I test drove a 2000 C5 today with a mild cam/heads/headers/full exhaust. It ran flawless and I am definately considering trading in the C4 for a C5 with lower mileage. My question is whether reliability or drivability is affected by engine mods like cams and heads. I plan on driving 9hrs to Carlisle this summer along with a few other weekend trips. The purpose of buying the new corvette would be to get a lower mileaged, more reliable car for these trips. Will I be good with a car with mild engine mods or should I stay with a stock motor??

 

My H/C stroked LS6 will be 10 years old this June, over 40,000 trouble free miles.


Errrr.. save for a few bad valve stem seals that were easy to fix.

 

When were the valve springs replaced? That is what toasted my last engine... I didn't know they were a maintenance item


Typically a bigger cam = bigger lift.. more stress on springs.

 

There are lots of members and former members who took their car to a competent shop. Many Many great stories with little or no issues. Most will say so in open forum.. However I had had literally hundreds of people, who did the work themself , or went to a cut rate shop.. there are lots of these shops out there. Many will make you sign a waver when they dyno your car in the event it blows up. I've heard hundreds of horror stories behind the scenes in PM where people wish they never touched their car.
You need to do the research, get references, etc. Make sure if you are buying a modified car, that you get documentation as to what they did.. what parts were used, dates and receipts etc.
Bill aka ET

 

My take on it:
If its your only car leave it stock. If its your second car (toy) mod away.

Answer to your question:
A stock cam will go 100k with very little maintenance. You will be very lucky to get half of that with a fairly modded car. Valve springs should be checked every 15k-30k miles depending on how aggressive the aftermarket cam is.

http://www.americanheritageperformance.com/

 

My feelings well.

 

Thank you very much for the input, it's appreciated. I don't know a lot about engine mods. The dealer is familiar with the car and knows where all the mods were done. Motor work was done at a local shop that I'll be able to research, everything else was done at Carlisle over a few years. I planned on finding out exactly what cam and heads were in the car. I didn't know about the valve spring maintenance. Assuming the motor shop ends up being reputable it is close enough that I could get the springs and other motor maintenance done every spring or as often as needed. Thanks again, as always I learn every time I post here.

 

A stock LSX motor was certified at 200K during the testing. A mandate by Dave Hill. I've had many members PM me over my 16 years here, stating their C5 is still going strong @ 200K and 300K, even some at 400K, and with no internal issues, following the OLM, and using the correct oil. these motors were certified at 200K in testing, torn down and every spec was still within tolerance.

This motor in stock form, is almost bullet proof.

Bill aka ET

 

If the mods are not too wild or radical, you should be fine. The details are in the installed components, how they are designed to work together, and the tune.

If the cam, heads, etc. are good quality and installed by a competent shop, then you should be fine. As others have said, you will need to change the valve springs out around 15-25K miles with a moderate lift cam.

Per Evil Twin, get a detailed list of the mods, the manufacturers, specs, etc. if at all possible. Once you obtain them, post them in this forum and get some ideas about how they match up. That's key. Mods must be matched, aligned, and tuned properly. Might not be a bad idea once you have this list, to consult a Chevy small block speciality shop to get their opinion. If you get the name of the shop that did the mods, calling them for a history is certainly a good idea.

If the mods are all designed to work and flow together, installed properly, and tuned accordingly, you should be fine. However, if any of the above is not within specs, you could be driving a ticking time bomb. Just do a little homework first and be safe rather than sorry.

The good news is most owners are very picky about their babies and do things the right way. Especially true for garaged kept Corvettes.

 

I agree on leaving it alone if it's your only car, or sticking to bolt ons like full exhaust

 

There are basically two types of people on this forum.. Those that are OCD and those that want to do things cheaply as possible.. I see it all the time; what are the cheapest brakes ?, I use regular fuel with no problems! Why would I spend 3,000 dollars on forged wheels when I can get reproduction C7 wheels for 600 dollars?

The OCD guys do their homework, seek advice, do the research and spend the money to do it right. They would rather overkill a project then to ever take short cuts to save a buck.

ON this forum there is a bell curve of members at both ends of the curve.
about 40 % of the members on this forum are OCD, the other 40 % are not so focused on doing it right and more focused on doing it as cheaply as possible. And there are the 20% remaining that are just the average corvette enthusiast, enjoying their car with little intention of making any dramatic changes in anything.

Just my observation over 16 years here..
Oh yes... Of the OCD guy, about half are go fast guys the other half are wax on and wax off guys with aesthetic mods. and sprinkled in are the guys that want a little of both..

Then there is the Other group... who will bolt anything on their car, with no vision or forethought. those who think that more is always better. Would not know subtle or what research means,
if it bit them in the butt.

Some people obviously know what they are doing here, and more obviously, some don't have a clue.
Just my observation over 16 years here..

I could be dead wrong with my observations.. Its just my observations.

Bill aka ET

 

Agreed, 100%. Minor bolt ons are fine (CAI, catback, shifter, etc.) but once you open the engine up the game changes.

There are PLENTY of LS based motors out there still running strong and reliable with 200, 300, hell even 400K+ miles on them. Maintenance is key, it's as simple as that.

In regards to mods, I strongly disagree. Do your homework, match your parts carefully and inspect/replace when necessary. A modded car can be extremely reliable. I wouldn't think twice about hopping in mine (if it wasn't put away for winter) and driving it to Florida (from Michigan) as is right now. It's all about picking a combination that works together, not just buying whatever donkey dick cam is popular on LS1 tech this week and trying to drive it with a mail order tune.

 

What's different about an aftermarket cam (besides the obvious things) that would cause it to only last half as long as a stock cam? I can't see having a higher lift/longer duration causing it not to last as long...

 

NOTHING! The added lift will wear valve springs faster, and at that point they become a maintenance item and need to be checked at intervals (check with the cam/spring manufacturer) and changed when needed. The cam itself is not going to wear out any faster unless there is a physical defect or an issue in the manufacturing or heat treating.

 

I could see the extra valve spring wear, but I wasn't understanding why the cam itself would wear out faster....maybe I just misread his post...

 

OK, once again just my opinion, but if you are looking for a dependable and problems free C5 I would stay with a stock or close to stock car. Like others that have already commented I don't count shifters, catbacks, headers, wheels etc as actually modded. If you really want an enhanced C5, find a clean stocker then find a good shop with a good rep to do whatever work you are considering. In the past I've gone both the internal build route and the intercooled supercharger route. Today, if I decided to go for a really large power increase today I do believe the only way I would go would be supercharging. I found the power gain, driveability and reliability to be terrific without having to tear into a perfectly good motor that has proven itself capable of great longevity if the internals are left alone. Just my two cents but the two cents are based on fairly lengthy personal experience. Good luck!

 

A good rule of thumb I always went by when it came to modding my bikes is external mods (i.e., exhaust, intakes, ECU tunes, etc.), maintains stock reliability, but internal mods can degrade reliability as compared to stock...I know the C5 is no bike, but I would the think the same principle would apply...

 

 

Mail order parts, Harbor Freight tools, amateur mechanic, what could go wrong?

 

Nothing with that type of mentality/attitude!
Of course nothing will go right either!