3rd Anniversary of no valve adjustments- It's not Hydro!

[MASSIVE TYPE IV]

NOTE: EVERYTHING YOU ARE ABOUT TO READ WAS DONE BY A PROFESSIONAL SEEKING INFORMATION, IN NO WAY SHOULD THIS PROFESSIONAL'S ACTIONS PROMOTE THE GENERAL PUBLIC TO DO THE SAME! I do not care if I waste the engine- I am gaining information! I know the symptoms of tight/loose valves by ear and feel, if you do not- DON'T ATTEMPT THIS!

As of February 10th I went 3 solid years without adjusting a single valve in my 912E engine!

For those of you that do not know the history behind the engine in my primary daily driver- I'll give you a run down.

August 7, 2002- completed assembly and dyno tuning of a 2056 "E" spec engine built primarily from used parts for the 912E, the engine dynoed at 125HP and 135 lb/ft of torque. The only new parts that were used were valves, seats, guides, camshaft, lifters and bearings- vereything else came from a blown test engine from a few months prior.

ALL ENGINE PARTS WERE CRYOGENICALLY ENHANCED!

Engine was installed into my 912E 3 days later. Valve adjustment was checked as standard operating procedure when the engine was removed from the dyno and two valves needed adjustment (#1 intake and #4 exhaust)

Fast Forward to Feb 2003 as I prepared the car for a Porsche Club driver's Ed event I decided to check the valve clearances. By this point I had driven the car, with that engine 9,000 miles according to my log book.
When the valves were checked I found one that was a tad tight, the number 2 exhaust valve- I adjusted it and drove 5 hours to the PCA event where I put 200 ROAD COURSE miles on the car over the weekend, many times with the engine past redline and even with the oil light on! ( I didn't care if I killed it)

I drove home 5 hours and drove the car another 5,000 miles before another oil service (testing different synthetic oils) at which time I checked the valves- they were spot on!

Fast forward over the span of 2.5 years.... I drove the car near everyday and purposely ran it without changing the oil for over 10K miles at a time, one time for as much as 18K miles when using my favorite oil- Royal Purple full synthetic. Since the engine was so reliable and never needed attention I seldom even checked the oil, but when it was changed I'd pop off the valve covers and just check the valve clearances by feel- always spot on, right at zero lash where I put them!

By this time (September 2005) I had logged 88K miles on the engine since it was installed and figured it needed a very good service before Len and I took it on an 1800 mile trek to the SCCA Run Offs to help our racers out. At this point I reviewed the logs and then checked the valve guides, did a leak down, did a compression chack and a few more things. The valves were still left untouched!

Now, 3 days ago the engine just logged it's 96,000th mile and had went 3 years and a few days without a single valve being adjusted- mind you this was an engine built primarily with used parts, that was not super blueprinted. It was built "Old school" by feel 100%- I don't think I measured anything but the piston/skirt clearances and the deck height!

So, whats the moral of this story?

* Setting your valves at zero lash with chromoly pushrods is acceptable for thousands of miles of use, despite what you may *hear*.

* An engine that is not ran with CHT more than 375 degrees does not see issues that promote more frequent valve adjustments

**** I feel that this feat was made possible ENTIRELY by the cryogenic enhancement of all the valvetrain components. The cryo stress relieved the components prior to assembly/adjustment as well as helped the components to have controlled expansion/contraction cycles, thus allowing the valvetrain to stay adjusted perfectly for almost 90,000 miles through purpose neglect and abuse.

Without Cryogenics this would have never been possible.

[R2.0]

Question on pushrods: Cryo before or after cut to length?

I would think after, since the whole point is stress relief and cutting/fitting induces stress. However, that would make offering a "Cryo'd Valvetrain Kit" almost impossible - the user would have to send the pushrods back to you after fit up, which would put a big halt to the engine build process.

R2.0

[MASSIVE TYPE IV]

Mine were done before... The stress relieving is just one benefit, it's superceded by the more controlled expansion rates and contraction rates as well.

I do not sell any components that have been cryoed, other than lifters.. This is because the process adds a ton of time to orders and complicates retail sales to the point where we have to charge way too much for the components- Just like coated bearings and pistons.

BUt Cryo is a standard for my engines!

I am looking into building a cryo chamber here and processing my parts in house, if that happens it will save a ton of hassles. The guys I work with at www.percryo.com have said they'll set me up 100% and share the profiles we created with them for the deep cycling work (-275F) so the transition would not be painful like starting from scratch.

[67 newbie]

Jake,

We used those guys for some cutting blades here at work, per your recommendation, while it did not benefit us enough to justify the cost I must say those guys were great to work with. They were very informative and extremely knowledgable. I can see why you use them, their website has a good bit of info as well.

Glad to see the great results, are you using the stock cooling system?

[MASSIVE TYPE IV]

Yes its stock cooled. The EFI upgrade keeps the heads 60 degrees cooler than the carbs did!

How much longer did your tooling last than non cryoed? what differences did you see?

I have most of mine done, hell they even cryo my rifle barrels!

[Ephry73]

That is amazing ! WOW.....Jake, Are you at least checking the valve lash? Or did I miss that?


E

[MASSIVE TYPE IV]

Ummn, checking the lash IS checking the valves...

When you run zero lash it's easy. If the pushrod spins, but the rocker doesn't "Rock" you are there!

[67 newbie]

Unfortunatley we saw no differences at all.

These "blades" are about 10lbs each. there are 20 attached to an arbor and 8 stationary. 4 on each side. We feed in seat fabric scrap and grind it up. The arbor is turning at tremendous speed (I have never bothered to take the pulley ratios and work it out, but I believe it to be in excess of 5000 rpm), we even pump air into the bearing housings for cooling.

Now since we did this testing almost 2 years ago, we have upgraded many things because heat was killing the blade life. It would be interesting to see if anything has changed.

We now use a proprietary coating that actually draws on the carbon in the D2 tool steel. It makes the blades very very hard, an unfortunate side effect is that instead of the blades wearing, it creates chips in the blades. But even where the chips are the face is still sharp. In this particular application it seems that we need the blades to be as hard as possible, balancing that with brittleness.

[67 newbie]

The EFI had a huge impact on the temps, I guess it all goes back to a tuned effecient engine, makes all the difference.

[MASSIVE TYPE IV]

Look into DLC coating.... It imbeds in the material and is just as hard as a diamond, but not brittle at all.. we have used it on valves and reduced stem/ guide wear to near zero...

BUT its VERY expensive.....

Yes, the EFI made a huge difference in my engine, temps were the biggest- In the past I ran head temps of 325 al the time, now I run 275.

[Santas Brother]

We testing Cryo treatment on some Carbide cutters
at the last place I worked.

Life increased,but the % improvement matched the
increase in cost,so the net gain was minimal.

Factor in extra hassles for inventory,shipping,etc,we didn't bother.
But it did work.

[tallqball]

What type of lifters are in the 912E? Ceramic or??

I'm one of the many that lost a cam. In this case it was an original. I rebuilt a 100K mile engine, and was advised to stick with the stock cam because it still had stock EFI (couldn't afford the carbs yet).

The engine had been apart before me, so it is possible the lifters were not where they belonged. I got about 30K miles out of the rebuild before it was just not fun to drive.

[Can Drive Soon]

Very impressive..

[MASSIVE TYPE IV]

The lifters in the 912E are Johnsons.. When I built this engine, ceramics were not yet developed for the TIV.
If I were building it again it would get Ceramics- No doubt.

I'm slowing putting together a 2270 for the car, it is also built pretty much from used parts as well-

[Bruce2]

I've been doing the same thing with my engine, but for the last 5 years now. Zero lash with steel pushrods in cryo'd lifters and cam. No valve adjustments in the last 5 years.
Coincidentally, I also used percryo.com