I’ve only ever seen one of these 8 port heads, they are pretty agricultural but a huge improvement over the standard head.

A dare you not to laugh out loud as the ports open fully about a minute or so into this.

[video]https://m.youtube.com/watch?v=hHjf9zhQIRk&feature=youtu.be[/video]

Oh my…

… want one.

my clubman never sounded like that 🙁

(except maybe when I ripped off the exhaust going through a ford)

😯

Is it even legal to do that to, what motoring terms is, a pensioner?

I thought this was going to involve 8 naked midgets.

Think I have done a little sex wee 😯

Ooh that was good, enjoyed that! 🙂

Ooof I’m about to get my mk2 running again with it’s tuned cooper motor. It doesn’t sound quite like that though..

KAD 16v head FTW shirley?

Also looks like about 30% of the fuel is going over the windscreen rather than into the engine due to the pressure standoff 😉

Whiney old straight cut box 😆

Nice sound 😆

[/quote]Also looks like about 30% of the fuel is going over the windscreen rather than into the engine due to the pressure standoff

Pressure stand off? What’s that? The ability to balance the fuel flow rate into the head v through it?

That’ll need an air filter and possibly a re-jet 😀

Mmm, flat slide throttle as well.
Gorgeous.
And driven as god intended.

IME that’ll shred it’s front tyres in days, wheel spin in every gear and be “undriveable” in the wet though you’ll grin from ear to ear. Along with lift-off oversteer making you drive everywhere with your foot on the floor 😉

Awesome. Only ever seen pictures of cars with 8-port heads, never in the flesh.

Would love to still have my Mk3 but tinworm took hold and never went away.

That looks like a fun car!

I was not going to laugh out loud, I was determined not to laugh out loud!

I laughed out loud………. 😆

mcmoonter

Pressure stand off? What’s that? The ability to balance the fuel flow rate into the head v through it?

A reciprocating internal combustion engine does not burn its air/fuel in a “continous” process. It only ingests a cylinder charge of air & fuel during the intake stroke (intake valve open, piston moving downwards (see note)), and so even though you can’t see it, the air column trapped in the intake trumpets is stopping and starting moving multiple times a second. This sets up a standing wave, as the pressure wave bounces off the closed intake valve and rebounds up and out of the intake. If there is fuel still in the intake system at this point, that fuel vapour gets caught up and ejected out of the front of the intake trumpets by the pressure wave. These effects can be mitigated by correctly timing the injection event, and by getting injector position /targeting optimised. When an air filter is fitted, often the fuel isn’t lost, as it gets “hung up” in the filter volume and re-ingested on the next intake stroke. However, this guy is running without filters (or a bonnet) and so the fuel is lost to the slipstream. This means his engine could be running dangerously lean at some points, which is NOT a good thing to happen!

(Note: for the sake of brevity/simplicity, i’ve ignored the inertial effects of the incoming air charge and hence the fact that cylinder filling does not actually entirely occur over the geometrical intake stroke only (ie TDC -> BDC))

Lovely, can’t beat an A series with a tuned engine and straight cut ‘box.
Air filters or an air box would sort out the fuel going the wrong way?

That’s making me realise I’m missing my straight cut whine, need to rebuild the ’72 1380 5 port sitting in the corner of the garage, wishing I could afford an Arden though.

A very cool video 8)

I love the liquid fuel dancing around on the throttle plates at part throttle 8)

And the fuel mist in the inlet’s when the throttle is almost fully open 8)

Plus… isn’t the head on backwards? Mini’s I’ve seen have the inlet between the engine and bulkhead.

Plus… I’ve never seen an injection set up with the fuel injectors before the throttle plate…

Sounds nice though 8)

Top explanation Maxtorque. Would the airflow on a standard A Series with siamesed inlet ports be as vulnerable to this effect or would the flow rate be too low to notice?

Arden head becomes a crossflow head design, so the exhaust stays at the back, the inlet then moves to the front. Not sure if its an 8 injector head and the second set, that you can see only come into play when max throttle is asked for, as when the throttle is closed on a slide throttle, no fuel would be able to get in and would need a bleed for air and fuel behind the slide throttle.
Thoughts from Max on this?

‘King awesome! That’s what a car ought to sound like! I doubt very much anyone would step out in front of him, unless they’ve got serious earphones one, making that racket.
Is that in the UK,the architecture looks different, some how.

Not an 8 port but I rallied a 1275 (well 1312) with a 40DCOE. We had to remove and rebuild the bulkhead with an airbox to make it fit. The noise was wonderful and it would suck small dogs off the footpath. Oh and an intercom was required.

mcmoonter
Top explanation Maxtorque. Would the airflow on a standard A Series with siamesed inlet ports be as vulnerable to this effect or would the flow rate be too low to notice?

All engines have standoff to some degree, you usually just don’t see it. The big issue for the std siamesed port head is charge robbing, and this is especially true when moving to fuel injection, that has a “timing” (ie a crank position synchronous element) associated with it.

It also generally worse on engines with aggressive cam profiles (lots of valve overlap) because at low engine speeds there is not enough intake air momentum, and the air charge gets blown back out the cylinder due to the late IVC.

I’d imagine this engine just uses 4 staged (ie pre throttle) injectors. As it looks like the slides are fully shut at zero throttle there must be idle bypass ports around the slides.

I’d also be wanting an air filter on that

I’ve fitted twin 45’s to my Mk1 MX-5.

I’m not the most popular person in our household as I’ve been taking it to work at 4:30am for the last week. It’s not the quietest. Currently has filters fitted due to vented bonnet but I’m saving for some Emerald Racing adjustable trumpets. That’s not going to help 🙂

I love the old A series lump, it brings back so many memories, I fired up my 1330 and let it run till for a while, partly just to hear it’s lovely beat. My neighbour appreciated it to and we had a chat whislt it ticked over in that Typical A series way!

I have a BMC tractor here with a diesel A series motor in it. Low compression means it takes about 20 minutes and 3 batteries to start the thing. Not ideal as a getaway vehicle on a bank job 🙂

mcmoonter – as always, you are a man of inestimable good taste.

My 1430 is still running around Balsall Common!
That took a lot of research to get that right 😉
Australian spec 850 block (different water jackets), re-sleeved, steel billet crank, twin 40 DCOES, cam so aggressive it wouldn’t tick over under 2k!
Add a straight cut box, very rare Cooper copper exhaust, lsd, full spaceframe, rose jointed coilovers all round, etc.
Used to eat Porsches, etc for fun.
Miss driving it – don’t miss the fuel bill!

Ahhhh , what a beaut , came to work in my 1071 this morning , straight cut box waking everyone up and the added zest of Castrol R , only a 5 port though . I have driven a 1460 8 port with injection on throttle bodies – that was a beast

Me and my dad are currently prepping our 1380 for a Respray following minor unintentional bodywork modification that occurred whilst backing it off the ramps. 🙄 it sounds good but not as good as that. I’m pretty tempted to build up a 998 with a k-series head conversion. Went in one not that long ago and it was ace fun screaming away. Can’t wait to get ours back on the road. I fear that progress is about to a reach to a standstill due to my dads bowling season is about to start. 😥