Finally got it running:2.0Ltr Type4

[Ol'fogasaurus]

Hi everyone!

Got the car dynoed yesterday at HR-Engineering:139Hp and 173Nm(127Ft/Lb).The horsepower surprised me,but I had hoped for more torque.As you can see on the dyno graph that it all ends at 6000Rpm:thats where the valvefloat starts and the rev limiter is set to.The curve would have continued for a few hundred of Rpm's but that would involve converting it to dual valve springs.
I'll leave it for the moment and(hopefully)enjoy it this summer.

Cheers,Arnoud

Thats a good idea. Get some positive use out of it before tearing apart again. Heck, you might even find out some other things you want done with it in this build after you put it back together otherwise you would have to start over again by tearing it apart again.

The story of one's life isn't it .

Lee

[Arnoud]

Hi Lee!

I still have an 82mm crank+flywheel,103mm Chinese Nikasil cylinders with JE Pistons,5.5" rods and a pretty virgin case stored on my shop's attic..that will be the next type4 project.
But first a 200Km/h speedo for the speedtrials on the German Autobahn to the first of may bug meeting in Hannover(Maikäfertreffen)

Cheers,Arnoud

[Bruce.m]

If you are brave you could try beehive single springs, instead of dual springs but the heads would still need some slight machining to the guide boss.

[Arnoud]

If you are brave you could try beehive single springs, instead of dual springs but the heads would still need some slight machining to the guide boss.

Hi Bruce!

What annoys me is that the curve was still climbing so what would the result have been horsepower wise if we could hav revved it 4-500rpm higher?
The engine will have to come out if the gearbox gets noisier and I still want to make a better set of fan shrouds then I might consider a drop in beehive setup.Pulling the heads and machining the guide bosses is not a problem,changing to different valves is not what I want to do.

Cheers,Arnoud

[Ol'fogasaurus]

https://www.bing.com/search?q=beehive+s ... showconv=1

A short discussion on Beehive springs. These are not the same style of beehive springs I was thinking of though.

Lee

[Eddie010]

Arnoud the previous engine I had (2.0 liter) could go up to 6500 with single springs.
But that was a schleicher 316 cam, maybe because that cam has not so much lift as the 86A.

But good result on the engine, will be a nice driving engine.
Love the riechert cooling.

PS my current engine has also single springs, but they are special ones (oteva) from JPM.
They run 6000 with a 86B cam.

[Ol'fogasaurus]

Arnoud the previous engine I had (2.0 liter) could go up to 6500 with single springs.
But that was a schleicher 316 cam, maybe because that cam has not so much lift as the 86A.

But good result on the engine, will be a nice driving engine.
Love the riechert cooling.

PS my current engine has also single springs, but they are special ones (oteva) from JPM.
They run 6000 with a 86B cam.

Taaa-daaa!

Lee

[Arnoud]

Arnoud the previous engine I had (2.0 liter) could go up to 6500 with single springs.
But that was a schleicher 316 cam, maybe because that cam has not so much lift as the 86A.

But good result on the engine, will be a nice driving engine.
Love the riechert cooling.

PS my current engine has also single springs, but they are special ones (oteva) from JPM.
They run 6000 with a 86B cam.

Hi Eddie!

That's odd:the valve springs I used are listed as 98-102Kg,the Oteva's per the CSP website are only 90Kgs?
I wonder what in the listed numbers I dont see that make single 90Kg Oteva's handle a wilder cam whereas heavier spring cant cope with a milder cam?
Thanks for sharing your experiences.

Cheers,Arnoud

[Ol'fogasaurus]

Arnoud the previous engine I had (2.0 liter) could go up to 6500 with single springs.
But that was a schleicher 316 cam, maybe because that cam has not so much lift as the 86A.

But good result on the engine, will be a nice driving engine.
Love the riechert cooling.

PS my current engine has also single springs, but they are special ones (oteva) from JPM.
They run 6000 with a 86B cam.

Hi Eddie!

That's odd:the valve springs I used are listed as 98-102Kg,the Oteva's per the CSP website are only 90Kgs?
I wonder what in the listed numbers I dont see that make single 90Kg Oteva's handle a wilder cam whereas heavier spring cant cope with a milder cam?
Thanks for sharing your experiences.

Cheers,Arnoud

As the springs compress, due to the cam lobe's height and angle/shape, pressure via. the spring pressure changes. Higher lift and the spring get stiffer (compresses more), lower lift and the spring (usually) does not go to its (potential) top pressure (based on its design among other things). This is why the springs you get are supposed to match the lobe lift and shape.

Lee

[Bruce.m]

Not an expert but the theory is that when you hit the spring’s resonant frequency they bounce around & lose control. The typical Scat single spring is good to 5.5k apparently, which I didn’t think was really worth it since stock T4 has 5.6k red line? The Scat single is 121lbs closed and 232lbs open @ 0.51”

The JPM spring that CSP sell is lower pressure than a Scat single but presumably has higher resonance? 109lbs closed and 187lbs open @ 0.53”

Stock type 4 is 104lbs closed and 191lbs @ 0.33”

(All those figures are from CSP)

[Ol'fogasaurus]

Not an expert but the theory is that when you hit the spring’s resonant frequency they bounce around & lose control. The typical Scat single spring is good to 5.5k apparently, which I didn’t think was really worth it since stock T4 has 5.6k red line? The Scat single is 121lbs closed and 232lbs open @ 0.51”

The JPM spring that CSP sell is lower pressure than a Scat single but presumably has higher resonance? 109lbs closed and 187lbs open @ 0.53”

Stock type 4 is 104lbs closed and 191lbs @ 0.33”

(All those figures are from CSP)

When the springs are compressed (by the cam lobes and the rest of the assembly) there could be some bouncing around, but I would suspect that the RPMs at that speed probably there isn't time for much of it. When the push rods and parts are at the bottom of the lobe there could be some bouncing around at higher RPMs.

I have not kept up with engine component designs for several years now, but from what I hear and see, things are changing in the cam designs and components about as fast as it did starting roughly in the late '30's/'40's and in the later directions. Which means that there can be... OH YEAH! and AW $HIT out there for sale too.

Materials and designs change quite a bit, say from round springs to flat metal springs and then the combining the two together for instance. The Beehive design has been around for a while but I am not sure for how long ago it got into engine design.

I got talked into a couple of things that, while they did work, it was to where the "brag about them" ended up.

If I remember correctly the flat springs were added to the assembly to stop the bouncing of the springs.

Lee

If I remember correctly the "Beehive springs" are progressive in their action. I did a search and found this: https://www.bing.com/search?q=are+beehi ... de&pc=LCTS

Lee