Camshaft grinds for turbo

With Turbo and Super charging you can create massive horsepower with vw motors.

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dejan
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Re: Camshaft grinds for turbo

Post by dejan » Fri Jul 01, 2011 1:39 pm

And what do they say about IN -FK87 end EX -FK10 @112 ,1600 Turbo 1,4s end double springs valve.

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so67vw
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Re: Camshaft grinds for turbo

Post by so67vw » Sat Jul 02, 2011 12:07 pm

dejan wrote:And what do they say about IN -FK87 end EX -FK10 @112 ,1600 Turbo 1,4s end double springs valve.
I'd say lots of RPM, not at all fun to drive on the street, and unless you have a serious bottom end, BOOOOOM.... If you are racing it with the right gears it could be kinda fun, but I personaly like have'n more CCs, drivable HP, lots of grunt, and still able to use pump gas... In the long run less cost with better results... That's just my opinion though... You do what you want and have as much fun with it as you can...

dejan
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Re: Camshaft grinds for turbo

Post by dejan » Sun Jul 03, 2011 1:45 pm

so67vw wrote:
dejan wrote:And what do they say about IN -FK87 end EX -FK10 @112 ,1600 Turbo 1,4s end double springs valve.
I'd say lots of RPM, not at all fun to drive on the street, and unless you have a serious bottom end, BOOOOOM.... If you are racing it with the right gears it could be kinda fun, but I personaly like have'n more CCs, drivable HP, lots of grunt, and still able to use pump gas... In the long run less cost with better results... That's just my opinion though... You do what you want and have as much fun with it as you can...
I want to realize higher RPM so go to that variant of CAM.
We all know that more RPM more horsepower , they do not have to mean.

(1,600cc x 5500rpm x 10,5CR)\910=101.5HP
(1,600cc x 6500rpm x 10,5CR)\910=119.9HP
(1,600cc x 7500rpm x 10,5CR)\910=138.4HP
(1,600cc x 8500rpm x 10,5CR)\910=156.9HP This looks at Honda VTEC VTI :wink:

--- Always leave more horsepower

jinx
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Re: Camshaft grinds for turbo

Post by jinx » Mon Aug 01, 2011 1:38 am

are there any cams that can do bothe NA and boost ?
id like to build a motor but in stages

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Wally
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Re: Camshaft grinds for turbo

Post by Wally » Mon Aug 01, 2011 2:01 am

Yeah, I call them n/a cams and they work very well in a boosted engine too.
Because you have a bit lower CR in a turbo engine, just don't get too crazy on duration ;-)

jinx
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Re: Camshaft grinds for turbo

Post by jinx » Mon Aug 01, 2011 2:55 am

Wally wrote:Yeah, I call them n/a cams and they work very well in a boosted engine too.
Because you have a bit lower CR in a turbo engine, just don't get too crazy on duration ;-)
so anything without an overlap? i dont want stupid revs either if i can help, so just a NA cam that is suitable?

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Wally
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Re: Camshaft grinds for turbo

Post by Wally » Mon Aug 01, 2011 4:34 am

No, certainly not. Turbo engines love overlap as much as n/a to some degee, large duration just gives even less respons down low as turbo engines run much less compression ratio, so take it easy on the wild side of the profile range, unless you build a drag race car.
Duration is not exactly the same as overlap btw.

jinx
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Re: Camshaft grinds for turbo

Post by jinx » Mon Aug 01, 2011 10:00 am

Wally wrote:No, certainly not. Turbo engines love overlap as much as n/a to some degee, large duration just gives even less respons down low as turbo engines run much less compression ratio, so take it easy on the wild side of the profile range, unless you build a drag race car.
Duration is not exactly the same as overlap btw.
ah ok, ta, yea i know the is some differance, just thought they may go hand in hand tho

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CobraJet
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Re: Camshaft grinds for turbo

Post by CobraJet » Wed Oct 19, 2011 11:42 am

I'm building a 1700 T4 with stock crank, rods, and heads. This will be a street engine and I'd like to keep it under 7000RPM, preferably 6500RPM if at all possible. It won't be a daily driver, just a weekend warrior/ice cream getter that I hope will eat just about anything around here.

This'll get driven awhile NA while I work on manifold/header for a turbo. A buddy of mine wants to give me a cam and lifters to go with it. He has these T4 cams in his garage now.

(108° LC) 1.065 BC
Valve Lift .426
233° Duration @ 0.050

(102° LC) 1.055 BC
Valve Lift .470
250° Duration @ 0.050

(108° LC) 1.080 BC
Valve Lift .470
250° Duration @ 0.050

This car will be running Megasquirt and a big intercooler when it goes turbo. Which cam would you go for or should I just break down and buy one?

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Type 4 Unleashed
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Re: Camshaft grinds for turbo

Post by Type 4 Unleashed » Thu Dec 01, 2011 4:38 am

Stripped66 wrote:
Type 4 Unleashed wrote: There are so many springs out there that you can get your over the nose pressure and still have .150" before coil bind, and your whole valve train will thank you for it not to mention your wallet.
This is absolutely the most stupid valve spring advice I've ever read. You would do yourself a favor to read up about "spring surge" (under damped spring harmonics). Excessive clearance to coil bind does not provide the harmonic damping the spring manufacturer intended and contributes to spring surge (and broken valve train parts).

Pick a valve spring based on the pressure you need on the seat and at full lift, that sets up within the range of installed heights you can accommodate (either using shims on the spring cup, or retainers and keepers that can offset your installed height), and run the manufacturer's suggest clearance to coil-bind. Do not pick a large spring like a K800 (which is good for 480+ lbs over the nose) and set it up with 0.150" clearance to coil-bind for 400 lbs over the nose. Yeah, it's cheap, but it's completely ignorant of the engineering that went into the spring; and while you might run it without valve train failure, for how long?


This isn't a new concept, but some of you need to open your eyes and learn something, instead of propagating dogma. If you want a good read, a recent tech article in HotRod Magazine provided a good summary: http://www.hotrod.com/techarticles/engi ... index.html
HotRod Mag wrote:Thinking has evolved on how much safety margin is needed. About 0.060 inch used to be the textbook minimum, with more OK and even desirable. That's still an acceptable standard for everyday performance use, but Massingill says that in some cases "0.060 has become the maximum rather than the minimum." Godbold notes that "from high-speed video and testing, it is clear that adjacent coils contact as you approach the valvetrain limiting speed. Hence, modern springs are designed to run near coil bind and use the coil-to-coil interaction for improved damping at or near max lift. This interaction is one of the most effective means of dampening spring surge, but the valve spring must be properly designed in terms of solid stress to safely use this interaction." Depending on the intended use, the spring and cam-lobe design, and the engine builder's preferences, you will now see coil bind safety margins vary from as low as 0.015 inch to as high as 0.120 inch, with tighter numbers predominating on very stiff valve trains. In a serious valve train, anything more than 0.150 inch can cause spring surge, which can greatly reduce the available spring load needed to close the valve.
There has also been several good discussions about spring surge on the speedtalk.com forums, with contributing comments by some of the best racing engine builders in the US.

The spring manufacturers were smart enough to specify the clearance to coil bind, and for a very good reason; don't be stupid enough to ignore their specifications and make up your own clearance.


I thought I would post an update: There is currently a board member that is running a 2.2 ltr Turbo motor that puts out about 400 rwhp on the dyno. The relative engine components are as follows: WEB 163 with .500" valve lift, CB VW650 valve springs installed @ 1.520" which will give .170" before coil bind, and has gone as high as 7500 rpm, and he notes none of the issues previously mentioned such as broken parts from spring surge or valve float, probally because he has no spring surge or valve float, who would of figured. My opinion was based on my experience with my own builds which are naturally aspirated, and here is someones experience with forced induction.
Richard

EMW

“Have you ever noticed how some people never
have the money to do it right, but can always
find the money to do it twice ?”

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Stripped66
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Re: Camshaft grinds for turbo

Post by Stripped66 » Tue Dec 06, 2011 2:10 pm

Type 4 Unleashed wrote:

I thought I would post an update: There is currently a board member that is running a 2.2 ltr Turbo motor that puts out about 400 rwhp on the dyno. The relative engine components are as follows: WEB 163 with .500" valve lift, CB VW650 valve springs installed @ 1.520" which will give .170" before coil bind, and has gone as high as 7500 rpm, and he notes none of the issues previously mentioned such as broken parts from spring surge or valve float, probally because he has no spring surge or valve float, who would of figured. My opinion was based on my experience with my own builds which are naturally aspirated, and here is someones experience with forced induction.
What update? How many miles have you put on your heavy PSI springs?

Good for Wally. He's gone about a year on the VW650 springs; will he ever break any with his current set-up? I respect what he's doing but I don't run his engine combo and he doesn't run mine; neither do you for that matter.

I've got 18K miles between two sets of Crowers and I'm going to continue installing the correct spring at the recommended clearance to coil bind, and I'm going to continue recommending others to do the same. Taking a risk and running a blanket statement, instead of what the manufacturer recommends, isn't advice I'm willing to give to anybody.


BTW,
Type 4 Unleashed wrote:I have talked to Chris at Pac Racing about the Beehives I bought from them that are recommended to be ran at .050" before coil bind, because they are designed to be ran close to coil bind.
Where do you run 'em? Do you run these at 0.150" clearance from coil-bind, or do you run them at/near the recommended specifications?

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Type 4 Unleashed
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Re: Camshaft grinds for turbo

Post by Type 4 Unleashed » Wed Dec 07, 2011 8:10 pm

Hi Jason

The PSI Springs are for a future build, and when I run them I'll post.

I have well over 50K on a set of Howards Cams 1.260" SBC Zero Tolerance Drop In Springs, Max Lift .640", installed @ 1.780", coil bind @ 1.062", valve lift is .560" comes out to .158" before coil bind, oh and push rods are 3/8" .080" wall.

You want to run your springs close to coil bind that's your choice, my thinking is the opposite, mine are set up to do a lot of performance miles on the street, and it works.

The Beehives are a different animal, and I went a different route, the springs are PAC 1233 recommended installed height @ 1.670"(seat pressure 105#) coil bind @ 1.060" Max lift .550" (open pressure 270#), valve lift will be .560", installed height will be changed from 1.670" to 1.680", seat pressure will drop from 105# to around 95#. But since I purchased these, PAC had come out with a new 1533 Nitrided spring that gives 120# @ 1.670" and 285# at a Max lift of .575". But to change springs now I will have to have new Titanium retainers made for the new springs, so I will see.

My point being, for example Pluto is no longer considered a planet ? And the New thinking is the Minimum is now the Maximum or is it the Maximum is now the Minimum ?

For builders that are not sure what to do, the safe bet is to follow the manufactures recommendations, everyone else follow your own path.
Richard

EMW

“Have you ever noticed how some people never
have the money to do it right, but can always
find the money to do it twice ?”

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Stripped66
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Re: Camshaft grinds for turbo

Post by Stripped66 » Wed Dec 07, 2011 10:00 pm

Type 4 Unleashed wrote: My point being, for example Pluto is no longer considered a planet ? And the New thinking is the Minimum is now the Maximum or is it the Maximum is now the Minimum ?
It's material-, design-, and application-specific, which goes back to my point to consider the manufacturer's recommendations. I'm not saying take a set of archaic K800's and run them at 0.040" from coil bind because that is the flavor of the month. What I'm saying is if the spring I need comes with the instructions to run them 0.040" from coil bind, I'm not going to add another 0.100" and call it good; if that's the case, it's the wrong spring (IMO) and a more appropriate solution exists.

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shag55
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Re: Camshaft grinds for turbo

Post by shag55 » Fri Dec 09, 2011 3:19 pm

Exactly! The manufacturers do the testing to find the best possible height to coil bind between fatigue by compression and dampened resonance. Some springs will actualy fail faster with the added clearance due to under dampening. This is why the manufacturer gives there guidelines in the first place. On my PSI springs they recommend .060-.100 max and this is where the best results will be even in long endurance runs or long term daily driven.
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hugging corners
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Re: Camshaft grinds for turbo

Post by hugging corners » Mon Jun 11, 2012 8:18 am

Im not sure if am permited to bring this great tread back, but this is my bible.
I am putting my turbo build back on track after 6 months hold, and searching for cams.
Here is youtube showing tcs120, but those bugs are N/A, why just not eangle120.
I am brainstorming this reversed engeneering here
any ideas?


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