blown 87

What is that old saying, those who turn their swords in to plows are destined to plow for those that did not.

Sorry to have turned this in the wrong direction, but every time I think of places like CA, IL, NY and others I think about gun rights.

I am done with the gun part of this thread, you folks carry on with it if you like.

tlsmith1999

LT1 conversion

928mac

I am not worried about it.
It is a simple gog belt pulley that I can have built here in town.
Our machine shop at work has some of the best people and equipment in North America if not the world.
One of our best machinists at work here said he could build these in his sleep at his home where he has a CNC milling and lath.
I will talk to him more later today and see what it would cost to run off 50 or so of these.

soooo

Would steel be a issue? And why? Cost would be way less.
If it is, then the other choice would be Titanium.
The cost of that would be about 4 times as much

I will only persue this if we really need to.
It is close to Christmas and time and money are short.

FYI

Brad

Cosmo Kramer

If your cam gears are still OK why not do what MrLexse and AO did?

Buy a cheap toaster oven and do it yourself.

https://rennlist.com/forums/2568761-post4.html

Landseer

I bookmarked it!
Its an answer for the proactive amongst us.

Cosmo Kramer

If you are curious as to how tough the DFL-1 coating is, check this thread out.

Rod bearings coated with DFL-1 on a 500 hp twin turbo V6 were pulled and inspected after 20000 miles. No wear.

http://www.techlineforum.com/viewtopic.php?f=10&t=114

Whitesands

The ones on my engine were coated by,
www.finishlinecoatings.com
I bought them through a Rennlister, they've only been on a short while so don't know how they will hold up.

928mac

The machinest will come by my house friday to take a look at the gear and see if his machine with cut that style of tooth.
He said that if his wont then he knows one that will.
Off the top of his head, for one gear it may cost $300
of course the price will go down with a bulk run of gears.

I will talk to him friday about the difference in metal that can be used and the difference in cost.

Brad

Gregg K

I don't like chiming in on subjects like this, even if I am a mechanical engineer and machinist. I don't know the factors involved. But it does seem like a fairly simple problem. The only two things that have any degree of difficulty are the tooth profiles and the material of the gear and tooth surfaces. It's either broached, or milled on a horizontal type setup with a cutter that has the tooth profile. And either an index head, or a cnc. I guess indexing heads are like horse and buggy now. But I could pull this off in my garage here, except for any surface treatment. I doubt there are harmonic vibrations that have any constraints on the design. And the forces are probably within the range for the application of the belt drive system, or it wouldn't have been used in the first place.

I find it odd that this gear is no longer being made. If anyone wants to find a machinist who would be happy to do it, I can almost guarantee that submitting a post over at www.practicalmachinist.com would not only yield a quick result, but a whole host of engineering ideas and precautions. That's the place to go for this, in my opinion.

928mac

Thanks Greg,

I was hoping someone else would chime in.
I am not a machinist but just down the hall from me are lots of mechanical engineers (I'm a automotive engineer and mechanic) and they say that it should not be a issue and agree with me.
But as you also said it will depend on the profile of the tooth and thats why the machinist is going to come over and inspect my gears to check the profile.
It will still be do-able but will affect the cost.

Gregg K

The tooth profile is a standard. Since Gates makes a belt for it, finding that profile is simple. But as mechanics, we know nothing is ever simple.

If all fails, someone should be able to find Porsche engineering papers on the gear profile. No doubt it's a metric or DIN (I've forgotten everything, din?) specification. I have the Porsche of milling machines (Deckel). And when I rebuilt that machine, I discovered all kinds of interesting specifications. You think Porsche's are fun to work on. Try finding a metric taper pin with metric threads for attaching to a metric slide hammer.

GregBBRD

That sounds pretty much like people are low on inventory.

SSF confirmed that they are NLA...but they also have 16 on order (for me). It will be interesting to see what happens.

Imo000

I have a spare set of 32V pullies. My father has a gear cutting shop, if he can't make it (might not have the right machine or cutter for it) he should knwo someone else that can. I'll ask him next time i see him. Making gears in not cheap, even if it's done in a CNC.

sweet928

1. When are these usually checked / replaced?
2. Is it with the TB job? Should I buy a set now for my OB just in case?
3. Can they be checked easily to determine condition?

Ethre

1) replaced when they start to show wear. Maybe ~40k miles?
2) easily done at the same time
3) Feel them for rough points. If they edges are sharplike, they' will kill the belt eventually. Visual inspections work pretty well (if it looks off, it probably is). Shiny points indicate the coating is going and it will need replacement soon.

You're gear is a different gear though (square tooth). Its been NLA for longer. Currently your only option is to buy a used one.
I was looking at ways to get these produced, but have gotten very busy recently. I'll get back to looking at that in the future. They've got a very odd profile tooth relative to other gears.