The shop I use for balancing wasn't too impressed with the balance of Skat cranks.
-Chris

Same here. FYI, my scat crank for my '66 912 was *way* out of balance, out of the box. Carrillos were right on. Crank was the STD weight, not the ultralight. All of the heavy metal came off the rear-most counterweight.

before
http://www.lnengineering.com/balancebefore.jpg

after
http://www.lnengineering.com/balanceafter.jpg

Thanks to all who provided the GREAT information in this thread!
I just read the whole thread, and learned much!

Another great debate.

No, no debate when there is a right way and wrong way....

There is right way. THere is NO wrong way.

as long as it is..........ballanced . That would be the right way.

correct

Early in this thread, someone (maybe Henry) said that they didn't know the grit of a red Scotch-Brite. I've used them for 20 years in autobody and while there is no official grit rating for
Scotch-Brites, the red is very close to 400 wet sanding. It will be a bit coarser if you press really hard, especially wet. The gray is very close to 1000 grit, green is more like 280-320, and white has virtually no abrasive effect at all, we mostly use them for cleaning overspray off of glass. They only seem to dull, not really scratch glossy paint, they will scratch soft aluminum a little bit.
Thanks for another great thread guys, it's nice to learn the easy way for a change.

All is in balance, all in harmony, all is well.

Of course there's a debate. An age old debate about style and craftsmanship.
The debate is in the craft.
How a job is performed determines that art, the style and the craftsmanship.

Supertec engines have the craftsmanship that reflex Henry's side of the debate.

Yeh, but I bet they break more than they should.

Knowing what your doing does make a difference.

My engines do not break, even if moderately abused. Others just make excuses. Craftsmanship is a given, but knowledge is key. I measure and verify 100% of every single parameter of every component, and the entire assembly. I use what is considered the BEST, not by hearsay, by by real engineers in the field. I verify what they say, I double check their data, I call and talk to every competitor to verify that what I have chosen is the best available. I analyze the data given to me. Does it really make sense, does it check out with what the manufacturer states. I do not go by what others say, but by my own analysis. So far I have not been wrong. If you want a Porsche engine that will turn over 8500RPM and not break, talk to me. That’s turn 8500RPM all day long, not just in spurts. I do not make engines for sale, so I do not have anything to gain. I will soon have the ability to present 100% dyno testing, at the crank, results of the engines. I will share all this info, no cost. TO date I have had to live with rear wheel dyno testing. Not bad, but subject to some interpretation’s If it isn’t dynoed, it isn’t real.
.

Craftsmanship is never a given !!

I'll bite! I'm willing to learn, show me.
Please post the engine specs and pictures of the 911 engine you built that turns 8500 RPM all day.
This is after all a 911 engine rebuilding forum and yet you don't really seem to understand specific 911 engine characteristics.

I have noticed that you refuse to answer even the simplest request.
Which machinist believes as you do about the 20 gram issue as it pertains to Porsche rods?
Let's see that engineering degree?
If you've ever rebuilt a 911 engine, let's see it, or at least tell us about it.
If Carrillo rods are used in FI, which team?
If you use a bolt welded to a wrist pin, how did it effect the hardening of the pin?
If you weld a bolt to a wrist pin, do you have to reuse it when new pistons are installed?
How many Nikasil cylinders have you honed with a flex hone and what did the rings look like after 20K miles?

I can back up what I say with experience.

Those who know build, those who want-a-be bloviate.

Bloviate:To speak or discourse at length in a pompous or boastful manner.

Way to stay on topic!

Cheers

You weld a nut or bolt to a wrist pin by finding a nut or bolt the just fits inside the hole, a light press fit. The nut or bolt is inside the wrist pin, not on the end of it. Then using a TIG welder with a very fine point you weld the nut in several places, at the tips of the hex, to the wrist pin. Just enough so it can't get loose. The heat is isolated to tiny spots on the very end of the wrist pin. Since the pin still fits and slides freely all the way thru the piston and rod, its pretty safe to assume no damage was done to it. 95% of the pin never gets much more than warm. I picked up the pin by the other end with my bare hand, didn't get burned. So the heat treat is not affected in any way that would cause a problem. New pistons come with wrist pins so a unique pin is not a problem. The purpose was to match a single very light piston plus wrist pin to the rest of the piston + WPs that were all heavy. IE take 10 grams ea off 7 pistons (or out of the inside of the wrist pins) or add 10 grams to one piston by putting the weight inside the wrist pin.

I have a 911 engine I recently finished in my garage, I even have some pictures of it apart, somewhere. If I come across them I will post them. This particular engine I had metal improvement company shotpeen the crank, the rods, rockers, head bolts. I had also micropolished the crank. I balanced the crank and rods, pistons, and flywheel, pressure plate, clutch all to less than one gram (the scale is digital so its automatically +/- last digit, 0.5 gram). I know I have posted pictures of the scale and crank balancing equipment before. I also rehoned the cylinders (steel ones) with the Sunnen hone. I machined the case and put timeserts in everywhere. To clarify I DID 100% of this work (except the shot peening) myself, no outside machine shop did it for me.

So you watch ORilley too. Thats a plus.

I have not refused to answer, but why should I?

Snow man, I'm curious, how many 911 engines have you built?
Thanks.

Only 5 911 engines, but all race engines. Overall I have build about 35 engines, of all several types, again all out race engines. I have only built about an additional 15 "stock" rebuilds, mostly when I was in my teens and early twenties and couldn't afford race parts. A race engine is an engine that you build and rebuild 15 or 20 times each because you have to to check all the tolerances and interference problems. So about 35,000, hours devoted to race engines, plus another 20,000 hours learning about race enbines.

Ask Henry how many "real" all out race engines he has built. He has probably built a zillion regular Porsche engines, but they are not all out no bucks spared race engines that take a 1000 hours to build each and bo ko bucks. Stock engines are doing what the manual tells you to do, plus a little extra hands on learning, Not really very educational in terms of racing.Its interesting that an all out Porsche race engine has almost no Porsche parts in it and the ones that it does have are heavily modified. Same for Chevy, a Chevy race engine has almost no chevy parts in it, maybe a highly modified Bowtie block and that’s it. For example in both engines, custom rods, custom pistons, modified crank and journals, even to the point of stroke, journal size, ring size, tension, rods, valves, valve springs, retainers, rockers, porting, oiling, and on and on. An all out race engine is an year long project, and you can't count the dollars. The 8500 rpm engine I referred to is the best normal mortals like me can do, the next 500 rpm is in the realm of the guys with pointed hats and even more dollars than you can count. But that’s the realm of the big time racers with a staff of 10 to 20 people, several engineers. My reading of Henry is that he makes 7500rpm engines for weekend racers using nearly stock parts. These engines are about 5 times cheaper than an 8500 rpm engine and god knows how much cheaper than a 9000 rpm engine. The F1 guys are an order of magnitude over this level. If BMW says they can't afford it, and they have in the past, its a LOT of money.

TO clarify I suspect that Henrys "race" engines cost about $25k to $30K ea. For a real race engine your looking at 1000 plus hours at about $85 per hour, plus $15k (wholesale) in parts. That’s about $125K in round numbers. Disagree with this, Henry??? I hope not cause thats what the racers state they are spending (clearly not weekend racers). How many $100 K engines have you done?

I don't know how to answer snowmans question without bragging or perpetuating a pissing contest.
So I'll honor Waynes' request and pass.

Cheers

55,000 hours rebuilding engines? That's 27 years full time. hmmm.

Thats correct but over a 40 year period, but I also just received Waynes request, so end of thread.

5?

At the risk of this all getting off course again and the fact that I don't want to post a topic that has been hashed over this much I shall ask a question related to the topic. I have to ask nice as Henry currently has my heads :) . Could someone post a picture of what a deglazed cylinder looks like. There is a very good picture of one before the process and the ones on the test bench have a hand in them so it is hard to see. My cylinders look typlical for the pre-glazed but would like to know how they should look after. I am using scotch brite pads but they are fine grit. I bought red ones but there must be different red ones. I am trying to figure out if I should go buy medium ones. The fine grit removed the oil coating at the base of the cylinder where the piston skirts sit but the very bottom of the cylinder is still rougher than the part where the piston runs. Should it all look the same when completed or will the area where the piston runs still be smoother and be darker.

I used Henry's method with the red ScotchBrite (7337?) pads. I believe they say "Medium" grit.
Goetze rings seated quickly , motor has done about 4k miles since back in service.
I don't exactly have a high end camera to really see the cylinder walls. Only 3 megapixel but maybe this helps?
http://forums.pelicanparts.com/uploa...1165677489.jpg
http://forums.pelicanparts.com/uploa...1165677500.jpg

Dfink,
The term de-glaze referes to the finish that is on the inner surface of the cylinder bore. If it is glazed it looks very shiny (like freshly glazed and fired pottery) and will not cause a new set of rings to seat because of the lack of an abrasive surface. To de-glaze is to roughen up this glossy surface (the topic of this thread) so that there is a set amount of roughness that will help the rings wear in or "seat". This creats a propper seal between the rings, pistons, and cylinder walls.

Sorry if too spelled out, didnt want to leave holes in the answer.

No thats fine. I understand what deglazing is but never with this type of cylinder. With the old V-8 we always honed the cylinder and they came out looking like new the entire surface. It seems with the nikasil you will not get an entirely new looking surface using scotch brite. So I was just wonder how it is supposed to look with this method and if I achieved that with the veryfine grade I bought as opposed to the medium grade. I think mine are probably fine. It has been stated that the scotch brite is not hard enough to actually roughen the surface so I assume all we are really doing is giving it a super good cleaning with the scotchbrite. If I am wrong on this and the medium scotchbrite will actually roughen the surface then I will go out and buy the medium and redo them all.

The purpose of the ScotchBrite is to clean the oil deposits (glaze) from the existing cross hatch in the Nikasil. If your cylinders have no cross hatch left in them (usually 100K miles+) then the cylinders will need to be honed. I recommend having this done professionally with a diamond hone. This will give you the best chance for success.

Remember that honing will remove a small amount of material so check the freshly hones cylinders for consistency and size.
If your pistons were undersized before honing will only make it worse.

They have a really nice cross hatch left. I am pretty sure that even with the fine scotch brite I have them ready to go. I will see if I can get a good picture of the cylinder at the bottom of the cylinder where it is easy to see the difference between the last inch that has never seen wear and the rest of the cylinder. There is now less of a difference since using the scotch brite and soap. I don't think the entire cylinder will every look like that last inch without re-honeing.
Also this may be a good spot to ask this.
Should I leave the cylinders dry or coat with oil. My first feeling is that they should be coated but some have suggested leave them dry to break in the rings. Dry just worries me a bit....

As long as the cylinders are true, it should be possible to do a light hone, just enough to scuff things up, say .0002", but the key is to do it with proper equipment and diamond stones like Henry said. There is no need to coat the bores with oil for storage reasons. It's up to you for assembly - I have seen it both ways - a light rub down of non-detergent non-synthetic oil or a spray of wd-40 on the bores.

OK here are a couple pictures of my cylinders after cleaning. I don't think I want to hone them but do they need more cleaning with the scotch brite. I know it is hard to tell from pictures. I see in the pictures you can see the oil that has gotten into the cylinder from storing the piston in there so maybe not such good examples. The light from the flash really show this. You can't see that normally.

This one show all the way down you can see the ring marks at the top of the piston.

http://forums.pelicanparts.com/uploa...1165792203.jpg

This one (maybe) shows the contrast between the bottom never worn and regular wear areas.

http://forums.pelicanparts.com/uploa...1165792263.jpg

I will suggest it again. The grape style hone. Removes nothing but will put the required scratches back into whatever you are using. Cleans much quicker and better than scotch brite pads and puts some new scratches in the tube for the new rings. T he silicon carbide material is not as hard as diamond but its hard nuff to do the job.

But first you must check dimensions. If its out of round and worn you may need new stuff to fix it.

A picture's worth a 1000 words. Grape or bottle brush hone is too rough by it's self. High ra numbers produce premature ring wear.
104,000 miles
http://forums.pelicanparts.com/uploa...1085762194.jpg

New
http://forums.pelicanparts.com/uploa...1085762209.jpg

Used cylinder honed (grape hone) as per manufacturers instuctions.
http://forums.pelicanparts.com/uploa...1085764857.jpg

I love these threads, were people at all levels offer their oppinions and share their expertise.

Just to add a bit more fuel to the fire and this comes from my experience with BMW cars and bikes.

Nikasil has a Nickel matrix which is fairly hard and ductile, with
about 4% of rather small ~4 micron size Silicon Carbide particles, which in essence is the medium that retains the lubrication in the cylinder.

Now, two other bits of information. The Nikasil coating is normally about .07mm thick or .0025" to .003" and here is the kicker; It is affected by high sulfur content fuels....this is somewhat ofset by increasing the combustion temperatures. Do you all remember the first BMW V8 engines, yes the ones that the Nikasil coating was peeling off.....

So, my experience has been to leave the cylinder surface basically alone, just touch it up with water and Scotch-Brite in the direction of piston movement.

Like it was mentioned before, I'm not trying to convince anyone, just sharing my experience.

I really don't want to stir up the hone don't hone debate. I am not going to hone as I don't own one and I am not going to buy one. I am just wondering if the pictures look like I have done enough or do I still need to perform some more cleaning with a medium pad instead of the fine pad I used. I seem to having trouble locating the red medium pad locally.

Henry, which grit did you use? the grapes come in several grades.

It has been many years since the hone was purchased but I believe it was a 320.
We used the hone recommended by the manufacturer and the honing oil supplied with the hone.

Don't get me wrong, it worked. It gave us a very nice finish and the rings seated well.
It was not until the freshen up that we noticed the excessive ring wear. On the first engine we blamed the oil and the break-in process. The more we saw this phenomena the more we started to understand that the problem was the cylinder surface. After measuring the RA it all began to make sense.
What I am reporting is not written in a book, is not a theory or a wild a** guess. Short ring life as described has been observed over and over again.

--

Its sort of strange as the same process produces longer ring life on many Iron block applications. Are you using moly or chrome rings? I also noted that differen't ring manufacturers specify differen't finish requirements for their rings. I use chrome rings and haven't noticed a difference. But then again chrome rings are usually hard to break in. Moly is soft and breaks in easily. In any case I go with the ring manufactuers specs for their rings.

It could be that the extreemly hard surface in the cylinder dosen't comply easily with the normal ring seating specs and as a result the "normal" ring specs are wrong. The manufacuturer is not going to address this in any case because they want you to buy a new matching set of cylinders and pistons.

How did you determine that there was excessive ring wear? I usually find that the piston land is worn out, much more than the ring itself.

Different materials have different specs.
RA ratings for cast iron cylinders is quite often around 18-20.

We generally use Goetze rings, OE for Mahle Nikasil cylinders.
We also ran Hastings rings and experienced slightly better wear characteristics.

We measured ring gaps to detect ring wear.
Rings gapped between .017-.020" measured .040 to .60 after 15 -20 hours of racing.
Cylinders starting with a correct RA number show less than .005 wear with the same engine hours.

In street engines we see far less ring wear. If an engine is going to see 150K or more which is quite often the case with our rebuilds controlling this initial wear is critical.

Does anyone have a good picture of what a good clean un-honed cylinder should look like. One that has had the scotch brite cleaning.

I certainly don't have Henry's expertise, specially regarding Porsche engines, however, I do agree that with Nikasil cylinders the ring end gap over time in use will give you a good read on the initial condition of the cylinder surface.

Now, can we dig up more information on the subject matter from those out there that have re-ringed Nikasil cylinders?

Actually the thought behind the Nikasil cylinders, in racing that is, was that by making the cylinder surface very hard and the rings the wearable component one could maximize the life of an expensive component and expedite the rebuilding process.

Just picture droping a race engine, popping the jugs and droping a new set of rings (of course, assuming that the short block wasn't damaged), having a new set of heads ready and voila you had yourself a new race engine....

So, we know that a profilometer reading of ~5 RA is what new cylinders come with and ~ 3 RA is what used cylinders measure. So the question becomes, what can be done to used cylinders to bring them to~ 5 RA.

Anyone out there care to chime in....

Well im now faced with this same dilema again, I rebuilt my 3.2 with 140k on the clock last year. The cylinders specked out and had good cross hatch left so I did the scotch brite thingy. This engine as run about 150 miles then got removed for the car to go for a bare metal respray and the engine is now in bits to be converted to a 3.0 MFI engine. Ive examined the piston rings on tear down and it looks to me like the rings failed to seat. The cylinder walls are now very shiny with very little hatch left and the top ring is showing that only about the lower 40% was in contact with the cylinder wall and the lower ring probably only about 10-20% is showing any signs of wear. Is it simply that 150miles isnt enough to make the rings fully contact or has something gone wrong? Engine seemed to run good with no smoke when hot.

Im pretty convinced that these cylinders will need to be re-honed if not re plated. My question is this theres much debate about what if any honing should be used however it obvious that after the cylinder plating is done by the manufacturer they must use some sort of honing process to give there recommended RA, so what are the manufacturers using and why carnt this be used?


Steve