CNC Billet Steel Cam - Jurgen Nowak

[txoval]

78.8mm Scat 4340 crank
92mm Super Squish pistons (if doing over would just go with flat tops)

2095cc

Tims Stage 2 heads, 45mm Dells, 9.8CR…should have gone higher, but went conservative due to clearances with domed pistons.

Scat Forged 1.25 ratio rockers…ended up with .515” valve lift

1-5/8 A-1 merged header/race muffler.

Pulls hard from 2500-7000…Jurgen will insist on using Thorsten Pieper lifters

[cmaxcliff]

Do VW engines have a tendency to break cast camshafts? Porsches do sometimes and the racers have many theories as to why. The solution was to have steel cams made but the first attempt failed because the lobes wore because the wrong steel was used. That steel required that it be surfaced hardened after grinding but that wasn't done. Tool steel was the solution because the surface is still hard after grinding. It is also a good idea to DLC the lifters to avoid wear.

The 356 uses Type 1 straight cut gears and I have used a few different types. In 14 years I have had 2 cast cams break and both times were with the gear pictured. Further comparison against 2 other types shows that this gear weighs twice as much as the others. I haven't checked the balance but I wouldn't be surprised if it is out of balance.

[Olli from NJ]

txoval,

Thank you. I have a nice new set of Thorsten Pieper lifters just waiting to go into an engine.

I sent Jurgen an e-mail this morning asking if he would send me some cam specs. on the JN15,JN5 and the JN6.

Olli

[58 Plastic Tub]

[txoval]

JN6

Total Duration: 306
LSA: 108
Lift at cam: .417
Duration at .050: 288
Lift with 1.1:1: .459
Lift with 1.3:1: .543

If you want more strip than street...go with the JN4

He has some split duration race cams as well

[cmaxcliff]

Do VW cast cams have any tendency to break in extreme use?

Is that why some people use steel cams or is there a different reason?

[txoval]

I have never heard of them breaking or having a tendency.

[Alstrup]

[58 Plastic Tub]

[txoval]

I looked at the wrong column on the spreadsheet

261 at .050

288 at .020

237 at .100

136 at .300

[txoval]

JN5

312 total

296 at .020
258 at .050
226 at .100
120 at .300

[58 Plastic Tub]

Thanks.

Looks like the JN6 has faster ramps, but they still look a bit slower (45 deg difference between advertised and .050" duration) than the cams everybody likes (86b, etc.). An 86b has 38 deg difference between advertised and .050" duration, it's 54 deg on the JN5. Deviations like that always make me perk up -- they're curious to me.

... but I know just enough to be dangerous. I'm interested in some real-world feedback, and you gave us some on the JN5.
_________________
Stan Galat
"A single point in isolation is a reference point. Two points is a line. Three points is a trend. Trends don't lie."

[Alstrup]

[Olli from NJ]

I sent Nowak an e-mail yesterday asking for cam specs. No response yet.

Alstrup, any more information that you can share about the Nowak cams.

I am right now planning a 2332 (street engine for a Thing) looking for strong mid-range and hard pull to 6K ish. 44 Webers, 42X37 smallish port heads from PDP. 9.2-9.5:1 Looking at Engle K8, FK44, Web 86B, 533,

Olli

[cmaxcliff]

I really didn't have the full picture about cams until I took a selection of over 10 street and race cams to be checked by a Cam Doctor. The peak acceleration variation is between cams is eye opening and the high numbers may make power but they wear out or break parts.

[txoval]

His cams are precise…no variation between lobes and numbers match as advertised.

Per his sheet, the JN5 and JN6 can be used with single HD springs. Oteva or just the outer VW650 spring

[Wreck]

I'm running a JN4 about 274degree@ 0.050" ,0.550" lift with 1.3 rockers . pulls hard to my limiter at 7200 . single beehives 48mm valve .

I second that they are very accurate . Jurgen will also customise cams to what you want .

So far about 9000km daily driving , using TP lifters that have seen 2 other cams and have about 50000km on them .

[58 Plastic Tub]

Thanks for the testimonials. I very much like the idea of a tool steel cam/lifter combo, as I've had 3 cams go flat or pit on me now.

It's mostly the profiles that give me a bit of pause. I know they're accurate, and I know why they have such gentle ramps... but I also know that more aggressive ramps make power earlier. I drive the car, but not like a daily driver. I want stuff to last, but I've never had more than 20,000 miles on any T1 before I tore it down and tried something else. My car is not an airplane, so I'd rather err on the side of power now, than the Gene Berg/Bob Hoover "it'll never last 100,000 miles if you don't run an easy cam with 7:1 compression".

There's a sweet-spot between having a time-bomb in the back end and having something lazy. Maybe (for sure?) I'm getting old, but while these cams really intrigue me, I kinda' wish he had something closer to a more conventional profile.
_________________
Stan Galat
"A single point in isolation is a reference point. Two points is a line. Three points is a trend. Trends don't lie."

[H2OSB]

[txoval]

He has at least two "all out performance cams"

Want me to email you the spreadsheet? The JN4 that Wreck posted seems to fit your description as well