Forged Pistons And Conrods On A Zetec ...

[Guest J-Bond]

Hi guys ...

 

a got some questions about this topic ...

 

a broken spark plug almost destroy my cilinder number 4 .... so ... it's time to rebuild and get some serious stuff....

 

 

 

I will port & polish all the head .... to get all the power of the engine ...

 

I got the AT power ITB's ... and the "original" header of GBS .... on the 2.0 Black Top Zetec.

 

i think this kit will be fine ...

 

http://www.ebay.com/itm/221317772293?ru=http%3A%2F%2Fwww.ebay.com%2Fsch%2Fi.html%3F_sacat%3D0%26_from%3DR40%26_nkw%3D221317772293%26_rdc%3D1

 

... they are.. HI-Comp JE Pistons and Eagle Con Rods.

 

and .. i will use some ARP stuff too...

 

http://www.ebay.com/itm/321246026052

 

http://www.ebay.com/itm/331083066315

 

......

 

maybe we change this ones too ....

 

http://www.ebay.com/itm/Ferrea-Dual-Valvesprings-Ti-Retainers-Ford-Focus-ZETEC-2-0L/270780692887?_trksid=p2047675.m1851&_trkparms=aid%3D222007%26algo%3DSIC.MBE%26ao%3D1%26asc%3D18776%26meid%3D3283425784178208969%26pid%3D100005%26prg%3D8532%26rk%3D2%26rkt%3D5%26sd%3D221317772293%26

 

 

....

 

and, we will change too the con rods bearings and crank shaft bearing .... ACL i guess ..

 

 

ahhh ... i use a Haltech Sprint 500 ECU.

 

i was thinking in MSD Dis-2 and MSD Coil and Wires too ...

 

the idea is to get 190 whp on a 630 KG Zero GT ... .. and a bulletproof Engine ... (hope so)...

 

 

... so .... what do you thing ..??? is this the correct way ??? and the right products ??? or do you preffer another configuration ???

[Guest Alan_builder]

 

the idea is to get 190 whp on a 630 KG Zero GT ... .. and a bulletproof Engine ... (hope so)...

 

... so .... what do you thing ..??? is this the correct way ??? and the right products ??? or do you preffer another configuration ???

 

Please read the Zetec tuning forums You can get to them via my web site.

 

190 BHP is fine as is from the standard engine internals, Change the cam may be required, dump the inlet and exhaust for top of the range kit with a half decent ecu and you are 185BHP min. You will need a new clutch, so 1.8 flywheel drilled for a pinto clutch and balanced.

 

So save yourself lots of wonga or send it to me.

[Guest J-Bond]

190 WHP are like 240 or more BHP .... that's the reason why i will forge ....

[Guest J-Bond]

ok ...

 

i pressume than the stock internals can handle 240 BHP.. but i don't wan't to blown another engime ... ( i got some ones on my list ... and Alfa Romeo is not Cheap, Mazda neither)

 

i guess the Standar Zetec got 10:1 compression ... this one got 1 point more .. 11:1 .... i will use the injectors from Audi a3 1.8T AGU from my brother car...

 

And in Chile.. our better gasoline is 97 Octane SAE .... is like 89-90 RON ... so .. another time ... your gasoline is much better than the chilean one...

 

and ... i need to change at least 1 piston ... so ... and here in chile .. the good spares for cars got stupid prices ... that's the reason ..... is cheaper 4 original pistons than 4 forged pistons from ebay .... and ... "the engine is open ... why we don't do it all at the same time .... i'm not a fan of open the engine everytime to change little things... maybe is more expensive in one time ... but cheaper at the end ...

 

 

I hate the Original Cam Pulley system of the Zetec .... but ... with that system i could change the valve timming without use new pulleys ... ( i bought the Kent Cams Pulleys for "Zetec's" ... CA96 is the model ... but ... i guess is for the 1.6 engine .. with a pin and not "conical"... or do you recomend me another sistem ????

 

maybe we could made here a custom header too ... with bigger tubes...

 

i will contact with Dunnel or Raceline .... (i already have the water pipe and the sump from raceline)

 

regards

[brumster]

Ok, I'm not massively savvy with Zetecs but I'll cover some points from other engines.

 

The forged rods/pistons achieve a couple of things. Firstly, it's clear they are altering the compression ratio in some way but I've no idea if that's by way of doming the top, a different rod length or a different piston crown height. Either way, it's reasonable to assume that the top of the piston is now closer to the cylinder head on the compression stroke. The second is that they are going to be lighter and stronger for use at higher revs, so they are really intended to be used with some performance cams and some fairly extreme ones at that.

 

Given a target of 240bhp and as has been said you're going to be looking at longer duration cams. The concern then comes that, given that longer duration and possibly higher lift, you have no issues with piston-to-valve contact... particularly as you've upped the compression by changing these rods and pistons. So some clarification from the cam manufacturer of lift figures, coupled with some knowledge of how the pistons are different... just to ensure the two don't interfere with each other. Even if they do, it's not impossible to address, pocketing the pistons or fiddling with thicker head gaskets.

 

It's all knock-on factors isn't it. They're oversized pistons by the look of things, so block will need a small overbore/hone. You've got the cams, which will need verniers to get the best out of, and you're not going to make a high-revving engine like that and not put ARP bolts on the rods, new bearings all round, new rings, work the head, new valve guides, maybe bigger valves, then you're re-cutting the seats, yada yada yada.... like you say, if it's all open, might as well do it right the first time.

 

Before you know it that's a £6k engine.... if you're doing it all yourself

 

So just go in with eyes open...

[Guest Alan_builder]

240 BHP? I am sure 225BHP is OK on the stock engine. Please see and read the 6 links (I think) on tuning the Zetec which I link to on my web site. You can read for yourself and make your own judgment.

 

From memory there is a problem in most installations with the sump. These get changed. Ford in there wisdom made a 2 part sump on the Blacktop so they could stiffen the sump walls and reduce vibrations in the block (Ford siad get a better ride). So use the original 2 part sump not the one from a Silvertop or an after market replacement. Get the pistons, conrods, crank shaft flywheel and clutch assembly balanced. I read the issue on power as being vibration not force.

 

Many said don't rebore as you will loose the treatment to the cilinder walls.

[Guest J-Bond]

i will take all the ideas and comments in consideration ....

 

first.. when the piston is on top... obviosly the valves (the 4 of them) are closed... so.. with diferent cams.. you only change "when they open", the time of the "open valves until they are close again" ... and how much they open at the maximum point ....

 

i was thinkingin forged conrods and pistons.. and good bearings... to make a good and reliable internals of the engine....

 

i don't think to change the size of the valves... maybe change some angles and port the head to make a perfect tunnel with both manifolds, a polish all the tunnels to elimininate the "hot point's" ... i don't like the tunnels when looks like mirrors... and i don't like the arrow or diamond angles in the tunnels... i prefer more circular angles... (sorry for my english ... i don't speak the "technician english" frequently ... )..

 

i guess i will cut the valve guides... or build some custom ones...

[Snapperpaul]

Don't polish ports waste of time, some rough is good to help fuel atomisation and prevent pooling

 

I thought the ST170 engine badged as Duratec also known as Blacktop had forged internals as standard

Forged pistons are for safety at revs 8000 or more

Forged pistons are for compression of 10.5 or more and to survive detonation

[brumster]

first.. when the piston is on top... obviosly the valves (the 4 of them) are closed... so.. with diferent cams.. you only change "when they open", the time of the "open valves until they are close again" ... and how much they open at the maximum point ....

 

Remember it's at the top 2 times per cycle look up something called "valve overlap". While they are closed on the end of the compression stroke, this is not the case at the end of the exhaust stroke.

[Guest J-Bond]

Brumster .... i know the piston is on top 2 times per cycle. ...

 

but .. when the piston is on the superior point ... wherever stage is ... the valves are closed ...

 

when the piston is going down ... the valves are opening ... and when the piston is moving up ... the valves are getting closed .. but when the piston is UP .. is impossible (o normal working... not a broken engine) ... to open the valves ...

[Guest chris brown]

Brumster .... i know the piston is on top 2 times per cycle. ...

 

but .. when the piston is on the superior point ... wherever stage is ... the valves are closed ...

 

when the piston is going down ... the valves are opening ... and when the piston is moving up ... the valves are getting closed .. but when the piston is UP .. is impossible (o normal working... not a broken engine) ... to open the valves ...

Not true depending on cam the overlap can be considerible meaning both exhaust and inlet will be open at TDC at the end of exhaust stroke.

[Snapperpaul]

Inlet valve opens before TDC as piston is rising

Exhaust is still open after TDC

Extra camshaft lift may need cutouts in pistons