Technical Cilinderhead flowing

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Technical Cilinderhead flowing

TurboCinqy1250

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Hi,

I still have my 1.1 head incl. inletmanifold from my old engine and I was wondering if it's a goed idea to flow the inlet channels with a multi-tool. So bigger inlet ports, better cornering and if it's possible bigger inlet valves.

And when I'm done to replace it for the other one and measure if it's better or worse. Only I don't want to lose to much torque.

It's for a HP turbo 1.2 engine.
 
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arseofbox

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Yeah, sounds like a good idea.

I heard a while back a guy with a 1108cc head was fitting valves from the Bravo into it...so that could be something to look into perhaps?
 

Oldschool

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You have to be a bit careful with porting the 8v FIRE heads. If you take material off the wrong end you will go to thin and the risk of breaking through is quite big. When you cut up a head you will see what I am on about.

Bigger valves is no problem. If you choose some with a longer stem and use some spacers to keep the spring tension correct. This way you can use lighten valve train and/or re-profiled cam without any problems.

Main restriction will be the valve guide and near the valve head. Flowing should be done afterwards on a flowbench. Finish it off with multi angle valve cut.
 

Catseyes

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TurboCinqy1250 said:
Hi,

I still have my 1.1 head incl. inletmanifold from my old engine and I was wondering if it's a goed idea to flow the inlet channels with a multi-tool. So bigger inlet ports, better cornering and if it's possible bigger inlet valves.

And when I'm done to replace it for the other one and measure if it's better or worse. Only I don't want to lose to much torque.

It's for a HP turbo 1.2 engine.
Its one thing to match ports on the inlet but I wouldnt attempt the head yourself, leave this to someone that has done it lots of times as they will know the limits on what can be removed.
 
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TurboCinqy1250

TurboCinqy1250

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just started to make the inlet manifold a little bigger

2x-spruitstuk.jpg


2x-spruitstuk2.jpg

( the aluminium stuff is from 1 port.)
 
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arc

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id be looking toward binning the standard one and getting a better inlet manifold made. the stock one is, well, crap.

how far down are you taking material out? watch out for the waterway on the base of it!
 
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TurboCinqy1250

TurboCinqy1250

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The aluminium is quite thick around the ports so I think it isn't a big issue to grind a lot. (I think it is about 3mm around)
Only there is a chance that it goes wrong....oh well then I need to buy another one and start all over again.
This one I get when I bought my 1.2 engine. So it was a spare one.:D

I tried to grind all the way te ports maybe it is a little smaller in the back of the ports but not much.


[edit]
Just calculate a little and normal it's about 25mm diameter (4.91 cm2) and after it's about 30mm diamter (7.07cm2) is about 44% bigger.
[/edit]
 
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rallycinq

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As Arc says, watch out for the waterways and I think that if you onl;y open up the head end then the gas speed will fall as the port opens, rather than stays constant so open up a bit more near the TB.

Cheers

D
 
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TurboCinqy1250

TurboCinqy1250

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The beginning of the manifold is twice as thick then the end 1-2-4 inlet.
So I think the port size is everywere the same. I wil make a small cardboard paper that identic on the inlet hole. Than I should see if the ports are all the same at all places.
 

Oldschool

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TurboCinqy1250 said:
The beginning of the manifold is twice as thick then the end 1-2-4 inlet.
So I think the port size is everywere the same. I wil make a small cardboard paper that identic on the inlet hole. Than I should see if the ports are all the same at all places.

Don't forget that you have firing/filling intervalls 90-270-90 degree (cam rotations) intervalls with the standard manifold, which make it a bit more akward.
 

stefz

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Dont open up the ports too much, its easy to get carried away..

The ratio for port diameter to valve size is about 1.2-1.3:1, measure your inlet valve diameter * by 1.25 will give you an idea of how wide the ports should be (just as a rough guide).. Ports too big and air speed will be slower and you will lose torque. keep them no bigger than 1.3:1
 
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TurboCinqy1250

TurboCinqy1250

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Oke thanks.

inlet valve is 31.5mm std. Maybe I put some bigger in it. max 33 I think.

And the port is about 30mm rond. So it is still smaller then the valve.

I just grinded the backsite of the hole a little further than before. I think the diameter is everywhere the same right now. 2 down 2 to go and then I need to polisch the outside again(n) Because I did it just 1 year ago

HT-Inlaatspruitstuk.jpg

The otherone that is still on my car.
 

GhostWKD

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Wow! that polished inlet manifold looks fantastic :eek: Great work and very informative pics/posts (y) keep up the good work, it will be interesting to see how the car behaves with this ported out inlet fitted :cool:
 
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TurboCinqy1250

TurboCinqy1250

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When I'm done I will take a run with a G-tech Pro RR Aceleration device and after the swap I will make a 2nd run and measure the difference between the 2 manifolds.

http://www.gtechpro.com/rr.html

I will do the same with the 32 to 40mm TB and gasflowing the cilinderhead. So I can see the results before and after.
 
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TurboCinqy1250

TurboCinqy1250

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This afternoon I checked the inlet ports of the head and manifold. But the manifold holes are standard much smaller than the head ports. So I think this isn't a bad modification for each cinq.

The ported manifold holes do almost match to the head.
 
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I would love to have a go at making a custom inlet manifold. I know i am capable of making one, but adding coolant to it would be an issue. I think i would snake pipes between the inlet pipes if you know what i mean alot smaller pipes than what is used for inlet pipes. What would be a good pipe to use for the inlet size? just match to the size of the inlets on the head?

Jordan
 
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