Fordmods Logo

PORTING 

 

Page 1 of 2 [ 18 posts ] Go to page 1, 2  Next

 
 Post subject: PORTING
Posted: Thu Sep 06, 2007 12:07 am 
Stock as a Rock
Offline

Age: 27

Posts: 125

Joined: 5th Mar 2007

Ride: eb xr6

Location: sydney
NSW, Australia

i gots a a stage 5 JMM cam and a similar motor to the JMM dev 5 package except i only have a mild port. just wondering if the loss in tourque from porting is worth the outright power. Anything in particular i should look out for or have done and who have some people used in sydney area!

 

_________________

XR 1992 161 RWKW 14 sec 1/4s

Top
 Profile  
 
 
Posted: Thu Sep 06, 2007 6:50 pm 
Getting Side Ways
Offline
User avatar

Age: 49

Posts: 6467

Joined: 18th Dec 2006

Ride: 93 ED sedan

Power: 161 rwkw

Location: Rockhampton
QLD, Australia

Porting is done to give air speed to increase torque. Also with that, if the cam has a decent duration, then you will need a rise in compression to compensate.

 

_________________

http://youtu.be/jJTh9F3Vgg0

Top
 Profile  
 
 
Posted: Thu Sep 06, 2007 7:14 pm 
Getting Side Ways
Offline
User avatar

Posts: 3115

Joined: 20th Dec 2004

Ride: Falcon

Location: Adelaide
SA, Australia

cjh wrote:
Porting is done to give air speed to increase torque. Also with that, if the cam has a decent duration, then you will need a rise in compression to compensate.


I think he is referring to enlarging the ports to increase flow/hp which usually decreases airspeed/torque.

 

_________________

Stoke me a clipper, I'll be back for Christmas

Top
 Profile  
 
 
Posted: Thu Sep 06, 2007 7:35 pm 
Getting Side Ways
Offline
User avatar

Age: 49

Posts: 6467

Joined: 18th Dec 2006

Ride: 93 ED sedan

Power: 161 rwkw

Location: Rockhampton
QLD, Australia

stockstandard wrote:
cjh wrote:
Porting is done to give air speed to increase torque. Also with that, if the cam has a decent duration, then you will need a rise in compression to compensate.


I think he is referring to enlarging the ports to increase flow/hp which usually decreases airspeed/torque.


That comes back to where you take it off, and how much.

 

_________________

http://youtu.be/jJTh9F3Vgg0

Top
 Profile  
 
 
Posted: Thu Sep 06, 2007 11:30 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 1807

Joined: 6th Feb 2006

Location: CENTRAL
VIC, Australia

i remember a favorite FM quote, "pissing in the dark" LOL
Top
 Profile  
 
 
Posted: Thu Sep 06, 2007 11:45 pm 
Getting Side Ways
Offline
User avatar

Age: 49

Posts: 6467

Joined: 18th Dec 2006

Ride: 93 ED sedan

Power: 161 rwkw

Location: Rockhampton
QLD, Australia

fastleno wrote:
i remember a favorite FM quote, "pissing in the dark" LOL


Yeah, yeah, but If you have half a clue, then its got to be better, eh?
I have only ever 1 set of heads flowed,( as in checked on a flow bench, after I did them ) I ported & polished them. They were Red 308 pre-pollution heads with L34 valves. The guy I did them for paid for them to be tested on a flow bench. He came back and told me that they flowed 480 HP ( he didn't tell me at what lift). This was before it became popular to fit VN 5.0L heads, and before you could get a carby manifold to suit VN heads.
Anyway, turns out that that p!ss in the dark turned out well.

Oh yeah, the engine was a Red 308 with a stroker crank, which took it to 367 cubes, had a turbo 400 auto, 3.36 Sals LSD, running 275/60R15 Yoky's 352's and was punching out 320 HP at the wheels using 95 RON fuel, and would get over 500k's on a tank ( 75 HJ Holden ute ) with half a ton of plumbing gear in the back around town. He was very happy with it.
Its been over 10yrs since I did that. The last time I it was about 2yrs ago, has same engine in it, but now has a 9" diff.

 

_________________

http://youtu.be/jJTh9F3Vgg0

Last edited by cjh on Thu Sep 06, 2007 11:52 pm, edited 1 time in total.

Top
 Profile  
 
 
Posted: Thu Sep 06, 2007 11:52 pm 
Getting Side Ways
Offline
User avatar

Age: 40

Posts: 1807

Joined: 6th Feb 2006

Location: CENTRAL
VIC, Australia

i guess thats why its called pissing in the dark, there are times when the piss makes it in the bowl first up other times it takes adjustment to miss the seat :).
Top
 Profile  
 
 
 Post subject: Re: PORTING
Posted: Fri Sep 07, 2007 12:13 am 
Getting Side Ways
Offline
User avatar

Age: 48

Posts: 7029

Joined: 18th Apr 2005

Location: Hobart
TAS, Australia

XR 1992 wrote:
i gots a a stage 5 JMM cam and a similar motor to the JMM dev 5 package except i only have a mild port. just wondering if the loss in tourque from porting is worth the outright power. Anything in particular i should look out for or have done and who have some people used in sydney area!
stick with the mild port. no point go pissing in dark unless theres room to adjust & funds to play with. :lol:
In my opinion, torque is more important then absolute power. that is, if you're going out to break the land speed record. what I mean is, a well balanced all rounder is what you should aim for! :wink:

 

_________________

Mind f**k!!! it works on feeble minded ignorant sheeples... there's plenty of em on this site... some are very intelligent but by god they are so thick!!!

Pakrat wrote:
You can buy them seppertly

Top
 Profile  
 
 
Posted: Sat Sep 08, 2007 12:00 am 
Getting Side Ways
Offline
User avatar

Age: 49

Posts: 6467

Joined: 18th Dec 2006

Ride: 93 ED sedan

Power: 161 rwkw

Location: Rockhampton
QLD, Australia

Here's some in the dark porting.

 

 

Attachments:
My 88EA cyl head ported & polished. 002.jpg
My 88EA cyl head ported & polished. 002.jpg [ 406.48 KiB | Viewed 56 times ]
My 88EA cyl head ported & polished. 004.jpg
My 88EA cyl head ported & polished. 004.jpg [ 332.32 KiB | Viewed 52 times ]
My 88EA cyl head ported & polished. 003.jpg
My 88EA cyl head ported & polished. 003.jpg [ 334.13 KiB | Viewed 55 times ]

 

_________________

http://youtu.be/jJTh9F3Vgg0

Top
 Profile  
 
 
Posted: Sat Sep 08, 2007 1:29 am 
NSW Cruise Moderator
Offline
User avatar

Age: 39

Posts: 7331

Joined: 5th Nov 2004

Gallery: 12 images

Ride: TE50

Location: ɹǝpun uʍop
NSW, Australia

Who cares, your off topic anyway.. try and help the guy not show us your handy work with a dremel.

XR 1992, get intouch with Joe from Crescent Motorsports at liverpool, or Jaysen from Jays RPD, these guys have done alot of porting stuff and would be able to give you pretty direct answers as to what port sizes would suit your application. if you need some contact numbers, Joe is a sponsor here you can get his info from the various banner adds round the place, Or PM me, I can put you in touch with Jays RPD.

Cheers mate, hope that was a little more helpful.

Also where are you based? what part of Sydney?

Might also influence where you go as well.

 

_________________

Image

I have a car.

Top
 Profile  
 
 
Posted: Sat Sep 08, 2007 9:27 am 
Getting Side Ways
Offline

Posts: 6449

Joined: 11th Nov 2004

this surly is some pissing in the dark. the swirl ridge is still there you polished the the intake ports and seem to have left out the pics of the most important part of the ports. No pics of bowl at all??

next time turn the light on

 

_________________

PERMANENTLY BANNED

Top
 Profile  
 
 
Posted: Sat Sep 08, 2007 7:19 pm 
Smokin em up
Offline

Posts: 264

Joined: 19th Sep 2005

Location: Perth
WA, Australia

most of the gains are in deshrouding the chamber ,bowel and short side radius work. There are a few pictures of JMM chamber work on this forum which shows what is needed to be done for chamber. Also there is an Autospeed article on AU head porting which is of help.

It takes a while work out what is really needed. Try reading some books like "How to build, Modify and power tune Cylinder Heads" by Peter Burgess and David Gollan/ How to build and modify Chevrolet small block V-8 cylinder heads.
There are a few others and quite a few articles on the net. You DONT need a flow bench to port (although it helps) and there are alot of porters who dont fully rely on flow bench figures for their porting. Airspeed is a big factor.

Pictures of professionally ported heads are a big help.

For starters smoothing the bowel transitions is a good place to start.

 

_________________

Turbo 6s rule

Top
 Profile  
 
 
Posted: Fri Sep 14, 2007 5:56 pm 
Stock as a Rock
Offline

Age: 27

Posts: 125

Joined: 5th Mar 2007

Ride: eb xr6

Location: sydney
NSW, Australia

Thanks for your replies (the ones that helped) all i was trying to establish was that if there was a loss in tourque due to the bigger port, and if there was is it worth the gain in outright power as tourque is what makes it fun. Ill get on 2 crescent i think thanks

 

_________________

XR 1992 161 RWKW 14 sec 1/4s

Top
 Profile  
 
 
Posted: Sun Sep 16, 2007 6:44 am 
Stock as a Rock
Offline

Age: 31

Posts: 167

Joined: 13th Aug 2005

Ride: R34 GTR

Location: Melbourne
VIC, Australia

whats with the mirror finish??? Your living in the 70's man! Your not meant to Polish......u lose power.

 

_________________

LUMPY-6

Top
 Profile  
 
 
Posted: Sun Sep 16, 2007 9:44 pm 
Getting Side Ways
Offline
User avatar

Age: 49

Posts: 6467

Joined: 18th Dec 2006

Ride: 93 ED sedan

Power: 161 rwkw

Location: Rockhampton
QLD, Australia

efmarek wrote:
whats with the mirror finish??? Your living in the 70's man! Your not meant to Polish......u lose power.


Yeah, and I was there, and you weren't even an itch in your dadys pants.
The mirror finish is to help eleviate the carbon build up, which can cause pre-ignition in hi-comp ratio engines.
Here's one for you, your 21, yes???, take a step back and have a look at all of whats going on in the performance stakes/gains.

 

_________________

http://youtu.be/jJTh9F3Vgg0

Top
 Profile  
 
Display posts from previous:
Sort by  
 Page 1 of 2  [ 18 posts ]  Go to page 1, 2  Next

Who is online

Users browsing this forum: No registered users and 29 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

 

 

It is currently Sat Dec 16, 2017 10:25 am All times are UTC + 11 hours

 

 

(c)2014 Total Web Solutions Australia - Australian Web Hosting and Domain Names