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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Piston swapping with out machining?

  • Thread starter Thread starter Joey7508
  • Start date Start date Dec 5, 2007
J

Joey7508

Member
Oct 23, 2005
198
0
17
Kerrville TX
Dec 5, 2007
#1
  • Dec 5, 2007
  • #1
I bought a Fordracing short block. It was one of the explorer left over ones. So it is brand new standard bore block, crank rods, and hyper-u pistons. All new. I have maybe 5000 miles on it. I want to switch out the rods and pistons with a set off DSS lower compression forged piston and race prepped rod,they are basically stock rods with ARP bolts. A little better rings and some better head gaskets while I am there. They will make the pistons in standard bore no problem there, but the guy I spoke to over at DSS said I shold have the block looked at or even bored 30 over. I am trying to skip the machining and just swap out the pistons. What do you guys think?
Here is the over all plan. I am putting a single turbo set up on the car now. I want to run it on low boost until I get the money for the engine I want which would be a purpose built Boss block 331. I am running TF heads, intake, f cam on my stock block right now, and want to run the turbo on what I have now. I know I should buy the built engine first and turbo later, but where is the fun in that.
So do you see any problem with switching the pistons with out machining the block? I think it would just be like re-ringing an engine.
 

white99gt

Founding Member
Aug 8, 2000
4,649
1
0
stockbridge,Ga(near atlanta)
Dec 5, 2007
#2
  • Dec 5, 2007
  • #2
I would have the bore checked.If you dont want to go that far.Leave everything alone and dont waste your money on a half ass rebuild and spend all the money on the real motor.
 
J

Joey7508

Member
Oct 23, 2005
198
0
17
Kerrville TX
Dec 5, 2007
#3
  • Dec 5, 2007
  • #3
Do you think I should try and put some boost on that stock bottom end or wait on that too?
 

Hickfied

Member
Nov 9, 2005
413
0
16
Morganton, NC
Dec 5, 2007
#4
  • Dec 5, 2007
  • #4
As long as your tune was remotely close (IE no wash down or detonation) and the engine wasn't defective from the factory, you should be fine with just honing the block a little, as 5k miles isn't anything.

Although I would have your rotating assembly rebalanced.
 

2000xp8

SN Certified Technician
Aug 8, 2003
8,016
1,613
194
NJ
Dec 5, 2007
#5
  • Dec 5, 2007
  • #5
white99gt said:
I would have the bore checked.If you dont want to go that far.Leave everything alone and dont waste your money on a half ass rebuild and spend all the money on the real motor.
Click to expand...

Exactly.
 

white99gt

Founding Member
Aug 8, 2000
4,649
1
0
stockbridge,Ga(near atlanta)
Dec 5, 2007
#6
  • Dec 5, 2007
  • #6
Joey7508 said:
Do you think I should try and put some boost on that stock bottom end or wait on that too?
Click to expand...

Up to you.
I personally drove mine (99) with a stock bolt on setup(2 years) while building the bad boy..Was hard to think about the power but the out come was well worth the wait.

Plus why spend money two or three times.
 

5spd GT

"the 5.0 owns all"
Founding Member
Aug 7, 2002
9,516
6
99
Arkansas
Dec 5, 2007
#7
  • Dec 5, 2007
  • #7
The advice is pretty solid in this thread and I have to agree.

There is just to many production tolerances between pistons. Just because both brand X and brand Y pistons have the same bore size, they can still vary within several thousandths.

It is those several thousandths that make or break engine longevity and reliability.

Then you would also like a nicely laid out cylinder wall, which will require some grit honing to get a proper ring seal for the new rings.

I have no doubt that many backyard guys have did the swap and did "okay" with it, but it is not something suggested by me.

Good Luck with it all.
 

vristang

15 Year Member
Mar 31, 2005
4,933
101
124
Seattle
Dec 5, 2007
#8
  • Dec 5, 2007
  • #8
Put forth the effort to do it right, or don't bother doing it at all........

The bore should be honed to the ACTUAL pistons!
 
J

Joey7508

Member
Oct 23, 2005
198
0
17
Kerrville TX
Dec 6, 2007
#9
  • Dec 6, 2007
  • #9
Advice taken. I will wait.
 
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