Match Porting Inlet Manifolds

Aussie Officially Full-On Dubber

296 posts · joined Sep 2006 · 27 Jan 2014, 8:35 pm

#981769

Does anyone have any useful links to a 'How to' article or similiar for match porting manifolds?

Where can I get some of the blue dye to guide the process?

Should the inlet manifold exactly match the head ports or be slightly smaller?

Does anyone sleeve their manifolds to ensure head ports and manifold ports always align properly? Maybe a dowel?

Do people go as far as measuring volume of manifold ports (after the porting process) to make sure that all are equal?

cb john Wolfsburg Wizard

470 posts · joined Jun 2007 · 27 Jan 2014, 10:07 pm

#981775

Aussie wrote:Does anyone sleeve their manifolds to ensure head ports and manifold ports always align properly? Maybe a dowel?

Sleeving is what I do...

matberry Moderator Go hard or go home

8,114 posts · joined Mar 2006 · 28 Jan 2014, 9:11 am

#981786

yes

Matt Berry Motorsports...air cooled advice, repairs and mods Ph 0408 704 662
OFF-ROAD,CIRCUIT,DRAG,STREET,ENDURANCE

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 28 Jan 2014, 10:49 am

#981789

http://forums.aussieveedubbers.com/viewtopic.php?tid=27021

If you plan to do just one set of Heads Ian, just use a texta like Niko to mark out the flanges.

I prefer to use a dowel on the intake stud, (two nuts locked on the stud and turned to size),
and this way, you can make the port exactly the same size on both,
with the confidence that they will match time after time.

I like to bolt the assembly together and use a long shanked burr from the chamber side.
(assuming you are using tall manifolds?)
Some projects require cutting the manifold off and re-welding after you have your cross section complete.

If you choose not to make a precise fit,
as the CB stuff arrives,
you will need a smaller port in the manifold so you never get an obstruction.

To me the size of the port becomes a waste of time in that case,
especially if you have an over sized 44 valve in the first place.

Ideally the port should taper in size from the seat throat up to the carb flange.
At the very least, the cross section at the head flange should be the smallest part of the manifold.

No need to measure port volume,
just measure your work with inside calipers,
or a suitably made template.
Card board or tin, is good on a threaded stud.

westi wrote:That's mad Alan.

Aussie Officially Full-On Dubber

296 posts · joined Sep 2006 · 28 Jan 2014, 7:45 pm

#981831

dangerous wrote:http://forums.aussieveedubbers.com/viewtopic.php?tid=27021

I prefer to use a dowel on the intake stud, (two nuts locked on the stud and turned to size),
and this way, you can make the port exactly the same size on both,
with the confidence that they will match time after time.

Thanks Dave. Just to clarify - you effectively sleeve the manifold studs on the head using a couple of nuts machined down to be a tight fit with the manifold mount holes?

psimitar Son of Jim - Creator of Good

2,506 posts · joined Jan 2009 · 28 Jan 2014, 9:22 pm

#981839

I've always used a shanked stud and then made sure the manifold stud holes are a snug fit over the central shanked area of the stud. same as sleeving but I prefer using shanked studs instead of fully threaded. The fully threaded just don't locate as nicely as the shanked studs.

here ya go for some fairly cheap engineers blue EBay Engineers blue

madness is in the eye of the beholder 👍

dangerous 23 Windows of Awesome

5,901 posts · joined Jan 2005 · 29 Jan 2014, 5:50 am

#981855

Aussie wrote:
dangerous wrote:http://forums.aussieveedubbers.com/viewtopic.php?tid=27021

I prefer to use a dowel on the intake stud, (two nuts locked on the stud and turned to size),
and this way, you can make the port exactly the same size on both,
with the confidence that they will match time after time.

Thanks Dave. Just to clarify - you effectively sleeve the manifold studs on the head using a couple of nuts machined down to be a tight fit with the manifold mount holes?

Yes Ian.
It effectively becomes a "shanked stud" as psimitar would say,
but is larger in diameter than anything off-the-shelf,
because the holes are mostly so large.

P.S. always Loctite the two nuts before they are machined to size.

westi wrote:That's mad Alan.