Broken block? Check this out

[psfracer]

That's the marketing approach FRPP is using.

And i think that is because it wasnt a problem except for high horsepower or "race" applications.

 

[Wicked97]

Got the short block put together just a matter of time before we get it installed!!

 

[Mystickeith50]

Nice man.

 

[beefcake]

what compression did you guys go with

 

[Wicked97]

11.5 to 1

 

[beefcake]

11.5 to 1

you guys love that 11.5 to 1

we were shooting for between 10 and 10.5,

 

[kdanner]

11.5? The domes sure look a lot bigger than the 12.7 2013 CJ pistons I have here.

 

[wbt]

11.5 to 1

Unless the pistons are recessed in the block at TDC there is no way that is 11:5:1....

 

[My08Stang]

Got the short block put together just a matter of time before we get it installed!!

I'm sooooo jealous!!!

 

[86merc]

11.5? The domes sure look a lot bigger than the 12.7 2013 CJ pistons I have here.

The dome profile looks different. I am sure Eric could provide the piston info.

 

[Wicked97]

11.5? The domes sure look a lot bigger than the 12.7 2013 CJ pistons I have here.

Unless the pistons are recessed in the block at TDC there is no way that is 11:5:1....

The dome profile looks different. I am sure Eric could provide the piston info.

i was a little wrong its actually 11.1 cr with the stock 58 cc chamber the dome is tall because the valve pockets are much deeper than stock yielding the same positive cc's

 

[wbt]

i was a little wrong its actually 11.1 cr with the stock 58 cc chamber the dome is tall because the valve pockets are much deeper than stock yielding the same positive cc's

Yes they are deeper because the dome is taller. Here is a stock Coyote piston:

Can you post a side profile pic of the block with a piston at the top of the bore?

If it's really only 11:1 I don't see the benefit of running a larger dome. Generally your flame travel will be less optimized resulting in less fuel burn leading to a loss in power vs. a piston that is more flat on top.

 

[Wicked97]

Yes they are deeper because the dome is taller. Here is a stock Coyote piston:

No way I am buying the piston you guys are showing as 11:1 with everything else being the same. Can you post a side profile pic of the block with a piston at the top of the bore?

i think the heads are already on...

The Valve Pockets go way deeper then what you have pictured.

 

[wbt]

i think the heads are already on...

The Valve Pockets go way deeper then what you have pictured.

I am taking that into consideration and edited my post. Too bad we can't get a side profile view. That is an aggressive amount of dome.

 

[ford20]

i think the heads are already on...

The Valve Pockets go way deeper then what you have pictured.

I don't know a lot about engines at all but looking at this picture from Livernois that uses the stock 11:1 CR the reliefs in the pistons for the valves do look a lot deeper.

 

[wbt]

I don't know a lot about engines at all but looking at this picture from Livernois that uses the stock 11:1 CR the reliefs in the pistons for the valves do look a lot deeper.

That is a result of increasing the dome size like with the piston's JPC has shown. The more material you have up top, the larger the valve reliefs.

The get the full picture one would need the piston in person with some calipers to know what is really going on.

 

[ford20]

So then what is the benefit of a bigger dome then? Is it to make the piston stronger and less susceptible to breaking when you increase the boost on the car?

 

[Wicked97]

That is a result of increasing the dome size like with the piston's JPC has shown. The more material you have up top, the larger the valve reliefs.

The get the full picture one would need the piston in person with some calipers to know what is really going on.

So then what is the benefit of a bigger dome then? Is it to make the piston stronger and less susceptible to breaking when you increase the boost on the car?

Are you guys trying say that im not being truthful? Because im not sure why it would benefit me to no be straight up about this....

If the Valve Pockets go deeper into the Deck then you will need a bigger dome to make up for the material removed for the valve pockets

I got more pictures i am uploading now......

 

[wbt]

Are you guys trying say that im not being truthful? Because im not sure why it would benefit me to no be straight up about this....

If the Valve Pockets go deeper into the Deck then you will need a bigger dome to make up for the material removed for the valve pockets

I got more pictures i am uploading now......

I don't take anything at face value. That is just my nature as I tend to question everything and it may come of as not trusting the source.

I am really trying to understand why you would go to such lengths to change the piston profile so drastically to maintain the same compression level as a stock piston. What is the motivational factor behind this?

 

[Wicked97]

I don't take anything at face value. That is just my nature as I tend to question everything and it may come of as not trusting the source.

I am really trying to understand why you would go to such lengths to change the piston profile so drastically to maintain the same compression level as a stock piston. What is the motivational factor behind this?

Not sure why i would be considered an untrusted source....

I always try to play it straight with you guys..

We have changed the valve pockets to give us room for bigger valves and cams.. why would you not change it?