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Discussion Starter #1
Starting the motor build.

Porting the cylinder head. Must say the stock ports suck. Wow!
99591
 

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Discussion Starter #3
99626
Update on porting the intake port from the manifold side. Adding more taper to the center divider, while trying to maintain a radius. As oppose to popular belief, knife edging the intake port divider is a huge mistake. If you want to knife edge only the exhausr port divider.

Made the valve guides flush, which i only do on the intake side. Exhaust needs all the help it can get because of heat.

Im also going to epoxy the floor, and the roof side of the bowl.

Im currently in a make shift setup, since selling my house, so im a bit slower than what it would usually take.
 

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Discussion Starter #4
99627
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Here is all the carnage from the first motor.
The rod bolt decided to come undone.
I can still salvage the cases for a big bore kit. And crank is clean surprisingly, i checked on V-blocks for center.

Already picked up a 2009 cooper S motor with a 6spd. Going to tear it apart, refresh the bottom end and bolt up the 2012 cylinder head.
 

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Discussion Starter #5 (Edited)
99683

Filling the roof side of the bowl in the intake port with marine epoxy. I'll update with the epoxied intake floors.
 

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Discussion Starter #11
The Marine epoxy bit ?
I've been doing epoxy work for the past 10 years on all sorts of applications, but mainly race bikes.

The epoxy allows me to fill in any dead spots in the intake port, thus creating a quicker filling port. Which equals to a much more responsive engine down low, and in between shift points.

Also filling the intake port floor and reshaping it allows me to add some radius which changes the approach leading up to the back of the valve.
This will increase your low lift flow, which is much more important. Its a misconception that low lift to mid lift flow does not contribute to peak horsepower numbers.

The bowl filling removes a nasty transition leading up to the valve seat. This specific addition extends peak power.

One last bit. Turbo motors and Naturally aspirated motors are built exactly the same way in every way. Except you wouldn't run the same compression, and you would run less agressive cams along with a higher Lobe Seperation Angle. Which reduces overlap, and minimizes raw fuel getting dumped down the exhaust port.

But i see alot of misinformation about bigger ports for turbo motors leaving all things equal. You only increase port dimensions if you increase the displacement of the engine, not because its turbocharged.

Hope this helps.
 

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Lots of knowledge in here. I ll be following you closely. I am currently port matching mine and had the exhaust side knife cut as you mentioned. I wont be filling with epoxy the intake cause the volume will get worse on high revs plus goinh for 77.5 pistons, slightly larger.

Στάλθηκε από το SM-G960F μου χρησιμοποιώντας Tapatalk
 

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Discussion Starter #13 (Edited)
99821

You can see how much i built up the floor, which now i can shape and begin dropping the floor from around where the port splits all the way to the valve.

Ill see if i can find a side profile shot so you can get an idea.
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I use plastesine to keep the epoxy from drying over the valve seats.

Its not pretty work, hence most shops dont promote this work. And labour intensive.
99824


Here is the epoxy in raw form on both the roof and floor side before beginning to port.
 

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Discussion Starter #15
It will see dyno and track. No flowbench.
I've spent too much time on dynos and flowbenches'. Usually the same things render similar results, and truthfully i have no desire to spend anymore time then necessary. Its a car to do some track days and beat it.

The winner is always track E.T. and even more importantly MPH trap speed.
I've had bikes with 200hp that are slower than 186hp bikes in E.T. and Mph.

We dont race dyno's or flowbenchs, and if you chase those numbers you can start to confuse things and spiral off into neverland.
Been there already. Track splip is my only measurement.

With this cylinder head im aiming for an additional 30 to 40 hp at the same boost. Im adding a big core intercooler, and deleting the catalytic.

And then ill mess around with KTAG and with igntion,fuel and so forth.
 

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As I was watching your intake valve seats I saw that you have big differences. What model is your mini? Is it a n14 jcw or cooper s? It seems that mine is better shaped under the intake valve in the area you filled with resin.


Στάλθηκε από το SM-G960F μου χρησιμοποιώντας Tapatalk
 

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Discussion Starter #18
Thats a big difference in chamber. And looks like the bowl has been blended.

I have a late production 2012 cooper S. I think its a N18, but its only a guess. Im not versed in these cars.

The motor i bought for the bottom end is a 2009 Cooper S. I'll have a look at the cylinder head.
 

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Sorry for messing with your engine thread but you mentioned that intake should not have a knife cut between the 2 intake passages. Is there a specific cause to back this up, cause all the head porting shops are shaping them with great results. Polishing is just an aesthetic finish.
Thanks, vaios

Στάλθηκε από το SM-G960F μου χρησιμοποιώντας Tapatalk
 

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Discussion Starter #20 (Edited)
If you remember as kids, we would grab a flat sharp piece of grass and blow into it. The by-product would be a harsh sound caused from the turbulence.

You dont want turbulence anywhere facing into incoming air.

That includes the throttlebody butterfly blade, which i radius the edges.

Hope thar helps.

Polish finish creates a smooth finish which doesn't allow congruent air flow. I have the smoothest area at the MSCA/choke point.
 
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