelerate out of each tight turn towards the next. I've lined up a 16v KAD conversion Mini for this one, great noise!

Just out of interest, what kind of power figures are the cars getting in each of these videos?

The imp, integra and v10 are unreal!

Just out of interest, what kind of power figures are the cars getting in each of these videos?

The imp, integra and v10 are unreal!

Imp = 100bhp + I'd think and very light!

Integra = just north of 200bhp...will be more like 230 this year. Again very light. Circa 900kgs maybe?

V10 = 600+ bhp is not unheard of in that class but I'm not sure. Something silly no doubt and again very light car.

BMW = 150bhp standard but had a bit of head work and a lumpy cam.

KAD mini...no idea!

Jason Moyle Racing

Todays update comes courtesy of Jason Moyle Racing.

I might have mentioned earlier in the thread that my competitors all have some tasty under bonnet mods and that the Polo would need some extra horses to stand a chance. I decided that throttle bodies would give the required bump in performance and provide an interesting project to work on. Throttle bodies of course present a significant financial/time investment; one that can only be fully realised if they are breathing through a well prep'd cylinder head.

Whilst I would love to DIY port the head I just don't have the time or kit. Enter Jason Moyle; who I came across on Club GTi. He's a hill climber with a fondness for 8 valve Volkswagens and knows more about cylinder head prep. than I think I could learn in 5 years. Check out his website: JMR Clubsport or look him up on Club GTi's forum.

I've just had my first email update on progress and I've popped all the info below:

Here's the Polo cylinder head strapped down onto the flow bench for testing

The light blue graph shows a standard 1300 8 valve Golf head. The green graph shows this head ported to flow better. The dark blue graph shows the standard Polo GT head.

The Polo GT head matches the modified Golf item at low valve lift. The Polo then begins to out perform the Golf in the mid-range due to having a bigger inlet valve. Flow restriction caused by the standard nature of the Polo head chokes flow at higher lifts...what does mean? It's a good starting point, but Jason can see room for improvement!

After the base readings were taken it was time to inspect the valve and inlet port. I'm told the shape of the valve is 'horrible', the short side of the port is 'poorly shaped' and the throat is way to small for the size of the valve. It all sounds pretty negative...but it isn't! All of these areas will bring improvements to flow and thus performance when worked on. She's got potential!

Even though he has other work on Jason couldn't resist opening up the venturi and de-lipping the back of the valve; just to see what sort of gains can be had. This resulted in a 6cfm peak gain and 5cfm spread across a wider range of valve lifts. I think it's great to see what a little bit of work can gain.

Absolutely delighted with what will come and Jason's proving a pleasure to work with. Regular updates via text message and a in-depth explanation of whats going on. I'll keep the thread up to date as it comes along!

Edited 23 January, 201214 yr by Tav

I've been thinking about getting my 8v head flowed, as ill be running a high performance Newman cam and a weber DCD, what sort of price are you looking at for the work?

I've been thinking about getting my 8v head flowed, as ill be running a high performance Newman cam and a weber DCD, what sort of price are you looking at for the work?

That's TBC once all valves/tappets etc. are checked and depending on machining etc. I need it back in bolt on condition so might be a few extras on mine that you might not normally need. I'll be sure to share costs once it's done and we see what results are.

Thanks very much,

It does seem that to get 100+bhp N/A out of the 86C chassis 8v engines, head work is a must!

I eagerly await updates!

Thanks very much,

It does seem that to get 100+bhp N/A out of the 86C chassis 8v engines, head work is a must!

I eagerly await updates!

That's what I'm hoping for...110+ would be amazing. But sticking with stock CR for now and not sure what sort of cam will work with GT pistons.

Thanks very much,

It does seem that to get 100+bhp N/A out of the 86C chassis 8v engines, head work is a must!

I eagerly await updates!

That's what I'm hoping for...110+ would be amazing. But sticking with stock CR for now and not sure what sort of cam will work with GT pistons.

Great to see you back and with such an interesting project!

Regards cams, i think you can get away with 272/272 without valve/pistons meeting. Remember Andy posting something up sometime back that when they tried a piper cam (280/280 iirc) cam on Yoofs old 3F that the piston had to have some valve cut outs to get it to work.

Can't remember for the life of me what cam he had but someone i know had a polo 3F with all the usual mods (exhaust, manifold, chip, GTI afm etc etc), a home port and polished head and a uprated camshaft and he produced 100+ bhp with dyno graph to prove. So with a healthy well tuned engine, that head, a lairy cam and throttle bodies instead of the OE injection you should be able to see 110bhp.

Good luck with it all and i will keep a close eye on this.

Looking forward to seeing more on this! My dad is good mates with Jason and i'd be getting him to do some work on my GT in the future, so I'm eager to see how this turns out

Can vouch for his work too, i've been in his Mk1 Golf a few years back and it is absolutely brutal!

Great to see you back and with such an interesting project!

Regards cams, i think you can get away with 272/272 without valve/pistons meeting. Remember Andy posting something up sometime back that when they tried a piper cam (280/280 iirc) cam on Yoofs old 3F that the piston had to have some valve cut outs to get it to work.

Can't remember for the life of me what cam he had but someone i know had a polo 3F with all the usual mods (exhaust, manifold, chip, GTI afm etc etc), a home port and polished head and a uprated camshaft and he produced 100+ bhp with dyno graph to prove. So with a healthy well tuned engine, that head, a lairy cam and throttle bodies instead of the OE injection you should be able to see 110bhp.

Good luck with it all and i will keep a close eye on this.

Kerrly hit 105bhp from what I gather - I have the cam from the engine in my cupboard

Take a Seat

Cylinder Head Update #2

Following on from the last cylinder head-centric update I can report that Jason's been busy and had the cylinder head away for machining. I received a text message accompanied by a couple of photos mid-Fajita-cooking. Almost burnt the chicken!

Below is a photo of the head as it was when it arrived at JMR.

...and here's the results of the valve seat machine work. The seats have been cut with 3 angles in an attempt to improve flow at large valve openings. The lead in edge as been cut back in an attempt to de-shroud the valve during initial opening. This should have a positive effect on flows in the low-mid range:

Of course any improvement to the cylinder head needs to be verified by readings from the flow bench. The pink line in the graph below illustrates the 3 angled seat's positive effect on flow; with an obvious increase at the larger openings. We're not seeing much of an advantage between .300 and .400 which Jason suggests is because it now has a bigger appetite for air. Opening the throat and venturi should provide that and will be be the next job! Jason predicted an increase of 6CFM from those modifications.

[

I'm really starting to trust his experience now and I'm confident that'll be the case. Can't wait to find out!

At this point we've decided to aim for 70CFM. A standard Golf GTi head with a 40mm valve makes 72CFM and an easy 110-112bhp. We're already up from 55.8CFM to 62.5CFM and still lots more to do.

I've acquired another GT head to use for parts. Apparently the valves need a lot of work so it'll be easier to test knowing there are spares. Never know it might become Evo II.

Edited 1 February, 201214 yr by Tav

Restoration

As much as I'd like to concentrate on adding go faster bits there is a fair bit of restoration required; the car is 19 years old after all. I've collated a lot of bits and bobs into this update.

Here we can see the rear beam after it came back from sand blasting. The beam had a very rough finish, I think they used quite aggressive media, but it worked none the less:

Beam painted up with satin black spray on Hammerite. Key words there being: satin and spray. No matte, no gloss and certainly no brush strokes on this car! Fitted some very firm G-Lader site rear beam bushes supplied by Polo Performance Parts. My top tips for fitting:

• Chill bushes in freezer before fitting (thanks Pete)
• Wet & Dry sand the inside of the beam where the bushes are to be fitted
• Use spray on lube - I had some 3in1 silicon to hand
• Press in using g-clamp or bench vice making sure to keep the bush square
• Tap home with a mallet. Using a mallet from the out set will not work, you've got to press them!

Other assorted parts. Stuart and I sandblasted these our selves at Donald's; another hill climb competitor with a 900BHP Evo and a suitably well equipped workshop. Once blasted we treated them to primer and satin Hammerite.

Sandblasted VWII G40 carrier.

Primed and painted in satin silver.

Similar treatment for the G40 calipers. Also fitted new seal, dust covers, sliders and rubbers from Bigg Red.

Borrowed a proper brake hose flaring tool from a local chap. He gave me a quick 5 min lesson and after a few practice shots I think I'm getting the hang of it!

No I need to get all of these parts back on the car. Seriously considering getting a blaster as well, quite satisfying restoring parts and some are getting more difficult to find new or in good condition.

Absolutely top work as always. Sorry if I've miss read, or missed it completely, but has the head had any flow work done to the ports?

Absolutely top work as always. Sorry if I've miss read, or missed it completely, but has the head had any flow work done to the ports?

Despite the already tasty gains there's been only a little tickle to the port. Rest have come from valve seat, small modification to back of valve and that's about it. Once real porting start we should see a big increase.

Fantastic!

Any pictures of the valve backs?

Also, do you know how exactly he modified them? Ground or lathe work?

Yeah the guy that' doing the work was talking about it on clubgti iirc, very intersting is headwork, I was never aware that much consideration went into doing it properly.

Great progress, can't wait to see videos of this thing tearing around some country lanes.

Can I ask what the wheels are? Not the smoors, the bronze ones?

Fantastic!

Any pictures of the valve backs?

Also, do you know how exactly he modified them? Ground or lathe work?

I'll be sure to ask and get before + afters. I'm sure Jason will send them through in an update anyway.

Yeah the guy that' doing the work was talking about it on clubgti iirc, very intersting is headwork, I was never aware that much consideration went into doing it properly.

Great progress, can't wait to see videos of this thing tearing around some country lanes.

Can I ask what the wheels are? Not the smoors, the bronze ones?

Compomotives. Not that light be seem very strong. Bought them off of buster on here. Most excellent deal too!

very intersting is headwork, I was never aware that much consideration went into doing it properly.

same here man. so much to think about

Have you got any plans regarding the bottom end? more importantly the combustion chamber?

The heron design is very in-efficient, with hardly any "squish" area and a bad located spark plug ( All of which I'm having to contend with too! )

Have you got any plans regarding the bottom end? more importantly the combustion chamber?

The heron design is very in-efficient, with hardly any "squish" area and a bad located spark plug ( All of which I'm having to contend with too! )

Next year for bottom end. Enough effort/cash getting sunk into the top end this year that it can wait. I have however found a 50k mile GT bottom end and will be picking it up next week. Could prob. bore it out, try and get forged pistons, balance it and get her revving a bit higher and see about upping the CR to 11:1+...but your talking about £1k+ There's always decking the block and playing with the standard pistons which would be more appealing if the car were to stay 8 valve. I'm watching your project with interest!

I was gonna say have a look at my thread as that's the sort of work i've done.

I've just recived my cylinder head back from having a new set of guides and valves fitted, going to give the ports abit of work before i re-assemble it!

Tickle in my Throat

Cylinder Head Update #3

Another update courtesy of JMR as more head work is undertaken.

You can see the rough grind marks from where Jason has opened up the throat.

In the graph below you may notice that the peak and dip that was present at .300" has changed. The peak is still there, but now the flow continues to rise steadily, instead of lessening.

Peak flow is up to 67CFM at .500" and 64CFM at .400". The later being the important figure, as this is likely to be our largest figure for lift given our choice of cams. Still another 6CFM to find before we reach our target.

We've lost a little flow in the low lift range. Jason is quite confident this is caused by the poor valve shape and that by modifying it we will see this rectified.

As always the above is backed up with a quick session on the flow bench.

Edited 3 February, 201214 yr by Tav

Looking great!

This is exceptionally interesting, and well laid out updates!

However, what does CFM actually stand for and what units is it measured in?

I'd like to understand what you're talking about a little more.

Cfm is the acronym for cubic feet per minute.

A measurement of volumetric flow, the higher the better.