Serious Concerns Over Parts Availability

[spork2367]

Originally Posted by KJL

This whole thing really struck me when I did some clutch work on my car, after putting it all back together I have an oil leak out of the transmission slip yoke seal which had been replaced. the oil was dripping onto the exhaust which passes directly under it so I had to be fixed. After determining the issue was excessive play due to spline wear, which is very odd for a car with just 24,000 miles on it, I decided to order another one. No-can-do. One of those parts that slowly disappeared from the shelves. With the help of Bill Boudreau (ZFdoc) we found a yoke with the same spline count but was a 1330 so I had to use a 1310/1330 conversion Spicer joint which are also hard to find plus he had to do some machining to the yoke by shortening 30mm so it would fit. Re-sleeving is another option.

Also, why is it so difficult to build aftermarket electronics for these cars? This may be a stupid question but why doesn't GM sell the specs for these devices so they can be reproduced?

Part of the reason these discussions drift to opinion is because there are a lot of owners who are blissfully unaware of actual parts shortages and or what it would cost to have those parts remade.


95% of the transmission is identical between ZR-1s and non, but if you break that 5% part, you're screwed.


Lose one liner due to a piston or ring issue on a 93-95 car and if you can't track down a good used one, you are spending well over 3k for pistons and liners without labor.

No matter what anyone wants to say, there are parts shortages, and some of the repairs would be considered cost prohibitive based on what the cars are worth. If you have a higher mileage driver, that may be worth 12-15k, you really have to love it to spend 4-5k on an engine rebuild. Worse yet, someone hits you from the rear at a red light and the insurance company totals the car. There are used bumper covers around, some take off quarter panels, a few trim pieces. Good luck finding the bumper cover supports that go between the aluminum and the bumper cover. They are ZR-1 specific.

Originally Posted by We Gone

I'll just drive mine until It can't be fixed anymore than sell it for parts and move on! I'm sure I'll be long gone before that happens..

Probably the best way to look at C4s in general!

[A26B]

Re: OE Sleeves & Liners


I have at least 36 NOS Sleeves, more likely closer to 75.
For good used, I have a LOT. Most are 8 cyl sets of low miles take-out sleeve/rod/piston/ring/pin during 368+ engine builds by Doug Rippie & Lingenfelter. I don't really know how many of 90~92 & 93~95, but probably add up to 20+ engine sets. Corey Henderson, Mark Haibeck & Aaron Scott probably have that many more at least, plus more in the hands of individuals.

As far a condition of those take-outs, I would venture 99% are within GM spec. The set from my 60K 94 were within spec.

However, NEW piston rings are essentially extinct, leaving only used ones for repairs. For old school guys like me, rings were never re-used & cylinders re-honed so new rings would "seat" properly. Modern materials & manufacturing such as used in the LT5, have made reuse of "in-spec" rings feasible.

I think it's important to note that most ZR-1 will likely never need to replace sleeves, rods, pistons, rings. Most of what we have sold to customers were for engines damages by catalyst dust backflow (rare & restricted to mostly 1990 models), damage from SPT screws, broken or improperly timed cams and Tensioners not properly re-set.

With normal maintenance, LT5's with 200K+ are known & 125K+ is common. So how many ZR-1 LT5's will ever see that?

It just doesn't take a lot of deep, internal parts to keep these engines in use. Removal of the plenum provides access to the vast majority of LT5 maintenance items.

Quote:

Originally Posted by We Gone View Post
I'll just drive mine until It can't be fixed anymore than sell it for parts and move on! I'm sure I'll be long gone before that happens..

Probably the best way to look at C4s in general!

A very feasible means to take care of the fleet of ZR-1's. It's not going to require a large number of them to do it.

[Dynomite]

Originally Posted by A26B

With normal maintenance, LT5's with 200K+ are known & 125K+ is common. So how many ZR-1 LT5's will ever see that?

One Maintenance item I think about is the Chain Guides wear (and only the two chain guides pushed by the Tensioners). There have been a couple instances (only 2 that I am aware of) of timing chain failure or chain guide failure (still have no clue on what caused the Timing Chain Failures).

Jerry.....what is now your best estimate on Timing Chain guide longevity and replacement?
(I know it depends on Engine Oil and Engine Oil Maintenance for example)

[phrogs]

Originally Posted by spork2367

Good luck finding the bumper cover supports that go between the aluminum and the bumper cover. They are ZR-1 specific.

I have two of them more than happy to sell these unobtainim parts for less than a DIS module.

[A26B]

Originally Posted by Dynomite

One Maintenance item I think about is the Chain Guides wear (and only the two chain guides pushed by the Tensioners). There have been a couple instances (only 2 that I am aware of) of timing chain failure or chain guide failure (still have no clue on what caused the Timing Chain Failures).

Jerry.....what is now your best estimate on Timing Chain guide longevity and replacement?
(I know it depends on Engine Oil and Engine Oil Maintenance for example)

We need to differentiate between the guide & guide facing. Guides, for all practical purpose, don't wear out or break. Insofar as the guide facings, I have enough facings to last another 395 years, based on sales average over the last 5 years. Or, I have 1,975 sets in stock & you can do you own math.

FWIW, I have a good inventory of both new & used guides & there are always used guides available, due primarily to the lack of need.

Guide Facing Longevity: Hard question to answer with so little sales volume to work from. Considering 23+ years of age on less than 7000 ZR-1's, I would say a very long time. I would guess most of my sales are because of the "while I'm in there" syndrome, which I endorse. I've heard of a couple of broken pivot guide facings over the years. However, if guide facings follow the trend of other parts, once they begin to fail in ernest, the frequency of failure will increase, like the fuel pressure regulator.

Timing Chain Failure Causes: A couple that I know of failed due to other parts failing & ultimately damaging the chain; cam cover chain guide screws coming loose (didn't remove before powder coating) This is another part that is done "while I'm in there." I don't get to see a lot of sprockets to judge wear, but only rarely do I ever sell any of the chain sprockets. Worn sprockets usually accompany worn chains.

IWIS manufactures Secondary Timing Chains for us now. I have no concern that they will not be available for the forseeable future. IWIS is a major supplier for cam chains for European automobiles. IWIS chains are pre-stressed to seat the links & pins, just like the OE chains are. They have a slightly heavier side bar and still fit the OEM sprockets perfectly. We have had them installed in 2 3 exotic LT5 racing engines, turning upwards of 8500 rpm. in racing events.

[spork2367]

Originally Posted by phrogs

I have two of them more than happy to sell these unobtainim parts for less than a DIS module.

They aren't unobtanium, they are just extremely difficult to find. I have one spare set I picked up not too long ago.

But for someone it will be about knowing where to find one when they really need it. We know a lot of these parts are out there. As long as there is a forum like this, we have a good medium to locate a lot of them.

Hopefully the DIS craze goes away when Jerry gets his released.

[rkreigh]

I'm confused why everyone wants to rip out the lt5 when it's some of the electronics that are rare. Jerry is working on the DIS and as soon as some one needs one let me know.


I'll sell you mine and use the money for putting a megasquirt on it. coil on plug is WAY better than coil packs and the megasquirt offers a very affordable option to the unobtanium DIS parts. keep in mind there are 7000 of these made and they rarely fail. by the time they do Jerry is likely to have completed a solution. GM isn't going to share tech data guys, they won't even give out dyno sheets for goodness sake so that's not going to happen. And as Jerry will attest, reverse engineering is very hard work.


Overall the lt5 is an anvil, I just put 106k on mine, and if I hadn't lost a hose and run the car hot so often (ac), the head gasket would not have failed.

these are 200k plus engines, just not that many people run them enough to find that out

I used to worry about the hard parts like main bearings, and the stock rings are not to be found. But if you want to keep the lt5 stock, the take out parts are available from folks that updated to 4 inch liners. those stock parts are pretty good and I think we are too quick to discard them.


I had the stock crank, bearings, and rotating assembly with liners and matched pistons and basically couldn't give it away a few years back. Look at how long the liners and pistons stayed at auction because the bid didn't meet reserve at the NCM!!!

yes, there are many parts that can be tough to get, but gents like Jerry and many talented folks step up to address that. In the age of 3d printing and modern electronics, with a bit of work, the old gal can be updated to use the new stuff. racers do it all the time and it's really not as hard as some would think.


we have the technology to keep the beast alive despite the challenges as long as there is a desire and some $ to do so.

[Hog]

From a performance perspective: The advantages of Coil Near Plug (CNP) over a single coil system as used on the GEN-II LT1/4 can be marked. The advantages over a multicoil system such as is used on the 90-95 DOHC LT5 are much less, the plug wires are a lot shorter.

Much of anything fun comes down to money. Sometimes it takes more than average to overcome the will of some to hold onto "rare" components. I'd love to see how many SLP T-Rams are actually installed on cars compared to the number that are hid away somewhere for bragging rights alone.
I was disgusted to see Ferrari V-12 cam blanks for some disgustingly low price. The guy had hundreds of them. Different story for our LT5s, though the custom ones that are available are pure engine porn.

[rkreigh]

no doubt the factory ignition works great until it doesn't the DIS is going for stooopid money just like thermostat housings and other odds and ends


I've set myself out to wear out as many of these parts as possible rather than worry about getting them.


I haven't had any serious worries and always able to work around the issue at hand


I'd worry more about not using the car


life is too short not to

[KJL]

Are the ECMs, DIS and CDMs interchangeable between model years? That would be helpful info to have. What would happen if I plugged my 95 ECM into my 92? Or are they split between 90-93 and 93-95?