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

Help with ring filing

  • Thread starter Thread starter new46stang
  • Start date Start date Dec 15, 2007
N

new46stang

Member
Jun 5, 2002
146
0
17
AZ
Dec 15, 2007
#1
  • Dec 15, 2007
  • #1
Hey All,

Need some help with my file fit rings (more of confirming specs). I am building my 331 finally that will be N/A. The rings are Perfect Circle and the reccomendations on specs are:

Top Comp Ring:
Moderate performance: .016 - .018 (I was hoping to be in this range)
Nitrous Street: .020 - .022 (Ended up here)

Intermediate Comp Ring:
Moderate Performance: .020 - .022
Nitrous Street .024 - .026

Below is where I am at with the top rings, the secondary rings are at .022 for now.

Top Compression Ring:

#5 .021 #1 .020

#6 .022 #2 .021

#7 .021 #3 .021

#8 .021 #4 .021

So my questions are:

1. Should I take cyl #1 to .021?
2. Should I take all of them to .022?
3. If I go to .022 on all should my secondary be .024 or .025?

So to calrify, I did not want to be in the nitrous catagory. When I started this, my largest happened to be .022 untouched. My tightest was .019 if i remember correctly. One of my secondary rings had a pit on the face of it so I am waiting on a replacement ring.

Hopeing for Rick91GT or some of the other builders to help build my confidence on this! Heh. Oh, btw I am hand filing these puppies.

Matt
 

BlownFiveLiter

have car, will race....wait, it doesn't run
15 Year Member
Nov 29, 1999
3,133
18
108
Chicagoland
Dec 16, 2007
#2
  • Dec 16, 2007
  • #2
All file-to-fit rings should be oversized, so you can file them to your specifications. You probably should mic your bores at several points to make sure they're bored to the proper size, and if they are for the rings you ordered, replace the rings that are out of spec. The manufacturer should be on the hook for the replacement.
 
N

new46stang

Member
Jun 5, 2002
146
0
17
AZ
Dec 17, 2007
#3
  • Dec 17, 2007
  • #3
Thanks for the reply. What I know is that the rings are for a 4.030 bore according to the part number etc. From what I can measure on the bore, it is under 4.030 maybe by a couple thou. Are you saying that the ring package is way outta spec? When I found the defective one and called adperformance back, he said for the most part (for warranty purposes) the rings would have to be untouched for any concideration. Perfect Circle was pretty cool about the one ring but I couldn't get the replacement from them unless the could verify the order. I think I am at a little disadvantage because I bought from adperformance who bought from CHP who probably bought from Perfect Circle. Are the current specs I have bad for running N/A Street? Are there any other opinions out there?

I appreciate any guidence from the engine builders out there!!

Matt
 

oz

Founding Member
Jun 29, 2000
1,079
10
58
Plymouth, MI
Dec 17, 2007
#4
  • Dec 17, 2007
  • #4
In my opinion, what you have is fine. I wouldn't anticipate much loss of power based on the slightly larger end gap.
Another thing to consider is that unless you have incredibly accurate measurement tools, .001 is very hard to verify. It is within what I would consider acceptable measurement error.
What you could try is to try different rings from the same set in #5 if you have not already to see if you get one to more closely match the others.
 
N

new46stang

Member
Jun 5, 2002
146
0
17
AZ
Dec 18, 2007
#5
  • Dec 18, 2007
  • #5
I did try to move my largest ring, #6 around to the other cyls to no avail. Could anyone take a stab at my 3 direct questions? I guess at this point I will just set it up for nitrous and if I run the juice down the road I will be ok. Do rings setup for nitrous end up running less compression when you test the cylinders or not really? I'm trying to do this thing right from the ground up. I'm close to $2500 and I dont even have a shortblock yet..... I don't want a couple thousandths of gap to get in my way.

Matt
 

5spd GT

"the 5.0 owns all"
Founding Member
Aug 7, 2002
9,516
6
99
Arkansas
Dec 18, 2007
#6
  • Dec 18, 2007
  • #6
Are you measuring them in the cylinder bore?

If so, how far down the cylinder bore?
 
N

new46stang

Member
Jun 5, 2002
146
0
17
AZ
Dec 18, 2007
#7
  • Dec 18, 2007
  • #7
Yes, I am measuring them in the bore about an inch or so down and using the piston to square them up.

Matt
 
You must log in or register to reply here.

Similar threads

Which SN95 axles for 93 LX, disc brakes, ABS rings?
  • dan50
  • Mar 22, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
15
Views
361
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Apr 3, 2026
7-UP BILL
M
Engine Unexplainable Exhaust Pop and Gurgle
  • Mrnissen122
  • Feb 14, 2026
  • Fox 5.0 Mustang Tech
Replies
12
Views
459
Fox 5.0 Mustang Tech Feb 18, 2026
Noobz347
T
Fox Convertible top issues
  • TDM389
  • Feb 15, 2026
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
Replies
5
Views
241
1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- Feb 15, 2026
General karthief
3
Eight inches is enough for me...
  • 351MooseStang
  • Nov 27, 2025
  • 1974 - 1978 Mustang II Talk & Tech
Replies
5
Views
497
1974 - 1978 Mustang II Talk & Tech Mar 2, 2026
Bullitt347
M
2001 v6 heater return pipe leak question
  • mnky99
  • Nov 11, 2025
  • SN95 V6 Mustang Tech
Replies
1
Views
201
SN95 V6 Mustang Tech Nov 11, 2025
mnky99
M
Share:
Bluesky Email Share Link
  • Mustang Forums
  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech
Menu
Log in

Register

  • Forums
  • What's new
  • Media
  • Resources
  • Contact
  • Sponsor
X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?

X

Privacy & Transparency

We use cookies and similar technologies for the following purposes:

  • Personalized ads and content
  • Content measurement and audience insights

Do you accept cookies and these technologies?