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-   -   How can I tell if my engine has been ported? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/how-can-i-tell-if-my-engine-has-been-ported-1021243/)

OniFC 12-23-12 09:10 PM

How can I tell if my engine has been ported?
 
As the title states I'm trying to find out if my engine has been ported and if there is a way to tell without dismantling the engine and inspecting the ports. I know it was rebuilt but do not know if it was just a "stock" rebuild. I took a trip recently to my home town and met up with a friend that has a 91 N/A GXL, mine is a 90 N/A GXL. He has a similar setup to mine, headers, cat delete, to a single side cat back, his is HSK hi-power and mine is Corksport power series. They both have about the same amount of miles since rebuild but mine seems to have more power, and different idle characteristics. I know it's not much to go off of but I figured with the vast knowledge of the forum someone would be able to answer my question or point me in the right direction.

ben.farnath 12-23-12 09:21 PM

With the lim off if it was bridged you can feel the extra bridgeport down the intake port on the irons. As for a street port not sure

K-Tune 12-23-12 09:39 PM

How much vacuum does it pull at idle?

OniFC 12-23-12 09:50 PM


Originally Posted by ben.farnath (Post 11324980)
With the lim off if it was bridged you can feel the extra bridgeport down the intake port on the irons. As for a street port not sure

Thank you! I'm planning on installing the Pineapple 5 & 6 port sleeves so I'll check then. I'm not sure what kind of port it could have. It has a very pronounced exhaust cycle. Even with the stock exhaust it was very pronounced and even more so now that it's an unrestricted system.

OniFC 12-23-12 09:54 PM


Originally Posted by K-Tune (Post 11324996)
How much vacuum does it pull at idle?

I'm not sure. I've been looking at getting a vacuum gauge. What would the idle vacuum pull be if it were ported?

CALPICO 12-23-12 10:43 PM

if it was a stock port on an engine with good compression, vacuum would be around 17mmhg but ported could be anywhere from 10mmhg to 15mmhg

Spirit-RE 12-23-12 10:54 PM

Vacuum depends on what RPM its idling at too.

OniFC 12-23-12 10:58 PM


Originally Posted by CALPICO (Post 11325044)
if it was a stock port on an engine with good compression, vacuum would be around 17mmhg but ported could be anywhere from 10mmhg to 15mmhg

The lower the mmhg would indicate a more aggressive port given the engine has good compression?

OniFC 12-23-12 11:07 PM


Originally Posted by nate91242 (Post 11325055)
Vacuum depends on what RPM its idling at too.

It idles approximately at 800rpm

barkz 12-23-12 11:16 PM

^ irrelevant until you get a boost/vac gauge

OniFC 12-24-12 12:39 AM

I'm going to pick up a vacuum pressure tester on Friday and I'll report my findings then. But in the mean time I took a quick video of my car idling. I know it's black but it was dark when I took it.
<iframe width="420" height="315" src="http://www.youtube.com/embed/4i0ohR7aswg?rel=0" frameborder="0" allowfullscreen></iframe>

FelixIsGod29X 12-24-12 09:29 AM


Originally Posted by ben.farnath (Post 11324980)
With the lim off if it was bridged you can feel the extra bridgeport down the intake port on the irons. As for a street port not sure

If it was bridged ported he would know it right away :lol: brap brap baby!

K-Tune 12-24-12 11:02 AM

Doesn't "sound" ported, but then again street porting isn't supposed to affect idle quality.

OniFC 12-24-12 12:15 PM


Originally Posted by K-Tune (Post 11325363)
Doesn't "sound" ported, but then again street porting isn't supposed to affect idle quality.

I know it's not bridge ported, but I'm definitely getting a vacuum gauge to see what it's pulling.

barkz 12-24-12 11:05 PM

just get an after market boost gauge to replace the iffy-at-best electronic stocker

Black Knight RX7 FC3S 12-25-12 01:33 PM

the best cheap way is to take off the intake manifolds and stick a small mirror that you can bend into the intake port, shine some light in there and look at the port. You can also try and feel the shape of the port with your fingers. If the ports are "sharp", its still a stock port. If you see that the bowl has been smoothed out, its likely that its also ported.

Driftology 12-25-12 04:04 PM


Originally Posted by OniFC (Post 11324973)
As the title states I'm trying to find out if my engine has been ported and if there is a way to tell without dismantling the engine and inspecting the ports. I know it was rebuilt but do not know if it was just a "stock" rebuild. I took a trip recently to my home town and met up with a friend that has a 91 N/A GXL, mine is a 90 N/A GXL. He has a similar setup to mine, headers, cat delete, to a single side cat back, his is HSK hi-power and mine is Corksport power series. They both have about the same amount of miles since rebuild but mine seems to have more power, and different idle characteristics. I know it's not much to go off of but I figured with the vast knowledge of the forum someone would be able to answer my question or point me in the right direction.

sorry I don't have an answer to your question but I am running headers and high flow cat and I was wondering how loud the setup is with the hks exhaust?

OniFC 12-25-12 05:07 PM


Originally Posted by Black Knight RX7 FC3S (Post 11326064)
the best cheap way is to take off the intake manifolds and stick a small mirror that you can bend into the intake port, shine some light in there and look at the port. You can also try and feel the shape of the port with your fingers. If the ports are "sharp", its still a stock port. If you see that the bowl has been smoothed out, its likely that its also ported.

Thanks! Like I posted before I'm getting the Pineapple 6th port sleeves and I'll make sure to check that out while I have the intake off.

OniFC 12-25-12 05:11 PM


Originally Posted by Driftology (Post 11326141)
sorry I don't have an answer to your question but I am running headers and high flow cat and I was wondering how loud the setup is with the hks exhaust?

With not cat it's only loud at WOT, I would say since you have a cat it will sound nice and not make your ears bleed at full throttle.

OniFC 12-25-12 08:13 PM

I just got it cleared up by the guy that rebuilt the engine. It is not ported.

Demi hallow 12-26-12 03:07 PM

Tell your friend to check his vac lines for leaks and see if there is one, if there isn't compare your air to fuel


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