Engine Foxbody Came With These Pistons

885.0h

New Member
Jun 27, 2016
17
0
1
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?
 
  • Sponsors (?)


n18an.jpg
 
  • Like
Reactions: 1 users
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?
 
Last edited:
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.
 
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?
 
Last edited:
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.
 
  • Like
Reactions: 1 user
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....?
 
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.
 
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
 

Attachments

  • 124299d1299769261-need-help-identifying-motor-ford-302-038.jpg
    124299d1299769261-need-help-identifying-motor-ford-302-038.jpg
    230.3 KB · Views: 228
  • Like
Reactions: 1 user
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.
 
  • Like
Reactions: 1 user
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
 
Last edited: