Engine Foxbody Came With These Pistons

885.0h · Aug 18, 2016

Hey whats up fellas trying to figure out why my car has these pistons and not the ones with valve reliefs, Car had a rebuild before I got it has 98 gt40p heads, stock cam, dished pistons with no valve reliefs any idea what year had these pistons cant find anything on it, could this setup cause detonation and or high c/r?

stykthyn · Aug 18, 2016

Some pics would go a long way.

RangerJoe · Aug 18, 2016

Dish or dome pistons? Again, need pics.

Joe

mikestang63 · Aug 19, 2016

stykthyn · Aug 19, 2016

Still no pics

885.0h · Aug 22, 2016

sorry guys been busy here ya go

stykthyn · Aug 22, 2016

Going out on a limb, those look like low compression pistons from a crown vic or Thunderbird.

885.0h · Aug 22, 2016

stykthyn said:
Going out on a limb, those look like low compression pistons from a crown vic or Thunderbird.

Okay cool I see you have the tfs1 cam I do as well, this shop I was going to have put the cam in said they couldn't due to no valve reliefs on these pistons is this true?

stykthyn · Aug 22, 2016

I wouldn't reuse those pistons. Find an explorer short block or purchase a new set of hyper pistons.

Mustang5L5 · Aug 22, 2016

stykthyn said:
Going out on a limb, those look like low compression pistons from a crown vic or Thunderbird.

Wouldn't ford still stamp a ford pn on the top?

Like this

EDIT:
Well, does appear they may be 5.0 crown vic pistons

Sent from my big ass iPhone 6 using Tapatalk

885.0h · Aug 22, 2016

Thats them! Any idea as to what would happen if these were paired with gt40p heads?

stykthyn · Aug 22, 2016

Without a clay measure I'm going to assume severe ptv issues.

Mustang5L5 · Aug 22, 2016

Yeah, you'd have to clay the motor. And I would assume the shop has already done that hence their recommendation to get new pistons.

To be honest, having those pistons suggest the block used to be in a crown vic.

885.0h · Aug 22, 2016

How should I go about this then kind of bummed, Could these pistons get notched and the ptv issue be gone and run the cam? or I could buy a set of hyper pistons slap them in and be good to go with the tfs1 cam? im unsure on pricing between the two. Thanks for your info so far cleared that question up and opinions are appreciated

EDIT: Can ptv issues cause detonation?

stykthyn · Aug 22, 2016

Were crown vics roller motors? I see the dogbones and the spider hold down in the intake valley. I'm wondering if someone just didn't order the wrong rebuild kit.

885.0h · Aug 22, 2016

stykthyn said:
Were crown vics roller motors? I see the dogbones and the spider hold down in the intake valley. I'm wondering if someone just didn't order the wrong rebuild kit.

What I don't get though is why would they put these pistons in here in the first place kind of going backwards? On the receipt it says its an explorer long block....?

stykthyn · Aug 22, 2016

885.0h said:
How should I go about this then kind of bummed, Could these pistons get notched and the ptv issue be gone and run the cam? or I could buy a set of hyper pistons slap them in and be good to go with the tfs1 cam? im unsure on pricing between the two. Thanks for your info so far cleared that question up and opinions are appreciated

EDIT: Can ptv issues cause detonation?

You're not notching those. Ptv causes catastrophic damage to your heads, valves, and your pistons.
Best case scenario, have new hyper pistons installed or find a used short block.

Mustang5L5 · Aug 22, 2016

885.0h said:
What I don't get though is why would they put these pistons in here in the first place kind of going backwards? On the receipt it says its an explorer long block....?

Still haze access to the block? On the side of the block near where the headers bolt up will be the block p/N. Can you tell us what that is? May help identify the origin of the block.

Give this a read

Mustang5L5 · Aug 22, 2016

885.0h said:
On the receipt it says its an explorer long block....?

Well, a long block inplies the heads were bolted on as well. Are you sure they are GT40P heads? This engine already ran with the 40Ps? If so, what are you changing that the shop is now concerned about PTV clearance?

It is possible someone rebuilt it with the wrong pistons. A lot of people think all 5.0's are the same when they are not.

885.0h · Aug 22, 2016

Mustang5L5 said:
Well, a long block inplies the heads were bolted on as well. Are you sure they are GT40P heads? This engine already ran with the 40Ps? If so, what are you changing that the shop is now concerned about PTV clearance?

It is possible someone rebuilt it with the wrong pistons. A lot of people think all 5.0's are the same when they are not.

I believe they are gt40p heads (says gt40p on head and has 4 bars)?, the shop who rebuilt this motor before I bought the car is not the one saying the tfs1 cam wont go in due to no valve reliefs, could this just be an 98 explorer motor with crown vic pistons put in? I've looked in the past for the casting numbers I will look again asap

Engine Foxbody Came With These Pistons

New Member

I want to measure mine. It doesn't look that tall.

I leave the horn on while driving

I want to measure mine. It doesn't look that tall.

New Member

I want to measure mine. It doesn't look that tall.

New Member

I want to measure mine. It doesn't look that tall.

That is…until I whipped out my Bissell

New Member

I want to measure mine. It doesn't look that tall.

That is…until I whipped out my Bissell

New Member

I want to measure mine. It doesn't look that tall.

New Member

I want to measure mine. It doesn't look that tall.

That is…until I whipped out my Bissell

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That is…until I whipped out my Bissell

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