Pinto Car Club of America

Shiny is Good! => General Pinto Talk => Topic started by: bigh4th on November 03, 2004, 07:50:34 PM

Title: 71-73 2.0 compression change?
Post by: bigh4th on November 03, 2004, 07:50:34 PM
Does anyone know how the compression was changed on the 2.0 from 71 to 73?  I need to replace at least the head on my 73, but i have a 71 2.0 that will be a little more work to put in.  I know the 71 had more power, but i'm not sure if the combustion chamber was changed or pistion height.  For some reason i beleive the piston height is actualy taller on the 73 as i remember them comming up to the top of the block where as the 71 doesn't quite get to the top.

Anyone have any clues?

-Harry
Title: Re: 71-73 2.0 compression change?
Post by: buzzman on November 22, 2004, 09:45:42 PM
it was the piston 71s had flat top piston 73 is dished    mill the head .100 safely every .040 is 1 comp point i had 118 of mine   BuzzBomb
Title: Re: 71-73 2.0 compression change?
Post by: buzzman on November 22, 2004, 09:47:54 PM
it was the piston 71s had flat top piston 73 is dished    mill the head .100 safely every .040 is 1 comp point i had 118 of mine   BuzzBomb
Title: Re: 71-73 2.0 compression change?
Post by: bigh4th on November 22, 2004, 11:53:18 PM
Hmmm...  Have you seen 73 pistons that are dished?  The reason i ask is because when i pulled the head off of my 73 the pistons were flat-tops.  Kinda caught me by surprises as I figured just about everything got dished pistons in 73.  I guess theres a chance the engine was rebuild or a 71 was swapped in its place.

if it is indeed the pistons, i'll just swap the heads off the 71 cause when i pulled the head off my 73 to replace a burnt exhaust valve, i missed on on the #2 cylinder and it idles rough.  Oddly enough, it misses every 3rd revolution.

-Harry
Title: Re: 71-73 2.0 compression change?
Post by: kris kincaid on November 23, 2004, 01:10:20 AM
Any idea of what the compression is on a '73 2.0? If its low, maybe I'll put a turbo on mine until I blow it sky high. Then I'll have to find  Turbo Coupe!  :o
Title: Re: 71-73 2.0 compression change?
Post by: turbopinto72 on November 23, 2004, 10:55:15 AM
The compression ( stock) on a 73 is 8.2:1
Title: Re: 71-73 2.0 compression change?
Post by: pintojoe on December 14, 2004, 06:22:11 PM
David Vizard's book on 2.0-liter 71-74 list three pistons for the 2000cc motor.
The compression height varies between 1.588 and 1.640 a diff of .052.
Compression ratio 8.2 1.588" (40.35mm)
                         8.6 1.611" (40.91mm)
                         9.2 1.640" (41.65mm)
I believe the 1971 got the 9.2 comp piston, the 1972 got the 8.6 comp piston and the 1973-74 got the 8.2 comp piston. All were flat tops.

Pintojoe
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