i actually emailed these guys a while ago to see if it was worth importing some heads. they are having all sorts of problems setting up to cast a new batch and can't even give an estimate of a price
michael
| ausmini https://ausmini.com/forums/ |
|
| Seven Port Head https://ausmini.com/forums/viewtopic.php?f=5&t=6034 |
Page 1 of 3 |
| Author: | Chris [ Sat Apr 02, 2005 9:48 pm ] |
| Post subject: | Seven Port Head |
Seven Port Danish head. http://www.akmracing.dk/pictures.htm Words by Vizard on the same site. |
|
| Author: | mickmini [ Sat Apr 02, 2005 9:54 pm ] |
| Post subject: | |
i actually emailed these guys a while ago to see if it was worth importing some heads. they are having all sorts of problems setting up to cast a new batch and can't even give an estimate of a price
michael |
|
| Author: | 68matic [ Sat Apr 02, 2005 10:15 pm ] |
| Post subject: | |
1. shite 2. would they just block up the two inlets and pop four holes in the front of the head? 3. would this then make it a cross flow head? |
|
| Author: | Chris [ Sat Apr 02, 2005 10:31 pm ] |
| Post subject: | |
68matic wrote: 1. shite
2. would they just block up the two inlets and pop four holes in the front of the head? 3. would this then make it a cross flow head? We used to do that with Peugot heads, instant xflow. Can't do it with a Mini as it is not a hemi head plus a lot of other reasons like spark plug holes and things. |
|
| Author: | drmini in aust [ Sat Apr 02, 2005 10:54 pm ] |
| Post subject: | |
MiniSport in UK have now bought all the patterns and design for these AKM 7 porters. Heads might be available sometime soon.. ask them. 
|
|
| Author: | GtiMini [ Sun Apr 03, 2005 9:24 am ] |
| Post subject: | |
Very interesting head design. Must be a bitch to change the spark plugs. |
|
| Author: | Mini Mad [ Sun Apr 03, 2005 9:33 am ] |
| Post subject: | |
Would it hurt it much compared to an 8-port that it doesn't have the extra exhaust port? |
|
| Author: | GtiMini [ Sun Apr 03, 2005 9:45 am ] |
| Post subject: | |
Mini Mad wrote: Would it hurt it much compared to an 8-port that it doesn't have the extra exhaust port?
I don't think so. The exhaust pulses are completely out of phase on those 2 cylinders. Therefore, each cylinder see that port and pipe as being dedicated to it during the exhaust stroke. But, in the perfect world a head would have separate ports and exit pipes. |
|
| Author: | drmini in aust [ Sun Apr 03, 2005 4:56 pm ] |
| Post subject: | |
Go to Marcel Chichak's site here and click on technical. Top item is comparative, up to date flow tests of most available heads including the Elder 8 port. http://www.starchak.ca/ |
|
| Author: | minstar [ Mon Apr 04, 2005 9:23 am ] |
| Post subject: | Stupid Question |
Doc, GTI et al. In 250 words or less explain to me a 7 port head, I can understand 8 port for a four cylinder but how do you have 7 ports for 4 cylinder Confused Matty. |
|
| Author: | Zizzle [ Mon Apr 04, 2005 10:21 am ] |
| Post subject: | |
Well you keep the siamese exhaust port (2 & 3 into one port). Allows you to keep the standard LCB exhaust manifolds etc. Minimal degredation in performance. Inlet ports get moved to the other side of the head. No need for siamese setup there, so 4 ports direct to the inlet valves. Whalla 7 port head. |
|
| Author: | fuzzy-hair-man [ Mon Apr 04, 2005 10:28 am ] |
| Post subject: | |
Each cylinder has it's own inlet port, cylinders 1 & 4 have thier own exhaust ports, cylinders 2 & 3 share the middle exhaust port. So there are 4 inlet ports and three exhaust ports, (the exhaust ports are similar to the normal mini head) I think the idea is that efficent flow of inlet gasses is much more important than the flow of exhaust gasses hence the head design. (and the reason I guess that turbos work) the firing order 13 4 2 means that no matter which way the firing goes ie 3421 4213 2134 back to 1342 there is no time that cylinders 3 and 2 are firing next to each other and so they never need to share the shared exhaust port at the same time. |
|
| Author: | drmini in aust [ Mon Apr 04, 2005 12:07 pm ] |
| Post subject: | |
And another advantage of 7 porter is, you can keep your camshaft, the lobe arrangement is the same. `ex-in-in-ex-ex-in-in-ex'. Most 8 porters except the Elder one need a new cam as the valve layout is different. `in-ex-in-ex-in-ex-in-ex'. Only complaint I've heard of the AKM 7 port are they are too bloody dear, and the ports too big....?? |
|
| Author: | fuzzy-hair-man [ Mon Apr 04, 2005 12:59 pm ] |
| Post subject: | |
Before I present Arrin's stupid idea number 2032 can some one tell me wether I am correct in saying that restrictions in the exhaust system do not matter as much as similar restrictions in the inlet system? hence the reason a car produces more power with a turbo than without. - trading a restriction in the exhaust for greater flow in the inlet... |
|
| Author: | drmini in aust [ Mon Apr 04, 2005 1:09 pm ] |
| Post subject: | |
To answer that I'd say a 7 porter gives nothing away to an 8 porter. Some of the 8 porters (Elder) have very tortuous ex passages just to avoid having a siamesed port! Defeats the purpose I reckon. OTOH there is power gained by doing exhaust port work on an A series head. Stock, most of 'em are pretty bad.
|
|
| Page 1 of 3 | All times are UTC + 10 hours |
| Powered by phpBB® Forum Software © phpBB Group http://www.phpbb.com/ |
|