Head porting literature

General tips/tricks/tools that could be utilized on any platform.

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Flatfourfool
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Joined: Wed Dec 26, 2001 3:01 am

Head porting literature

Post by Flatfourfool » Tue Jun 20, 2017 7:59 am

I have two types of vw heads i am looking into porting and am seeking advice into some published books for my reference on both na/turbo rabbit diesels and type 1 single port heads.
specific or general head porting?

I am aware of the search function.

Would love to hear from some of the folks I pay homage to every year @ sac speedway bugorama!

thanx
jake

Ol'fogasaurus
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Re: Head porting literature

Post by Ol'fogasaurus » Tue Jun 20, 2017 10:30 am

Triple "F", I don't have any detail literature but here is a grinding/polishing sale bit w/video included by the Eastwood company.

I go back to the "Porting and Relieving" days of Flathead Fords and to port matching intakes and headers to your heads. I haven't done it all that much but after talking to those who do do it for a living: I do recommend three things:

1) In "port matching" you limit the grinding and polishing to ~ (roughly) 1/2" to 1" each side of the join. Anything else you might do would be to clean-up to get rid of flashings... very slight clean-ups as you can easily mess with the fuel/air flow. (polishing too much may be detrimental or a waste of time for that matter)

2) Be-careful as to any radius changes unless you have a flow bench. A bad port job can end up flowing less than stock in-ported heads or make each cylinder flow differently. I have a friend who does do flow heads for a living (retired from the business now); during a discussion with him on the subject he has see ported heads from businesses that did not work well at all; again, worse than stock. The flow bench tells the truth.

3) Don't mess with the valve pocket or the guides unless you have a flow bench and you know what you are doing. The valve pocket is so important to how the flow/mix goes through the valves and into the cylinders.

I made some updates and added the following: part of the problem with messing with the valve pocket is dealing with the valve guides. If you shorten them too much or modify their support you can get accelerated valve guide wear and maybe even the valves may not have enough support allowing them to wobble hence not making a good seal or hammering the seats; I have known people who have ended up with this problem. The seals can also be affected.

Flatfourfool
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Joined: Wed Dec 26, 2001 3:01 am

Re: Head porting literature

Post by Flatfourfool » Sun Jun 25, 2017 3:12 pm

thanx fogasaurus
as far a guide wear.... shooting to get fifty thousand out the a/c and as many as possible form the mark one
are the rabbit heads as sensitive to a good guide grinding?
I understand this is a science and kind of a hands on thing I figure i will study and just not go cowboy with the die grinder
can u tell me some more about preventing dropping valves
marvol oil in the fuel maybee? keeping the valves adjusted lol
going to install 1.25 ratios on the stock cam... soon will be buggin about rocker geometry seems like if one messed that up guides would go out in a hurrry. Is there a type of seat u guys like? can i upgrade valve size using cheap stock duel port valves? duel or single springs? aluminum retainers? lighter wear out the guides?

thanks for ur time
karma shall make the pick n pull gods shine on u

Flatfourfool
Posts: 30
Joined: Wed Dec 26, 2001 3:01 am

Re: Head porting literature

Post by Flatfourfool » Sun Jun 25, 2017 3:12 pm

thanx fogasaurus
as far a guide wear.... shooting to get fifty thousand out the a/c and as many as possible form the mark one
are the rabbit heads as sensitive to a good guide grinding?
I understand this is a science and kind of a hands on thing I figure i will study and just not go cowboy with the die grinder
can u tell me some more about preventing dropping valves
marvol oil in the fuel maybee? keeping the valves adjusted lol
going to install 1.25 ratios on the stock cam... soon will be buggin about rocker geometry seems like if one messed that up guides would go out in a hurrry. Is there a type of seat u guys like? can i upgrade valve size using cheap stock duel port valves? duel or single springs? aluminum retainers? lighter wear out the guides?

thanks for ur time
karma shall make the pick n pull gods shine on u

Flatfourfool
Posts: 30
Joined: Wed Dec 26, 2001 3:01 am

Re: Head porting literature

Post by Flatfourfool » Sun Jun 25, 2017 3:16 pm

thanx fogasaurus
as far a guide wear.... shooting to get fifty thousand out the a/c and as many as possible form the mark one
are the rabbit heads as sensitive to a good guide grinding?
I understand this is a science and kind of a hands on thing I figure i will study and just not go cowboy with the die grinder
can u tell me some more about preventing dropping valves
marvol oil in the fuel maybee? keeping the valves adjusted lol
going to install 1.25 ratios on the stock cam... soon will be buggin about rocker geometry seems like if one messed that up guides would go out in a hurrry. Is there a type of seat u guys like? can i upgrade valve size using cheap stock duel port valves? duel or single springs? aluminum retainers? lighter wear out the guides?

thanks for ur time
karma shall make the pick n pull gods shine on u

Flatfourfool
Posts: 30
Joined: Wed Dec 26, 2001 3:01 am

Re: Head porting literature

Post by Flatfourfool » Sun Jun 25, 2017 3:16 pm

thanx fogasaurus
as far a guide wear.... shooting to get fifty thousand out the a/c and as many as possible form the mark one
are the rabbit heads as sensitive to a good guide grinding?
I understand this is a science and kind of a hands on thing I figure i will study and just not go cowboy with the die grinder
can u tell me some more about preventing dropping valves
marvol oil in the fuel maybee? keeping the valves adjusted lol
going to install 1.25 ratios on the stock cam... soon will be buggin about rocker geometry seems like if one messed that up guides would go out in a hurrry. Is there a type of seat u guys like? can i upgrade valve size using cheap stock duel port valves? duel or single springs? aluminum retainers? lighter wear out the guides?

thanks for ur time
karma shall make the pick n pull gods shine on u

Ol'fogasaurus
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Re: Head porting literature

Post by Ol'fogasaurus » Sun Jun 25, 2017 4:21 pm

I haven't worked on VW heads or manifolds as I had been warned several times about it as they are (supposedly) easy to mess-up.

One of my friends was an ACVW guy and had an airflow bench which he used when building performance engines. Trying to save some time during the engine building process he got the idea of buying some already ported heads from a reputable VW source. He flowed the heads when he got them and they flowed less than stock heads. After talking to where I got them he found out that they had digitized a set of flowed heads done by hand many years previous so their computer ported the heads based off that set of heads. He flow benched a head and sent it to them for a new program to be written. Soon after that he got tired of it all and retired.

I don't know who he was dealing with on the heads as I don't need anything like that.

Slow 1200
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Re: Head porting literature

Post by Slow 1200 » Mon Jun 26, 2017 2:26 am

Bill Fisher's How to hot rod VW engines book has ancient information in it but the porting section is pretty detailed and it includes single ports so that's a good place to start

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Piledriver
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Re: Head porting literature

Post by Piledriver » Mon Jun 26, 2017 3:04 am

Porting single ports is largely a waste of time.
No matter what you do to them, stock dual ports heads will outperform them.

The only sane reason to run single ports is to reduce performance to improve fuel economy.
They also are far less crack prone, mostly due to reduced power.
I, for one, regularly embrace our new robot overlords, as I am the guy fixing the robots...

Flatfourfool
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Re: Head porting literature

Post by Flatfourfool » Mon Jun 26, 2017 6:07 am

I'll get u off the line piledriver

Ol'fogasaurus
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Re: Head porting literature

Post by Ol'fogasaurus » Mon Jun 26, 2017 10:55 am

Slow 1200 wrote:
Mon Jun 26, 2017 2:26 am
Bill Fisher's How to hot rod VW engines book has ancient information in it but the porting section is pretty detailed and it includes single ports so that's a good place to start
I forgot I had the book. The "head work" section starts on page 46 with flow data at the end of the chapter. Yes, it is detail and full of facts but the point where he shows flow data indicates he probably is using a flow bench. Again, based on what I have been told you can make mistakes even with the great detail he gives. Even minor smoothing areas where sharp corners exists can and does change the flow characteristics of the area. You want as even flow in each of the ports as you can get.

If you do do it then just be very careful with the cutting tools as they can take away a lot of material in a very short time and they can get way from you and bounce around very easily. I have done enough port matching to be well aware of that. I prefer electric over air power porting tools in this case; lower RPMs and more torque which translates into better control.

Also be sure to wear hearing and not just eye protection but full face protection when doing this just to be safe. Stones can break not just inside where the blast is controlled to the small space but up towards the top of the port the fragments are not as well controlled. this is the same warning I was given by my machinist!

BE SAFE!

Flatfourfool
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Re: Head porting literature

Post by Flatfourfool » Fri Jun 30, 2017 1:37 am

that is great on every level ...
so how does bill fishers maximum singleport flow compare to a min quality call it factory duel port flow?

Flatfourfool
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Joined: Wed Dec 26, 2001 3:01 am

Re: Head porting literature

Post by Flatfourfool » Fri Jun 30, 2017 1:48 am

I knew a guy who would make emery flappers, but he never really told how he made his sons but 12 1/2 to 1 high school 1600 sp 64 that was enough to get sold in a hurry. I think he may of just swirled the the poop out of the thing, like what if u went all the way up a bugspray manifold with a flapper and what not?

any idea the word on the toilet bowl swirl on these heads?

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