porting intake and end castings? w\pics

[andrewvwclassic]

Was just finishing up my head porting and was reconsidering a thought I was initially against porting the intake and end castings. I was never keen with this because, it adds more space and makes it a less direct path on the intake and I cant see it making a whole lot of difference for the size it takes off the head and the liability of cracks maybe in that area. I was wondering if anyone has had dyno test with stock ported head aned regular intake and castings vs. the same setup with portede intake and cast5ings. I want to squeez all the hp I can with having some driveability. thanks

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[modok]

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.

[fivelugshortaxle]

Modok, why did Mark Hebert not take off the bump in the intake that was the support for the guide? Did the bump help create turbulence or was it simply for valve guide longevity?
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[Quokka42]

Get hold of a copy of How To Hot Rod VWs - taking the bump out created a hole that had to be TIGed up (called "heli-arc" in those days.)
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There has only ever been one man who was perfect, and they nailed Him to a cross.

[Alstrup]

Mmmmmwell, I kinda disagree on that Modok. But, you are correct with the part that "a little can get you a long way" And also the fact that some areas are best left alone if youre not going all in.

I have not done a lot of testing with stock heads contra ported heads on the same engine. but over the years I have seen several customer engines on the rolls with such set ups, and can therefor make a somewhat educated guess on the advantages with ported stock heads.

Stock heads typically flow about 100-105 CFM @ 25". Most home ported stock heads are in the 120ish CFM range, well ported versions are in the 130 CFM range. Perfect heads are in the 138-140 CFM range.

For instance. A 1600 type 1. W110 cam, stock heads, 9-1 CR, 1 3/8" header and decent muffler and Kadrons, usually peak at about 83-85 hp and 135-140 Nm torque.
Another 1600 with a W110 cam, nice ported stock heads with detailed seats, 9-1 CR, italian 40 IDF´s w. 28 mm venturies, 1 3/8" header and a 2" expansion type muffler, peakes at 94-95 hp and 150 nm torque.
Same engine was run with Kadrons for a while because the IDF´s needed a rebuild due to an engine fire that got caught in time. With the Kads the engine pulled 91-92 hp and 145 Nm torque.
A 1600 engine with well ported stock heads and an engine specific cam, carbs, and exhaust pulls 110 hp.
A 1600 put on the edge can pull up to about 135 hp still with stock valved heads.

An engine with center carburettor and stock end castings, say a 1914 with a CB 2280 cam, stock heads apart from a good valve seat job, 8,5-1 CR and a 1 3/8" header or a Vintage muffler pulls 83-84 hp and 165ish Nm torque. (The power is about the same even if you add more duration to the cam )
Same engine with detailed stock heads, same CR, same cam or a little more duration, detailed end castings can pull up to about 95 hp and 165ish Nm torque.
I have ONCE pulled 100 hp with a little more cam and lift (and still stock like idle) with a set of slingshot manifolds. But the set up needs more finetuning to be perfect.

Hope this helps.
T

[Quokka42]

Actually, the way I see it you are agreeing with Modok - stock heads will not benefit from more than a bit of a skillfull clean up and valve job until you present them with an increased capacity and/or cam. Datsun heads were the same - clean them up, even up the flow across the CSA of the port and remove as little as possible. Signs of good port design, I think.
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[andrewvwclassic]

[spencerfvee]

when I used to race vw stock cars on a dirt track .the class was 1600cc motors only . there was a lot of cheating back then lol we all thought of it as being a head of the other guys . since I worked in a shop .I had all the tools I needed. I found out that you could make a vw 1600 motor run. as clyd berg allways told me all the power is in the heads .I belive in velocity .bigger ports don't allway work well on a 1600cc motor .I allways opened up around the intake valve guide as much as I could with out weaking the head . the rest of the intake port I left stock .I did open up the intake manifold side to match the intake manifold .on the intake seat I allways left the lip alone under the intake valve seat .I allway thought of it as being a little venturi to help speed up air flow .I then cut the seat for a 36mm S&S valve then I would cut the inside of intake seat .to match the 36mm valve .on the ex. port I just did a clean up and i ported the ex. opening to the header .I liked using a 1 1/2 header .I then installed a set of S&S ex valves I then cut the heads for 10 1/2 cr a 1600cc motor loves 10 1/2 to 11 1/2 cr it wakes the motor up I understand you should ony run 9:1 cr for the street . I then unshrouded the intake and ex valves .I have to tell you a story about clyd berg one day he was out in the back of his dads shop and gen walked out to see what he was doing .clyd had a garden hose and he had the end of the garden hose on one of the intake ports he was looking at how the water came out of the intake seat .gene looked at clyd and said don't tell any one you did this . I told clyd I did the same thing .we both thought it was funny . good luck on your heads great job this is just my two cents on head porting I am sure that some will not agree with me. but that's why there are so many head porters out there that do it there way I know what works for me .and they know what works for them good luck take care have a great week end spencerfvee

[mark tucker]

well first off you dont effup the head with a square cutting end mill like you did. so....throw those away and buy some good heads already done. you were right to assume you couldn't do it. as far as drive ability.....if you cant drive take a taxi.....or hire a driver. Im not being a dick,but you sure dicked up those heads...butt good. thus the reason somuch shit/junk is at the swap meats

[spencerfvee]

dam mark don't hold back .what the hells in florida drinking water .? lol lol oh well you have not changed one bit. lol we love you any way mark lol peace to all spencerfvee

[rs58rag]

Should of left exhaust wall alone.

[Brian_e]

You will need to drill the guides and remove them before any real improvements can be made.

Some areas have zero effect on flow, and removing them just enlarges the port volume. The spring seat bump is one of those spots.

Straighten the port, pay attention to the 1/2" above and below the seat, and make sure you have a top notch multi angle valve job.

A 1776 with 40idfs, and a set of 130cfm stock valve heads is an awesome little engine.

Brian

[modok]

To be more specific I was working on a 113 casting, and testing out how much improvement with a 35.5 and 37mm valve, at .300 and .400 lift only.
Managed 10%more flow without enlarging the port at all.
The other side maybe I will hogg it out and look for that 120 cfm Alstrup says is possible!

The 311/040 with guide boss the port IS larger around the boss, so you take out the boss and now that area is too big, at least compared to around it, but the short turn above the guide will need more work on those I'm sure. Maybe I'll try one today. It keeps raining and nothing to do. Why does my flowbench read low with high humidity???? Should have built it out of metal not wood LOL

[spencerfvee]

hi modok lot of work to get a head to flow .one mistake and your back to base one lol keep use posted on how it works out when you make the port bigger. oi allways like reading your posts . not raining here been working on my vee all day spencerfvee

[andrewvwclassic]

Sorry just a speratic post I changed my mind on. I hate these stupid smartphones. I would never insult someone here.

[andrewvwclassic]

[mark tucker]

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.

[modok]

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.

[andrewvwclassic]

[spencerfvee]

don't let mark get under your skin. hes that way to every one .some times I don't know what the hell hes saying or why hes saying what he says to people lol I think your doing a nice job on your heads .. I ported my first set of head with a hand drill .lol and they turned out ok . your doing a better job than I did on my first set of heads . 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