Installed Comp Cams 278

SonicStangGT

Active Member

Mar 18, 2008

146

2

28

King, North Carolina

Mar 22, 2008

#1

• Mar 22, 2008

• #1

I just installed the 278's and have had a very bad turn out. Come to find out that I am having piston to valve issues. Thanks to this forums help I was able to figure this out. So now I Have to take the motor out and am going to try to cut reliefs in the stock pistons. Just trying to see if anyone has heard of this on a 2v. My dad sad that back in the day when they didn't have resources to get pistons they would do this. Also, what are some mods that I should do while the motor is out. Thanks for the info.:SNSign:

 

Winters98GT

Whoop...whoop-whoop-whoop-whoop...GANGNAM STYLE!!!

Founding Member

Nov 29, 1999

5,520

1,291

224

H Town

Mar 22, 2008

#2

• Mar 22, 2008

• #2

yep, its the standard with the 278's and also the 270's. Many claim to get away with the 270's and stock pistons, but over time, they all fall. Good luck.

put a set of headers on the car if you dont already have them. Depending on how many miles are on the car, it wouldnt hurt to throw a new set of motor mounts on the car also. 4.6's are notorious for busting motor mounts.

 

SonicStangGT

Active Member

Mar 18, 2008

146

2

28

King, North Carolina

Mar 22, 2008

#3

• Mar 22, 2008

• #3

Thanks for the info. I have shorties, but looking into a set of long tubes. Cant wait to get it back together, it sounds so good with the cams(other than the chatter of valves hitting pistons).

 

Warrior 102

New Member

Jan 22, 2003

231

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0

Macomb MI

Mar 22, 2008

#4

• Mar 22, 2008

• #4

278 are way to big for a stock motor.....

 

C

Chrome99

New Member

Jan 6, 2006

2

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0

Mar 23, 2008

#5

• Mar 23, 2008

• #5

If you cut the pistons dont you have to get you're assembly rebalanced?

 

SonicStangGT

Active Member

Mar 18, 2008

146

2

28

King, North Carolina

Mar 23, 2008

#6

• Mar 23, 2008

• #6

not sure if you have to or not. We have decided to use a set of forged pistons with flycuts. Also going to through a set of I-beam rods so I can run a bigger shot of nitrous. Start pulling motor this week.wish I had more money to work with but I do what I can.

 

98GTfromGA

Founding Member

Mar 17, 2002

291

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0

Memphis

Mar 23, 2008

#7

• Mar 23, 2008

• #7

the pistons have to be notched to run the 278 cams

 

SonicStangGT

Active Member

Mar 18, 2008

146

2

28

King, North Carolina

Mar 23, 2008

#8

• Mar 23, 2008

• #8

If anyone has any suggestions on which piston and rod setup I should use, it would be great. I'am looking at a set of probe or dss pistons and a cheap set of mustang depot rods off ebay.

 

T

truebluedroptop

New Member

Oct 12, 2006

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1

Mar 24, 2008

#9

• Mar 24, 2008

• #9

I just got a set of manley pistons with the valve reliefs cut, manley h-beams, moly rings, head studs and main studs, all this shipped to my door from MPH cost me 1936.51 hope this helps it's what tim recommended to me and I'm also going to be running those cams with a 200 shot

 

SADL-UP

Member

Jun 19, 2005

42

1

8

Massachusetts

Mar 24, 2008

#10

• Mar 24, 2008

• #10

I would look into the Diamond pistons...they offer a set off the shelf with valve reliefs. That is the setup i am running with the 278s. good luck...

 

SonicStangGT

Active Member

Mar 18, 2008

146

2

28

King, North Carolina

Mar 24, 2008

#11

• Mar 24, 2008

• #11

Thanks for the info, I'll look into both sets of pistons. I'am ready to go to the track. :Track: Its just finally getting warm, and I take my car apart.