Porting Head

[Nova-Boy]

I have got my head skimmed and cleaned and am currently cleaning my valves and lapping them in.

I have noticed the inlet port in nice and roundy but the exhaust port has got a sharp lip. Has anyone used a rotary file or similar to round this off a little and did it improve the flow any and would anyone recommend or not recomment it :?:

[Dicko]

tbh i wouldnt bother

you wouldnt see any performance gains unless you did some serious work, and unles you know what your doing you might make it worse

[Nova-Boy]

Ok then i wont. Just thought it might get the gasses out better.

I'm not paying for it and dont want to make it worse so i will leave it.

[match]

i took that lip off my head with a rotary file attached to a drill, you might not get a very noticable power gain but its worth removing any restrictions in the head that you can see. removing the lip will increase the gas flow and cause a better swirl of gasses through the head.

if its in bits why not do it?

[Nova-Boy]

Well i dont know. I might just have a little dabble at it if it wont do any harm. as long as i dont take too much off an fcuk the head i will be ok. Wont I?? :|

[Stuart]

erm I'd recomend reading two books, both by David Vissard (the god of head tuning) one is the SOHC ford engine book (since the heads are nearly the sam the concepts are applicable)

and also his book on general head work.

both on amazon.

also from my experience at uni its been noted that a polish on the inlet port is bad (unless your running at stupid rpm when turbulence is natural)

and also you have to keep the bottom radius of the inlet port as large as possible.

this isnt the same for the exhaust port, most of the air flow is at the top of both ports so mainly concentrate your efforts there

[match]

as i understand things a rough finish on your inlet ports is better (shot or rough sand blasted) as this causes the fuel to gain swirl in the inlet manifold therefore allowing better conbustion once it enters the cylinders due to the air and fuel getting well mixed in the swirl action??

what course at uni are you doing cambridge mate?

[match]

as i understand things a rough finish on your inlet ports is better (shot or rough sand blasted) as this causes the fuel to gain swirl in the inlet manifold therefore allowing better conbustion once it enters the cylinders due to the air and fuel getting well mixed in the swirl action??

what course at uni are you doing cambridge mate?

[Stuart]

just finished uni, see footer!!

and swirl isnt promoted by rough ports, turbulence is. similar effect but not exactly swirl, you get more swirl from a cunningly cammed 16V head lol.

turbulence and squish are whats handy in 8V engines.

but as i said vizzards books are the best, until i write one ;) lmao

[MC]

Don't take the lip of the exhaust port!

It is there for anti-reversion. Exhaust gasses move in sound waves. It doesn't just behave like a liquid. Read Vizzards books.

MC

[Nova-Boy]

ok i will leave it alone. lets just get the beast running eh? ( not that you can call a 1.2 a beast! lol)

[rgv_stu]

think he was refering to the lip in the port at the base , the short side radius. not the lip between head/exhaust ??

[Stuart]

when i was waffling allong i was on about the intake lol

dont touch the bottom of the exhaust port, unless you mean business lol

[Rane]

you can send me your head (DENMARK) and then I can Port your head
for 200 pound + delevery

RN-Porting DK.

[Will]

:o

[mikeoxford]

going by billy blydenstein ?500 prices thats not bad!!!!!!!!!!!

[Stuart]

but does the danish geezer cut bigger valves in etc, or is he jsut on about attacking it with a burr set lol

[Nova-Boy]

I dont need it doing that much! I'm not spending that kind of money on my 1.2 head when for that price i could have a 2.0 installed!

Well anyway to close this topic i am not going to bother and just get the head on the car!

Thanks for the advice everyone.

[burgo]

the roughness of the inlet port is needed as it stops the fuel vapour dropping out of the mixture if u do wanna clean it up then dont go ne lower than 80 girt emmery cloth but u can get the exhaust ports like mirrors however it takes fecking hours and once uve done one u gotta do the rest if ur really wanna do head work get another head to do it on as it takes ages well it takes ages wen all ur using is a dremel and wet and dry lol take alook at m alfa feature to see wot ive started on the inlet manifolds to b onist kinda wish i hadnt but ive started so ill finish and im sure some1 has got a diagram to show u wot to and not to remove

[MC]

Or you can send it to me and CP and have it ported for ?50.

[Dicko]

wanna port my inlet manifold for those kina prices :D

im sick to fcuk with it now taking forever (need a more meaty tool which isnt gonna damage it)