Excuse my ignorance, but what advantage does match porting your inlet manifolds have? Horse power? Better power range? torque?
Tell me a story guys and gals......:bounce
063bug ·
Aussieveedubbers · Tech Talk
Match porting advantages?????
https://forums.aussieveedubbers.com/threads/63039/match-porting-advantages
VWCOOL ·
reduces disruption of air flow, so yes and yes
hellbugged ·
a must do really....
unless you like having a speed bump in your intakes.👍
flat spots, would be one of the telltale symptoms
unless you like having a speed bump in your intakes.👍
flat spots, would be one of the telltale symptoms
063bug ·
any more comments.... % increase for example, I know that depends upon lots of factors but does the process of match porting produce a significant improvement or just something that is expected to be done to a performance engine....
Bizarre ·
I have the saying but it is "all part of the combo"
Match porting
3 angle valve grind
head work (biggest variable)
Match porting alone is not going to add 50% but a carefully built motor over a thrown together out of the box parts one "could" result in a 10-25% difference if it all the "best practices" were followed
Match porting
3 angle valve grind
head work (biggest variable)
Match porting alone is not going to add 50% but a carefully built motor over a thrown together out of the box parts one "could" result in a 10-25% difference if it all the "best practices" were followed
76camper ·
also depends alot on the state of the port before the match porting as to the power increase.
In the scheme of things its F.A but when your going to the effort of spending alot of hours or $$ on a good port job, its just stupid to neglect matching the manifolds to the ports.
In the scheme of things its F.A but when your going to the effort of spending alot of hours or $$ on a good port job, its just stupid to neglect matching the manifolds to the ports.
vw54 ·
Too many variables to say exactly how much increase it gives
some may say 100% some may say 1% but its part of a high performance engine its only a figure wots it matter
some may say 100% some may say 1% but its part of a high performance engine its only a figure wots it matter
dangerous ·
Match porting is probably not the description of what you need Alan.
Generally this is the term used to make the port OPENING in the head "match" the port OPENING in the manifold.
But if these are already close, there may be no significant gain.
More than likely you need your manifolds ported up their length
so that they are up to the same air flow capacity (or more) than your heads.
The normal process is to use a flow bench to see if the manifold reduces flow potential when it is fitted to the head.
But since your heads are on the engine already, you will have to make comprimises.
A basic match can be done by you, as per Alan Agyiks artical, but the shape and size of the area above the gasket, right up to the carb is also important.
You may even find that the cross sectional area of your venturi already limits your engine
thus negating any gains found elsewhere,
and a flow test of the entire head, manifold and carb(with air cleaner) will reveal all.
Twists and turns aside, there is a prefered method that has a gradual increase in area
from the throat of the seat up to the butterfly.
This will sometimes require welding on the manifold.
Generally this is the term used to make the port OPENING in the head "match" the port OPENING in the manifold.
But if these are already close, there may be no significant gain.
More than likely you need your manifolds ported up their length
so that they are up to the same air flow capacity (or more) than your heads.
The normal process is to use a flow bench to see if the manifold reduces flow potential when it is fitted to the head.
But since your heads are on the engine already, you will have to make comprimises.
A basic match can be done by you, as per Alan Agyiks artical, but the shape and size of the area above the gasket, right up to the carb is also important.
You may even find that the cross sectional area of your venturi already limits your engine
thus negating any gains found elsewhere,
and a flow test of the entire head, manifold and carb(with air cleaner) will reveal all.
Twists and turns aside, there is a prefered method that has a gradual increase in area
from the throat of the seat up to the butterfly.
This will sometimes require welding on the manifold.
Dasdubber ·
Well said and explained Dave - as you mention (which I neglected to in the 'sticky' article in this section) re. match porting, my standard port 2L type IV heads and standard manifolds were very close to start with. Hence why not too much attention was given to opening up the manifolds themselves along their entire runner length.
Alan, with your ports though, it may be more necessary to have a more accurate, graduated blending of the manifolds runners as Dave mentions above. I can't remember the size and shape of your inlet ports (not sure if I saw the heads prior to manifolds being bolted on)....do you have any pics of the inlets?
Alan
Alan, with your ports though, it may be more necessary to have a more accurate, graduated blending of the manifolds runners as Dave mentions above. I can't remember the size and shape of your inlet ports (not sure if I saw the heads prior to manifolds being bolted on)....do you have any pics of the inlets?
Alan
063bug ·
Thanks for the input guys....
Alan, I have attached the picture of my Stage 2 Steve Timms ported heads and I match ported the inlet manifolds the other weekend to ensure the size of the port was as close to the same size up the manifolds till it started to open up even more... Thanks for the tools to do it too.
Yes, Dave, my carbs will be the limiting factor as they are still the Dellorto 40's (with update kit). The engine seems to be still revving strong after 5000rpm (not game to rev it past this until I get it on the Dyno) and the power seems to come on at around 2000rpm.
Maybe I could pin you two down on the weekend and have a little chat.... If you are both going of course... Parklands show....
[ Edited on 12-6-2007 by 063bug ]
Alan, I have attached the picture of my Stage 2 Steve Timms ported heads and I match ported the inlet manifolds the other weekend to ensure the size of the port was as close to the same size up the manifolds till it started to open up even more... Thanks for the tools to do it too.
Yes, Dave, my carbs will be the limiting factor as they are still the Dellorto 40's (with update kit). The engine seems to be still revving strong after 5000rpm (not game to rev it past this until I get it on the Dyno) and the power seems to come on at around 2000rpm.
Maybe I could pin you two down on the weekend and have a little chat.... If you are both going of course... Parklands show....
[ Edited on 12-6-2007 by 063bug ]
Dasdubber ·
Yep I will be there Alan - will be good to catch up again.
PS Sorry I forgot to say the sanding flap wheels were all pretty cactus in that bag of bits I gave you with the die grinder. I thought they were in better shape but since I haven't used them for a while, I didn't remember they were so far gone! Hope you managed to sort something out.
PS Sorry I forgot to say the sanding flap wheels were all pretty cactus in that bag of bits I gave you with the die grinder. I thought they were in better shape but since I haven't used them for a while, I didn't remember they were so far gone! Hope you managed to sort something out.
VWCOOL ·
Can I match-port this?!
dangerous ·
Sorry Alan,063bug wrote:Thanks for the input guys....
Maybe I could pin you two down on the weekend and have a little chat.... If you are both going of course... Parklands show....
[ Edited on 12-6-2007 by 063bug ]
not going to Parklands.
If I can off load this flue, I will be climbing 'The Pinnacle' at Springbrook.
DB.
Craig Torrens ·
Now that would make a 1916 run like a 1300:P !!VWCOOL wrote:Can I match-port this?!
hellbugged ·
seeing as you have opened them up already,you may as well open up the chambers whilst your at it:thumbVWCOOL wrote:Can I match-port this?!
hellbugged ·
goodo, did you have fun doing it?063bug wrote:Thanks for the input guys....
Alan, I have attached the picture of my Stage 2 Steve Timms ported heads and I match ported the inlet manifolds the other weekend to ensure the size of the port was as close to the same size up the manifolds till it started to open up even more... Thanks for the tools to do it too.
Craig Torrens ·
Ummm did you notice the carbon in the inlet port ?!dumone wrote:seeing as you have opened them up already,you may as well open up the chambers whilst your at it:thumbVWCOOL wrote:Can I match-port this?!
hellbugged ·
shite, i thought there was a hole there in the head...........not a hole in the carbon!!!!
duffer
duffer
dangerous ·
Another method worth a mention is that the manifold must NOT be bigger than the head hole AT ANY POINT around the flange.
Even to the point where the manifold is about 1/2 mm smaller all around the edge of the hole.
In fact , I would normally make the manifold this 1/2mm smaller to avoid any low areas that might occur when trying to get a perfect 'port match'.
But above the flange the area of the hole can be progressively larger
so that the air picks up speed as it approaches the head(INSIDE the head would normally be ported a little larger in area to slow down the'charge' for the turn before the valve seat)
You probably know this Glen :
but that carbon can only build-up in the inlet port when the valve spring
has been failing to control the valve.(more spring dude!).
In that case it looks to have been occuring for a long period.
[ Edited on 12-6-2007 by dangerous ]
Even to the point where the manifold is about 1/2 mm smaller all around the edge of the hole.
In fact , I would normally make the manifold this 1/2mm smaller to avoid any low areas that might occur when trying to get a perfect 'port match'.
But above the flange the area of the hole can be progressively larger
so that the air picks up speed as it approaches the head(INSIDE the head would normally be ported a little larger in area to slow down the'charge' for the turn before the valve seat)
You probably know this Glen :
but that carbon can only build-up in the inlet port when the valve spring
has been failing to control the valve.(more spring dude!).
In that case it looks to have been occuring for a long period.
[ Edited on 12-6-2007 by dangerous ]
Craig Torrens ·
Funny story with this head. Glenn bought an engine off a guy who was selling it as a "1300", when we pulled the tinware off we realised it was a 1916....it was just so blocked with carbon the previous owner thought it was a 1300 !dangerous wrote:You probably know this Glen :
but that carbon can only build-up in the inlet port when the valve spring
has been failing to control the valve.(more spring dude!).
In that case it looks to have been occuring for a long period.
[ Edited on 12-6-2007 by dangerous ]
VWCOOL ·
Dave, I guessed it was just from a combination of LRP/valvesaver, heat and rich running.
All a bit O/T but as Craig alluded, it was a funny story. When I bought this 'spare parts' engine it was breathing from a daggy-looking centre Weber with a botched up linkage etc. I didn't care - I really only wanted the crank and flywheel for a super-steroids engine I'm getting built. Just for fun, I got it running 'on the ground' It ran - but only just.
The heads leaked. Taking off the tinware, the big barrels became noticeable. Lucky me!
It wasn't to be a 'spare parts' engine any more! It took me two days to chip out the crap from all ports with a sharpened screwdriver. A weekend at Stan Pobjoy's was the outcome; the heads have now been fully recoed with new springs and exhaust valves and a machine to clean the sealing surface. We removed and lapped the tops of the barrels; unknown mileage on this engine but the barrels/bores looked like new with cross-hatching still obvious. The rest of the engine looked/felt fine and clean (no soot etc) so we bolted it back together and I'll stick it into my L-Bug soon.
[ Edited on 8-9-2007 by VWCOOL ]
All a bit O/T but as Craig alluded, it was a funny story. When I bought this 'spare parts' engine it was breathing from a daggy-looking centre Weber with a botched up linkage etc. I didn't care - I really only wanted the crank and flywheel for a super-steroids engine I'm getting built. Just for fun, I got it running 'on the ground' It ran - but only just.
The heads leaked. Taking off the tinware, the big barrels became noticeable. Lucky me!
It wasn't to be a 'spare parts' engine any more! It took me two days to chip out the crap from all ports with a sharpened screwdriver. A weekend at Stan Pobjoy's was the outcome; the heads have now been fully recoed with new springs and exhaust valves and a machine to clean the sealing surface. We removed and lapped the tops of the barrels; unknown mileage on this engine but the barrels/bores looked like new with cross-hatching still obvious. The rest of the engine looked/felt fine and clean (no soot etc) so we bolted it back together and I'll stick it into my L-Bug soon.
[ Edited on 8-9-2007 by VWCOOL ]