If you skim your head vernier pulley is a good investment for a proper set up on valves angle opening, otherwise you'll have (even if little) a wrong one. Head is lowered regard its oem position, hence when valve starts to open piston is on an upper position (head related) than on stock, resulting on a wrong angle valve opening.

 

pocket pistons by 2mm, fit uprated valve springs, standard ones can't take that much lift, fit verniers, be careful with porting the port walls are quite thin and you risk going through.

 

thank you
that's was a big help.

but i have a question!?
how much head can be skimmed?
head and head work is very very chip here ?? instead of 650$ pistons!! ?

and i rather to improve my cr a little bit ,
( about 0.4, 0.5 + 10.5 to take ~11 compression ratio)

how much i can go and whats max limit of head to be skimmed!?
(expet pistons are deep pocketed)

tnx mate
sorry for my bad English

 

The only way to be sure is to do a dummy build (one that is used to check clearances, etc, with the head gasket to be used, no rings on pistons, etc) with some solid lifters set to zero clearance and the lightest springs you can find to just keep the valves closed.
One way is to use some plasticine laid in a thin layer where clearance is a concern and may be best for piston to head clearances. The other method uses a couple of DTIs (Dial Travel Indicators) on a couple of valves (if you are really fussy, check all valves or at least some plasticine for closest gaps) - with the engine at, eg, 10 degrees BTDC, gently press down on the valves and note the travel until the valve hits the piston or 5mm, whichever is the smaller. Then do it 9 degrees BTDC, 8 degrees, etc, until 10 ATDC or adequate clearance is confirmed - the advantage of doing it this way is that for some engine combinations TDC may not be the closest point to interferences between the head and valve and, with some calculation, you can figure out how much you can safely alter the timing and/or if a more power oriented camshaft will fit.
Personally, I would spend a little more money (not that much when you consider the total cost and that they will come with new rings) for new high compression pistons of the next oversize as they will have valve pockets to clear anything you are likely to use, will have the increased compression you want and you will have a perfect bore to piston clearance.

 

Tnx gordo

big help

im going to assemble whole engine on 2-3 next day's

and will check it out

 

Hello Behzad. Another persian on the forum ... woop woop

Post up some pics of the car

 

nariman

where do you live
persia or u.k
my astra needs serious body work.
I will post close ups after body overhaul.
that's long shot for you
that marooned one

 

I am in the UK mate, North Yorkshire

 

i made some changes in my project

first of all
i found early type flywheel and i machine it to reduce its weight slightly and then balance it whit cranck
if it be ok i will cancel, mading of custom cnc made flywheel to save some money.

second
my custom f20 gearbox finishid
1 - 2 - 3 - 4
from f20c
fdr 4.19 from f16w
i also use f16w 5th gear to achieve maximum top speed

porting is done, but trying to Polish ex side

i will post my pics soon

 

hi

i have problem whit uploading photos

can any one help

 

Hello again

i do i lota work this week
piston s deep pocket done successfully
special tnx to GORDO

all con rods weight balanced and the tolerance is all about 1 gr
also overall con rods weight reduced about 36gr and press forge mark removed.

itb is ready

i ordered one exhaust manifold from ebay, marked as direnza, seems good from pics
but will come to me about 10 days later.


sorry for my bad english, cause now is 5AM in tehran and im little sleepy

at last i have problems with uploading photos
what can i do?

best regards

 

Hi everyone

dose any one can send me good ign/feul map for me.
im running haltech but ms map also can help me

 

Hi
New uodates

I bought 87mm flat type accralite pistons
I calculated with head i skimmed befor cr is about 11.8:1
+1mm wasted stem for intk ex
Double valve springs
Jenvey direct to head 45 mm with 60 mm horn
Vernier adjustable pulley
Glycob racing bearings

AudiR8 / gallardo ign coils

From Q.E.D ( DEPSITE COILS)
i appreciate their cooperation.
They ship item as fast as possible to iran.

My set up changed a lot
I rebore engine with custom Tq plate
With 0.08mm cylander clearance ( qed /accralite said)
Glyco rod and big bearing measured and installed.

All con rods weight balanced with +- 1g tolerance
My head seats machined and tri angled for new set up!!!

Its in final process


But we still fight with each other for port size

I told my tuner that, gasket match is just ok( i do it before with myself and its finr)
But he show me lots of heads from mazda Honda peg that have very big ports!!
And he telling me i should open as far as we can to maximizing flow characteristics!!!!

I really confused

Could you any help please!?

 

If you're going on a 11,8 CR your plans is to go on big bhp. This mean you need big ports to have big bhp figures.
Stock head ports with ITB should let you reach 200bhp, wich is your aim for this engine?

 

That car is for drag racing or rare midnight runs, for killing some bmws(lol)
It isnt daily driving car i always use 104 octane, and i do my dailies with 3 cylinder 1.2 Mitsubishi Mirage (lol)

Ok back to main subject
How much i can open head ports?

It mached to gaskets (i do lot work to do this)
From both side, exhaust mirror finished
And intake is rough with 120 grit for maximize fuel/air mixing.
At this moment my jenvey Itb ports are at the same size of my head.

Now tell me how much i can go further after
Gaskets from both side( itb and gead)
I need max as possible Hp and Tq from my whole setup.
Sadly No one have experienced in this particular engine here an i must do with myself.
If it was ls series or Toyota jz my work be easier



Tnx

 

you cannot go too big with the ports, there is not enough material to work with, a good clean up and some detail work around the valve throat area, should be fine the standard head will flow enough air for 230 plus bhp.

 

If you're still running with the same size between ports and ITB then you are arrived. Had you previously check if it exist a larger ITB manifold?
Risse motorsport (Germany) with a 180deg turned head, can go to 285bhp mark on this engine, with ITC engine spec (9000/9500 rpm engine).

 

Different engines will have different port requirements as camshaft selection, valve sizes, port design, piston acc'n, etc. vary. Big ports are only really effective when the rest of the engine configuration works with them as otherwise you are losing port velocity (important for the 'ram effect' as the valve closes) which hurts lower rpm torque (power) with the rest compromising high rpm torque (power).
One of the most important areas of the port, for both power and torque, and especially at lower lifts is the valve seating region and the inch (25mm), or so, inside the ports. As a general rule, you want the ports to be as small as practical without restricting power, as that will help everywhere - so I would not concern myself with anything other than matching the head to the intake and blending it into the port over an inch or two, depending on how much was removed from the head face.
If your tuner chap is of the "bigger is always better" mentality, perhaps you should consider another as that is NOT the right way to look at it.
IIRC, Jenvey have a section where they give recommended intake lengths - valve to trumpet (horn) opening - and it is also available on the 'net, as are the suggested dimensions of the exhaust, diameter and length, for your particular setup. It is well worth getting this as close as possible as it is easy to make a 20+ hp difference between a optimum and a poor design - a 'off the shelf' manifold from a speed shop may happen to be right but could be quite wrong as well, so at least have a good idea what you want... if you have to compromise, go smaller/longer.
Don't forget the ARp, or equivalent, rod bolts as the OEM ones are barely good for 7k, some use the OEM rods to 8k+, but I would use 7k5, or maybe 7k75 tops with the good bolts.

 

I have arp, polished and weight balanced oem rods, 282° 11.2 cam, +1mm in/ex valves,
45 mm qed jenvey itb with 60mm horn,
Accralite flat top 87mm pistons ( my cr is now about 11.8)

My exhaust headers is one cheap priced
Stainless steel 4-1 90cm primary ( named direnza, i guess Chinese but quality looks good)

And about head
I dont go further gasket, thats what i get from your words.

Thanks gordo for your consideration.
Thank green dream.

If you see any hint, please make me happy

After these week drag im going to assemble my engine. If you find any important in my list
Please tell me.

 

Unfortunately, some manufacturers produce very nice looking crap. If you could post the actual camshafts I'll see what the recommended diameter and lengths are, so you can compare them to what you have - come to that, what diameter and length from the flange to collector, are the Direnza ones?

 

I do like to send you
But im in Iran about 4000km away from you,
Take extra money and time for shipment and double Tax :_)
But i can see dimensions of cams by dial gauge and side calipers.

My exhaust headers is Direnza
I guess primaries
43 mm diameter and ~ 95 cm length
To collectors 57mm

I can send you advertising
https://www.direnza.co.uk/vauxhall-opel-astra-c20xe-exhaust-manifold.html

My itbs
http://qedmotorsport.co.uk/qed-shop...uxhall-xe-c20xe/fuel-injection/throttle-bodies-qed-direct-to-head-various-types


Sorry i have a lota problem with uploading photos
And don't know why!!!
Please check the link above

 

Sorry, I mean write down the camshaft brand and model, or the specifications advertised for them - it is one of the ways English is confusing for non-native speakers and, TBH, even some of those :lmao:
The exhaust dimensions are close to what I would expect for a mild engine with a power peak around 7k rpm - maybe a little big in diameter, but should work OK.
A friend has used that DTH throttle body type to good effect, should work well.

 

Sorry, I mean write down the camshaft brand and model, or the specifications advertised for them - it is one of the ways English is confusing for non-native speakers and, TBH, even some of those

The exhaust dimensions are close to what I would expect for a mild engine with a power peak around 7k rpm - maybe a little big in diameter, but should work OK.
A friend has used that DTH throttle body type to good effect, should work well.

Sorry my bad

If i remember correctly cam was
Custom made named kms?!?
Hydro
282° duration
11.2 mm max lift
And valve lift @tdc was 2.1
And power band was between 3.5k -7.5 k
But tomorrow i will go to my work shop and
Measures the specs again

 

What timing for the camshafts - the angle for full lift?

 

I cant remember
I should ask

 

And about cg motorsport

Dose any one used or know em