Hi,

Ive decided to change out the pistons for my turbo app. I dont want to take any chances of head gasket failure....sooooooo


Can anyone lead me to the right place as to where I can find the F20Cs engine specs?

JE wants me to send them the information so that they can custom some pistons to work with the stock bore, and the rods.

Would this info be in the helms manuals???


Any help would be appreciated!

thanks guys!

 

In the Helms. Better yet, buy a piston and send it to them (along with the specs).

 

The required spec is NOT in the helm manual, you need to send them a piston.. My engine is being disassembled today and tomorrow for this purpose. (Among many other things) My shop has a very good relationship with JE and we will have custom pistons back very quickly. If you are serious about buying pistons and you are ready to buy then I can have another set ordered for you and it would probably be cheaper than going through JE .. We are getting 9:1 with very 1.5mm, 2mm and 4mm thick piston rings (I believe.)

JE currently has two sets of 87 mm pistons in stock at 9:1, but they are unsure if they will work in the S2000 Application. Apparently they didn't keep track of what engine it's for?? Anyways they may work in the F20C depending on what what the measurment from the top of the piston to the top of the piston pin is..

Chris

 

tough to say even with just a measurement from pin to top of piston, since its domed with valve cutouts.

They just have some pistons that were made close to spec- and someone didnt need them, pistons dont always need a specific parent engine.

They need to cc the combustion chamber, or take a casting of the chamber and then the piston so they can reduce the dome(compression) but not too much. I am curious as to what the final piece will be like, weight, size of the skirts, ring land sizes and such.

But good news is that JE knows what they are doing and after one set is worked out they will at least have the specs for an order, or even be able to tell you what changes are possible.

Chris:

Are you planning on lightening the crank? sheesh, a light crank/ti rods/FW would rev like a sport bike

Also, is anyone thinking about deck supports and a larger capacity radiator ?
I guess Im asking, how much power are you looking for? If you close the deck it would support more power and give your gaskets better reliability - or O-rings if they can manage those.

 

The combustion chamber averages 53.6 cc +/- 0.2 cc in volume

The thickness of stock compressed headgasket is approximately 0.5-0.75 mm.

Thus total volume of chamber + headgasket is approximately equal to:

(8.7/2)^2*Pi*0.05 + 53.6 = 56.6 cc

You can also assume that other misc crevice volume in the chamber will add at least 0.5 cc to volume, putting us somewhere between 57 and 57.5 cc for total combustion volume.

Obviously, this is too large to obtain an 11.1:1 compression ratio. Given a 499.5 cc swept volume per cylinder, total chamber volume must be:

(499.5 + x)/x = 11.1 or x = 499.5/10.1 = 49.5 cc.

This tells us that the piston dome (barring any glaring crevice volumes overlooked such as a piston severely below zero deck height - more than 0.5 mm) must be in the range of 7.5-8 cc in volume.

Simply removing the entire dome will get you into the 9.7:1 compression ratio range. To get to 9:1 will require a dish in the piston of approximately 3-4 cc. Be careful with this as you don't want to remove any designed-in quench. Thus, the dish should be centrally located in the piston leaving a flat upper surface around the edges, particularly on the thrust face sides of the pistons.

UL

 

the valve relief is approximately 3.5mm at the deepest point from the top of the quench surface(not the dome), I would expect the quench area to not extend above the deck, or at least not more than 1mm, putting in a circular dish may still need valve cutouts. They will need the cam timing, or at least a lift profile.

UL do you think they used a more aggressive ramp speed on the cams yet skimped on lift? Allowed by the rollers?
Possibly why the lift numbers are less than some others

 

Last year I had a set of pistons made for my 400hp D16 civic .I used Race Engineering , they help design the piston because I needed it to hold a 200hp shot of NOS.If you want I'll get you the number to call them just e-mail me.I would give it to you now but it's at my shop.

 

I think Chris is pretty much set on JE, and I dont think its a bad choice either

 

my pistons were made by JE .Race Eng. is a distributor and it was cheaper than going direct with JE and I'm a dealer for performance parts.

 

I am going through my shop who is a long time customer of JE, they are a dealer for JE. Thanks for the offer!