comp 270 issues

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dustang5398

New Member

Jul 27, 2004

13

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0

Aug 17, 2009

#1

• Aug 17, 2009

• #1

When i do my full pi swap in my 98 gt i am wanting to put comp 270's in while i have the heads out. I've read on here that it is a good idea to degree the cams. I've got no experience doing this. So my question is it possible to degree them w/o the the heads actually on the motor? B/c i was planning on having a shop do this. I can handle everything else.....

 

J

jomull55

New Member

May 20, 2007

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lucas, OH

Aug 17, 2009

#2

• Aug 17, 2009

• #2

degreeing has to be done with the heads and cams on the motor.

 

Tim2002GT

Founding Member

Apr 10, 2002

635

4

29

Tulsa, Oklahoma

Aug 17, 2009

#3

• Aug 17, 2009

• #3

I may be wrong, but you may have a problem with PTV contact with those cams on a NPI shortblock.

 

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dustang5398

New Member

Jul 27, 2004

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0

Aug 17, 2009

#4

• Aug 17, 2009

• #4

yes, i am aware of the ptv clearance w/ these cams. I really want to use them but i may have to notch out the piston tops for valve clearance.....

 

lvmustanggt

New Member

Apr 9, 2006

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Las Vegas

Aug 18, 2009

#5

• Aug 18, 2009

• #5

I have this cams , shop did the install and no ptv problem.

 

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dustang5398

New Member

Jul 27, 2004

13

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0

Aug 18, 2009

#6

• Aug 18, 2009

• #6

lvmustanggt said:

I have this cams , shop did the install and no ptv problem.

Click to expand...

You also have the full pi motor.

 

Tim2002GT

Founding Member

Apr 10, 2002

635

4

29

Tulsa, Oklahoma

Aug 18, 2009

#7

• Aug 18, 2009

• #7

dustang5398 said:

yes, i am aware of the ptv clearance w/ these cams. I really want to use them but i may have to notch out the piston tops for valve clearance.....

Click to expand...

Good deal, just wanted you to be aware of what you were getting into! Those cams do sound great though!

 

sick2v

New Member

Aug 5, 2009

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S.A. Tx

Aug 18, 2009

#8

• Aug 18, 2009

• #8

You need to degree heads with cams installed. As for valve clearance, I recommended a new set of springs. The comp 270 are lifted at .550 for both exhaust and intake valves. That's pushing it on a set of stock P.I. Heads. Especially if their used already, then wear and tear might be a heavier factor. You can get a set of comp beehive springs with .600 lift and you wont have to notch anything. Either way you can still run the cams on a set of P.I. heads.

 

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dustang5398

New Member

Jul 27, 2004

13

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0

Aug 19, 2009

#9

• Aug 19, 2009

• #9

sick2v said:

You need to degree heads with cams installed. As for valve clearance, I recommended a new set of springs. The comp 270 are lifted at .550 for both exhaust and intake valves. That's pushing it on a set of stock P.I. Heads. Especially if their used already, then wear and tear might be a heavier factor. You can get a set of comp beehive springs with .600 lift and you wont have to notch anything. Either way you can still run the cams on a set of P.I. heads.

Click to expand...

I've never heard of this before. I've heard of flycutting the pistons and modifying the bottem of the valves to clear ptv but not by putting in .600 lift springs.

 

J

jomull55

New Member

May 20, 2007

202

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lucas, OH

Aug 20, 2009

#10

• Aug 20, 2009

• #10

dustang5398 said:

I've never heard of this before. I've heard of flycutting the pistons and modifying the bottem of the valves to clear ptv but not by putting in .600 lift springs.

Click to expand...

He just means you need a stiffer spring so there's less chance your valves will float down and meet the piston. the stock springs aren't made for a cam that has .550+ lift