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spencerfvee
Samba Member
Joined: August 19, 2004
Posts: 3071
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 Posted: Sun May 24, 2015 5:34 pm Post subject: |
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great job glade it worked out for you.now I know I can use 37mm intake valves on a stock seat.now I learned something new today . are you going to try a bigger ex valve on the stock ex. seat ? spencerfvee
| modok wrote: |
After re-calibrating for wood swelling I'm at 119cfm at .400 lift.
37mm valve on stock port.
Not interested in higher lifts, but it can keep going up. I'm not finding a sunk valve helps like they did in how to hotrod. Maybe that is just because they had to sink it to get some 60 and 70 degree under there, bigger valve I don't have to sink it to do that. |
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raymon covey
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Joined: April 30, 2005
Posts: 189
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| Posted: Sun May 24, 2015 6:45 pm Post subject: Stock Valves |
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| The book how to hot rod vw's is a very good starting point on modifying the stock valve head however you can go much further if you are an experienced head porter. John from Air Cooled.net has previously stated that the valves are capable of flowing 40% more than the port which I would agree. A large amount of material can be removed on the sparkplug side of the port around and above the valve guide. The other side of the port and bottom is a dead air space. By sinking the valves you can put a good radius valve job on the seats which help a great amount. You will make a lot of chips and burn up a lot of time before you reach your goal. When I started in the 60's the 375 dual port head was a tremendous gain over a single port head. Today there are a lot of good heads out there for a reasonable price. I have a 1678 with stock valves and 48 IDA's that has ran in the 12's in 1/4 so it can be done. |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Sun May 24, 2015 7:24 pm Post subject: |
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Ok rainy day 311 head flow test!
flow at 300 and 400
numbers are a % scale, similar to cfm at 10" but not exactly calibrated
65-68 straight out of the scrap bin
66-67 3 angle quick seat cut with neway cutters
66-67 unshroud by cylinder to .160 gap
70-73 rounded the inside of the turn right under seat, not enlarged just made a smooth constant radius
69-74 smoothed out sharp turn over valve guide
69-74 rounded sharp turn under valve guide (did nothing)
68-72 took more out of short side radius under seat, opps, epoxied that back up
71-75 "ski-jump" type radius .030 deep starting .100 under 60 degree on the not shrouded side.
70-74 unshrouded to stock bore size
70-73 made ski-jump bigger
What should I try next??? |
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andrewvwclassic
Samba Member
Joined: January 25, 2012
Posts: 920
Location: los angeles
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| Posted: Sun May 24, 2015 9:27 pm Post subject: |
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Finished t5he intake valve side. i actually like how it turne3d out. I plan on decking these heads to 0 inches. I will be getting around 8.5:1 compression with a deck height of .060"
Too bad I bought some bugpack chromoly pushrods already before I decided to fly cut. if anyone wants them let me know they are new. had them sitting in a box for some time now. has anyone had any success cutting the already capped bugpack rods and recapping them maybe I can just mod them. I fear t5he fcaps might fall off if they are done twice. idk I tried puling one off a stock rod and they dont come out. maybe the bugpacks are a little cheapper though.
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modok
Samba Member
Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Mon May 25, 2015 4:04 am Post subject: |
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Try #3 I picked a 043 mexico with really TINY ports. Tiny enough that I can shape it just like I want without it already being too big.
I only worked on the chamber and 1/2 inch in behind the seat. Once again got stuck at the same flow numbers as the other 2 heads, right under 75 at 400. Tried a 36.5mm valve, and that brought up the flow at .300 but still 74.5 on the scale at .400 But I put a probe in there and found the velocity on the long side was not totally dead, actually had pretty good velocity, so Last thing I gave the "flange to guide" turn the "trapezoid" treatment. Ground the long side deeper just in the middle, and widened the short side. It actually worked! 74 and 78.5 on the scale. Converted to 25" numbers that's about 115 at .300 and 125 at .400!!! |
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FreeBug
Samba Member
Joined: March 12, 2012
Posts: 4278
Location: deepest, darkest Switzerland
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| Posted: Mon May 25, 2015 4:09 am Post subject: |
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| Thanks, Modok, that info you posted is gold! |
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Quokka42
Samba Member
Joined: December 02, 2010
Posts: 3117
Location: Melbourne, Australia
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| Posted: Mon May 25, 2015 4:35 am Post subject: |
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| andrewvwclassic wrote: |
| mark tucker wrote: |
not negative at all just honest. I very rarely let the crap fly. but somebody could of used those heads for something before they were butchered. What are bear goggles?  ?and why do I need to take some to some guys? and where do I take them??why cant they get their own bear goggles? we have lotsa brown bears around hear,but they don't usually wear goggles ,so Im kinda lost there just as the "apparent Im a head exspert" guy that did those heads. Hmm was he wearing the bear goggles?...or did the bear do it? No dont even blame it on the bear's. |
Like I said im sorry I did not mean to insult you. the darn post was my initial reaction and posted twice I meant to discard. like I said I will not insult someone for honesty. I do think your wrong though. I ported them per the bill fisher book. they look better in person and I have no worries of how they will perform. |
Actually, those who have been around a while know not to bother trying to decypher Mark's drivel. I suspect in reality he is a 14 year old that lives permanently on the internet in his Gran's basement. Those of us who are a bit older and experienced realise he probably just picked up all of his "knowledge" off the internet. Mark's number of posts suggest he spends all of his time on the internet, but the content suggests he is an insomnic nonagenarian Nazi who between building, driving and testing VW engines has spent more than 24 hours out of each day of the past 80 years on them, plus his V8 and Marine experience!
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There has only ever been one man who was perfect, and they nailed Him to a cross. |
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spencerfvee
Samba Member
Joined: August 19, 2004
Posts: 3071
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| Posted: Mon May 25, 2015 5:48 am Post subject: |
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hi if you look on page 112 on how to hot rod vw engines.it shows a easy way to shorten push rods .you can use a hand held hack saw .if you don't have a bandsaw .spencerfvee
| andrewvwclassic wrote: |
Finished t5he intake valve side. i actually like how it turne3d out. I plan on decking these heads to 0 inches. I will be getting around 8.5:1 compression with a deck height of .060"
Too bad I bought some bugpack chromoly pushrods already before I decided to fly cut. if anyone wants them let me know they are new. had them sitting in a box for some time now. has anyone had any success cutting the already capped bugpack rods and recapping them maybe I can just mod them. I fear t5he fcaps might fall off if they are done twice. idk I tried puling one off a stock rod and they dont come out. maybe the bugpacks are a little cheapper though.
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fivelugshortaxle
Samba Member
Joined: May 13, 2011
Posts: 4254
Location: Aumsville, Oregon
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| Posted: Mon May 25, 2015 6:22 am Post subject: |
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I think Mark's number of posts show that he's got a computer in his garage or shop and lives, eats, breathes motors. It doesn't take long to put up a ton of posts if you're a bit ocd.
And yeah, that was great info from you Modok....pure gold.
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Good things come to those who wait.
2332 with lots of goodies....
Rotating assembly balanced by Brothers VW
4340 84mm crank
AA 94mm p&c' s
Total seal 2nd ring, rest are Grants
5.5 h beams
Magnum straight cuts
Steve Long XR310 on a 106
CB 1.4 rockers
CB Magnaspark 2 distributor
NGK D7ea plugs
A1 lowdown 1 3/4 with single muffler
Dellorto 48's with 40 venturies
Kennedy Stage 2 with Daiken disc |
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Brian_e
Samba Member
Joined: July 28, 2009
Posts: 3290
Location: Rapid City, SD
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| Posted: Mon May 25, 2015 8:17 am Post subject: |
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| modok wrote: |
Tried a 36.5mm valve, and that brought up the flow at .300 but still 74.5 on the scale at .400 But I put a probe in there and found the velocity on the long side was not totally dead, actually had pretty good velocity, so Last thing I gave the "flange to guide" turn the "trapezoid" treatment. Ground the long side deeper just in the middle, and widened the short side. It actually worked! 74 and 78.5 on the scale. Converted to 25" numbers that's about 115 at .300 and 125 at .400!!! |
I found the same thing with a 37mm intake. They help up to about .350", but if you believe in a 87-89% throat diameter, then your throat might end up much larger then needed. The larger throat will require the rest of the port to be larger to maintain the taper, and then all of a sudden your port volume is getting too big.
I use the Wallace calculators to find my MCSA based on engine size and what I want it too rev too. I usually use this MCSA as my throat diameter, and use 87% to figure what size valve I need. Kinda gotta work backwards from your goals to see what sizes are necessary without getting too large.
For a lower reving engine (5500rpm max), the 37mm valve might end up being too big untill you are up to about 1960+cc.
Brian |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Mon May 25, 2015 3:19 pm Post subject: |
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| Brian_e wrote: |
but if you believe in a 87-89% throat diameter, |
I don't. as long as you can get 7-10 degree taper(like a venturi) from the small throat to the valve seat angles should be able to go as low as 80%.
Is that a good idea?? Not in all cases. If the valve lift is on the low side and shrouding is not a problem I see no downside to the larger valve. |
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Singerdude
Samba Member
Joined: March 07, 2015
Posts: 464
Location: Quebec, Canada
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| Posted: Mon May 25, 2015 9:36 pm Post subject: |
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| spencerfvee wrote: |
| I allway try to help out new people . that are new to vws . with the decline of new people getting into air cooled vws . I allways wecome them .if I were to be rude and unfriendly to new vw people .I am sure they would feal what the hell am I getting into. and they might just walk away and buy a Honda . in my ohio we have lost over 10 vw shows over the years we are down to 4 shows vw shows and only one vw show has show cars and drag racing.and look bug pack just got bought by empi one day empi is going to be the only new parts suppler .for vw air cooled parts . we need new people like you .to keep air cooled vws alive so keep posting I like what your doing to your heads .good luck peace spencerfvee |
Amen to that. |
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gforcepdx
Samba Member
Joined: March 23, 2008
Posts: 153
Location: portland,oregon
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| Posted: Wed Feb 10, 2016 2:32 pm Post subject: |
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| modok wrote: |
Unshroud the intake valves so there is .160-.180 gap with the valve lifted up .300-.400" 3 angle on the seats will help too.
I was just playing with some myself and found two spots in the ports that seemed to have high velocity. Removed about .030 of meterial in those areas and gained several%. Ground some more and it was back where I started LOL. Not much to gain in the port in a stock head. |
when you mention areas of increased velocity, are you talking about high points you can "see"?
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yes... I'm the one who destroyed this fine, vintage, automoble... |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Wed Feb 10, 2016 6:52 pm Post subject: Re: porting intake and end castings? w\pics |
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No. Velocity probe.
I have a little brass tube connected to a manometer, and move that around in the port and see what it reads.
Pulling 10" on the head, it can be 14" on the short side of the turn, it can be higher that that even on the actual surface, it can be so high it sucks the water out of the manometer because I only made it 24" tall LOL
the Bernoulli principle : high velocity=low pressure |
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gforcepdx
Samba Member
Joined: March 23, 2008
Posts: 153
Location: portland,oregon
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| Posted: Wed Feb 10, 2016 11:13 pm Post subject: Re: porting intake and end castings? w\pics |
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| modok wrote: |
No. Velocity probe.
I have a little brass tube connected to a manometer, and move that around in the port and see what it reads.
Pulling 10" on the head, it can be 14" on the short side of the turn, it can be higher that that even on the actual surface, it can be so high it sucks the water out of the manometer because I only made it 24" tall LOL
the Bernoulli principle : high velocity=low pressure |
no shit...
I've never heard of velocity probes but found a video of someone using one on a head under vacuum. All of the examples I found were running through some sort of electronics. But you're just lifting a column of water through two feet of poly? madness...
So you're bringing vacuum, then probing to look for areas of high/low pressure... like a feeler gauge. You don't post videos do you?
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yes... I'm the one who destroyed this fine, vintage, automoble... |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Thu Feb 11, 2016 4:08 am Post subject: Re: porting intake and end castings? w\pics |
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No, sorry I don't do videos.
Yes it's actually quite simple. Clear tubing, water, and red food color.
It's also not TERRIBLY hard to build a flowbench, actually. There are a few companies that make kits with digital sensors instead of simple manometers.........which would probably make things a bit easier. The most common flowbenches ever, like the superflow 600, not digital, and didn't need to be. Just vaccumcleaner motors in a wood box. Electric leaf vac/blowers can work too.
I think you can download the superfow 600 user manual for free if you google it, there's lots of good info there if you have an interest in this stuff. |
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mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Thu Feb 11, 2016 9:55 am Post subject: Re: porting intake and end castings? w\pics |
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| sinking valves dosent help squat. the how to hotrod vw's book is mostly shite. I dont have a computer in the shop. just because you see it in a book and read what is said dosent make it true.and that book is how old? and the writer/editeter knew what? oh he knew how to speal...speel?spael?spell.... and yes the ex needed work.and no you do not have to drive out the guides.also the head dosent know it is a vw....so...port it like a ford. |
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KROC
Samba Member
Joined: February 20, 2006
Posts: 359
Location: Vancouver B.C.
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| Posted: Fri Feb 12, 2016 9:49 am Post subject: |
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| modok wrote: |
| Brian_e wrote: |
but if you believe in a 87-89% throat diameter, |
I don't. as long as you can get 7-10 degree taper(like a venturi) from the small throat to the valve seat angles should be able to go as low as 80%.
Is that a good idea?? Not in all cases. If the valve lift is on the low side and shrouding is not a problem I see no downside to the larger valve. |
I have had intake seat throats at 93-94 With a single 45 seat and a radius below that made excellent power, so there are more than 50 ways to skin the cat..... |
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mark tucker
Samba Member
Joined: April 08, 2009
Posts: 23937
Location: SHALIMAR ,FLORIDA
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| Posted: Fri Feb 12, 2016 3:57 pm Post subject: Re: porting intake and end castings? w\pics |
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| diferent applications,different lifts, different sizes can all use diferent setups for best power. like heads & wifes one size dosent fit all.....or rather shouldent. |
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modok
Samba Member
Joined: October 30, 2009
Posts: 26787
Location: Colorado Springs
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| Posted: Wed Feb 17, 2016 2:30 am Post subject: Re: porting intake and end castings? w\pics |
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i thought about it today, and I decided........that the "throat" has been usually defined as the diameter of the 90 degree seat angle.
In the case there IS no 90 degree area under the seat cuts, because your seat ID is a french curve taper, raduis, asymetric, rocket nozzle shape, or a long 80-85 degree angle cut... where do you measure the throat?
I think then the term "throat" would have to be re-defined as the diameter measured at a specific distance below the actual seat angle, and this distance would be proportional to the valve size. You would measure the diameter of where the throat would be if there was one.
This might seem like a silly issue but........even the stock DP head has a tapered ID seat.
Maybe I DO believe in a particular% throat, depending how you define what a "throat" is! |
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