Advanced Tech Advanced tech discussion. Major rebuilds, engine theory, etc.
HIGH-END DISCUSSION ONLY - NOT FOR GENERAL TECH INFO

Headporting question

Old May 19, 2005 | 03:41 PM
  #1  
TheBlur's Avatar
Thread Starter
Registered User
 
Joined: Aug 2001
Posts: 239
From: Here
Question Headporting question

I know a lot of guys use die grinders and just start hogging out their heads but the idea of not removing material evenly on every port/chamber/etc kind of turns me away from going that rought. I know it's not crucial and a few thousands might not make a huge difference but I'm a perfectionist and I don't want to kill port velocity by over boaring them.

I was wondering, could you get a bridgeport or "Verticle Mill" with a dividing head and do a descent job ? I know it would require a custom fixture but would it be worth the trouble ?

Also, I am a rookie when it comes to head work so if anybody has any good reading material online or know of any good books let me know.
Old May 20, 2005 | 09:43 AM
  #2  
89305rs's Avatar
Registered User
 
Joined: Aug 2004
Posts: 375
Re: Headporting question

LT1 heads are so cheap. Just get a set and experiment. Nothing wrong with tring and failing. Worse case senario is you are out $100 for the first head you mess up . Not a huge issue.
Old May 20, 2005 | 11:36 AM
  #3  
OldSStroker's Avatar
Registered User
 
Joined: Oct 2002
Posts: 2,931
From: Upstate NY
Re: Headporting question

Originally Posted by TheBlur
I know a lot of guys use die grinders and just start hogging out their heads but the idea of not removing material evenly on every port/chamber/etc kind of turns me away from going that rought. I know it's not crucial and a few thousands might not make a huge difference but I'm a perfectionist and I don't want to kill port velocity by over boaring them.

I was wondering, could you get a bridgeport or "Verticle Mill" with a dividing head and do a descent job ? I know it would require a custom fixture but would it be worth the trouble ?

Also, I am a rookie when it comes to head work so if anybody has any good reading material online or know of any good books let me know.
Do It Yourself head porting is a lot like DIY surgery: you may be successful and you may not be. You need to measure the final results (power) and whether or not the "patient" survives.

A lot like sculpting, you just need to remove the material that doesn't belong there. Knowing what to remove is more difficult than doing it.

To answer your question, a non-CNC vertical mill can't get to all the contoured surfaces in the ports with just X, Y and Z-axis motions. Even if it is a 5 or more axis CNC, you still need to tell the computer what shape you want the port. Usually this is done by replicating a good port that has been hand ported.

The Search function is very useful on this forum.

David Vizard has some good books on cylinder head porting. Joe Mondello runs a school for porting and has some literature on it. Google is your friend.

FWIW, the engine builders I know do not do their own head porting, and the good head porters I know don't build engines. Similarly, the surgeons I know don't do MRIs or CT scans, and the radiololgists I know don't do surgery. Sure, all MDs do a "surgery rotation" and a "radiology rotation" during med school, but I don't want a doc who doesn't do surgery all the time cutting on me. Similarly I would have Bret (SStrokerAce) build my engine, but I wouldn't have him port the heads.

My $.02
Old May 20, 2005 | 01:24 PM
  #4  
marshall93z's Avatar
Registered User
 
Joined: Feb 2003
Posts: 2,639
From: Mooresville, NC
Re: Headporting question

Originally Posted by OldSStroker
FWIW, the engine builders I know do not do their own head porting, and the good head porters I know don't build engines. Similarly, the surgeons I know don't do MRIs or CT scans, and the radiololgists I know don't do surgery. Sure, all MDs do a "surgery rotation" and a "radiology rotation" during med school, but I don't want a doc who doesn't do surgery all the time cutting on me. Similarly I would have Bret (SStrokerAce) build my engine, but I wouldn't have him port the heads.

My $.02
Very true!
Old May 20, 2005 | 02:01 PM
  #5  
SStrokerAce's Avatar
Banned
 
Joined: Oct 2002
Posts: 6,518
Re: Headporting question

Originally Posted by OldSStroker
Similarly I would have Bret (SStrokerAce) build my engine, but I wouldn't have him port the heads.
Oh thanks for the vote of confidence dad!

Anyways neither would I.

There are some guys who can do both engine building and head porting. I'd rather spend my time working on getting everything else right and get the best heads for the motor that I can. The biggest deal is that you have to understand what the head needs to do and what the porter is doing in there even if you can't do it yourself.

Bret
Old May 20, 2005 | 02:06 PM
  #6  
unstable bob's Avatar
Registered User
 
Joined: Jul 1999
Posts: 184
From: Wastelands of NJ
Re: Headporting question

Originally Posted by SStrokerAce
Oh thanks for the vote of confidence dad!

Anyways neither would I.

There are some guys who can do both engine building and head porting. I'd rather spend my time working on getting everything else right and get the best heads for the motor that I can. The biggest deal is that you have to understand what the head needs to do and what the porter is doing in there even if you can't do it yourself.

Bret
Lissen PUNK...you are gonna PORT MY HEADS... and you are gonna BUILD MY ENGINE...and yer GONNA LIKE IT!!!!
Old May 20, 2005 | 07:54 PM
  #7  
OldSStroker's Avatar
Registered User
 
Joined: Oct 2002
Posts: 2,931
From: Upstate NY
Re: Headporting question

Originally Posted by unstable bob
Lissen PUNK...you are gonna PORT MY HEADS... and you are gonna BUILD MY ENGINE...and yer GONNA LIKE IT!!!!
ROFLMAO!

You make my day just about every time you post, UB.

Jon
Old May 20, 2005 | 10:12 PM
  #8  
Joes94TA's Avatar
Registered User
 
Joined: Oct 2001
Posts: 401
From: VA
Re: Headporting question

Just make sure the head porter doesnt try to put 2.02 /1.6 valves on stock lt1 seats and you'll be fine.....LOL
Old May 21, 2005 | 12:05 AM
  #9  
marshall93z's Avatar
Registered User
 
Joined: Feb 2003
Posts: 2,639
From: Mooresville, NC
Re: Headporting question

Who would try and do that?
Old May 21, 2005 | 01:51 AM
  #10  
Camaro_Guru16NY's Avatar
Registered User
 
Joined: Nov 2002
Posts: 1,303
From: Jamestown, NY J&P MUscLE
Re: Headporting question

Originally Posted by unstable bob
Lissen PUNK...you are gonna PORT MY HEADS... and you are gonna BUILD MY ENGINE...and yer GONNA LIKE IT!!!!


ha ha thats funny
-john
Old May 21, 2005 | 07:12 AM
  #11  
unstable bob's Avatar
Registered User
 
Joined: Jul 1999
Posts: 184
From: Wastelands of NJ
Talking Re: Headporting question

Originally Posted by OldSStroker
ROFLMAO!

You make my day just about every time you post, UB.

Jon
Well, Pops, bringing da laffs is about all I'm good at. God knows I can't port heads or build engines. That is why yer punk kid Bret is gonna PORT MY HEADS... and he is gonna BUILD MY ENGINE...and he is GONNA LIKE IT!!!!
Old May 21, 2005 | 01:10 PM
  #12  
SStrokerAce's Avatar
Banned
 
Joined: Oct 2002
Posts: 6,518
Re: Headporting question

You crack me up... I still have to see these Dom heads! Don't know if I should be scared of them yet or not.

Bret
Old May 22, 2005 | 07:26 PM
  #13  
arnie's Avatar
Registered User
 
Joined: Oct 2001
Posts: 1,462
From: smog zone adjacent to a great lake
Re: Headporting question

Originally Posted by TheBlur
I know a lot of guys use die grinders and just start hogging out their heads but the idea of not removing material evenly on every port/chamber/etc kind of turns me away from going that route.
It's not the rate of removal that determines the end product, it is knowing where you are going to end up. Either with or without flow bench testing, along with the necessary skill, using templates can go a long way in duplicating port shapes. Yes, skill IS required. You claim to be a perfectionist. Depending on how much time you intent on investing in this one set of heads, using the appropriate material poured into the ported ports, and 'pulled' out for analysis/inspection can be very revealing, in regards to an overview of your accomplishment.
Originally Posted by TheBlur
I know it's not crucial and a few thousandths might not make a huge difference but I'm a perfectionist and I don't want to kill port velocity by over boring them.
A "few thousandths" won't do it, but a 16th here or there EASILY could. Anyway, then do our homework. You'd be surprised how much quality info can be gained by following various lists/forums. One bit at a time. If you want the info now, it ain't gonna happen. Or, you can choose to be a bit conservative. No, it won't give you the flow of a top flight expert, but you won't be hurting yourself either. It depends. You want the upmost in flow gains, or do you want to make respectable gains for cheap.
Originally Posted by TheBlur
I was wondering, could you get a bridgeport or 'Vertical Mill' with a dividing head and do a descent job ? I know it would require a custom fixture but would it be worth the trouble?
In a word... No, just not practical.
Originally Posted by TheBlur
Also, I am a rookie when it comes to head work so if anybody has any good reading material online or know of any good books let me know.
In that case, what I stated above, may be ill advised. Vizard, Yunick, even GM endorsed publications can be helpful. You did not state how 'competitive' you expect the finished product to be. Others have advised to go to a pro for the headwork. I agree, as to that being good, sound, safe advice. If that is your intent, then make an effort to seek out a 'quality' pro. As pros go, not all are equal in results you pay for. Frankly, AFAIC, some head porting/engine building 'pros' (not unlike some MDs) should be in another line of work. As the standing joke goes, "what do ya call a med student that graduates at the BOTTOM of his class?" A doctor!!! I've looked as various diplomas hanging on walls in patient rooms, and not one did I see, that included the doctor's 'ranking' in his/her graduating class. It is flawed reasoning, to accept, that a person's title, automatically makes that person qualified. As the lesser qualified 'pros' remain in business, it comes down to (ironically) how knowledgeable the 'customer' is in regards to the service they are seeking. Because ignorance is bliss, blind faith/trust in a given pro just doesn't cut it with me. The best to you in your endeavor.

Last edited by arnie; May 22, 2005 at 07:47 PM.
Old May 22, 2005 | 08:53 PM
  #14  
TheBlur's Avatar
Thread Starter
Registered User
 
Joined: Aug 2001
Posts: 239
From: Here
Thumbs up Re: Headporting question

Originally Posted by arnie
It's not the rate of removal that determines the end product, it is knowing where you are going to end up. Either with or without flow bench testing, along with the necessary skill, using templates can go a long way in duplicating port shapes. Yes, skill IS required. You claim to be a perfectionist. Depending on how much time you intent on investing in this one set of heads, using the appropriate material poured into the ported ports, and 'pulled' out for analysis/inspection can be very revealing, in regards to an overview of your accomplishment.

A "few thousandths" won't do it, but a 16th here or there EASILY could. Anyway, then do our homework. You'd be surprised how much quality info can be gained by following various lists/forums. One bit at a time. If you want the info now, it ain't gonna happen. Or, you can choose to be a bit conservative. No, it won't give you the flow of a top flight expert, but you won't be hurting yourself either. It depends. You want the upmost in flow gains, or do you want to make respectable gains for cheap.

In a word... No, just not practical.

In that case, what I stated above, may be ill advised. Vizard, Yunick, even GM endorsed publications can be helpful. You did not state how 'competitive' you expect the finished product to be. Others have advised to go to a pro for the headwork. I agree, as to that being good, sound, safe advice. If that is your intent, then make an effort to seek out a 'quality' pro. As pros go, not all are equal in results you pay for. Frankly, AFAIC, some head porting/engine building 'pros' (not unlike some MDs) should be in another line of work. As the standing joke goes, "what do ya call a med student that graduates at the BOTTOM of his class?" A doctor!!! I've looked as various diplomas hanging on walls in patient rooms, and not one did I see, that included the doctor's 'ranking' in his/her graduating class. It is flawed reasoning, to accept, that a person's title, automatically makes that person qualified. As the lesser qualified 'pros' remain in business, it comes down to (ironically) how knowledgeable the 'customer' is in regards to the service they are seeking. Because ignorance is bliss, blind faith/trust in a given pro just doesn't cut it with me. The best to you in your endeavor.

I really appreciate the time you took out to give me such a well thought out and very insightful answer. Thank you very much

Lance
Old May 22, 2005 | 09:34 PM
  #15  
Joes94TA's Avatar
Registered User
 
Joined: Oct 2001
Posts: 401
From: VA
Re: Headporting question

Originally Posted by marshall93z
Who would try and do that?

I'd rather not say, lets just say I've seen it with my own eyes...

Thread Tools
Search this Thread

All times are GMT -5. The time now is 10:11 PM.