um why?
you dont trust cosworths bolts?

id just run them as they are

 

as far as i know they already come with arp bolts stock
my eagle rods came with arp bolts

 

WRCwannabe: um, because risking an 8 grand engine rebuild for the sake of resuing old bolts is a false economy


ososlozx3:I'm pretty sure your right there buddy, I contacted Cosworth, they just said "We no longer support the Zetec"... well thanks alot lol


Looking to use the replacement ARP2000 bolt.

 

I've got them on the bench at home, and I know for a fact that they have ARP 2000 bolts in them. Do you need the dimensions?

 

Yes please buddy!

 

Here's a pic of the rod and box.

This is the part number on the beam of the rod

Here are the ARP 2000 marks on the bolt head

Top thread diameter is .371" on my not recently calibrated dial caliper. Threads per inch matched up to 24, so it seems to be a 3/8ths-24 bolt. Non of the metric thread gauges matched up.

Underhead length appears to be 1.50"

Overall bolt length is 1.895", and it takes a 12pt 7/16th socket on the bolt head.

Hope that helps! Do you have Cosworth pistons for your motor? I'm going to get custom ones made to fit the 22mm piston pin.

Denny

 

Denny.... you are THE MAN!
Thanks buddy, thats massive, massive help to me.

Yeah I have the Cosworth WRC pistons. Though they are coming out for this rebuild, as they have done 60k and its time for a freshen up.

Rather than get expensive custom ones made, you could use these:
http://www.ariaspistons.com/products/acurahonda.html
Honda F22A1 2.2L SOHC 3320301
3.386 / 86.00 Bore; 1.215 comp height; -21cc dish

They are what I'm using on the rebuild. My tuner has been using them for a while and rates them highly (he only likes Airas and CP really)

 

Hmmm, interesting, to be honest I hadn't thought to look at pistons meant for other brands. Does the Honda F22 use a 22mm wrist pin? Does your builder say what he's calculated the static compression ration at with zetec heads and these rods and pistons? The compression ratio listed for the Honda is 8.2:1, and the Honda has a 95mm stroke compared to the Zetecs 88mm stroke. Honda's usually have pretty tight combustion chambers too, not sure what the volume is on those, the distance from the piston to the deck, the crushed head gasket thickness, etc.

I'm trying to get around 10:1, because I have a roots style supercharger. Can a zetec block take an 86mm bore?

Now you are saving me time and money!

Denny

 

Arias makes some of the best pistons anywhere. I have used them for many builds (non-Focus). If they will work on a Focus, I would chose them over any other brand.

 

Denny - Yeah, its a 22mm pin. The Zetec is 84.8mm bore as standard, and can be taken to 86mm with no problems.
I think Ian said it would give me about 8.4:1, which sounds like its going to be too low for your needs.
The next piston down in that list shows a 10.5:1 CR, which might be nearer to what your after. The Zetec runs a 2cc smaller comustion chamber than the Hondas, the Zetec gasket is .27 and the Honda .28
Honda deck height is 00.1

I would have thought valve to piston clearance wont be an issue unless your running a very high lift cam.

 

Simon, you are now the man! I'm going to have to do some more investigation!

Keep me aprised of your progress, I may end up going turbo and am interested in how it goes. I have an old Saab 2L turbo, and I know what a 2L turbo at 8.5:1 off boost feels like!

Denny

 

if you want to bring the compression up because of a big dish piston just deck the head! I don't know what people see wrong with this? .015 .020 should be enough to get you back to stock compression.

 

Thanks Jared,

I may end up doing that, I was simply trying to avoid altering the head if the pistons could be ordered to fit, or something exists that works. I realize that the top of the piston is the bottom of the combustion chamber.

I just want to make these decisions with all the pertinent information. Why cut the head if there are pistons to fit? I just want all the information before i create metal chips!

Denny

 

My point is why spend 600-700 bucks on a set of custom pistons when a $400-450 set of the same quality will work you just have to spend $50 to deck the head. Also what if you buy the custom pistons and one gets damaged somehow like a cracked ring land. If you have an off the shelf piston you call the supplier and a week later you have a new piston. If you have to have another custom one made you are looking at 6-8 weeks minimum, plus the increased cost. Just things to think about.

 

Good point! Does anyone have any data on what the combustion chamber volume is on a Zetec head that's been decked .020"?

 

I just checked on the bolts, I have set of ARP 2000 200-6209... which is spot on, apart from its 1.600 to the underside... do-uh!

I need these... http://www.summitracing.com/parts/ARP-200-6207/

 

Simon,

As you know i run the Arias pistons and WRC rod combo from Ian H. I had my bolts checked by the guy that balanced my bottom end as i was nervous about them as it would have been the 3rd time the bolts had been re-tightened.

He checked the threads and there was nothing wrong with them and he said that he would reuse them without worry. Being as yours will only be getting tightened for a 2nd time they will be more than ok?

 

All true Steve... I just worry too much lol

 

If anyone should worry it is me with my luck......you will be fine

 

You are a bit cursed Steve, but lets hope you're due some good luck

 

Moving into the line of "fire" here--did anyone have an answer to Denny's question about the combustion chamber volume of a decked zetec head with .020 off? Or was this taken up in the zetec forum?

--Scott