Jump to content
HybridZ

L28 dual duty build


mforget

Recommended Posts

Hi, i am currently restoring a 77 280z that i will be using as a dual duty street/occasional track day car.

 

I am pretty set on building my L28 instead of doing a swap but i would like to get some advice on this topic.

 

Ive spent several days searching on the forums and heres my current plan :

 

Have the block opened to do ring/bearings as a preventive mesure.

 

Install the 10-2003 schneider cam kit from z-store : http://www.thezstore.com/page/TZS/PROD/10-2000 (is this a good choice??)

 

Triple weber carb setup, need advice between DCOE 40 or 45

 

MSA 3-2 headers.

 

MSA twice pipe exhaust

 

Early ZX distributor to get the timing right for the webers.

 

HD clutch upgrade.

 

Does it sounds like a good setup?

 

Im looking more at reliability than high hp numbers.

 

Thanks in advance!

 

Link to comment
Share on other sites

  • Replies 49
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Posted Images

You might search out some of JMortensen's comments about cam profiles.  He's a proponent of big profiles and says that most people can go much bigger than they think, if I recall correctly.

 

HD clutch is vague.  A lightened or lightweight flywheel would be worth consideration.  Fidanza, or a lightened 240mm flywheel are common ways to get there.

 

There are some programmable timing options out there that might be better than just taking whatever curves you get with a ZX distributor.  And you'll have a hard time finding an early ZX distributor in good shape.  You'll probably have to buy reman.  But you could transfer the centrifugal advance mechanism over, probably.  You can also get electronic ignition via other routes.

 

If you're going to have the head off you might as well have some work done, if you can find a shop that knows.  That seems to be where people get the most bang for buck.

 

Just regurgitating.  Add real detail to your plan before you tear things down and you'll avoid headaches.

Link to comment
Share on other sites

You might search out some of JMortensen's comments about cam profiles.  He's a proponent of big profiles and says that most people can go much bigger than they think, if I recall correctly.

 

HD clutch is vague.  A lightened or lightweight flywheel would be worth consideration.  Fidanza, or a lightened 240mm flywheel are common ways to get there.

 

There are some programmable timing options out there that might be better than just taking whatever curves you get with a ZX distributor.  And you'll have a hard time finding an early ZX distributor in good shape.  You'll probably have to buy reman.  But you could transfer the centrifugal advance mechanism over, probably.  You can also get electronic ignition via other routes.

 

If you're going to have the head off you might as well have some work done, if you can find a shop that knows.  That seems to be where people get the most bang for buck.

 

Just regurgitating.  Add real detail to your plan before you tear things down and you'll avoid headaches.

 

Hey, thanks for the comments, yeah i already saw some of his posts, i dont know who should i trust about those cam specs.

 

I dont mind to sacrifice some streetability but not to the point that the car will be no fun to drive at all on the streets....

 

By HD clutch i mean something stronger than oem....Probably ACT

 

The distributor question is something i will have to adress, i didnt take enough time reading about the availlable options yet....

 

Head work is definately on my list if i can find some knowledgeable people over here(canada) to do the job.

 

I have the engine on my stand right now waiting for my plan to be finalized....

 

So any other inputs on this are welcomed!

 

Thanks!

Link to comment
Share on other sites

Honestly you will have way more trouble dealing with tuning the triple Weber's than a big cam.  I had Isky 490 lift 290 duration and it was totally fine for street use. I used a pair of bored out SU carbs and all my friends with triples said not to change to triples as mine ran so well and triples would just be a headache.   I would highly recommend a well set up set of SU carbs for the street.  As for the ignition I would go with one of these 123ignition datsun.

Link to comment
Share on other sites

How many miles on it? If it has relatively low miles, I would pass on rings and bearings. I've heard some people say that the new bearings aren't actually as good as the old ones in terms of quality - may or may not be true. The L series is a durable motor though.

 

Since you want reliability over power, I'm not sure why you'd switch to triple carbs from EFI. Seems kind of counterintuitive. Depending what kind of power you'd like, it might be better to get MegaSquirt, and get a really good tune on a stockish motor.

Edited by rturbo 930
Link to comment
Share on other sites

Honestly you will have way more trouble dealing with tuning the triple Weber's than a big cam.  I had Isky 490 lift 290 duration and it was totally fine for street use. I used a pair of bored out SU carbs and all my friends with triples said not to change to triples as mine ran so well and triples would just be a headache.   I would highly recommend a well set up set of SU carbs for the street.  As for the ignition I would go with one of these 123ignition datsun.

 

Looks like some very nice distributor there, but definately not cheap.....

 

With an SU setup, do you even have to upgrade the distributor or the stock 280z one would do the trick?

Link to comment
Share on other sites

How many miles on it? If it has relatively low miles, I would pass on rings and bearings. I've heard some people say that the new bearings aren't actually as good as the old ones in terms of quality - may or may not be true. The L series is a durable motor though.

 

Since you want reliability over power, I'm not sure why you'd switch to triple carbs from EFI. Seems kind of counterintuitive. Depending what kind of power you'd like, it might be better to get MegaSquirt, and get a really good tune on a stockish motor.

 

83k miles, i heard the same thing from an old mechanic friend of mine.....

 

Your right about the triple weber setup, i think that most people do it for the same reasons, looks, sound and style.....Resale value also probably....

 

The car will be fully restored with the engine bay repainted etc.....It would be totally sick to have them under the hood but reading all the posts about the tuning issues, i may have to reconsider and go megasquirt instead.....

 

Im not a big fan of carbs, even if i have some experience tuning them back in the days (not webers)......Webers would be the only ones i would put down there for the reasons already explained.

Link to comment
Share on other sites

If it's genuinely 83k miles and not 183k, then I would recommend you leave the bottom end alone. It has plenty of life left. I would consider that low miles for an L series.

 

Also worth mentioning, in some cases, the stock exhaust manifold may actually make more power than the headers. I'll have to dig up the thread where this is discussed. Headers do sound better though if you want to sacrifice a few HP. I would.

 

Here's the thread: http://forums.hybridz.org/topic/102748-build-after-24-years/

 

I don't know what your budget is, but another option for you is ITBs. Jenvey makes ITBs that bolt on in the place of DCOE carbs. They look pretty good, sound great, and of course there's the benefit of fuel injection. Expensive though, and on a low power build may not be worth doing.

Edited by rturbo 930
Link to comment
Share on other sites

If it's genuinely 83k miles and not 183k, then I would recommend you leave the bottom end alone. It has plenty of life left. I would consider that low miles for an L series.

 

Also worth mentioning, in some cases, the stock exhaust manifold may actually make more power than the headers. I'll have to dig up the thread where this is discussed. Headers do sound better though if you want to sacrifice a few HP. I would.

 

Here's the thread: http://forums.hybridz.org/topic/102748-build-after-24-years/

 

I don't know what your budget is, but another option for you is ITBs. Jenvey makes ITBs that bolt on in the place of DCOE carbs. They look pretty good, sound great, and of course there's the benefit of fuel injection. Expensive though, and on a low power build may not be worth doing.

 

I saw those ITBs.....Very nice in my opinion...But pricey yes...

Link to comment
Share on other sites

 

Does it sounds like a good setup?

 

Im looking more at reliability than high hp numbers.

 

 

Seems like you really have a vision of what you want to see when you open the hood.  Triple Webers.  The early ZX distributor has about the same timing as your 77 unit, and 77 has a decent electronic ignition module.  No great reason to change distributors.  In addition to what I mentioned above about cam profiles, others have tried the mild cams and been disappointed. 

 

Your list is the basic "incremental change" list that people put together, then wish they'd gone bigger or spent money elsewhere when they were done.  Seriously, the only thing on the list that will add much power is the cam profile, and without the head work the potential won't be realized.  If you're going to do actual track time, spending money on suspension might be more effective.

 

Again, I'm mostly regurgitating what I've seen.  You've only searched for a few days but if you keep reading you'll find that you're about to spend much money, time, and effort and have essentially the same performance when you're done, with less reliability.  

 

Your list is more of a "this part broke what should I replace it with" list, instead of a performance build list. Don't like EFI - switch to carbs, clutch wore out - go heavy duty, distributor died - get a ZX replacement, etc.

Link to comment
Share on other sites

Seems like you really have a vision of what you want to see when you open the hood.  Triple Webers.  The early ZX distributor has about the same timing as your 77 unit, and 77 has a decent electronic ignition module.  No great reason to change distributors.  In addition to what I mentioned above about cam profiles, others have tried the mild cams and been disappointed. 

 

Your list is the basic "incremental change" list that people put together, then wish they'd gone bigger or spent money elsewhere when they were done.  Seriously, the only thing on the list that will add much power is the cam profile, and without the head work the potential won't be realized.  If you're going to do actual track time, spending money on suspension might be more effective.

 

Again, I'm mostly regurgitating what I've seen.  You've only searched for a few days but if you keep reading you'll find that you're about to spend much money, time, and effort and have essentially the same performance when you're done, with less reliability.  

 

Your list is more of a "this part broke what should I replace it with" list, instead of a performance build list. Don't like EFI - switch to carbs, clutch wore out - go heavy duty, distributor died - get a ZX replacement, etc.

 

Hey, thanks for the comments!

 

Yeah im aware that not much hp can be get from those engines without spending ton of money.....

 

Suspensions, brakes etc will be done, but in that area i already know what to do.

 

So if i want to get some hps without breaking the bank, you would say big cam, head work and megasquirt?

 

I may go this way and add some headers and exhaust to get some sound....

Link to comment
Share on other sites

 

So if i want to get some hps without breaking the bank, you would say big cam, head work and megasquirt?

 

 

That is the essence of what I've extracted from what's out there.  But I just saw your comment in the other thread about your LS engine in the BMW track car.  So the real question is, do you want to make "vintage" power or just power?  Or be unique?  Some people out there are actually destroking their L28's to make a high-revving lower power potential engine that's fun to drive.  Lots of different things you can do.  

 

Just trying to fit your stated goal and add a few not obvious things, like the fact that you'll have essentially the same ignition system with a ZX distributor as what you have now.

Link to comment
Share on other sites

That is the essence of what I've extracted from what's out there.  But I just saw your comment in the other thread about your LS engine in the BMW track car.  So the real question is, do you want to make "vintage" power or just power?  Or be unique?  Some people out there are actually destroking their L28's to make a high-revving lower power potential engine that's fun to drive.  Lots of different things you can do.  

 

Just trying to fit your stated goal and add a few not obvious things, like the fact that you'll have essentially the same ignition system with a ZX distributor as what you have now.

 

Vintage power is what i would like best for this car but not at the expense of spending ridiculous amount of money....

 

And by "power" i mean something around 200-250 hp, it would be perfect for what i intend to do with this car....

 

I already have my high hp track beast so im not looking into that kind of build with the Z......Not for now at least....

 

But sadly, it looks like much $$ will have to be spent to get to those conservative number...lol

 

For the ZX distributor thing, i read somewhere that the curve on them was more adapted(but not ideal) for the webers than the stock one but i may be wrong on that one......

Link to comment
Share on other sites

You can hit 200 pretty easily. A good tune and just a few basic mods should get you there. 250hp will take more effort. Some good headwork and a cam, plus tune, I'd say would get you in the ballpark.

 

What's your budget?

Edited by rturbo 930
Link to comment
Share on other sites

You can hit 200 pretty easily. A good tune and just a few basic mods should get you there. 250hp will take more effort. Some good headwork and a cam, plus tune, I'd say would get you int he ballpark.

 

What's your budget?

 

If i could spend around 2k to get there it would be ok....

 

I can do the cam myself but i would send the head for the headwork....

 

I do most of the work myself on my cars execpt some internal engine works that i rather not mess with.....

 

I just dont want to get to a point that i would regret to not have swapped another engine instead.....

Link to comment
Share on other sites

I just dont want to get to a point that i would regret to not have swapped another engine instead.....

 

Seems like you have some internal dissonance.  Wobbling between power, nostalgia, and money.

 

This thread actually covers everything you're thinking about, just for a stroked engine.  And the guys who've built power in the past, like JMortensen and John Coffey and others, have added to it.

 

http://forums.hybridz.org/topic/24798-na-31lhead-camshaft-questions-no-shortcuts-max/

Link to comment
Share on other sites

Seems like you have some internal dissonance.  Wobbling between power, nostalgia, and money.

 

 

Spot on....lol

 

Everything was pretty clear until i pulled out that damn engine out of the car for the restoration project....

 

Now that i have it on the engine stand, it is less and less clear what will happen next.....

 

But this thread is very constructive, thanks for all those advices!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...