Lets talk about valve size - 16V's
Racer
Joined: Feb 2002
Posts: 499
Likes: 19
From: Duluth MN
Originally Posted by danglerb
I know nothing of the details of porting, but those look like round holes, wouldn't it be fairly easy to make them larger round holes?
Easiest place to host picts is right here, just become a full member.
Second choice is, http://www.imagehosting.com/index.php totally easy, no signup, browse, upload, and copy the link.
Easiest place to host picts is right here, just become a full member.
Second choice is, http://www.imagehosting.com/index.php totally easy, no signup, browse, upload, and copy the link.
That's dumb. You have to be a member to post photos that would benifit the people that are interested in these cars and how they work. I don't own a 928. I own a 914. So I'm too cheap to become a member.
Addict
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Joined: Jun 2003
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From: Helsinki, Finland
Originally Posted by Hacker-Pschorr
Has anyone measured the valve spacing? Meaning the distance between the center of each valve? Yes I realize they are (should be) the same, just curious.
Euro
40/2 + 6 + 45/2 = 20 + 6 + 22.5 = 48.5mm
US
38/2 + 8 + 43/2 = 19 + 8 + 21.5 = 48.5mm
Nordschleife Master
Joined: Oct 2006
Posts: 8,575
Likes: 5
From: Orange, Cal
Originally Posted by 918-S
Sure, but there is some real science involved in porting heads. It's not as simple as hogging out material. Done incorrectly and you can actually end up with worse heads than you started with. The euro heads have Porsches engineers behind the work that was done.
That's dumb. You have to be a member to post photos that would benifit the people that are interested in these cars and how they work. I don't own a 928. I own a 914. So I'm too cheap to become a member.
That's dumb. You have to be a member to post photos that would benifit the people that are interested in these cars and how they work. I don't own a 928. I own a 914. So I'm too cheap to become a member.
No you don't have to be a member, just use the link I posted and put a link to the images in the thread if it won't let you put the actual image in, or PM a link to somebody that is a member and let them post the images.
Racer
Joined: Feb 2002
Posts: 499
Likes: 19
From: Duluth MN
Originally Posted by danglerb
Science would be great, but I suspect some "cookbook" level porting will improve just about any factory head. Chances are good Porsche's engineer's had goals like good fuel economy and ease of production, not getting the last 10 or 20 hp out of the motor. Can't say at this point I disagree with that view, stock Euro S heads sound fine to me.
No you don't have to be a member, just use the link I posted and put a link to the images in the thread if it won't let you put the actual image in, or PM a link to somebody that is a member and let them post the images.
No you don't have to be a member, just use the link I posted and put a link to the images in the thread if it won't let you put the actual image in, or PM a link to somebody that is a member and let them post the images.
Man of many SIGs
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Joined: May 2005
Posts: 8,724
Likes: 12
From: Florida, USA
I found this HERE and I thought it may be helpfull to some of my 16V brethren.
While your right, some people do make a living off this, it is not the reason why I'm not sharing. There are a few reasons...
1. Its not an easy "bolt on" thing. So, its not an easy thing to write about and answer questions. I don't have time to walk everyone through this on a forum that I check every few days.
C. Every head is different and the guides I use are custom made to the head.
5. For the 3-4 people that would actually understand and carry through with it, there will be 15 people that will tell me I do it wrong. That has grown very old, as old as the amount of drama on this "tech" forum. Especially from the "protected"
Let me give you a "head" start. A 2.7ltr intake valve is 48mm SOooo, you are looking for a BB Chevy valve that is close to 1.890", which will be 1.88 0r 1.90" The most common use a valve 11/32 stem(which is a hair smaller then 9mm). They can be ordered and bought through Ferrea. If your looking for exhaust valves, the can be ordered with a sodium filled stem, see link. Use other pages on the link for intake valves..
http://www.ferrea.com/general-result...tegory_id=6036
You will need all the supporting hardware, guides, seats, locks, retainers, etc...
These are not what I would use but they are good for any street/De car.
Is that enough?
1. Its not an easy "bolt on" thing. So, its not an easy thing to write about and answer questions. I don't have time to walk everyone through this on a forum that I check every few days.
C. Every head is different and the guides I use are custom made to the head.
5. For the 3-4 people that would actually understand and carry through with it, there will be 15 people that will tell me I do it wrong. That has grown very old, as old as the amount of drama on this "tech" forum. Especially from the "protected"
Let me give you a "head" start. A 2.7ltr intake valve is 48mm SOooo, you are looking for a BB Chevy valve that is close to 1.890", which will be 1.88 0r 1.90" The most common use a valve 11/32 stem(which is a hair smaller then 9mm). They can be ordered and bought through Ferrea. If your looking for exhaust valves, the can be ordered with a sodium filled stem, see link. Use other pages on the link for intake valves..
http://www.ferrea.com/general-result...tegory_id=6036
You will need all the supporting hardware, guides, seats, locks, retainers, etc...
These are not what I would use but they are good for any street/De car.
Is that enough?
Thread Starter
Administrator
Joined: Aug 2001
Posts: 27,584
Likes: 3,100
From: Up Nort
Keep in mind the valves in a 944/951 head are farther apart compared to a 928 head. Not sure how much this will limit the size of the valves you can install.
I'm sure somebody has those measurements lying around.
I'm sure somebody has those measurements lying around.
Man of many SIGs
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Joined: May 2005
Posts: 8,724
Likes: 12
From: Florida, USA
I thought the heads were the same. There was talk at one time about the feasability of putting 944/951 heads on a 928. Maybe Dave or Garrity can comment. They do head work for both cars.
Thread Starter
Administrator
Joined: Aug 2001
Posts: 27,584
Likes: 3,100
From: Up Nort
Valve spacing and an extra water port are the differences.
I have an 8V 944 head somewhere in storage I was using to compare with.
It has been done before, the main issue is the 928 cam lobes not being 100% centered over the lifter of a 944 head.
The water port isn't that big of an issue with a track car. IIRC it causes problems with trying to hook up the heater valve.
I have an 8V 944 head somewhere in storage I was using to compare with.
The water port isn't that big of an issue with a track car. IIRC it causes problems with trying to hook up the heater valve.
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