Terminology question. - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars
The Pub For General Discussion

LinkBack Thread Tools Display Modes
post #1 of 5 (permalink) Old 12-30-02, 02:48 AM Thread Starter
Ex Member
Fairlane Boy's Avatar
Join Date: Nov 2001
Location: Perth
Posts: 717
Terminology question.

What does port matching mean?
Also, What does it mean to "O-ring" your block?

Best wishes
Fairlane Boy is offline  
Sponsored Links
post #2 of 5 (permalink) Old 12-30-02, 03:27 AM
Officially Bored with 347
svo347's Avatar
Join Date: Jul 2001
Location: Perth West Oz
Age: 44
Posts: 3,585
Port matching is to grind/polish the intake manifold ports to the exact size & shape to those in the head or vise versa giving an unrestricted path to the valves.
Same with the exhaust ports being cut pertectly to the extractor pipes.
O ringing refers to a circular groove about .25mm deep or less being cut into the block and head. A special gasket is used that once inplace & torqued is virtually leakproof ie locwire head gaskets


Member of the "TKTDSGM " Group..
svo347 is offline  
post #3 of 5 (permalink) Old 12-30-02, 03:40 AM
Registered User
Join Date: Jul 2002
Location: In hiding
Posts: 864
port matching is usually done by working each port ie the head and the manifold, to the gasket that is going to be used - in most cases this is the only way to "see" that the ports are in fact true to each other. Even the gasket must be properly aligned/trimmed to achieve the best uninterrupted air flow through the ports.

The "o" ring is usually made of copper or sometimes mild steel and is often incorporated into the gasket but not always.

A motor is "o" ringed to contain very high compression esp with blown engines. Quite often a solid copper (head) gasket will achieve the same result without the expense of machine work.
T3man is offline  
post #4 of 5 (permalink) Old 12-30-02, 03:47 AM
Registered User
Join Date: Jul 2002
Location: In hiding
Posts: 864
Oh, and porting is usually accompanied by polishing wherein the tracts from the valves to the ports are "sanded" or "polished" as smooth as possible to remove any roughness associated with the normal casting and machining processes. Very time consuming and sometimes difficult depending on the length and size of the runners, but the results are always measureable.
T3man is offline  
post #5 of 5 (permalink) Old 12-30-02, 04:23 AM
Veteran Ford Member
Join Date: Feb 2002
Location: Searching for a new home
Posts: 3,657
Port matching describes the process of ensuring that the inlet manifold and the inlet ports on the cylinder head are "matched" so that they are (1) properly aligned (2) have the same surface area and (3) the casting irregularities are smoothed.
The effect is to maximise air flow characteristics on the inlet side.
O-Ringing an engine block involves cutting a thin groove in the cylinder with a special tool and inserting a thin (often copper) wire into the groove that sits proud of the block by about 10 thou. This wire then comes into contact with the head gasket and forms a considerably stronger seal. Typically copper head gaskets are used as well. You usually find this work done on blocks that develop high compression ratios or which use forced induction (upwards of 12lb boost).
The same process can be used on cylinder heads as well.

Hope this isn't oversimplified.
russellw is offline  
Sponsored Links

  Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars > Fordforums Community > The Pub

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode

Similar Threads
Thread Thread Starter Forum Replies Last Post
NA LPG Question, EA dash question Troutman LPG Tech 3 07-23-02 08:17 AM
NAPARM- Thread Preview Question batbo6 The Pub 5 07-23-02 03:58 AM
Job application question: HSE2 The Pub 8 05-06-02 01:12 AM
6 Months from now - I pop the question! Scottie2Hottie Ford Probe Forum | Mazda MX6 Forum 27 12-09-01 07:51 PM

Posting Rules  
You may not post new threads
You may not 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

For the best viewing experience please update your browser to Google Chrome