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Porting question,need clarification,not in search?
Thread Starter
Racer
Joined: Sep 2005
Posts: 449
Likes: 1
From: Victoria
Porting question,need clarification,not in search?
I have a spare 89 intake and plenum im going to port and polish using info gained from the forum and will fit when completed.
My question is and im unable to clarify it in a search on the topic,
In reference to the intake, can I gasket match the intake ports(between the intake and heads)or will this cause the ports not to line up correctly,as Im not sure what the DIFFERENCE is in the original dimentions of both the head and intake ports in relation to the new gasket as the ports in the heads,naturally, are not exposed at this time so I can check.
My question is and im unable to clarify it in a search on the topic,
In reference to the intake, can I gasket match the intake ports(between the intake and heads)or will this cause the ports not to line up correctly,as Im not sure what the DIFFERENCE is in the original dimentions of both the head and intake ports in relation to the new gasket as the ports in the heads,naturally, are not exposed at this time so I can check.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Geoff
Gasket matching is using the gasket as a reference to port both intake and head to same dimensions.
If you only "true" up the intake then it is possible it may be bigger than the stock port resulting in a mismatch.
Will check gasket against one of my spare heads later tonight for you.
Gasket matching is using the gasket as a reference to port both intake and head to same dimensions.
If you only "true" up the intake then it is possible it may be bigger than the stock port resulting in a mismatch.
Will check gasket against one of my spare heads later tonight for you.
Thread Starter
Racer
Joined: Sep 2005
Posts: 449
Likes: 1
From: Victoria
Geoff
Gasket matching is using the gasket as a reference to port both intake and head to same dimensions.
If you only "true" up the intake then it is possible it may be bigger than the stock port resulting in a mismatch.
Will check gasket against one of my spare heads later tonight for you.
Gasket matching is using the gasket as a reference to port both intake and head to same dimensions.
If you only "true" up the intake then it is possible it may be bigger than the stock port resulting in a mismatch.
Will check gasket against one of my spare heads later tonight for you.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Put your gasket up to the head aligning the bolt holes. Then also on your intake, youll see where youre at. Have ported quite a few TPI bases and encourage it. Will take a lot of time to do it right and go all the way through if you have the patience.
Would not worry about "polishing" afterwards, wont really make a performance difference. Use the carbides for the larger cutting then the "tootsie rolls" or flap wheels to smooth it out some.
Would not worry about "polishing" afterwards, wont really make a performance difference. Use the carbides for the larger cutting then the "tootsie rolls" or flap wheels to smooth it out some.
Thread Starter
Racer
Joined: Sep 2005
Posts: 449
Likes: 1
From: Victoria
Put your gasket up to the head aligning the bolt holes. Then also on your intake, youll see where youre at. Have ported quite a few TPI bases and encourage it. Will take a lot of time to do it right and go all the way through if you have the patience.
Would not worry about "polishing" afterwards, wont really make a performance difference. Use the carbides for the larger cutting then the "tootsie rolls" or flap wheels to smooth it out some.
Would not worry about "polishing" afterwards, wont really make a performance difference. Use the carbides for the larger cutting then the "tootsie rolls" or flap wheels to smooth it out some.
'RODJ ' is checking the gasket size against a head for me.
I plan to port the spare plenum i have(neither intake or plenum planned to be simeased )tidy up the entry of oem runners,
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
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Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
EFI manifold is dry. Airspeed in a TPI is so strong doubt the motor would care one way or the other. If you match it to the head entry/gasket and port the base if you did the heads later all youd need to do is another quick match to the intake entry and youre set. 
Thread Starter
Racer
Joined: Sep 2005
Posts: 449
Likes: 1
From: Victoria
Basically original,have comp cam 1.6 rollers and lt4 springs and retainers ready to install,when I finish the porting job.
the porting of the intake and plenum is a learning curve for me.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Ok.
Stock ACL intake gasket on stock head.
Looking at a pair of ports ,the gasket is spot on the center divider.
However ,in the outside corners it sits back from the port edge especially the top corners which are approx 2mm back in the middle of the radius.
If only doing the intake this would give a miss match in those areas the "wrong " way .Better to go from small to large rather than other way.
Not sure how the pro's do it ,but essential to maintain gasket in correct position when marking up on either head or intake.
The bolt holes in the gasket are larger than the bolts allowing a movement away from dead on which would defeat the purpose of matching.
Will try and get you some pics tomorrow
Stock ACL intake gasket on stock head.
Looking at a pair of ports ,the gasket is spot on the center divider.
However ,in the outside corners it sits back from the port edge especially the top corners which are approx 2mm back in the middle of the radius.
If only doing the intake this would give a miss match in those areas the "wrong " way .Better to go from small to large rather than other way.
Not sure how the pro's do it ,but essential to maintain gasket in correct position when marking up on either head or intake.
The bolt holes in the gasket are larger than the bolts allowing a movement away from dead on which would defeat the purpose of matching.
Will try and get you some pics tomorrow
Team Owner
Joined: Dec 2007
Posts: 20,974
Likes: 261
EFI manifold is dry. Airspeed in a TPI is so strong doubt the motor would care one way or the other. If you match it to the head entry/gasket and port the base if you did the heads later all youd need to do is another quick match to the intake entry and youre set. 
Thread Starter
Racer
Joined: Sep 2005
Posts: 449
Likes: 1
From: Victoria
Ok.
Stock ACL intake gasket on stock head.
Looking at a pair of ports ,the gasket is spot on the center divider.
However ,in the outside corners it sits back from the port edge especially the top corners which are approx 2mm back in the middle of the radius.
If only doing the intake this would give a miss match in those areas the "wrong " way .Better to go from small to large rather than other way.
Not sure how the pro's do it ,but essential to maintain gasket in correct position when marking up on either head or intake.
The bolt holes in the gasket are larger than the bolts allowing a movement away from dead on which would defeat the purpose of matching.
Will try and get you some pics tomorrow
Stock ACL intake gasket on stock head.
Looking at a pair of ports ,the gasket is spot on the center divider.
However ,in the outside corners it sits back from the port edge especially the top corners which are approx 2mm back in the middle of the radius.
If only doing the intake this would give a miss match in those areas the "wrong " way .Better to go from small to large rather than other way.
Not sure how the pro's do it ,but essential to maintain gasket in correct position when marking up on either head or intake.
The bolt holes in the gasket are larger than the bolts allowing a movement away from dead on which would defeat the purpose of matching.
Will try and get you some pics tomorrow
Looks like I would be better off not doing these particular ports to be on the safe side..