NOS Exhaust Pipes vs Reproduction

[Sheldon S.]

I have a 1971 454 auto car that i am restoring. I now have complete set of NOS pipes for the car, and only repo mufflers. The pipes are only the service replacement type that clamp onto the mufflers. Gardeners Exhaust is now making the correct style of exhaust for this car as I have just provided them with the pipe so they can reproduce them. They will be the correct style with the pipes welded to the mufflers.
Will I either gain or lose points by using the NOS pipes with clamp on mufflers vs using the correct style of repo system. Also is the sound different with the original pipes due to the double wall? I am not sure which way to go. Like to hear your comments!!
Thanks
Sheldon

[Harmon C.]

Re: NOS Exhaust Pipes vs Reproduction

Until a reproduction exhaust system is made and the judges get a chance to check it out and find as many little or big mistakes made I don't think their is an answer to your question. If you provided NOS pipes thats great but if I was making the part I would start with a known original factory installed set. Why copy a copy? I have seen a few factory installed exhaust systems. With todays picture files we have experts on every part on a Corvette from Bowtie cars and know original cars. If they don't use double wall pipe some judge will find a way he can tell the difference and take a deduction.
Our judging system gets better every year so a five year old Duntov on a restored car may not make the 97 now even if it was never driven. Judges find more little things that are not 100% correct by checking side by side pictures at home and using this new information to teach other judges on the field what to look for so cars must get better every year to make the 97.
As an example if the old factory installed pipes had marks going the length of the pipe at the bends on all cars seen so far from the tooling used back then and the new reproduction pipes had no marks and the bends were 100% correct otherwise you may get a deduction from the judge who knows he is correct and soon all judges will be looking real close for this known problem.

[James W.]

Re: NOS Exhaust Pipes vs Reproduction

What Lyle is saying is all too true. Known deviations get passed around quickly. The question to ask yourself is, are the points I would save worth the money I spent? I almost popped for original tires until I looked at the deduct for good repros. Didn't seem to be worth it

[Robert E.]

Re: NOS Exhaust Pipes vs Reproduction

Correct me if I'm wrong, but I do believe factory side exhaust was no longer available post 1969, so side exhaust on a '71 will receive a total deduction for configuration as they weren't available for that year.

Robert

I have a 1971 454 auto car that i am restoring. I now have complete set of NOS pipes for the car, and only repo mufflers. The pipes are only the service replacement type that clamp onto the mufflers. Gardeners Exhaust is now making the correct style of exhaust for this car as I have just provided them with the pipe so they can reproduce them. They will be the correct style with the pipes welded to the mufflers.
Will I either gain or lose points by using the NOS pipes with clamp on mufflers vs using the correct style of repo system. Also is the sound different with the original pipes due to the double wall? I am not sure which way to go. Like to hear your comments!!
Thanks
Sheldon

[Ridge K.]

Re: NOS Exhaust Pipes vs Reproduction

Until a reproduction exhaust system is made and the judges get a chance to check it out and find as many little or big mistakes made I don't think their is an answer to your question. If you provided NOS pipes thats great but if I was making the part I would start with a known original factory installed set. Why copy a copy? I have seen a few factory installed exhaust systems. With todays picture files we have experts on every part on a Corvette from Bowtie cars and know original cars. If they don't use double wall pipe some judge will find a way he can tell the difference and take a deduction.
Our judging system gets better every year so a five year old Duntov on a restored car may not make the 97 now even if it was never driven. Judges find more little things that are not 100% correct by checking side by side pictures at home and using this new information to teach other judges on the field what to look for so cars must get better every year to make the 97.
As an example if the old factory installed pipes had marks going the length of the pipe at the bends on all cars seen so far from the tooling used back then and the new reproduction pipes had no marks and the bends were 100% correct otherwise you may get a deduction from the judge who knows he is correct and soon all judges will be looking real close for this known problem.

Lyle, quick question, if you will be so kind.
We could probably all agree, that service replacement parts were available thruout the model run for any given year of (now vintage) Corvette models. They had to be offered ofr wrecked cars, and the occasional "lemon part" that was installed on the assembly line.
A quick example is that I found a NOS intake manifold, in a GM box, with the exact Winters casting date, as the build month of my 1967 Corvette (a part number that is only for 1967 big blocks).
My question is: would a NOS part sold during the model year, be considered a "copy"? Wouldn't it just be exactly the same as the assembly line bin parts? Thanks in advance. Ridge

[Terry M.]

Re: NOS Exhaust Pipes vs Reproduction

Lyle, quick question, if you will be so kind.
My question is: would a NOS part sold during the model year, be considered a "copy"? Wouldn't it just be exactly the same as the assembly line bin parts? Thanks in advance. Ridge

[Terry M.]

Re: NOS Exhaust Pipes vs Reproduction

Correct me if I'm wrong, but I do believe factory side exhaust was no longer available post 1969, so side exhaust on a '71 will receive a total deduction for configuration as they weren't available for that year.

Robert

You are correct Robert, but where was side exhaust mentioned above?

[Patrick H.]

Re: NOS Exhaust Pipes vs Reproduction

Correct me if I'm wrong, but I do believe factory side exhaust was no longer available post 1969, so side exhaust on a '71 will receive a total deduction for configuration as they weren't available for that year.

Robert

Robert,

I don't see him referring to side exhaust at all in his post.

Patrick

[Robert E.]

Re: NOS Exhaust Pipes vs Reproduction

Thanks guys, I need to get my prescription glasses corrected. When I read pipes, side pipes came to mind. I apologize for my error.

Robert

[Ridge K.]

Re: NOS Exhaust Pipes vs Reproduction

First let me say I hope Sheldon doesn't feel like I'm hijacking his thread. The discussion of NOS parts seems to fit.
Terry, I always appreciate your commentary. Especially concerning potential judging issues, your thoughts are always extremely helpful, and I appreciate them very much.
Very quickly, my definition of NOS parts. is a obviously new and unused part, that is verifiable with either a correct era, original (and aged) GM part sticker, or found still in a correct era, GM parts box, as sold over a GM parts counter, and a correct GM part number is obviously stamped on the box end panel (not written in pen as many "for sale" parts are). I am fortunate of having the personal experience of having purchased GM parts since about 1969, which aids me personally in verifing correct parts.
I agree 100% with you, that a service replacment parts sold in say,...1985, for a 1967 Corvette, may have some variations designed to help it fit additional models. And, could have variations such as embossed parts numbers, or lack of, such as is found in service replacement mufflers.
But, I gave a very good example of a Winters intake manifold I found, and purchased, that exibits an original foundry casting number exactly in the timeframe that the model it was installed on were rolling off the assembly line. Is it rare to find such a part?......yes. Is it impossible?.......no, I have a shop full of them.
My question to Lyle, if he agrees that such parts exist, as pretty much proven that parts are available for sale in dealerships for the current model year, would those parts be considered a "copy".
I've discussed this issue with many experienced judges. The majority have told me that when they encounter a component that appears to be a NOS part installed, they take the time to determine if the parts is correct in design (as ssembliy line installed parts). I have had (only a couple) of experienced judges, tell me that "NOS service replacement parts ARE different than original parts".
I consider Lyle's views on the mark, and hoped he would add some further detail to the comment about "copy of a copy".
As always, thank you for your invaluable help, as I learn the finer points of correct restoration of these cars, that all of us members dearly love. Ridge

[Steven G.]

Re: NOS Exhaust Pipes vs Reproduction

Thanks to all for exaust system input. As I understand previous comments, well informed judges can probably fine clues that may conclude where a repro. or duplicated exaust system has been used. I guess one should use a rusted original (no leaks) rather than guess what repro. scores the best, until the word gets out that their's is an exact repo. if, when it may become available. Guessing again, repro.mufflers, like ex. pipes will not recieve full credit as well. This seems like a guessing game to me when we are trying to achieve points.

[Sheldon S.]

Re: NOS Exhaust Pipes vs Reproduction

I was trying to figure out whether using NOS pipes all the way to the mufflers would be worth more points even though they were not welded to the mufflers like they came from factory or to use a good reporoduction system that is continuous pipe welded to the muffler. I have read previous posts that people had used systems from corvette central and they had commented they lost very little for them. The systems that gardner is building is single wall but is supposed to have the same wrinkles and flat spots like originals. Is there any judges out there that would like to comment on this???
Thanks
Sheldon

[Steven G.]

Re: NOS Exhaust Pipes vs Reproduction

The exaust system, Heat riser Valve &Tail Pipe has a total of 50 points. originality 28, condition 22. It seems that a good repo. system could recieve full condition score and deduction for originality up to 28. Could anyone comment on this? I guess this could vary depending on the judge, and the construction tecn's of the repo. exaust, however if it looks good, fits good, how could originality not be worth some points?

[Terry M.]

Re: NOS Exhaust Pipes vs Reproduction

If the deduction for originality is total (in the case you cite 28 points) then all the condition points are lost. The line item has to get 10% of the originality points in order for condition points to be assessed.

To those of you looking for an assessment of the Gardner system(s) I would suggest they are too new for many judges to have seen them. I know of one car at the Nationals in St. Louis which had a 2.5 inch Gardner system. The owner made some modifications, and he told me he received no deduction for the exhaust. I hasten to point out that was one system under one circumstance -- but it is a good beginning.

[Steven G.]

Re: NOS Exhaust Pipes vs Reproduction

Terry, Great information always!! Myself and probably other new members should visit ncrs store and purchase judging dvd collection to better understand ncrs scoring.