Compression Differences Between Zetec and SVT - Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum
Ford Focus Forum
HomeContact UsAbout UsGalleryDiscussion ForumsMarketplace


Go Back   Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum > Exclusive Vendor Discussions > Focus-Power Tuning

Focus-Power Tuning Discuss about forced induction upgrades and performance tuning for your Ford Focus.
Sponsored By: Focus-Power


Search This Forum | Image Search | Advanced Search    
FocusFest FocusFanatics Merchandise

Reply




 
LinkBack Thread Tools Display Modes
Old 03-17-2006, 09:45 AM   #1
Focus Addict
 
CDSilver5DoorSVT's Avatar
 
Join Date: Dec 2003
Fan#: 2262
Location: Ridgeley, WV
What I Drive: Waiting For The Cobras Point By....

Posts: 894
FF Reputation: 13 CDSilver5DoorSVT Great Standing Member
Buy-Sell-Trade Rating: (39)
Compression Differences Between Zetec and SVT

What is the makes the compression ratio different between the two, I know the combustion chamber in the SVT is smaller, what about the pistions and rods(rod length) and stroke.

I'm in the middle of a situation and need some answers(I figured Tom would know them).......

Currently have a customer who rebuild an SVT with Zetec JE 9:1 Pistons and Eagle Rods and need to figure out where his compression is..........

Any help would be greatly appriciated......


CDSilver5DoorSVT is offline  
    Reply With Quote Quick reply to this message
Sponsored Links
Advertisement
 
Old 03-17-2006, 09:48 AM   #2
Focus Fanatic
 
pspringe's Avatar
 
Join Date: Jan 2005
Fan#: 17992
Location: Knoxville
What I Drive: 95 Metro, 03 Sonic Blue SVT

Posts: 1,725
FF Reputation: 5 pspringe Good Standing Member
Buy-Sell-Trade Rating: (1)
Probalby, 9:1.
__________________
Hofstadter's Law
"It always takes longer than you expect, even when you take into account Hofstadter's Law."

Kariertes Hemd und Samenstau, ich studier' Maschienenbau.
pspringe is offline  
    Reply With Quote Quick reply to this message
Old 03-17-2006, 10:02 AM   #3
Focus Addict
 
CDSilver5DoorSVT's Avatar
 
Join Date: Dec 2003
Fan#: 2262
Location: Ridgeley, WV
What I Drive: Waiting For The Cobras Point By....

Posts: 894
FF Reputation: 13 CDSilver5DoorSVT Great Standing Member
Buy-Sell-Trade Rating: (39)
Not to be rude, I need to know a positive......I'm being told by others the opposite direction(12)....When we were tuning the Zx5 yesterday at McNews Ray asked Tom what an SVT Short Black with a Zetec head combo made and Tom said 9.5:1(belive that was the number).....I'm looking for the opposite setup.......
CDSilver5DoorSVT is offline  
    Reply With Quote Quick reply to this message
Old 03-17-2006, 07:02 PM   #4
Focus Enthusiast
 
v8focus1's Avatar
 
Join Date: Jan 2004
Fan#: 2562
Location: Fort Ashby,WV, United States
What I Drive: 2002 PW Focus SVT Malibu Blue

Posts: 81
FF Reputation: 20 v8focus1 Great Standing Member
Buy-Sell-Trade Rating: (1)
We do know that the SVT has smaller combuston chambers, and a thicker head gasket. Do the pistons have the same dish volume? Does anyone know exact numbers? If you were to use the SVT head, SVT head gasket, on the SVT block, with the SVT crank, Zetec rods, and Zetec(rated) 9.0:1 pistons equals what CR? I can do the math if neccissary, I only need the specs.
__________________
Ian Saville-Modification Specialist/teacher
2000 Zx3 SHOcus(Yolk)(3.0L DOHC SHO swap)
2002 Zx3 PW BBK SVT engine/trans swap(Malibu Blue)
260hp, 213tq thanks to McNews
v8focus1 is offline  
    Reply With Quote Quick reply to this message
Old 03-17-2006, 09:39 PM   #5
FF Affiliate
 
1turbofocus's Avatar
 
Join Date: Oct 2003
Fan#: 1123
Location: Belmont, NC
What I Drive: 2000 ZX3 / 2002 SVT Turbocharged

Posts: 22,800
Points 52,974, Level 100
Points: 52,974, Level: 100 Points: 52,974, Level: 100 Points: 52,974, Level: 100
Level Up 0% Completed
Level up: 0% Level up: 0% Level up: 0%
Forum Activity 47%
Activity: 47% Activity: 47% Activity: 47%
FF Reputation: 154 1turbofocus Excellent Standing Member 1turbofocus Excellent Standing Member
Buy-Sell-Trade Rating: (28)
I can check it again to see but im thinking the CC of the SVT and the ZX3 are very close and the added compression from 9.6 to 10.2 comes from the pistons in the SVT

So im thinking a ZX3 head on a STV shortblock would be roughly 10 to 1 compression but not 100% sure it was a long time ago that i did the CC test

If you need it i have both heads and can CC them again

Tom
__________________
Focus-Power: Your #1 Source for Ford Focus Speed, Tuning & Performance!

Customer Support
AIM: hpdyno
Email: hpdyno@aol.com
Phone: 704-249-3745
Site: focus-power.com

Elder 1turbofocus
1turbofocus is online now  
    Reply With Quote Quick reply to this message
Old 03-18-2006, 12:16 AM   #6
Mtn. Dew
 
Lil_RedZX3's Avatar
 
Join Date: Jun 2003
Fan#: 101
Location: Changing, WV
What I Drive: 2013 Taffeta White Civic Si

Posts: 7,221
Points 15,841, Level 80
Points: 15,841, Level: 80 Points: 15,841, Level: 80 Points: 15,841, Level: 80
Level Up 99% Completed
Level up: 99% Level up: 99% Level up: 99%
Forum Activity 0%
Activity: 0% Activity: 0% Activity: 0%
FF Reputation: 45 Lil_RedZX3 Great Standing Member
Buy-Sell-Trade Rating: (3)
Quote:
Originally posted by 1turbofocus
I can check it again to see but im thinking the CC of the SVT and the ZX3 are very close and the added compression from 9.6 to 10.2 comes from the pistons in the SVT

So im thinking a ZX3 head on a STV shortblock would be roughly 10 to 1 compression but not 100% sure it was a long time ago that i did the CC test

If you need it i have both heads and can CC them again

Tom
No, we're talking about JE 9.0 to 1 pistons with Zetec rods in an SVT block with SVT head.
Lil_RedZX3 is offline  
    Reply With Quote Quick reply to this message
Old 03-18-2006, 12:34 AM   #7
Oni
Oh yeah!
 
Oni's Avatar
 
Join Date: Jun 2005
Fan#: 24899
Location: Mustang, OK
What I Drive: An unloved Focus

Posts: 2,522
FF Reputation: 4 Oni Good Standing Member
Buy-Sell-Trade Rating: (6)
"The bottom end gets a little work as well. New pistons are used to push compression from 9.6:1 up to 10.2:1, and stronger forged connecting rods replace the delicate cast iron rods of the base engine. At the back of the crank, a new dual-mass flywheel is used to damp vibrations and improve shift feel, but it's what's on the other side of that flywheel that has us excited. The Focus' biggest mechanical shortfall was its transmission. While robust and drastically overbuilt, the gear ratios in the Focus's box were way too tall--another sacrifice for fuel economy. We expected SVT to answer that criticism with a close ratio version of the same MTX75 gearbox, but instead they turned to Getrag for an all-new six-speed transaxle."

http://sportcompactcarweb.com/roadte...6scc_focussvt/

The bumped compression if I'm not mistaken was created (or at least was in a discussion I brought up before) by making the dome or dish on the piston's head a little more shallow. So the zetec blocks are not the same for the SVT and standard ZX3? Has anyone called SVT and asked them? I'm sure they could give you the specifications for each volume in the figuring out the compression ratio.
__________________
SVT Squad #80
1365 of 3985
Born: 04/25/2003


formerly known as the member ilcowil
Oni is offline  
    Reply With Quote Quick reply to this message
Old 03-18-2006, 06:22 AM   #8
FF Affiliate
 
1turbofocus's Avatar
 
Join Date: Oct 2003
Fan#: 1123
Location: Belmont, NC
What I Drive: 2000 ZX3 / 2002 SVT Turbocharged

Posts: 22,800
Points 52,974, Level 100
Points: 52,974, Level: 100 Points: 52,974, Level: 100 Points: 52,974, Level: 100
Level Up 0% Completed
Level up: 0% Level up: 0% Level up: 0%
Forum Activity 47%
Activity: 47% Activity: 47% Activity: 47%
FF Reputation: 154 1turbofocus Excellent Standing Member 1turbofocus Excellent Standing Member
Buy-Sell-Trade Rating: (28)
9.0 (Zetec) Pistons in a SVT block (both blocks ZX3/SVT have the same deck height) with either head would be very close to the same compression all other things being equal like the head gasket and how far the piston is in the whole Etc.

Tom
__________________
Focus-Power: Your #1 Source for Ford Focus Speed, Tuning & Performance!

Customer Support
AIM: hpdyno
Email: hpdyno@aol.com
Phone: 704-249-3745
Site: focus-power.com

Elder 1turbofocus
1turbofocus is online now  
    Reply With Quote Quick reply to this message
Old 03-18-2006, 10:15 AM   #9
Focus Fanatic
 
project2point's Avatar
 
Join Date: May 2005
Fan#: 23521
Location: ohio, United States
What I Drive: 2010 genesis coupe track

Posts: 1,589
FF Reputation: 7 project2point Good Standing Member
Buy-Sell-Trade Rating: (3)
so if i put a svt shortblock on a zetec head it will only be 9.6:1? or would it still be 10.2:1?
__________________
2010 genesis coupe 2.0t track.... Just a few things...
project2point is offline  
    Reply With Quote Quick reply to this message
Old 03-19-2006, 10:58 AM   #10
Focus Fanatic
 
Join Date: Sep 2004
Fan#: 12900
Location: Rockville, MD
What I Drive: 2003 SVT Focus

Posts: 1,643
FF Reputation: 1 crazymechanic Good Standing Member
Buy-Sell-Trade Rating: (1)
the combustion chamber are nearly identical in size. the extra compression of the svt is due to a taller piston. put an svt shortblock on a zx3 head (unmilled) and you should have nearly identical compression to the stock svt. the zx3 block and the svt block are supposed to be EXACTLY the same, with the exception of the oil squirters on the SVT engine. I've heard the head gaskets are slightly different in thickness too, but I'm not sure which one is thicker. if you use the SVT shortblock, with a zx3 head and SVT head gasket, you should have the same compression as the SVT
crazymechanic is offline  
    Reply With Quote Quick reply to this message
Reply

Bookmarks & Social Networks

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the Ford Focus Forum, Ford Focus ST Forum, Ford Focus RS Forum forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.



Thread Tools
Display Modes

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On



All times are GMT -5. The time now is 12:24 PM.


Copyright 2002-2015 FocusFanatics.com. All Rights Reserved : Privacy Policy : Advertise Information

Focus Fanatics Ford Focus Forum offers many fun ways for you to engage with other Ford Focus Owners from across the world. Whether it be about the aftermarket performance modifications, technical how-to's, European tuned suspension or awesome fuel economy similar to the Mazda CX-3, Audi S3, Mazda MX-5 Miata and Acura TLX. You can find all Ford Focus, Focus ST and Focus RS related information here. Join our Ford Focus discussion forums and chat with local Focus enthusiasts in your area. If you own other makes have a look at Challenger Hellcat Forum, Charger Hellcat Forum, Cadillac ATS-V Forum, Cadillac CTS-V Forum, Lexus RC-F Forum, Lexus GS-F Forum, Mercedes GLA Forum, Mercedes GLE Forum and Volvo XC90 Forum.





Search Engine Optimization by vBSEO 3.6.1