Jump to content
adam

Rebuilding L series motor - Worth it?

Recommended Posts

Hi all, 

Thought I'd be a little old fashioned and use forums instead of modern age Facebook social media.

Those of you who have rebuilt your L series motors, whether it be L24, 26 or the L28, has it been worth the effort?

Let's be honest, in this day and age, you can buy much quicker cars and motors.

I'm currently running a stock L28 with triple carbs and a full exhaust, it does the job and love the fact I can squirt it around town without breaking speeding fine records. It's a little tired, chewing through oil, leaking a bit here and there.

Was thinking of a standard rebuild, possibly flat tops and mild cams but the question, did you take it a bit further? Was it worth it?

If you could do it all again, what would you do differently? Original L series is my goal but should I waste my time?

Keen to hear from those who have done it.

 

Thanks, 

Adam

Share this post


Link to post
Share on other sites

You question is a bit "How long is a piece of string", Adam.
And it depends on what your expectations are...

The big $ is in the cylinder head - if you want performance that's where the bulk of the $ go.
If you are aiming for under 250hp (flywheel), then a standard bottom end is fine.

Have a read of this thread if you haven't already - it cost the owner, all in with a new Scorcher Dizzy ,$6,000


 

Share this post


Link to post
Share on other sites

Apologies, quite evident that I didn't elaborate enough.

The zed I have wasn't built to go fast, it's predominately a weekend twisties car. It has plenty of go at the moment to be fun.

Although it has plenty of go, it's at the point where, 'it could do with a freshener'. By that, it's losing a bit of oil in it's usual places and blows some smoke (could be from running a tad rich also).

I have another car which is tracked and is the 'go fast car' so I don't necessarily need another. But in saying that, if I were to go and build a motor, those that have spent the little extra coin for head work, oversized pistons or even going to flat tops from the standard dished, has it been worth it? 

Should I spend the extra coin on a cam, new pistons, head work, etc. For an additional... 20hp gain? Or if I was to do new rings and a hone, do I just leave it at that because the extra $500 per horsepower isn't worth it?

Obviously the response would vary from person to person but I am just curious to hear thoughts, create conversion and activity on the forum social media platform again.

Also thanks for the link, I have read it before, definitely to the level of something I would consider doing. 

Share this post


Link to post
Share on other sites

In a word Adam :YES

Yes it is worth it.

I have been lucky enough to have belonged to a Zed Club for 35 years and have seen, not all of it but most of it.

In my experience the Lseries engine stacks up well against all comers . It may not have it over all transplants but they have to work hard to put a L series down. The Barra transplants are hard to come to terms with as they are a cheap motor and look at home in a s30 engine bay.

But I am old sckool. A  S30 without an L-series  engine is just an other modified car.    

Edited by Bonkers

Share this post


Link to post
Share on other sites

Get your car dyno'd so you understand how much there is to be gained. That'll give you some perspective for... $150??

Share this post


Link to post
Share on other sites

Thanks, Bonkers, that's the kind of response I was expecting..

No intentions on doing a motor swap at all. I have a spare L28 here that's stripped and ready to go in for a rebuild but was on the fence about going that little more or a stock standard build.

As mentioned, completely understand that everyone's responses will be different but I was hoping to create conversation. Was actually expecting someone to say, 'dont even waste your time on small/minor modifications, go hard or do nothing at all'.

And Cracker, already dyno'd current motor. Would be nice to compare before and after's but it's another complete motor going in.

Original intention was to sonic test bores, go largest flat top pistons possible, standard stroke, just cleanup ports of the head with mild cams and call it a day. Didn't know whether it was worth going over bore if there was minimal gain. Now I'm thinking of just fresh bearings and rings lol 

Share this post


Link to post
Share on other sites

Adam you sound as if you are happy with the configuration of your power plant .

But would like a little more drive ability from it.

So if you have a L28 sitting around and don't wish to spend big dollars. I would look at this .

The 42 and 54 blocks both have there pro's and con's pending on who you speak to. If the bore is standard put in 240Z pistons. If the bore is worn and you will need over size pistons . You can take a number of paths here. 1mm over size is common but pistons are becoming hard to find. 

A lot of us put in Z24  or KA24 pistons. A few install the LD28 crank with 240Z rods with 2 or more head gaskets.

Or stay with the standard L28 or L26 crank with 240Z rods. But you may want to deck 1mm off the block and slot the holes in the chain guides to take up the slack in the timing chain. In this configuration with a n42 head and Z24 pistons give around 9.6:1 and KA24 gives around 10.4 :1 from a 2990 cc engine.

This is standard machining and off the shelf parts. This is only a sample starting point for a weekend warrior with a few K to spend and wants some change in their pocket . But it won't buy much at MacDonald's 

  

Share this post


Link to post
Share on other sites

Not an L28, just a little L18.

Old engine, pretty much worn out after 20 years (stock bottom end, unknown mild cam, minor head work and 38mm SU's) - 69hp at the rear wheels

Same engine carefully rebuilt with 87mm flattops, bit more head work, 72 degree cam and 1 3/4" SU's - 102 hp at the wheels.

No, its not the most powerful engine around, but the difference pre and post rebuild was considerable. I rebuilt it myself, total cost of all parts and machining was well under $2K for that extra 33hp. Would the next 33hp gain be just as cheap ? I doubt it....

 

Edited by 1600dave

Share this post


Link to post
Share on other sites
16 hours ago, adam said:

 

And Cracker, already dyno'd current motor. Would be nice to compare before and after's but it's another complete motor going in.

So what was the result?

Share this post


Link to post
Share on other sites

 

3 hours ago, cracker said:

So what was the result?

84rwkw from memory

Share this post


Link to post
Share on other sites
2 hours ago, adam said:

 

84rwkw from memory

To me that makes a rebuild worth it. I was getting 84rwkw from an old L24 with a cam and an exhaust.

For a fresh L28 you'll get 110rwkw+ and it'll make a huge difference with a lightened flywheel. You'll love it.

There's a certain charm about a bone stock zed, but if it's not the original motor you might as well go for it. I love my L28 with triples (I also love my original zed, but it's a different kind of love :P)

For a cheap alternative, make sure your diff ratio is fun enough, and if you have a WR box, go to CR and get your flywheel lightened. Will add 30% fun for not much cash at all.

Share this post


Link to post
Share on other sites
3 hours ago, cracker said:

To me that makes a rebuild worth it. I was getting 84rwkw from an old L24 with a cam and an exhaust.

For a fresh L28 you'll get 110rwkw+ and it'll make a huge difference with a lightened flywheel. You'll love it.

There's a certain charm about a bone stock zed, but if it's not the original motor you might as well go for it. I love my L28 with triples (I also love my original zed, but it's a different kind of love :P)

For a cheap alternative, make sure your diff ratio is fun enough, and if you have a WR box, go to CR and get your flywheel lightened. Will add 30% fun for not much cash at all.

Awesome! So no matter what route I go with the rebuild, it should be a huge difference. I actually didn't think the power was all that bad power wise; good to know there should be a bit more in it!

 

Will definitely try and strive for Lurch's build on that customer's car minus head work I think at this stage. 

Share this post


Link to post
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.
Note: Your post will require moderator approval before it will be visible.

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...