GazJenno

Hi Guys, thought I'd give exhaust manifold porting a try and after some pointers... this is what ive done so far







tools being used that I had lying around as Im tring to be a cheapskate



so far just use the grinding bit... so heres my questions

Does it look right so far?
Are the tools good for the Job and how smooth does the ports have to be?
Should I port the exhaust ports on the head a little bit too?
Will this need a re-map straight away?
Should I port the bottom part of the uppipe abit too (the up-pipe is still attached to the turbo and would rather not remove it)?

Cheers
Gaz

GazJenno

anyone got any tips, pointers, answers for me? I guess I better carry on what Im doing anyway no good having one prot done lol

BTTT

oadamo

iTrader: (1)

looking good i bet that was a good days work with then grinding stones lol.i use carbide rotary burrs it makes the job alot quicker. you might aswell port the turbo side now you have the exhaust off. you want it as smooth as possible on the exhaust side to hele the gases get out quicker. finish it off with a small rotory flap wheel about 60-80 grit.
adam

GazJenno

Cheers for the reply mate... ive now done two, didnt take that long at all tbf about 30mins or so they seem to chew through it pretty quick.

Do you think I should port the head? and the up-pipe?

the up-pipe has the exhaust tube on the inside of the flange so not sure how to do this? dont wanna weaken the welds.

Also when you say the turbo side, do you mean abit of the turbo exit and the down pipe? or the up-pipe to turbo part?

oadamo

iTrader: (1)

ideally you want to do the whole lot. if your trying to go bigger then the gasket and your planing on opening up the gasket aswell make sure the gaskets you have will let you go bigger because if they have a pressed ring you will split them trying to open them up. dont no if you will feel the diff tho when its done i do a lot of heads with good results on the flow bench but exhausts are tricky f++kers to test lol.
adam

GazJenno

Lol... well I was thinking of just taking the heads out abit so they match the gaskets and the manifold. Not going to take any of the ports out more than the gaskets. I'm not expecting much gain at all, maybe a better spool up which might give some more torque lower down the rev range but not expecting alot. Cheers again though!

sponners

iTrader: (4)

deffo worth doing the uppipe. I wouldn't bother with doing the head (unless the heads are off)

....no need to go too wild on ex manifold as the std port size is actually the same as the port on the head! ......its the gaskets that have a larger diameter hole, and this is what leaves the soot line.

GazJenno

well the head isnt off but I can still port the exhaust ports on the head to the same size as the gasket which will then meet the new bore size of the manifold ports too... you think that would help?

I think I might just do it, I am crazy enough to!

oadamo

iTrader: (1)

put a rag all the way in then when your finished pull the rag out. it stops most of the bits getting to the valves. get some more pics up
adam

GazJenno

Another good tip, cheers! ... I have actually started a project thread on everything im doing so all my pics are in there. Its called "Project Rex Racer" although I dont think its gonna be a racer any time soon! will add pics as I go along!
Gaz

GazJenno

Just a thought but if I bore the exhaust ports on the head out to meet the gasket I'm not likely to grind into water or oil galleries am I?
Gaz

tjmatt

iTrader: (1)

The last thing you want to is bore out the exhaust ports on the head without knowing what you're doing. I suggest you read a book about cylinder head porting before you do anymore.

1) You don't need to open anything up to the gasket size. They gaskets are bigger so they don't interrupt the flow through the port if they are offset on the studs slightly. There is no way in hell they should dictate the size of the port before and after it.

2) bigger ports will slow the gas speed and reduce torque and spool.

3) variable size ports and runners (if you open them up around every gasket) will only hurt flow rate.

4) you should really port anything without a flow bench to prove it helps.

Porting standard headers (after the join - not in the head) only works because the exhaust manifold is unlikely to perfectly match the cylinder head. Making the ports bigger guarantees no obstruction, and may help reversion at low gas speed due to the step introduced. It also removes some of the carbon build up after years of use. The up-pipe is also an area for small gains.

GazJenno

Ok, valid points... I am writing on here for advice hence the questions.

I never planned on going nuts on the head, was just gonna taper the last 4-5mm of the port so it would flow smoothly into the newly bored out manifold.

Even then I wasnt going to take the ports on the head out as much as I had on the Manifold.

Although I have bored the manifold out, again only the last 4-5mm is tapered to just within the gasket. The main thing I did on the manifold is grind off the casting marks and help reduce the angle of the few bends I could actually reach. Hopefully this will lessen the turbulance within the gasses and allow better flow.

I may not know a great deal about porting itself but Im just trying to use my common sense and some of the stuff I have learnt about Thermo-Fluid Dynamics to improve gas flow.

Again thank you for your input even if it seemed like you were being abit condescending.

Gaz

tjmatt

iTrader: (1)

I apologise - just didn't want you to start hacking up your cylinder heads.

What you've done sounds good (and actually looks very good), remove carbon, casting marks and make sure there are no interuptions to gas flow. Once you start opening up the cyclinder head to you negate that as well as affect many other things.

The port size in the cylinder head is a specific size for a reason and is vital to engine pergormance. It's size dictates the gas speed and the gas speed affects its momentum. Its momentum helps pull more exhaust out of the combustion chamber and hence more fresh inlet charge in. Unless you know what you're doing often more harm can be done than good.

I recommend if you can get hold of it reading "Theory and Practice of Cylinder head modification" by David Vizard if you're interested in this kinda stuff and haven't read it already. An old book but the principles still apply.

Apologies for before - smoothing interruptions is good - just don't necessarily use the gasket as a reference.

BTW I'm not sure if tapering the end of the port would be good or not, i'm fairly sure it wouldn't as the right angle step you have helps impede gas flowing back into the port (helps make it one way if you like) and that is a good thing.

GazJenno

Dont worry about it, I appreciate the advice and your concern for my engine. I have finished the work on the manifold now and I am happy with what Ive done too. After thinking about it more and after some of the stuff you put out there I think Im going to leave the head as it is untill the future when Ive learnt more and when I have the proper equipment like the use of a flow bench. I am intrested in this sort of thing and will most likely look into the book you suggested.

You can probably tell I have no problems getting stuck in to working on my car and trying different things, after all thats how we learn and progress. If you sit back and think things through thouroughly then I feel there should be no issues and at the end of the day if it goes wrong it can always be fixed one way or another.

I shall put some more pics up when I can, probably in my project thread, which will show some of the other stuff Im doing too.



Thanks again for the help and advice!
Gaz

oadamo

iTrader: (1)

hi i has dug up my pics of doing this same thing as you are trying to do.
you only need to port the pipe side that connects to the head manifold on the pass side as the other side pipe diameter does not increase into the other side.

adam

link pipe


grind down weld


smooth it out


then crack the top ring off



then smooth it in