Bought a 73 - a new engine?

[Guest sailor bob]

I've been a member for a while but I am a total virgin to modifying a drive chain.

I am posting because I bought a 73 and the engine is running good but it's belching smoke. I started off thinking staying original, but after pricing a rebuild I am certain I can buy a drop in for alot less money.

Is it too much for a novice to install a 240sx engine in this car? The real question is which swap is the most managable for me? I am not a mechanic, but I seem to have a certain amount of dog scense when it comes to mechanical issues. More power is essential.

BTW I'm in Newfoundland Canada - it's virtually impossible to get a turbo l28 here unless $$$

SB

 

Edit - I have had two other Zs and currently have a stock 77

[240z!!!]

there is a guy from ebay thats selling a ton of z parts he has many parts cars....honestly your best bang for your buck and an easy install is a l28 stroker....if your wanting to go turbo, most of the l28 na motors can easily be turbo'd......just do a search on na to turbo conversions.....

best of luck

[Guest sailor bob]

There are some less than reputable ebay sellers and the better one doesn't ship to canada. Hope you don't mean "Datsun parts" - go to Classic Z and search that name.

As I said I am not new to datsun - had my first one in 1976. Currently have two.

To stroke a l28 - I have to get one first and the kit to do the upgrade is not cheap. A machinist is required.

I am just wanting to haul out what I have and install a more powerful, reliable engine that will turn this car from a smoke belcher to a honda vtec killer with the least amount of $$ and time.

I found a thread - "so you want to..." great info but seems pretty biased to the bigger RB engines - they cost a fortune down here ($3500+) still to be modded to fit more $$. I am hoping there will be an easier fix.

[2eighTZ4me]

Welcome aboard Sailor Bob!

 

What color smoke is it belching? Black, blue, or white? Black is running rich, which can be fixed without a rebuild, blue is oil smoke - and in some cases can be fixed without a rebuild (sometimes it does require a re-ring though), and white smoke (steam) is water/antifreeze, which can most likely be attributed to a head gasket gone bad. That can be done without a total rebuild too.

 

How many miles on the car/motor? Do you WANT to keep it stock? That's the impression I got from your post. That would be your cheapest route more than likely. You can also buy a used L-Series motor and drop it in a lot cheaper than a rebuild.

 

Unless, you absolutely have to have power - then start looking at a small block conversion. Turbo starts to get pricey when you start upping the boost levels. And, I've heard once you start raising boost levels (without tweaking fuel/air), it's very difficult to stop due to the addictive nature..at which time, it's usually too late and you've toasted another motor.

 

Bang for the buck is probably a small block Chevy.

[Guest sailor bob]

Well 2eighTZ4me, The current engine seems to pull like new, it has 165 lb across the board, but smokes something awful. It is consuming a large amount of oil as well - over a litre per 100 miles.

Smoke is lightish but with a tint of some black - I am not loosing coolant. I thought it was a carb problem (rich) - got rebuilds from Ztherapy - the car now runs nicer and the carbs are easy to tune, but still smokey. Recently I thought about oil rings being seized (car only has 46000 miles) because the PO (second owner) says it was stored for 15 years and was smokey ever since he had it. I threw a litre of ATF in the oil and ran the s--t out of it for 100 miles. Oil change (old like tar) and thought I saw an improvement, but after a good run ... still the same.

I am currently running 10w40 detergent added oil and hoping something magical will happen, but preparing for a change.

I don`t need a beast (but if it cost the same I would probably go for it) - I would be happy with a street car that wasn`t an embarassment beside a VW or Honda.

I like her look and she is pretty zippy as is, but if I have to spent two grand to get the engine done, I would just a soon spend the money on something other than a L24. Its a great little engine, but I already have a stock Z.

Attached a picture of the two Zs in the yard with my truck in the background.

[Daeron]

Bob, seafoam that engine.

 

Add some to the fuel, add some to the motor oil (act like it is ATF/high detergent motor oil) and then suck some thru the vacuum lines. I think its actually ridiculously easy to seafoam carb'd cars, you just gotta get the air intake to suck it up somehow.

 

Change the spark plugs while you are at it. I;ve seen a few good old NGK BPR6ES11s lately that failed for no good reason other than living a tolerable (20K) lifespan.. they look good, they arent so old that you'd think they were a problem, but sure enough....

 

Otherwise... a 240SX engine and trans would be simple enough to install but you would likely want to turbocharge it before too long. a 300ZX driveline comes to mind as well.

 

If you really think you've got the horse sense, then seriously, consider trying to get a turbo'd L28 engine together under megasquirt. http://www.diyautotune.com read up on it and think about it like this.. if you can stop the smoke then you've got all the time in the world to find the right buy in the right location. OR, you could read enough to determine that your rebuilt Ztherapy SUs, a new cam, and a nice hot ignition system would suffice for enough pep to settle you down.

[Guest sailor bob]

Hey Daeron - I am going to look into that Seafoam stuff today and give that a whirl, I am fighting the change of the season up here. By that I mean the weather is on the cusp of going winter - when it does the car won't be outside for at least 5 months, So I am trying to find my direction befor storing the car - winter project.

Plugs and wires are brand new - about 200 miles. Plugs look as they should - tanish grey/dry and like I said she pulls really hard.

I was planning to go with a mild cam, header, rear end and ignition upgrade. I have already purchased a set of 3.9 gears and a E12-80 distributer and have a line on a 1970 head (E31?) that is cammed.

So, Needless to say I would rather solve the problem than replace the engine, but it appears to be unreasonable to expect a solution at this point. I will bare the adjacent drivers waving away my smoke long enough for one more oil change and a shot of "seafoam". May still end up with leaking oil rings and valve seals, but they will be very clean.

I am reading that the SR20det is a good choice for a change? (If I should do the change) Does the 240SX 5 speed go in with out modification? What rear end would suit it or is the current setup suitable?

Thanks for your input guys.

[2eighTZ4me]

I don't understand the infatuation with a 4 banger. The guy wants cheap power. A SBC is THE way to go if you're on a budget and want something that has been swapped into a Z and documented on numerous occasions. By the time you get done making an SR20 or KA24 powerful enough to keep up with a SBC - you've spend double what you could have had with a V8. To each his own I guess. I just responded based on "inexpensive" and "power". If you want to go exotic, by all means have at. Just realize it is going to be quite pricey by the time it's all said and done with - as I stated before. Especially when you add a turbo to the mix.

 

Here's an idea - get an L28 block - short block. With pistons rods etc. - they show up here every now and then for $150 or so. Tear that down and rebuild during the winter months, get your cammed E31 head, plop it on, and voila - you have a motor ready to drop in in place of Ol' Smokey.

 

There's tons of options available to you, as these cars lend themselves well to all kinds of motor swaps - in the end though, it's what YOU want.

 

I can't speak for a 240SX 5 speed bolting to a SR20, but can vouch for the fact that it will hook up to an L-series motor with some modifications. And if you have an R200 rear end, that'll be plenty enough for almost anything you can throw at it.

[blue72]

I'd have to agree with 2eighTZ4me about the small block probably being the most economical choice for the money. As long as you are savy, get a good price on parts, and do most of the labor yourself then it's the most horsepower for the least money.

[Daeron]

Well, there is no infatuation, the gentleman suggested a 240SX engine (KA24) or an SR20 himself, and I advanced the suggestion of a VG30 as well (since he seemed to like nissan motors.)

 

The plain reality is that any of those options, Nissan and non, 4 through 8 cylinders will require about the same amount of effort to put the driveline in. the Nissan transmissions may be a bit simpler to hang onto the Zcar, but any of the above mentioned engines will require custom mounts.

 

I am all ABOUT keeping the engine swaps in the family, but they ARE right: the best bang for your buck comes from a Jags That Run SBC V8 conversion. On top of THAT, once you have a SBC in there, your upgradability gets ridiculously simpler...

[silverarrow27]

...I can't speak for a 240SX 5 speed bolting to a SR20, but can vouch for the fact that it will hook up to an L-series motor with some modifications. And if you have an R200 rear end, that'll be plenty enough for almost anything you can throw at it.

 

To use the KA transmission you must swap the sr bellhousing over to the KA transmission so it will bolt onto the sr20 engine.

 

Why bother with that when most sr20 swaps come with the transmission anyway.

[Guest sailor bob]

Back again, bought two bottles of "seafoam" haven't put it in yet. It wasn't in the first couple of places I tryed, so I bought a can of "Wynns" tuneup in a can - also supposed to free bound up rings etc... I am going to give that a hundred miles. I will do another oil change soon then try the seafoam. If that doesn't do it - somekind of change will happen.

[Guest Widebodys30]

This may be a silly question,

but are you sure it isn't overfilled with oil?

[cannonball55]

If you decide you want another 73 motor that runs fine shoot me a PM I just pulled mine for a swap. $750 + shipping oh comes with 4 speed trans also. You'd be back on track for cheap. Has a bit of upgrade (ported polished heads, bob sharp intake, holley 650 cfm carb) I'll go into more detail if your interested....

Thanks,

Stewart

[Xnke]

If it was me, after running the seafoam through the engine, I'd check the valve stem seals. They'll cause smoking like that, with no loss of cylinder compression.

[Daeron]

The seafoam was an attempt to remedy the smoking.

 

Bob, I would highly recommend you just find an L28 from an NA 280ZX to throw your cammed E31 onto and call it a day. You may find that you want to run higher octane fuel than you want, but my guess is that would land you around 200ish horses, and guess what? in a 240Z thats PLENTY... with 200 horses, its time to work on the suspension.

[Guest sailor bob]

Thanks for the input guys - I am fairly certain that the rings were gunked and the last hundred miles seemed to show that the heavy smoke is now all in the deceleration and the first moment of exceleration after. I can almost eliminate the smoke now by not gearing down when slowing down, all that = valve stem seals. So that is the next item on the list.

I am not certain that any one product broke them free (oil rings) or a combination of them all, but the last one I used was "Wynns" and it seems to be quite a difference. (After a couple of hundred miles of balls to the wall with ATF followed by detergent oil)

So my plan for the winter is closer to the original - new valve seals, E12-80 distributer (will rebuild over the next few months) and maybe header and exhaust if all goes well. It all works well even if an upgrade to an L28 is in the future and for the time being keeps the expences down a little.

Daeron - I agree the l28 is the best choice for me, if this doesn't pan out. It leaves me in a situation where I can still use all the gear I already have and intend to get. Plus it permits me to move one step at a time through the process without too much wastage on the way through. With the current economic situation a fella got to keep an eye on his expenditures.

I will post again when I get the seals in, for now I am optimistic.

[lgoodson@pacbell.net]

Consider a V8. LT1's are $700 up and T5's are 400 to 500, Course there are a few more parts needed.