A couple of 240Z questions

I looked at an early 240z today and really, really like it. Sophisticated it wasn't but boy was it fun to drive.

I noticed a couple of things while driving it though and given that I haven't got the foggiest about 240zs, I figured someone will have an idea what's going on...

1) How reliable is the stock oil pressure gauge? The one on the car was hovering around 0 when idling and was about as motivated as I am at 6am before I had my morning tea. I don't think it made it up past 1/4 when revving the engine.

2) Same goes for the water temp gauge, that was sitting a little past the middle but didn't seem to move higher in about 75-80 weather

3) I noticed that the bottom of the oil filter housing was damp/wettish with oil. I assume that's coming through the breather, do they normally blow some oil into air filter housing?

4) The car sports a K&N in the airbox and has a bunch of holes in said airbox above and below the carbs inlets. I assume that's supposed to ease breathing even though it's pulling in hot air from the engine bay?

It has been repainted, looks like a decent job even though some items that shouldn't be painted body color have been (like the rear light surround). It's got a couple of rust bubbles in the passenger rear wheelarch, bottom of the front fender and a few bubbles on one of the rockers. They don't feel 'crunchy' though so I don't think they need immediate attention. Probably in the next couple of years, but not right know.

Underneath it looks pretty clean and unmolested, no fresh undercoat hiding multiple sins. The old undercoat is peeling off but as far as I could tell (no access to a lift) it's only surface rust underneath. Interior is generally clean but the seats need recovering.

The current owner is hopefully going to have the oil pressure and compression tested so we get an idea of what the engine's condition is like. How hard would it be to find a replacement engine in decent condition in case the worst expectation is met and it wants a rebuild I can't afford right now?

I can only answer your last question because I haven't ridden in a L-series Z yet, but engines are easier than you would think to get a hold of. You can also chose between the 2.4, 2.6, or the 2.8. They all are direct bolt ins except for the 2.8 because of the fuel injection.

The 2.8 is a direct bolt in, just switch to carbs or add aftermarket efi. A turbo ZX engine swap is a popular option. The oil pressure is most likely the sender. That happens on most of them. It's easy to swap and inexpensive. The temp gauge was working fine. With a good thermostat and radiator, these cars don't over heat.

S30 Z cars, 70-78 240, 260 and 280, are very fun cars. They have a good after market, used parts are readily available and the cars are very easy to work on and modify. Try Hybridz.org for more info.

Check again for rust. Use a magnet to look for filler. Pay particular attention to the frame rails and rockers.

Well, looking again for rust might be an issue given that the car is about 3 hours away. Agreed, I should have taken a magnet but from what I've seen (and 'fingertipped') of the underbody and the fairly careful check of the lower part of the body, I'll probably end up eating my hat, err, am fairly confident the rockers aren't completely made out of Bondo.

THE worst rust will be on the underside of any Z car. It's always, look at the frame rails that hold the engine and look at the areas in the engine compartment around the battery.

The "sluggish" gauges aren't a deal killer, assuming the buyer is willing to bargain if they lead to your discovery BEFORE buying that the engine is on it's last legs.

The best news? In reasonably good condition the Datsun 6 pulls like a small locomotive. ASAP? Swap out the 4 speed for a 5 speed.

I hear they kick azz on the Wangan.

we have one as a Lemons car - rust was our biggest problem - in fact we had to replace both sides of the floor pan (drivers and passenger side) with some junkyard metal plate. Mechanically it's a pretty simple beast, the 2.8L bottom end on the 2.4L carbed head produces pretty good power and parts / hopups are cheap and readily available. The stock 2.4L has power comparable to a 1.8L Miata.

Fun to drive, gets lots of compliments and we ran the 30 year old engine flat out for 21 hours straight at a 24 hour Chump Car race before it puked a head gasket - i'd call that pretty reliable.

Dr. Hess wrote: I hear they kick azz on the Wangan.

Well, fortunately this one isn't blue, given my meager driving skills.

The owner was kind enough to take it to a mechanic to have a (partial) PPI done and I got the results last night.

Compression and leakdown on the engine are OK - compression varies between 165-175psi, leakdown varies between 3% and 10% and the oil pressure seems to be OK, too, between 30psi at idle and 60psi at 2200rpm. I would think that's pretty healthy for an engine that's 40 years old.

The mechanic didn't find any rust in the frame rails, it appears that I spotted all the rust with the exception of some rust at/near one of the rear lights. I'll have a chat with the mechanic later today to get a little more info but the underside of the car seems to be in fairly reasonable condition.

Looks like I might have to find another excuse why I can't partake in track fun if the owner and me can agree on a mutually acceptable price...

Wow - sounds great. Excellent compression for that old engine. It's got great oil pressure too - go for it.

The L series engine is almost bullet proof as long as you keep water and oil in it. They came with two types of carbs. The early (70-72) had dome top carbs and the 73 had flat top carbs. The dome tops are considered the better ones to have. The flat tops were okay but if you had trouble with them you throw them away and swap out for the domes.

The ZX 5 speed trans should be a direct bolt in. The only exeption may be if you have a really early monkey motion trans then all bets are off.

Good Luck

It's got the "dome tops" Hitachi SU-style carbs on it.

My '71 has a fair amount of rust around the battery area, and more around the drivers side tail lamp. I found most of that rust after I disassembled the back of the car. It was hidden with all the stuff on it. The floors and rails are solid however, as is the spare tire area which I've also seen rusted through on some examples. 240's can and do rust everywhere, be sure and get a VERY good inspection of all the sheet metal, and still be prepared for rust repair in the future.

They are however a lot of fun to drive. Some years back I drove an ITS version for a couple of years. On track they are even more fun, if a bit of a workout too!