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> What rocker arm ratios do people see?
stugray
post Apr 3 2013, 12:20 PM
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Important lesson learned!

I cut the pushrods to 270mm and assembled the 3/4 side and the valve geometry was completely messed up between 3 & 4. I was pissed!

My son noticed that even with the rockers torqued, they were not flat against the head. The larger studs that Jake sells were not fully seated into the heads and the rockers were sitting against the shoulder of the stud!

Ran them in and geo is now perfect between the two.

Just another thing that can screw you up when doing these measurements.
Still does not affect my rocker ratio measurements, just glad I measured all 4 cylinders before cutting the pushrods. If I had decided the length based on that one cyl, they would have all been wrong.

Stu
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worn
post Apr 3 2013, 03:22 PM
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QUOTE(stugray @ Apr 3 2013, 10:20 AM) *

Important lesson learned!

I cut the pushrods to 270mm and assembled the 3/4 side and the valve geometry was completely messed up between 3 & 4. I was pissed!

My son noticed that even with the rockers torqued, they were not flat against the head. The larger studs that Jake sells were not fully seated into the heads and the rockers were sitting against the shoulder of the stud!

Ran them in and geo is now perfect between the two.

Just another thing that can screw you up when doing these measurements.
Still does not affect my rocker ratio measurements, just glad I measured all 4 cylinders before cutting the pushrods. If I had decided the length based on that one cyl, they would have all been wrong.

Stu

I am not sure I remember what the studs look like on your head, but the stock studs have a wide shoulder above the threads for locating the towers. Like a dowel. I didn't understand this at first and made the holes in my shims too small for the shoulder. I doubt the locating shoulders are critical.
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Jake Raby
post Apr 3 2013, 06:43 PM
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QUOTE
So whatever Jake has done to his cams for a coating is NOT the same as a stock webcam.


So much for us just repackaging things and selling them, as had been insinuated by some who simply do not know and just wanted to start crap. The same goes for lots of other things that we've sold over the years that may appear to be like any other over the counter offering.

Not even Web Cam knows what we do to camshafts after they are delivered to us, and they've never asked. They know that I don't use their lifters, and they also never ask about what I do for lifters, because they don't care.

There is a reason why we have lost ONE single cam since 2004 and that one was MY fault. Hell that one was in my own personal engine.

We never use shims under rockers, so our studs are not optimized for them. Its been about 7 years since I had to shim a rocker stand to optimize valve train geometry.

I don't know whether to be pissed off at you, or really happy that you have gotten this far with the project. I hope you have smooth sailing with the rest of it, valve train geometry is the biggest bitch with these engines, period.

This post has been edited by Jake Raby: Apr 3 2013, 06:44 PM
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stugray
post Apr 3 2013, 09:39 PM
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Jake

I have promoted your hardware often, even after "the tirade".
I tell people that "If Jake sells it, it is the right part".

There are cases where you can get the same parts elsewhere, but the point I made by posting was that "sometimes" Jake does things that others dont. And perhaps we could learn from the differences.
In this case I was poining out that your parts appear to be superior to others.

Even your tech articles and videos (I have paid twice for your engine video) are the bibles for what we are all trying to do here. I do not contest that.

Me not running the rocker studs in all the way is my fault and no-one elses.

Stu
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worn
post Apr 4 2013, 10:35 AM
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QUOTE(Jake Raby @ Apr 3 2013, 04:43 PM) *

QUOTE
So whatever Jake has done to his cams for a coating is NOT the same as a stock webcam.



Not even Web Cam knows what we do to camshafts after they are delivered to us, and they've never asked. They know that I don't use their lifters, and they also never ask about what I do for lifters, because they don't care.

We never use shims under rockers, so our studs are not optimized for them. Its been about 7 years since I had to shim a rocker stand to optimize valve train geometry.


Now I am thinking I made a mistake. Could I have purchased a cam and tappets from you? I thought you didn't do that no more. Would've if I had known.

At this point I would think that you would have zipperino need for shims too, because you have CNCd the heads to a repeatable size. My heads aren't so lucky, but I am having fun as a complete amateur.
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Jake Raby
post Apr 4 2013, 05:45 PM
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QUOTE(stugray @ Apr 3 2013, 07:39 PM) *

Jake

I have promoted your hardware often, even after "the tirade".
I tell people that "If Jake sells it, it is the right part".

There are cases where you can get the same parts elsewhere, but the point I made by posting was that "sometimes" Jake does things that others dont. And perhaps we could learn from the differences.
In this case I was poining out that your parts appear to be superior to others.

Even your tech articles and videos (I have paid twice for your engine video) are the bibles for what we are all trying to do here. I do not contest that.

Me not running the rocker studs in all the way is my fault and no-one elses.

Stu



Maybe its just me, but this quote doesn't quite seem like "promotion" of my products:

QUOTE
After explaining that I bought a "Raby Cam package.." His exact quote was "Oh not another Raby Victim!".


That said I have no issue with the guys at FAT and never have. They are very good competitors and they are the only guys that you'll ever hear me say that about in this industry. That said, they are our competitors and they love to have a prior customer of mine call on them, just like we love it when their prior customers call on us. Thats part of taking pride in what you create and offer over the "other guy".

That said, what I find absolutely hilarious is the one person who offered a ton of expert help on this topic is a person who had NEVER set valve train geometry in his life until **I** spent an hour on the phone with him walking through every step required to achieve max lift and perfect geometry simultaneously. Doing that was like trying to lead a mule through the forest.

Anyway, all the things that happened, happened and I don't regret them. That exchange proved a lot of things to me and I made big decisions that have made life easier here. Like I said, it looks like you are now on the right page and heading toward success. Glad to be on a civil level with you now and we'll continue to agree to disagree.

QUOTE
Now I am thinking I made a mistake. Could I have purchased a cam and tappets from you? I thought you didn't do that no more. Would've if I had known.


As much as I'd like to close the store and not deal with it, I have an employee who has been the Manager since it opened, and she needs the job. If it wasn't for that, the Type 4 Store would not exist and we'd only sell engines, the way we used to back when life was easier, more fun and less stressful. Selling things at retail is about the worst punishment I have ever created for myself.

This post has been edited by Jake Raby: Apr 4 2013, 05:48 PM
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stugray
post Apr 4 2013, 09:21 PM
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Jake, the above quote was merely an exact comment (yes, I admit from a competitor).

Here is another quote:
"Order a new set from Jake. If he sells them, they are the right ones."

http://www.914world.com/bbs2/index.php?sho...=205835&hl=

I have also referred numerous people to your website for other items that are not easy to find elsewhere. I have also used every single part in your cam package with the exception of the cam itself (and lifters, I kept them as a set with the cam).

I have said from the beginning (even in my tirade) that "The parts that I received from you all appear to be top quality and exactly what I wanted. No complaints from that side of the transaction."

The issue here with this cam was because I tried to purchase the cam right in the middle of your whole cam policy change. I was told to just pick one and make the purchase and then we would have our consultation and then you would send me the cam I needed.
I received a cam within ~4 days of making the purchase when I had not yet made the appointment for the consultation! (I had assumed that you would hold the order until after). Then I sat on the parts for over a year until my "tirade" about the P&C set.
At that point I gave up on the paid for consultation.
It was clearly my fault for putting a cam that was not what I needed in my engine the first time around.

My assumption that I could survive with an intake lift of 0.368*1.3 = .478 would have been OK.
When I found what I REALLY had it was a no-go.
As posted above (see top of page 2), the cam card showed "Valve lift = .368" which did not raise a flag until I measured greater than .500

Stu
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stugray
post Apr 29 2013, 01:31 PM
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After going through all of this measuring and having Jake respond on this thread, it just occurred to me:

Jake did not comment at all about what the stock rocker ratios are on these engines and how I was supposed to interpret the cam card supplied with the cam.

Maybe Jake would explain:

Why, everyone says that these rockers are all 1.3 when I measure 1.4 on the intakes (8 sets of rockers).

What was the expected valve lift using the 9700 cam (cam card shows only Lobe lift).

Stu
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stugray
post Feb 4 2015, 02:21 PM
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Bump the above question for rdauenhauer.

Jake? Type-IV rocker ratios? Experience?
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914werke
post Feb 4 2015, 03:19 PM
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I missed this. Good read.
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Jeff Hail
post Feb 4 2015, 11:39 PM
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QUOTE(Racer Chris @ Dec 19 2012, 08:10 AM) *

QUOTE(stugray @ Dec 19 2012, 09:27 AM) *

I am also reading on Jakes cam instructions that I need .050 clearance from the Intake valve to the piston, but I WILL have only 0.023, so I guess i should just go with it?!?!

.050 is too close for an intake valve IMO. I don't like less than .120 in a race engine, .080 on the exhaust valves.

The valve lift numbers you're getting are suspicious.
There is no way you should have .548 intake lift.

It's pretty hard to believe that you have intake rockers with a ratio of 1.4.
I've never seen anything close to that, and if they are, that's desireable in an engine built for a race class requiring a stock cam and rockers.
I would trade you for them.

Either the cam is bad or there is something wrong with your geometry or measuring setup.

And the cam card is fubar - reminiscent of military-like precision. (IMG:style_emoticons/default/lol-2.gif)

[size=5]

Oh sheet. Could not have said it better. Love it when Chris shoots the Howitzer. Boom.
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Mark Henry
post Feb 5 2015, 06:27 AM
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QUOTE(Jeff Hail @ Feb 5 2015, 12:39 AM) *

QUOTE(Racer Chris @ Dec 19 2012, 08:10 AM) *

QUOTE(stugray @ Dec 19 2012, 09:27 AM) *

I am also reading on Jakes cam instructions that I need .050 clearance from the Intake valve to the piston, but I WILL have only 0.023, so I guess i should just go with it?!?!

.050 is too close for an intake valve IMO. I don't like less than .120 in a race engine, .080 on the exhaust valves.

The valve lift numbers you're getting are suspicious.
There is no way you should have .548 intake lift.

It's pretty hard to believe that you have intake rockers with a ratio of 1.4.
I've never seen anything close to that, and if they are, that's desireable in an engine built for a race class requiring a stock cam and rockers.
I would trade you for them.

Either the cam is bad or there is something wrong with your geometry or measuring setup.

And the cam card is fubar - reminiscent of military-like precision. (IMG:style_emoticons/default/lol-2.gif)

[size=5]

Oh sheet. Could not have said it better. Love it when Chris shoots the Howitzer. Boom.

(IMG:style_emoticons/default/agree.gif)
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barefoot
post Dec 7 2015, 04:34 PM
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QUOTE(stugray @ Feb 11 2013, 12:13 AM) *

QUOTE
It is not possible that you are the first to discover the rocker ratio is different than what everyone has believed for 40 years.


Chris - I had three reputable machine heads sit and watch the dial indicator "go-round and round" and measured .520 on two different cylinders and after swapping out the rockers from two different engines. (more than FIVE separate measurements). The cam lift is .368 per Jakes cam card and measurement ....

I have two complete sets of 1.4 Intake rockers. Exhaust rockers measure closer to 1.3.

Stu

Just getting into cam selection for my street 2056 w/ carbs.
Curious about rocker ratios, so I made some measurements with my dial calipers
on my late 2.0 rockers with the 10mm adjusters and was surprised to see that the intakes & exhausts are different. Just measuring the rockers alone I got 1.41" from center of pivot bore to center of adjuster screw for both in & ex. However the exhaust had 0.92" from the center of pivot bore to center of pushrod cup while the intake dimension was 1.02"
This results in an exhaust ratio of 1.53 & intake ratio of 1.38.
Note that these are eyeball estimates with the rockers laid horizontal as I did not have height stand or CMM equipment to use.
I don't know what ratio the earlier 1.7 rockers are and if different from intake to exhaust, anyone have this info ??
It seems like folks like to use the early 1.7 rockers fitted with swivel foot 911 adjusters
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Dave_Darling
post Dec 7 2015, 05:30 PM
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The ratio of all of the stock rockers "should be" the same. But there seem to be variations from rocker to rocker, so it's generally a good idea to measure everything.

--DD
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stugray
post Dec 7 2015, 07:31 PM
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QUOTE(barefoot @ Dec 7 2015, 03:34 PM) *

QUOTE(stugray @ Feb 11 2013, 12:13 AM) *

QUOTE
It is not possible that you are the first to discover the rocker ratio is different than what everyone has believed for 40 years.


Chris - I had three reputable machine heads sit and watch the dial indicator "go-round and round" and measured .520 on two different cylinders and after swapping out the rockers from two different engines. (more than FIVE separate measurements). The cam lift is .368 per Jakes cam card and measurement ....

I have two complete sets of 1.4 Intake rockers. Exhaust rockers measure closer to 1.3.

Stu

Just getting into cam selection for my street 2056 w/ carbs.
Curious about rocker ratios, so I made some measurements with my dial calipers
on my late 2.0 rockers with the 10mm adjusters and was surprised to see that the intakes & exhausts are different. Just measuring the rockers alone I got 1.41" from center of pivot bore to center of adjuster screw for both in & ex. However the exhaust had 0.92" from the center of pivot bore to center of pushrod cup while the intake dimension was 1.02"
This results in an exhaust ratio of 1.53 & intake ratio of 1.38.
Note that these are eyeball estimates with the rockers laid horizontal as I did not have height stand or CMM equipment to use.
I don't know what ratio the earlier 1.7 rockers are and if different from intake to exhaust, anyone have this info ??
It seems like folks like to use the early 1.7 rockers fitted with swivel foot 911 adjusters


Sorry BOB says that you are wrong regardless of what you measured:

QUOTE(bobhasissues @ Dec 18 2012, 08:40 PM) *

Stu,

Nobody will try to help you if you continue with your argumentative attitude.

MY Raby cam card shows the peak cam lift and peak valve lift based on 1.3 rocker ratios. I would think your card shows the same.

All factory Type IV lifters regardless of 1.7, 1.8 or 2.0 have a 1.3 ratio. Go with 1.3, stop trying to re-evaluate a known value.

Jake's article explains that shims and pushrod lengths will affect total lift.
Look at the value for peak lift valve on your cam card and shoot for that.


So according to Bob, your measurements are wrong (even though what I measured was about the same).
My measurements were with the rockers actually moving the valves on the engine so I would expect yours to be a little different.

QUOTE(stugray @ Mar 26 2013, 07:25 PM) *

Ok, so I decided to go with a webcam 86b instead of the other.

I measured it prior to installation.
The wecam 86b has an advertised "Valve Lift" of .500/.500 Int/Exh.
http://www.webcamshafts.com/pages/automobi...691_001095.html

So I measure the cam and get: .365/.365 lift at the cam.

.365 * 1.37 = .500 valve lift.

So apparently Webcam knows that these rockers are closer to 1.4 than 1.3, but I must just be a "mentally ill idiot" just like webcam.....



I clearly show that webcam used 1.4 for the rocker ratio when they designed my cam
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barefoot
post Dec 7 2015, 08:50 PM
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[quote name='stugray' date='Dec 7 2015, 08:31 PM' post='2274588']
[quote name='barefoot' post='2274491' date='Dec 7 2015, 03:34 PM']
[quote name='stugray' post='1818427' date='Feb 11 2013, 12:13 AM']
[quote]It is not possible that you are the first to discover the rocker ratio is different than what everyone has believed for 40 years.[/quote]

Chris - I had three reputable machine heads sit and watch the dial indicator "go-round and round" and measured .520 on two different cylinders and after swapping out the rockers from two different engines. (more than FIVE separate measurements). The cam lift is .368 per Jakes cam card and measurement ....

I have two complete sets of 1.4 Intake rockers. Exhaust rockers measure closer to 1.3.

Stu
[/quote]
Just getting into cam selection for my street 2056 w/ carbs.
Curious about rocker ratios, so I made some measurements with my dial calipers
on my late 2.0 rockers with the 10mm adjusters and was surprised to see that the intakes & exhausts are different. Just measuring the rockers alone I got 1.41" from center of pivot bore to center of adjuster screw for both in & ex. However the exhaust had 0.92" from the center of pivot bore to center of pushrod cup while the intake dimension was 1.02"
This results in an exhaust ratio of 1.53 & intake ratio of 1.38.
Note that these are eyeball estimates with the rockers laid horizontal as I did not have height stand or CMM equipment to use.
I don't know what ratio the earlier 1.7 rockers are and if different from intake to exhaust, anyone have this info ??
It seems like folks like to use the early 1.7 rockers fitted with swivel foot 911 adjusters
[/quote]

Sorry BOB says that you are wrong regardless of what you measured:

[quote name='bobhasissues' post='1786515' date='Dec 18 2012, 08:40 PM']
Stu,

Nobody will try to help you if you continue with your argumentative attitude.

MY Raby cam card shows the peak cam lift and peak valve lift based on 1.3 rocker ratios. I would think your card shows the same.

All factory Type IV lifters regardless of 1.7, 1.8 or 2.0 have a 1.3 ratio. Go with 1.3, stop trying to re-evaluate a known value.

Jake's article explains that shims and pushrod lengths will affect total lift.
Look at the value for peak lift valve on your cam card and shoot for that.
[/quote]

So according to Bob, your measurements are wrong (even though what I measured was about the same).
My measurements were with the rockers actually moving the valves on the engine so I would expect yours to be a little different.

Of course my measurements are "static" and as previously described "dynamic ratio is a variable as rockers tilt, so cam producers have to settle on an average figure.
However there's clearly a difference in intake to exhaust rocker design as the photos show.
BTW this was constantly observed from rockers off 2 different 2L motors. i have no history on these, but assume them to be OEM.

Attached Image

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Bulldog9
post Dec 7 2015, 08:54 PM
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(IMG:style_emoticons/default/av-943.gif) Really? come on guys let it go already.
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stugray
post Dec 7 2015, 09:43 PM
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QUOTE(Steve Pratel @ Dec 7 2015, 07:54 PM) *

(IMG:style_emoticons/default/av-943.gif) Really? come on guys let it go already.


Notice that Jake never said what HE thinks the rocker ratios are....
If I had been wrong, I am certain that he would have pointed that out.
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930cabman
post Jan 8 2022, 06:14 PM
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What is the consensus from this dramatic post? can I gather 1.4 intake ratio and 1.3 ratio exhaust ratio??

Mr. Elgin claims 1.3 intake ratio and 1.25 exhaust ratio.

My gut tells me to believe Mr. Elgin, he has been around the block many times
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Superhawk996
post Jan 9 2022, 08:18 AM
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QUOTE(Steve Pratel @ Dec 7 2015, 09:54 PM) *

(IMG:style_emoticons/default/av-943.gif) Really? come on guys let it go already.


QUOTE(stugray @ Dec 7 2015, 10:43 PM) *

Notice that Jake never said what HE thinks the rocker ratios are....
If I had been wrong, I am certain that he would have pointed that out.


(IMG:style_emoticons/default/agree.gif)

The ratio is what the ratio is. It's not like VW Type 4 engine have a bunch of rocker ratios to choose from. Nor are there significant modifications to the rocker ratio that really raise the stakes for these engines to make way more HP.

Set the valve geometry as has been well documented by Jake and others. Beyond that it's just a waste of time.
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