Rebuilding A L24 engine and would need some help

[SLASH]

Hello guys i am a 240z owner with L24 with no modification at all Over Hong Kong, due to we don't have much 240z over here and not much garage that would have much knowledge and experience with these type of cars, i would really need some help.🥺

hope you guys won't mind for me to ask some stupid questions.

 

So once we trying to rebuild the engine we found out that there are lots of parts to be purchase, so i have bought tons of rebuild parts form Zdepot, then we found out that the Crankshafts in the L24 is scratched badly and not in a good condition, i am looking for a brand new one but no hope i believe the parts number is E3141 or E3142 if i am correct? 

some is suggestion me to get the L28 engine Crankshafts, but i have done some research that it's about 6mm larger?

So my question is if i really want to install the L28 Crankshafts what other parts do i need? will it fit just like the L24 crankshafts like plug and do or i have do a lot of work to get it run probably again? due to the size is bigger won't it hit the middle piece or valve?

because i just want to run the engine like stock.

i hope professional guys can give me some advice please, and sorry for my english, after all these years i want to get the 240z, now i finally got it but i am really lack of knowledge with the L-series engine.

i have installed a OER Racing carburetor as well to replacing the Su Dual Carbs.

 

[Patcon]

I believe to go to the L28 crank you will need a crankshaft, block and front timing cover.

Another option for the L24 crank is to buy one reconditioned out of the US market. Shipping would be the only real issue.

[HS30-H]

Your L24 crankshaft can be reground to suit replacement bearings in a factory designated undersize. All details are in the factory service manuals (do you have one?).

Forget about using an L28 crankshaft. It would lead to a domino effect of required parts (different connecting rods, pistons etc).

Looks like you will (possibly) be needing a rebore of the cylinder block, due to cylinder bore scoring. That would require an oversize piston set. If your current pistons are still in good condition (although replacement piston rings are advised) the other option would be to fit cylinder liners. Again this is detailed in the factory service manuals. If yu are very lucky then a thorough honing of the cylinders might be acceptable.

Surely there must be a competent engine reconditioning machine shop business in HK who can handle this?

 

Looks like your camshaft is an aftermarket (higher performance) grind, judging by the stamps on the end of it.

Was the car an original HK market version, or was it imported as a used car? The aftermarket camshaft makes me think the car has already been modified in the past.  

[SLASH]

On 11/20/2024 at 7:07 PM, HS30-H said:

Your L24 crankshaft can be reground to suit replacement bearings in a factory designated undersize. All details are in the factory service manuals (do you have one?).

Forget about using an L28 crankshaft. It would lead to a domino effect of required parts (different connecting rods, pistons etc).

Looks like you will (possibly) be needing a rebore of the cylinder block, due to cylinder bore scoring. That would require an oversize piston set. If your current pistons are still in good condition (although replacement piston rings are advised) the other option would be to fit cylinder liners. Again this is detailed in the factory service manuals. If yu are very lucky then a thorough honing of the cylinders might be acceptable.

Surely there must be a competent engine reconditioning machine shop business in HK who can handle this?

 

Looks like your camshaft is an aftermarket (higher performance) grind, judging by the stamps on the end of it.

Was the car an original HK market version, or was it imported as a used car? The aftermarket camshaft makes me think the car has already been modified in the past.  

Dear HS30-H thanks for the professional reply this really means a lot to me and helped me to think, this car is original import from the Uk the one with no air condition version, i have got it few years ago back in the time, after we bought it and lack of knowledge with the L series engine, after a few times run we have left it the storage then every time when i try to start up again the usually is too much fuel in the engine and all the sparks plug are flooded, we thought it was the fuel pump then we changed a new one still happening, and found out all the rust in the fuel tank, we though it was the rust blocking the fuel rail, after we changed to a new fuel tank, the problem is the same, then i have bought the oer racing carb cause we thought its the Su dual crabs is damaged, now we still got to much fuel even leaking out of the engine through the spark plugs hole,

and no man i don't have a factory service manuals, i have got a  L24 crankshaft which is refurbished  from japan which shipping during this weekend and see what will happening, cause in long term seems like getting a L28 to replace in it is a better option due to L24 engines parts are getting harder and harder to found now days.

with best regards bro i really appreciated guys like you giving me some opinion to see what to do next.

[SLASH]

On 11/20/2024 at 6:52 PM, Patcon said:

I believe to go to the L28 crank you will need a crankshaft, block and front timing cover.

Another option for the L24 crank is to buy one reconditioned out of the US market. Shipping would be the only real issue.

thanks for the reply patcon, shipping is not a problem usually the problem i am getting is people are keep trying to sell me the V07 crankshafts and keep telling me that it is okay to install on the L24 engine whcih is not

[HS30-H]

13 hours ago, SLASH said:

i have got a  L24 crankshaft which is refurbished  from japan which shipping during this weekend and see what will happening, cause in long term seems like getting a L28 to replace in it is a better option due to L24 engines parts are getting harder and harder to found now days.

Too late now, but I think buying and shipping a "refurbished" crankshaft from Japan was not necessary. You - surely?- could have had your existing crankshaft ground and polished locally to suit factory undersize bearings. You're going to be buying new bearings anyway...

As mentioned, the bores appear to be scored and will require either honing or reboring. Whoever is doing that work would - again, surely? - have had either the machinery or the contacts to grind the crankshaft.

L24-specific parts are not that hard to get. Most major components are available, restorable (like your L24 crank) or share parts with the other L-gata engine family. No reason to be chucking out an L24 in my opinion. 

13 hours ago, SLASH said:

...then every time when i try to start up again the usually is too much fuel in the engine and all the sparks plug are flooded, we thought it was the fuel pump then we changed a new one still happening, and found out all the rust in the fuel tank, we though it was the rust blocking the fuel rail, after we changed to a new fuel tank, the problem is the same, then i have bought the oer racing carb cause we thought its the Su dual crabs is damaged, now we still got to much fuel even leaking out of the engine through the spark plugs hole,

!!!!

At this point I'm going to bow out due to fire risk. I don't know who is helping/advising you, but it might be a good idea to change them rather than random mechanical componentry.

Good luck.