I know that mileage is not everything but it is a measure of some value so what is the suggested maximum? Or what has been the experience that any racer here has had, I'm thinking up to 100,000 km/60,000 miles. Would a valve train check be advisable for something at the higher end? Engine power would not be a priority early on, handling, grip, braking and transmission would be.
Cheers and thanks.

 

How does one tell for any use? This isn't a set number.

You have your garage queens that have been driven 120k miles but have been babies with 2k oil changes, regular other service and PM every 10k that sort of thing.

Then you have the rich kid whose parents bought him a 370Z Nismo Automatic to commute to Menlo school (local snob school) which was driven tail out every day with three sets of tires in 10k miles and put away wet, never saw a single oil change until just before selling; then sold with "low mileage" on it.

Yeah, it'd just be best to take you candidate cars into a garage (or DIY) for a leakdown test, compression, full inspection, etc. to determine if you're getting Mic's old car or the drift kid's piece of junk.

 

Due to my geographical situation almost all cars will be spread out a 1.000 miles or so therefore locating them on line is the only real option. Without travelling all over the country some initial sorting has to be done and mileage is one of the few measures available at that stage. Hence the question.

 

Speaking as a racer who's had brand-new cars all the way to ones just this side of the salvage yard, mileage can be deceptive. First, relatively modern cars like the Z34 with its FM-chassis are built so torsionally stiff that pure mileage won't usually affect them. But impacts and race damage can be notable, and if it's heavy, should be noted in the car's logbook. On the other hand, racecars usually age cosmetically (paint, headlights, windshields, etc) at about 5X the rate a streetcar goes through.

Sine the OP is asking whether mileage is a big factor in his search, I'd rate it about #3 or #4 on my list. A higher mileage Z34 at the right price would be a good deal if I was turning it into a racecar. But, as I usually advise, a full mechanical assessment should be a must to know how the car has been cared for (or not).

 

I've worked on many track cars thru the years. One thing that makes a bit difference to me is the amount of rust. A car that's been stored in a garage and is relatively newer is so much easier to work on than one that's been sitting outside for years. Every bolt, nut, clamp, bushing, etc. becomes a struggle to remove and a hustle and expanse to replace. When I look at a potential cars for track duty I'm not really concerned with milage. I will do a compression check to make sure the engine is relatively healthy, and I will check fluids to see if they look like they've been changed in some recent past. Of course the cosmetics and the interior don't matter much. Look under the car and under the hood and see if it looks like things will come apart relatively easily or will require an air hammer.

Also, the more stock the car is the better. While it's tempting to think that someone put on some aftermarket bits so you won't have to, in most cases that means that 1) wrong aftermarket bits were installed and/or were installed incorrectly and 2) the owner probably drove the car "fast and furious" and ragged the mechanicals within an inch of their lives.

 

Fortunately rust is not much of a problem here, in contrast rust seems common in the US. I'm just trying to get a rough idea of the life of these engines because, except for a possible valve train check, I want to concentrate on other race things first. But oil cooling will be a priority including a bigger sump.