Ported Cylinder Head Advice and Fitting

[beavy69]

Hey all, just bought a ported 1.3 head and kent AST2 cam that came with it on ebay.

[NB May want your screen brightness up to see pix better]

I have 4 main concerns:

1) The valve seats have been grinded right down (see pic below). Is that a bit dodgey? I thought they only did that in race spec heads?

http://i34.photobucket.com/albums/d149/beavy69/P1030797.jpg

2) Even though it is clear that the exhaust ports have had some work (as they also have had their valve seats completely ground flat), the exhaust ports have not been opened up nearly as much as the inlets:

http://i34.photobucket.com/albums/d149/beavy69/P1030799.jpg

Exhaust side:

http://i34.photobucket.com/albums/d149/beavy69/P1030800.jpg

The exhaust port width is 29mm and inlet width is 32mm.

http://i34.photobucket.com/albums/d149/beavy69/P1030801.jpg

Inlet:

http://i34.photobucket.com/albums/d149/beavy69/P1030803.jpg

The exhaust port height is 31mm and the inlet 38mm!

http://i34.photobucket.com/albums/d149/beavy69/P1030802.jpg

Inlet:

http://i34.photobucket.com/albums/d149/beavy69/P1030804.jpg

Is that normal or should I open the exhuast ports up a little when I give them a polish?

3) I have been over the face with a precision steel rule and it is flat aside from one small corner (approx 2cm in from that corner to form a traingle) Could I carefully file it and keep checking it or should I really get it skimmed.

I got quoted ?29.50 + VAT for a skim and ?48 + VAT for a crack/pressure test!!!

4) And having now seen the level of porting, will I get any probs running an AST2 with it (on a 1.3 block with a 32/34 weber), I think the springs are uprated ones and I will be relapping the valves to make sure. The bloke said I'd need to idle at about 1000rpm but I already idle at about 1200rpm.

Thanks for reading and in advance, for any advice,

7im.

[Adam]

Inlet ports/valves always need to be bigger than exhaust, as inlet gas is pulled in, whereas exhaust gas is forced out.

[stuartp]

^^^ agreed there but anit to sure on the other stuff!! I def wouldnt file the head, get it skimmed mate!!

[craig green]

Skim for sho', lap the valves then..
Just bolt it up & away you go. Good price btw.

[Adam]

You could polish the exhaust ports to a mirror finish, but do NOT polish the inlets, they need to be rough.

[beavy69]

I spose I should leave the valves in for the skim to stop sh!t getting in the hole?

[rysmee]

but if your going to grind in the valves as you say then your going to have to take them all out anyway.

[Mike]

noway, ive got the same item but a C14SE one?

Exactly the same sitting in my wardrobe lol

edit: not anymore, just sold it for ?180 on eBay lol

[leebo]

You could polish the exhaust ports to a mirror finish, but do NOT polish the inlets, they need to be rough.

why cant you polish the inlet to a mirror finish?

[Adam]

Because the inlets need to be rough so the fuel atomises with the air, and stays in suspension(like in a mist/vapour)

Try breathing on a mirror ;)
Thats what would happen to the incoming fuel/air if the inlets were mirror polished

Now breathe on a paving slab ;)

[leebo]

ha ha, great way to exlpain it i have to say. cheers man

[beavy69]

That is a good way of explaining it, I had originally thought of it as keeping the mixture turbulent at well.

Glad you got ?180 for your head. I paid ?79.00 for mine including the AST2 in housing complete with lifters and dizzy!

Although I did have to drive 1/4 of the way up the country to get it which cost about ?40 in fuel but that did the car a load of good as it normally only gets short journeys. It now revs to 7 thou! and havn't put the cam on yet. lol

[beavy69]

Just checked the head face again with a FLAT rule and turns out its ok! Good to go then! After I lap the valves and clean and polish (not the inlets of course)

A good tip from my uncle: To remove any surface grime and to make sure the head mating surface is dead flat I will be rubbing it on a piece of flat glass with lapping paste on ;)

[beavy69]

Having said that, final question: How do I know is I need to replace the lifters, there does not seem to be much wear at all to the rocker arms, but not sure how to check lifters?

[Adam]

Best to remove the lifters, and clean them, then re-fit.
Fully explained in haynes manual, and works well, made my old lifters completely silent even at cold starts.

[beavy69]

Sure but I don't know how to tell if they need replacing or not. All it says in the Haynes Manual is to immerse them in oil.

You see I have a GTE cylinder head (ready for turbo eventually) and those lifters move at the top BUT not all by the same amount, yet I don't know if that is OK and just down to how presurized they happen to be with oil. On the other hand the tops of the lifters for the head inquestion wont budge yet the inner bit inside the top moves. So does anyone know what to look for to see if I have to replace them?

[Stuart]

id take them appart and clean/wet + dry paper the plungers regardless of the movement....

if the head has been worked on previously and worked well, then id not touch the ports (even with a polishing kit) imho....

[beavy69]

Surely I should clean the sooty crap off though. So how do you take them appart?

[beavy69]

Sorry guys - too early in the morning - I just found the section in the Haynes, it was at the back with all the updates as usual.

[philip]

id always match port to gaskets, especially on exhaust, if keeping standard FI, as wont fuel right with opened up inlets, unless running a dta/mbe/omex ecu where you can adjust it.

from the pics the job on the inlets look quite good, ive just done a mates valver head, and got an sri 130 head to port + 2 1.4 nova heads i think im going to big valve/port to sell on! if any one may be interested!

def dont touch the inlets....have them too smooth and the fuel 'pools' and drips into the chamber, which could cause hotspots, and poor burning across top of piston!

exhaust should be mirror finish to let the gases escape smoother.

and how accurate is a 'flat' rule? just get a light skim

[Adam]

Surely I should clean the sooty crap off though. So how do you take them appart?
The soot will return within 10mins of starting the engine up anyway.

I just use brake/carb cleaner to clean all the internals of the lifters, then re-assemble them using some clean engine oil, and re-fit.

[Stuart]

as for port matching.... id be more inclined to play the anti reversion game on the exhaust side... ie the ports on the head are smaller then the runners on the exhaust manifold. google anti reversion ;)

[beavy69]

As intended guys. Am still gonna give the exhausts a little buff though, I can't resist.

I used multiple flat objects including a sheet of glass in the dark with a torch at every angle, the heads OK. Like I said I'll be pasting the surface just to sure and Novas use composite gaskets anyway which would accommodate anything I could have missed after my detailed inspection.

[Adam]

How can you be sure the glass itself is flat tho?

I was going to use a piece of glass, but was told glass aint flat.

So i just fitted the head anyway, and hoped it was fine,Lol.