Some facts about head flow

raygreenwood · Post by **raygreenwood** » Sat Jul 30, 2005 4:36 pm

HAM...the importance of velocity to proper fuel mixture is why I keep telling people to be extremely careful when sizing the runners on their fuel injection. Cross section is critical. Total voume of runner is critical.Too large of a runner cross section..and the port area inside the head becomes a restriction. No so much for overall volume...but for velocity. Same with too large of a valve head versus cross section of the runner (or even moderate cross section with way too much lift, past the curved radius of the stem where it meets the the back of the valve head) . If the opening is too large....the airflow can stall. This is more common on short strokes.
Couple these potential problems with injection pulses that are way out of time with the valve opening point and you can actually either have littkle velocity to take advantage of the "cloud" of injected fuel in the port....or you can end of splattering it all over the port walls of the head.....wherin surface tension then takes over requiring much more energy to pull that fuel off the port wall and atomize it.
All of these worries are actually more critical (just in my experience) than worrying about tuning of resonance pulses in fuel injection runners. Ray

John W. Kelly · Post by **John W. Kelly** » Sat Jul 30, 2005 10:30 pm

Alan, I stand by my term "superior". Don't forget that these engines were asked to produce a decent output (in heavy vehiles) all the while dealing with ever increasing emission requirements. Yes, much of the technology is awkward that was introduced during the "smog" era. A lot of this tech might not be of the performance variety but is a good bit of engineering never-the-less. If it wasn't for this motor, VW would more than likely gone watercooled (totally) much sooner. Still, the t1 is what gets me around in my DD or in my favorite camper bus and is a damn good engine. I am no enemy of it! I do agree with you about CFM numbers and port velocity. Too many people don't understand that.

Santas Brother · Post by **Santas Brother** » Sat Jul 30, 2005 10:35 pm

Can anyone suggest some serious sites or boards
dedicated to porting and airflow theory ?

Flow benches,swirl,etc.

Bruce2 · Post by **Bruce2** » Sun Jul 31, 2005 2:10 am

http://theoldone.com/

Bruce2 · Post by **Bruce2** » Sun Jul 31, 2005 2:35 am

Plastermaster wrote: I have seen $1,500 as a standard for top notch head work for the T1 factory head. This head will put you in the 180HP and up catagory and is often not recomended as a "street head" due to drivability. That is better achieved with smaller valve head, that will cost less but will get you more like 150-160 HP.

$1500 will get you an easy 200hp in a Type 1 engine:

http://www.cbperformance.com/catalog.asp?ProductID=1323

These ported 043 heads will get you a lot more than 160hp for $700 a pair.

http://www.thesamba.com/vw/classifieds/ ... ?id=185137

Santas Brother · Post by **Santas Brother** » Sun Jul 31, 2005 2:38 am

The had a lot of good info in their forum,but closed it a few days ago.
No word on why.

Bruce2 wrote:http://theoldone.com/

alsehendo · Post by **alsehendo** » Mon Aug 01, 2005 3:07 am

I don't mean to be negative, but why did you all not post these #s on the Samba thread since Lens info seem to be in response to it--kind of like preaching to your own choir here.

MassIVe 79 Vert · Post by **MassIVe 79 Vert** » Mon Aug 01, 2005 6:14 am

alsehendo wrote:I don't mean to be negative, but why did you all not post these #s on the Samba thread since Lens info seem to be in response to it--kind of like preaching to your own choir here.

Thread on the Samba was locked!

MASSIVE TYPE IV · Post by **MASSIVE TYPE IV** » Mon Aug 01, 2005 7:36 am

I'll tell you why the numbers were not posted on the Samba:

Danimal is a jackass, kind of like the 6th grade punk that wants someone to give him a chance to cause more trouble...

danimal is now BANNED from the samba, just like he is here on the STF because of his childish actions and constant efforts to cause trouble.

I did not want to further the BS on the samba by feeding danimals fire with his own fuel- period.

Plastermaster · Post by **Plastermaster** » Wed Aug 03, 2005 6:38 pm

alsehendo wrote:I don't mean to be negative, but why did you all not post these #s on the Samba thread since Lens info seem to be in response to it--kind of like preaching to your own choir here.

The samba thread was basically a debate between some of us and Danimal. How productive can that be? It would all fall on deaf ears. Here we can take the sharing of info up a notch.

Ron

Plastermaster · Post by **Plastermaster** » Wed Aug 03, 2005 6:51 pm

Bruce2 wrote:
Plastermaster wrote: I have seen $1,500 as a standard for top notch head work for the T1 factory head. This head will put you in the 180HP and up catagory and is often not recomended as a "street head" due to drivability. That is better achieved with smaller valve head, that will cost less but will get you more like 150-160 HP.
$1500 will get you an easy 200hp in a Type 1 engine:

http://www.cbperformance.com/catalog.asp?ProductID=1323

These ported 043 heads will get you a lot more than 160hp for $700 a pair.

http://www.thesamba.com/vw/classifieds/ ... ?id=185137

That is pretty much what I was thinking (180 and up) but I was refering to working with a stock head. To try and make apples to apples, I believe for the same price for head work from Len or DRD the T4 can make about the same Hp. The thing is we do not have anyone I know of trying to make ultimate Hp with the T4. I think Jake can make a 200-230 HP T4 for about the same cost as a T1 if he was to make the longevity and reliability equal to the same T1. The only stipulation would be starting with stock heads, since the T4 does not have aftermarket heads to use for a head start...Ha Ha Ha. Head start! Haha ha HEAD start! Get it? Ha ha!

Ron

Can Drive Soon · Post by **Can Drive Soon** » Wed Aug 03, 2005 9:54 pm

I love Vdubs but chevys are my other love. Go chevy small block

. There seems to be alot of mischiveous people on this forum, this dan guy and The Shadow. Probably more too.

Bruce2 · Post by **Bruce2** » Thu Aug 04, 2005 3:15 am

Plastermaster wrote:
That is pretty much what I was thinking (180 and up) but I was refering to working with a stock head. To try and make apples to apples,

You know what, nobody cares that a CB 044 doesn't have a VW logo on it. All anybody cares about is that you can make 200hp by spending $1500 on those heads.

MnMike · Post by **MnMike** » Thu Aug 04, 2005 4:31 am

Flamesuit on: actually the CB wedgeports are only $789 and matched manifolds are $199. Not bad, for a stock type head, with all the factory style cooling fins, and other important dimensions. Really, the best value in the T1 aftermarket.

Stripped66 · Post by **Stripped66** » Thu Aug 04, 2005 9:50 am

If you want 200 HP N/A, you're going to have to port the sh!t out of a T1 style casting, or a T4 casting. Period. I hesitate to think some of the original head debate is fueled by the misconception that it is easy to pull 200 HP out of a T1 only because you can now buy a relatively affordable set of heads that are on the shelf, and do not require a 3-6 month wait for the porter to knock them out.

Go to DKP III's website and look at their members' cars...how many of them are 200+ HP? (answer...not many) Notice all the different head-porters identified? It takes a lot of work to make that power with a stock-*style* casting; it takes even more work to make that power and maintain any bastain of "drivability" (e.g. just 'cuz you can drive it from home to the Foster's Freeze doesn't make it a daily driver

).

CB's wedgeports are about the greatest thing since sliced bread for T1's, offerring affordable power to the people...but just because they are readily available doesn't mean they are not extensively developed. They are heavily worked over and certainly near the limits of the casting...racers who want more N/A power are left to step up to CE's, Superflows or Angleflows. Can the stock-*style* casting make more power? Sure...but it's a helluva lot easier to go to a different, non-T1 style casting than it is to further work over a set of 044's or other stock casting.

The T4 casting has its own set of challenges and will require a lot of work to make big power...but understand the T1 style casting also requires a lot of work.