I just purchased my 2nd 70 Z (first was stolen). The car I bought has a clean engine but it feels a little tired and there is a small engine leak. I have decided to get the engine rebuilt as part of the restoration project. I called Zdoctor here in the bay area and they suggested installing a factory rebuilt 280zx motor as opposed to rebuilding the original 240z engine. Cost is about the same $5500. Does any one have any opinions on this. Does this price seem reasonable for a complete block and head. I unfortunately have no experience in this area. If anyone can recommend another shop in the bay area that would be great too.

Mark

If you are not concerned with authenticity go with the ZX motor. You will pick up some easy horsepower, just make sure that it's not a turbo motor with low compression. The price sounds pretty high to me, but I don't live in CA. Just as a comparison, Motorsport Auto has ATK reman. engines for 1795 plus 200 core charge for 79-83 ZX's. I know a lot of people would wonder about these engines but I have one in an old 280 I blew up many years ago. I converted the car to race in ITS and ran the ATK engine and never had a minutes trouble. I wasn't the fastest, but at least it held together, and at the time it was all I could afford.

If you just want a nice street car I would consider this, 5500 is about what IT racers were paying for Rebello engines back in those days. Atk's prices are low because they do such a large volume, once you have it you can hop it up later.

Thanks for the reply. I did a little research and found that ATK headquarters is only 30 minutes from my house in Danville, CA.

I think what I am going to do is buy a remaned 280 engine and install myself.Probably save a couple of grand. what year would you recommed or a particular head? Looking for compatiblility with the rest of the mtor I have with my stock '70z.

I am not trying to build a race car, just a high performance, improved version, street drivable classic.

Thanks Mark

For more information on what head to look for and which year engine is better take a look on the web links page for The Datsun Z Garage. This is a really good site Brian has that will give you the scoop on which heads are better and which year ZX engines give the most power. I personally have never done anything with any Z's newer than 78. All the engines up to 83 with swap into a 240. You just need to decide on what year you want to get the best head. After looking at his site you should be able to come up with a good idea about what works the best. One of these days I'm planning on doing a 240 with a ZX motor but I have another project to finish first.

Thanks for all the great advise. I have checked out the Z Garage and you are right there is a lot of good info. I was planning on purchasing a motor stand for this job. Any advise on that?

Mark

Engine stands are fairly cheap. Most auto parts stores carry them. Just get one rated for at least 500 pounds and get one you can rotate the engine one.

Just remember to decide on what you want before you buy, changing your mind half way thru a job wastes time and money. Been there, done that.

Originally posted by mmagnus

I just purchased my 2nd 70 Z (first was stolen). The car I bought has a clean engine but it feels a little tired and there is a small engine leak. I have decided to get the engine rebuilt as part of the restoration project. I called Zdoctor here in the bay area and they suggested installing a factory rebuilt 280zx motor as opposed to rebuilding the original 240z engine. Cost is about the same $5500. Does any one have any opinions on this. Does this price seem reasonable for a complete block and head. I unfortunately have no experience in this area. If anyone can recommend another shop in the bay area that would be great too.

Mark

That price seems kind of high to me. I don't know about ZX engines, but, regular Z engines are around $1,500 to $2,500 depending on the options.

In fact, after I think about it more... A ZX engine in a 240z would require a lot of modification. The ZX engine is fuel injected and will require a stronger drive-train (differential).

Take a look at some of the engine solutions from Motorsport Auto. They can get rebuilt engines that are a lot less expensive.

Anyway, that price just seemed too damn high for me. But, if it includes installation and all of the modifications to your 240z, it's probably right on.

A popular modification for the 240z is to use a 280z block. It's got more horsepower and almost identical to the 240z block. The head is very similar, but, you'll have to check to see if you have round or square exhaust ports.

Point is... check around... I think that price was high.

Okay, I just looked up prices at Motorsport. They have the following options for rebuilt engines:

'70 to '83 engines = $1,795

'84 to '89 engines = $2,750

You'll receive it in a crate to your house. I think they also charge for shipping. Not sure what that is....

It also says these prices are on an exchange basis only.

Thanks for the response but I am not sure why you say I would need to modify the drive line. If I am only changing the block and head, and they are almost identical to the 240, why would I need to modify the diff?

Mark

Originally posted by mmagnus

Thanks for the response but I am not sure why you say I would need to modify the drive line. If I am only changing the block and head, and they are almost identical to the 240, why would I need to modify the diff?

Mark

I wasn't sure how you were going to configure the car. If you were going to add a ZX engine with all of the ZX features (possibly a turbo), then you might want to look into that.

It's because of the additional power and torque.

You will be fine if you buy an L28 (280z) long-block and keep all of your other 240z components.

As long as you are going to stay with a fairly stock 280z or 280zx motor the driveline will not need to be changed. In Improved Touring we race 240's with probably as much power as you can expect from a stock ZX motor. The main thing is to make sure your driveline is in good shape. One of the weakest links in 240's is the u-joints, if you aren't sure of their condition, replace them. When you buy all six it isn't cheap but it is good insurance.

The only time you would really need to upgrade to an R-200 rear would be if you are planning to add a turbo or changing over to a V-8 or if you plan on drag racing. The R-180 shouldn't have any problem holding up to engines with up to 200 horsepower if you drive it reasonably and keep an eye on everything.

By going to a late model ZX block with carbs you will probably gain less than 50 horsepower. That is a fairly good gain if you plan on using the car on the street.

As far as converting to an R-200 it is mostly bolting in parts from a 75 or later 280 so it is not that difficult.

Thanks for the insight guys. As mentioned before, I not looking to make a HOT ROD nor a race car. I just want to improve what is on there and possibly beat the occational 911 on the road. I think I am going to go with a 280zx engine and possibly upgrade the intake also to accomedate the new head and to improve HP. Any idea what type of HP I could expect from stock 280zx motor using '70 240z stock carbs. I will probably be running headers also.

Mark

Since the ZX motors were in the neighborhood of 180 hp (gross) you are already ahead of an L24 by about 40 hp. As far as what you end up with there is no way to tell. Do your research, and put it together the way you want it or with what you can afford at the time. There are too many variables to consider such as compression ratio (depending on which head you choose) the intake you use, the cam, ignition, well you get the picture.

Take your time and you will get out of it whatever you want. Is 200hp out of the question? Probably not due to the displacement advantage. Like I said before, go to the Z garage web-site and do your homework before you start buying the parts.

Another good way to put some zip into it would be to find a 3:54 ratio rear end out of an automatic car. You should be able to pick one of them up pretty cheap, possibly even at a junkyard. It won't make a huge difference but it will be one you can definately feel.