Pinto Porting

[nismo.capri]

How do I know there is a vortex??????

Honestly if you are wanting to get the best results you need to be able to know how the gases go in and out.

May be that's why I was asking...

It is generated by the turbulance of the valve opening and the sucking of the exhaust port but it all starts with the combustion chamber.

I googled this up here http://www.ingentaconnect.com/content/p ... .alexandra

Abstract:

In this study, the characteristics of flow emerging from the inlet of the intake port in the cylinder were investigated experimentally. A particle image velocimetry (PIV) technique was used to measure the velocity distribution in order to observe and analyse the flow behaviour. High-image-density PIV provided acquisition of patterns of instantaneous and averaged vorticity and velocity, revealing the detail of the flow characteristics in the cylinder cavity. With this measuring technique, it is possible to study the effect of intake valve geometry on the flow behaviours. The results showed that the flow structure changed substantially along the cylinder stroke due to the geometry of the intake valve port.

Wifey works at the Uni she is going to see if she can dig it up, If she can I'll flick you a copy.

Its not texture on the back of the valve dude, its a tracked set of lines to ensure the gases are spinning into the cylinder in the right direction for the combustion chamber.

I have a hard time wondering how the lines and swirled valves do much at all to the flow. I think of it like this if I had a stream of water and was to divert the flow the stick I'd need to use would need to be substantial and go deep in to the flow to effect it. If I was to keep the stick close to the bank of the stream it would have little effect on most of the flow. Why is lines in the port different?

Not being rude but Do you do this for a living????

Nope, why should that matter?

I'd guess the guy who did the $15K shitter head you mentioned did it for a living.

And for your info The guy I mentioned has broken the 200hp barrier with cast crossflow and non crossflow heads.

He also is getting massive 300hp plus from BDA engines.

These are real figures not I think by the feel in the seat.

Can you get the figures?

Also not being rude, this is the internet and you could be some German Shepherd who's using your owners computer while they are asleep

I bet you've seen and heard your fair share of shit about the pinto. I'm not saying you or anyone else is making shit up I'm just trying to stick with information I can prove as fact.

I spent over 300 hours working flow benches and milling combustion chambers on jet sprint boat heads to get that last drop of power out of a small block chev only to have a rod stud snap and smash the whole thing to bits.

After 20 years in this trade you come to realise "Thats the way it goes sometimes".

Aint that the truth!

Do you Dave McCallum?

You'll know the boat http://www.pcrjetsprinting.com/

Biggest "350" Chev in the world at 540 ci

Engine

Type V8 Billet aluminium super-tall-deck, big bore, Small Block Chev. (only one of its kind on the planet) Kinsler custom made fuel injection manifold.

Displacement 540cuin (8.9 Litres)

Fuel VP M1 Methanol (alcohol).

Injection Kinsler Custom made (biggest injection manifold ever made for a SBC).

Cylinder heads AJPE Billet aluminum cyl heads-special order.

Ignition MSD Pro Mag 12 lightweight

Filters K & N

Instruments Autometer

Spark plugs Champion

Exhaust design Harris Race Pipes (Christchurch NZ).

Exhaust manufacture Motorcycle Exhausts (Christchurch).

Exhaust coating Cermakrome by Pro Coat (NZ)

Lubrication 5 stage dry sump system

Oil TOTAL

Engine builder Track Sport Engines, (Auckland. NZ)

Telemetry MoTeC ADL data acquisition.

Weight 190 KG (420 lb)

Performance 900hp @ 6000rpm. Uses 12 litres Methanol fuel per minute. (US Gallons 3.1/min)

Acceleration 2G’s force 0 to 120 kph (0 to 75 mph) in 2.3 seconds

Cornering 5 to 8 G’s of cornering force

[nismo.capri]

So are you saying theres no gain over using a twincam head other than cam timing?

If they are both 8 valve then there is no big reason why there should be.

Most I've seen have a lot better "looking" heads with a wide valve angle and better runner shape.

Port/combustion chamber shape isn't controlled by the number of cams. I'd say that generally the twin cam old school stuff is better than the same period single cam because the Twin cam stuff was the High performance end of it's day. You can have well designed 8 valve single cam head that will out perform an 8 valve twin cam. I'll dig through the flows of some standard heads and see if I can find an example but I don't think I've got much twincam 8 valve.

[Testament]

like you could make either layout flow 'x' CFM, but twin cam has some benefits in valve anges available to the designer. Twin cam also lets you have direct valve actuation (better for high rpm, less valve train componenets etc.) and different intake and exhaust valve angles (you can have sohc direct actuation but the vales have to all be in line).

And as you say most twin cam heads were for higher spec/performance models - so they generally flow better to start with. when you start to port things to buggery it doesnt matter so much what you started with provided the casting is good/has enough meat in it. but conversly if your not going crazy you don't usually have to do so much to get enough flow for more mildly respectable outputs.

[nismo.capri]

like you could make either layout flow 'x' CFM, but twin cam has some benefits in valve anges available to the designer. Twin cam also lets you have direct valve actuation (better for high rpm, less valve train componenets etc.) and different intake and exhaust valve angles (you can have sohc direct actuation but the vales have to all be in line).

For sure!

I'm not saying twin cams are bad or worse than a single. I'm just saying that just becasue it's a twin cam doesn't mean it's always better than a singe.... however usually it will be

And as you say most twin cam heads were for higher spec/performance models - so they generally flow better to start with. when you start to port things to buggery it doesnt matter so much what you started with provided the casting is good/has enough meat in it.

The port flow is always limited by the design, the pinto for example you need to take out the minium amount possible as the port is too big any way. That's why I'm heading out to the garage now to fill the port with epoxy putty

[Testament]

yeah - twin cam doesnt neccesarily mean things are better (or worse)

the original post i made was in jest a little bit - there is alot of discussion on pintos and the mythical 200hp ones, but it seems you really have to get things right to get anywhere even close to that. There are other comparable engines of the era which do it a little easier is what I'm saying. addmittedly not that useful a comment I guess.

Anyways

I'm not so sure about taking the guide boss out - the valve stem is still going to be there - so are you really gaining anything significant, and at what possible cost in reliability/longevity. I guess its a bit late now though

I will be interested in how filling out the bottom of the port to get a bigger short side radius goes, the fiat twin cam has a similar downfall, the ports are pretty generous on the more performance oriented models but generally have a pretty poor SSR and because of this it's thought if you want to do a real trick porting job you want the head off one of the smaller capacity models as they have smaller ports which give more room to play with (everything else is the same valve size/water gallery locations etc.) allowing you to raise the port centreline and get a bigger SSR.

[fishtailfred]

Cool

Porting a steel head must be such fun

Hi Fred!

Yeah I'm a sucker for punishment

The few alloy heads I've done feels like butter compaired to the cast iron I'm used to

No no, I was serious, it's SO easy to screw an ally head up, whereas the process would naturally be more gradual and controlled with steel.

So are you saying theres no gain over using a twincam head other than cam timing?

If they are both 8 valve then there is no big reason why there should be.

No big reason, but the valve train alone is a good reason :

Lower mass and intertia = lower spring rates for same lift/ramps = lower friction/wasted energy.

Plus, this also means that you can make it rev hard reliably more easily. Rockers are just nasty, and that includes modern engines with them like the sr20.

Sorry I took so long on the reply, some silly bastard decided to pay me a bunch to sit in a high rise in London and do SFA. Shit is it boring. I'd rather be.... collecting peoples garbage I think.

[slipsittin]

Nissmo I am trying to get Bob to give me a printout of the 4 biggest engine readouts and I wil chase it up when I go in there this week.

As for being a dog I consider myself more along the lines of a Jack Russell

The exhaust port needs to be D ported if you want any success man and the intake needs to be radiused not round.

You also need to change the shape of the combustion chamber to allow for the intake to be sheilded from the exhaust on overlap.

The water theory doesn't work when talking gases.... Gases need to be told what to do and you need to be able to contain what you do.

Its kind of like a plane flying through turbulance the atmosphere keeps the air at a pressure constant but the moisture makes it have air pockets and therefore makes the pressure alter as the plane flies through. To keep the plane steady they drop down to where the pressure is more stable.

In a port the pressure needs to be stable also and the gases sent through the inlet port in to the combustion chamber with little difference to gain the maximum amount of gas in the port and the least amount of fuel droplets left in the port.

Hope the epoxy works out ok for you

All the best with the head bro

[slipsittin]

One last thing.

I'm using the sierra dohc (so called lemon by some) in my project mk2 Cortina and without stripping beyond the cams coming out and efi ones fitted, headers being fitted and sidedraughts that engine goes up from 118bhp to 154bhp... food for thought.

Corey

[Spencer]

The water theory doesn't work when talking gases.... Gases need to be told what to do and you need to be able to contain what you do.

lol

[SloNLo]

Gases need to be told what to do

should give it the idea i think

[nismo.capri]

the original post i made was in jest a little bit -

I was just playing devils advocate

I'm not so sure about taking the guide boss out - the valve stem is still going to be there - so are you really gaining anything significant, and at what possible cost in reliability/longevity. I guess its a bit late now though

You are right because removing the guide boss looses a bit of low end for gains right up top and unless you have a high lift cam it's not going to get to the lifts with the increased flow.

I will be interested in how filling out the bottom of the port to get a bigger short side radius goes, the fiat twin cam has a similar downfall, the ports are pretty generous on the more performance oriented models but generally have a pretty poor SSR and because of this it's thought if you want to do a real trick porting job you want the head off one of the smaller capacity models as they have smaller ports which give more room to play with (everything else is the same valve size/water gallery locations etc.) allowing you to raise the port centreline and get a bigger SSR.

I wish it was as easy with the pinto

[nismo.capri]

No no, I was serious, it's SO easy to screw an ally head up, whereas the process would naturally be more gradual and controlled with steel.

It's certianly great when you want to make small changes..... big ones like removing the valve boss not so much

No big reason, but the valve train alone is a good reason :

Lower mass and intertia = lower spring rates for same lift/ramps = lower friction/wasted energy.

Good point!

Plus, this also means that you can make it rev hard reliably more easily. Rockers are just nasty, and that includes modern engines with them like the sr20.

The SR20 set up looks worse than the 2L from what I've seen of it!

Sorry I took so long on the reply, some silly bastard decided to pay me a bunch to sit in a high rise in London and do SFA. Shit is it boring. I'd rather be.... collecting peoples garbage I think.

Right now I'd kill for a job like that.'I'm in the middle of 3 projects that all finish about the same time and I have to keep the usually shit running

[nismo.capri]

Nissmo I am trying to get Bob to give me a printout of the 4 biggest engine readouts and I wil chase it up when I go in there this week.

Awesome!!!

The exhaust port needs to be D ported if you want any success man and the intake needs to be radiused not round.

You also need to change the shape of the combustion chamber to allow for the intake to be sheilded from the exhaust on overlap.

From what I've found the chamber on the 2L isn't bad at all for shrouding I've opened it up a bit on the important side.

The water theory doesn't work when talking gases....

I thought it did for homiginised flow?

The fuel gives the flow way more mass than if it was just air?

Gases need to be told what to do and you need to be able to contain what you do.

Its kind of like a plane flying through turbulance the atmosphere keeps the air at a pressure constant but the moisture makes it have air pockets and therefore makes the pressure alter as the plane flies through. To keep the plane steady they drop down to where the pressure is more stable.

That makes sence

In a port the pressure needs to be stable also and the gases sent through the inlet port in to the combustion chamber with little difference to gain the maximum amount of gas in the port and the least amount of fuel droplets left in the port.

Wont the pressure never be stable in the port becasue as the flow fills it the pressure will be dropping?

Hope the epoxy works out ok for you

All the best with the head bro

Thanks

[nismo.capri]

Gases need to be told what to do

should give it the idea i think

.....and here am I wasting all this time with the dremmil!

[Gaz]

What kinda dremel do ya have out of curiousity? How many hours and what bits do you recomend.. Just for anyone who wants to try for themself.

Gaz

[nismo.capri]

What kinda dremel do ya have out of curiousity? How many hours and what bits do you recomend.. Just for anyone who wants to try for themself.

Gaz

Supercheap "rotary tool kit" comes with flexi extension and a heap of bits, all for the princely sum of $40 is the best starting point IMO. It's not as fast at removing material as a die grinder or the 6mm bad boy electric porting tools which is what you need when starting out.

[cute wee gem]

I use a 6mm one with a long drive, works pretty well but a smaller one would be great for more detailed work like nismo is doing.

6mm sucked when I started on a 1275 mini head, definitely would have needed a smaller one but never finished it anyway.

[fishtailfred]

Sorry I took so long on the reply, some silly bastard decided to pay me a bunch to sit in a high rise in London and do SFA. Shit is it boring. I'd rather be.... collecting peoples garbage I think.

Right now I'd kill for a job like that.'I'm in the middle of 3 projects that all finish about the same time and I have to keep the usually shit running

Yeah, collecting garbage would be great, working with tibco business works designer when you are a genuine software developer on the other hand is just insulting and painful no matter how much cash is involved. Seriously thinking of resigning ey. Packing into the tube trains in the morning is also great sport and really helps the suit stay unsweaty... fuck london sucks 1 month down 11 to go, back in NZ in 1 year!!!

Is your super rotary kit air based? The bearings in the front of dremels do not last if you try any porting with them. OK for touch ups, waste of time for serious work. I bought an air tool shortly before leaving and it was the best money I ever spent on a tool. Can't find a pic of it, but it was a little red one in a little case bought from wairau engineering.

Fred.

[slipsittin]

Gases need to be told what to do

should give it the idea i think

.....and here am I wasting all this time with the dremmil!

You tend to get the carbs poping back under accelleration from idle (side draughts of course) with trying to get the gases flowing straight through the port.

If you go to your toilet flush it and watch how the water exits about 10 times you will get the picture of the valve opening in a well directed port. Thats the extent of the similarities of water and atomised fuel. (it sounds fucked up I know but it works, also its hard to explain to your partner why she can't use the toilet due to scientific reasons)

I always make the pinto heads spin the atomised air/fuel so the sheilded piece of the combutsion chamber is only blocking the operlap efficiency.

You are doing a great job with your tooling and are getting close to the right path thats why I posted the last post.

The most important thing also not listed in any books....

If a head is set up for turbo (only talking about ported ones) it will never give a good result on a carbed engine below almost peak RPM.

This is due to the volume of air that a turbo can push through the port as oppossed to the amount a piston can suck through the port.

I'm on a course for work from today and won't be back till Saturday, hope it goes good.

By the way the tools from Super Cheap are fine but a rotary burr is the way to go and last longer than stones.

[nismo.capri]

Is your super rotary kit air based?

Nope 125W electric. I don't even run it at full speed

The bearings in the front of dremels do not last if you try any porting with them. OK for touch ups, waste of time for serious work.

Yes with the dremmil brand, the super cheap jobbie had a flexi extension and I usually wear out the chuck before the bearings die

I bought an air tool shortly before leaving and it was the best money I ever spent on a tool. Can't find a pic of it, but it was a little red one in a little case bought from wairau engineering.

Fred.

After using the little one I always find the air die grinders bulky