Advice on L24E hp gain

[ArchetypeDatsun]

I have a 79 810 wagon that I purchased the beginning of last month has the original L24E was a 4 speed manual now has a 83 280zx 5 speed other than that it's completely stock. The 810 runs and drives strong how it should with no problems other than a minor small muffler leak.

 

My plan is to keep the original engine because it's such a great engine. I want add some power to it, exhaust since it's the old 30+ year old one and a header. I want to keep away from turbocharging it and keep it N/A along the lines of keeping it fuel injected as well.

 

I wanted to run a good sized exhaust 2.25" maybe 2.5" if i don't lose power at that size, a camshaft & some ITB's.

 

Anyone have better insight on making some power on the L24E I appreciate the help.

 

[cjack300zx]

That's is one clean looking wagon you have, I would love to own one of these one day. I dont know much about the l24e engine but typically an NA engine doesn't respond as well to mods as a turbo engine. There is power to be gained but just not huge amounts

[BluDestiny]

There is no real appreciable gain you can get from that engine without at least taking the head off and getting port work done. I would get mods that will support what your end goal is, so headers and a 2.5" exhaust would be a good place to start. 

 

I would hold off on the cam and fuel delivery until you get port work done. It would be a shame to spend $1500 on itb's and only gain 20hp because of the ports. 

[ArchetypeDatsun]

Thanks for the responses guys!

 

My goal is pretty simple, I guess I could start with porting the head and go from there the itb's is more for doing something different I know there's no huge gain. MPG's would probably fly out of the window if I put ITB's on, I may even go add the LD28 crank. I'm not looking for huge hp number just want to help the L24E respond a little better. I know an L28 would be a better choice but that's a the very last of my choice on my list.

 

If all really fails my second choice would be a RB30DE with a RB26 head, header & itb's but that might be a lot more than what I can afford right now.

 

I also wanted to add that I have the stock solid rear axle H190 3.70 gears.

Edited April 3, 2013 by ArchetypeDatsun

[Gollum]

There's no reason you can't build the L24(e) to 200+hp, even at the wheels. It just takes dedication to the details. There's also no reason NA hp has to equal low MPG. Yes they can be related, but MPG has more to do with tuning and driving style than it does inherent engine design. I've seen guys get 20% or more than EPA ratings out of an engine. I've also seen people that get 20% LESS than the EPA rating. I've owned B16 swapped CRX's and had friends with the same or similar swaps that put 150+hp to the wheels, nearing S2000 HP/Liter stats and we all FLOGGED them on a daily basis, and STILL got 35+mpg per tank. Even with the YS1 trans wit ha 4.44 final gear, cruising down the freeway at 4,500 I could STILL manage 35mpg no sweat.

 

So, with all that said, lets talk power.

 

What do you want? That determines your path limitations. Goals goals goals. Figure them out, or you'll chase nothing forever.

 

ITBs are awesome, cool, and just awesome. But they're completely pointless for 90% of us. They're way more about the look and sound, and if that's why you want to do it don't let ANYONE stop you. That's A-Okay with me. Novelty is a get out of jail free card. You can't rightfully disagree with someone's decision if it's about style, that's their choice. That said, a good log manifold with the right size, straight runners can make a lot more torque down low and be more responsive at street RPM ranges due to the higher velocity retained.

 

So, before we dive in, let me say that you should be prepared to invest either time or money. People often say "Fast, Reliable, Cheap, pick any two" and that's fairly true for the most part. I personally believe in an expanded philosophy of that, and that those three things are on a sliding scale and you can have certain amounts of each, and that some combinations are inherently better overall, or have a higher average of each. I also believe there's a 4th aspect, which is time. Almost any cost can be offset with time. Time gives you and edge to LEARN how to DO something YOURSELF. Tools to port a head are a helluva lot cheaper than getting a head ported by a shop, and can often be JUST as good. There are plenty of people who's FIRST port job turns out FABULOUS results, because they took their TIME to LEARN.

 

Onto business..

 

#1. Power is made in the head, but many guys just go hog wild porting the intake and exhaust ports to unreal sizes.... no no no no no.. just say no. If you could only touch ONE area of the head, focus on valve unshrouding. Your valve spends considerably more time at lower valve lifts than it does at high lifts. Going from a .450 lift cam to a .65 lift cam doesn't make NEARLY the difference that duration and overlap can make. Smooth out the ridge at the valve seat as much as possible. Scribe the head with the gasket to see how much meat you can take off around the valves to keep the radius as smooth as possible and you've gotten the largest flow increase most any street head will ever get. After that smooth out the bowl transition and raise the intake port as much as REALISTICALLY possible (in other words don't just port from the centerline but raise the centerline by leaving the floor alone and porting the top side.

 

#2. Think about everything as a SYSTEM. Don't just throw an exhaust on until you've thought about intake, cam, and head flow dynamics. Too many guys just throw a cam in and expect to make power. You also can't do a ton of head porting and expect the stock intake to do well on it. You can't throw a header on with a cam and expect 40+ hp to just show up at your door. Research, research, research. Once you think you know what you want to do, call a pro lie robello, or braap, and see what they think about your proposed setup and if they have any suggestions.

 

#3. In the process of all this, don't forget about your goals. Have clearly defined goals from the get go. Define them. Refine them. Detail them. Without proper goals you'll only chase NOTHING, for just about FOREVER...

 

#4 Ditch the stock EFI. It's rubbish. The sooner you accept that, the happier you'll be. Pure opinion, so take it as such. Most of the people around here like megasquirt because it's very DIY and that's what we're into, and why we own Z cars. Haltech and SDS are both great options if you want customer service on the phone and an easier to configure system. I suggest using a crank mounted trigger wheel instead of the dizzy, as it'll be more accurate and less prone to issues. They're about $30 and worth every penny.

 

 

 

In reality, just headwork, cam, exhaust, and a ported EFI manifold tuned by a good EFI system that's also controlling spark could net you around 150+ hp to the wheels on a fairly "mild" setup that'd be wicked fun and still capable of GOOD MPG, possibly better than you're getting now considering you can run closed loop on a wideband, shooting for learner AFR targets than the stock system does.

 

Just some food for thought.

[ArchetypeDatsun]

Thanks for all the great points, I will utilize them and rearrange my goals and set my sight on realisic mods.

 

I like to plan out a few choices some of course will rule out because either it's unrealistic and I'll never do it or money wise.

 

Getting rid of the efi is one of my main concerns I'm not big on electrical but this is something i want to do and get a megasquirt or some type of fuel management system.

 

Far as the head work that will be a challenge for me but with the tools in hand and time to do it I would gladly step to the plate.

 

Looks do have some part into my plans but I also want something that works not just looking pretty and doing nothing. I did mention the exhaust just because the stock one is pretty old and rotted looking. My last car was a 280zx I guess I in used to the sound it used to make when I had the original L28 with exhaust.

Edited April 5, 2013 by ArchetypeDatsun

[R3VO 3VOM]

Electrical on any of these older cars is actually quite simple if you track down the manual with the foldout pages and such. I found mine online for my Z. I'm not big on wiring either, but once you look at a diagram for it for a while it's easy.

 

But megasquirt is a very good EM system.

[ArchetypeDatsun]

I have 3 big shop manuals and 1 original manual strickly for this car. I been reading it on my spare time and getting to know everything about the 810.

[Tony D]

I wonder if the 200SX crossmember fits these like a 510? The VG-30 510 wagons I've seen with the Saudi Carb/Distributor have looked absolutely stock...like they were made for the car.

 

That being said, I helped a guy convert from his L24E to a bone-stock L28ET in a Maxima wagon...which he then cruised through CA Smog Check in...and couldn't believe how easy it was. He relocated to the east coast in that car, trailer ing his race Z, with his worldly possessions in on and around that L28ET wagon!

 

He had big ideas of making more power, etc etc etc... But in the end he was so happy with how the bone-stock L28ET ran in the car...he just left it!

 

If I had a Maxima Wagon like that...the Z32 NA in the back yard (automatic) would have a hard time remaining whole...

 

Parts. Is parts! LOL

[Heroez]

2.4, 2.6, 2.8 its mostly the same when it comes to the L-engine basics. Researching 240z 2.4 engines and looking at similar year 280zx EFI/turbo will yeild something applicable. Identicle even in some ways. But you are at hybridz. The possibilities. I have a 2.4 maxima head, very neat. It is desireable in certain applications. You can build what you have to 200 hp or so, then the cars body/chasis suspension/brakes etc need upgraded to stay in balance. Budget, a goal, it will be clear once you do a l o t of reading. Nothing personal but Im not a fan of goons. You could sell it and buy a turbo ZX? Most work would already be done, upgrade when you like! 180 hp out of the box baby! Whats this? T-tops? Whoo hoo!

Edited April 8, 2013 by Heroez

[ArchetypeDatsun]

2.4, 2.6, 2.8 its mostly the same when it comes to the L-engine basics. Researching 240z 2.4 engines and looking at similar year 280zx EFI/turbo will yeild something applicable. Identicle even in some ways. But you are at hybridz. The possibilities. I have a 2.4 maxima head, very neat. It is desireable in certain applications. You can build what you have to 200 hp or so, then the cars body/chasis suspension/brakes etc need upgraded to stay in balance. Budget, a goal, it will be clear once you do a l o t of reading. Nothing personal but Im not a fan of goons. You could sell it and buy a turbo ZX? Most work would already be done, upgrade when you like! 180 hp out of the box baby! Whats this? T-tops? Whoo hoo!

Trust me I've done a lot of reading been in this forum for years that's how I learned to navigate. The only thing I haven't really seen much is L24E anything just a few builds and a L24ET built.

 

No offense taken but I sold 280zx Turbo to buy this 810 took many years of waiting and being patient and I'm not about to sell it to buy another Z. I could tell you to sell your Z to buy a better car but who am I to tell you so, thats why they make different cars to suit difference in opinion and needs. I bought the wagon to make more room for my family as the Z was only a 2 seater and don't have taste for the 2+2 models. I'm a huge Datsun enthusiast not just strictly Z cars, in the future would most probably be buying a S30 or a 510 but keeping the 810 as long as I can. My plan is to still keep this a cruiser but make it a little funner to drive.

Edited April 9, 2013 by ArchetypeDatsun

[ArchetypeDatsun]

I wonder if the 200SX crossmember fits these like a 510? The VG-30 510 wagons I've seen with the Saudi Carb/Distributor have looked absolutely stock...like they were made for the car.

 

That being said, I helped a guy convert from his L24E to a bone-stock L28ET in a Maxima wagon...which he then cruised through CA Smog Check in...and couldn't believe how easy it was. He relocated to the east coast in that car, trailer ing his race Z, with his worldly possessions in on and around that L28ET wagon!

 

He had big ideas of making more power, etc etc etc... But in the end he was so happy with how the bone-stock L28ET ran in the car...he just left it!

 

If I had a Maxima Wagon like that...the Z32 NA in the back yard (automatic) would have a hard time remaining whole...

 

Parts. Is parts! LOL

You know it might fit maybe even with small modification it's very possible.

 

I heard people fitting Datsun Maxima sway bars onto the 810's because they thicker and bolt right in. Also read that a 280zx rack & pinion is very possible swap. As for a L28ET swap it would very possible I would do it but it's in the least of my options. Fitting a decent intercooler would be a problem for me if I ever wanted to go beyond stock power on the L28ET. Maybe a small water-cooled intercooler and turbo would be a better function.

[Gollum]

You know it might fit maybe even with small modification it's very possible.

 

I heard people fitting Datsun Maxima sway bars onto the 810's because they thicker and bolt right in. Also read that a 280zx rack & pinion is very possible swap. As for a L28ET swap it would very possible I would do it but it's in the least of my options. Fitting a decent intercooler would be a problem for me if I ever wanted to go beyond stock power on the L28ET. Maybe a small water-cooled intercooler and turbo would be a better function.

 

Intercooler requirements are directly related to heat output, which is directly a function of where you're at on your compressor map. But forget all the theory talk that could ensure, reality is:

 

10PSI is FINE on the stock turbo which can get you to 200rwhp when tuned right.

 

Change to a decent T3/T4 hybrid and you can run up to about 12-14psi with no intercooler and make as much as 250rwhp.

 

If you're willing to convert over to E85 you can probably get away with as much as 14-15 psi on the stock turbo with no intercooler, if not MUCH more in all reality.

 

The key to all this is TUNING, and that should be a high priority no matter WHICH engine you choose.

[Tony D]

"Change to a decent T3/T4 hybrid and you can run up to about 12-14psi with no intercooler and make as much as 250rwhp."

 

Ditto!

 

The stock L28ET in Europe was 200HP, not 180 like the states. Uncork the exhaust to 3", run a decent hybrid and fueling and you have easily hit 250 without an intercooler (more if you cam it and port a bit) -- I have seen 380ft-lbs on a car at 8.39psi at 4500rpms. It's not really the HP you want, especially in a wagon...you want that torque and it's hard to beat a turbo for that!

[ArchetypeDatsun]

That would be a ton of fun as I had a T3/TO4E in my 280zx I sold it was lots of fun and it was running on stock boost and no intercooler.

 

I've seen that a member that had that black 82 maxima with the L28ET swap had a top mount intercooler probably not the best way since it was getting all that engine heat.

[aarang]

I had an 810 wagon ages ago. The L24E developed a rod knock, so we pulled it out and transplanted just a plain jane L28E. Even just that swap made a big difference in how the car drove. Way more fun to drive after that.

[ArchetypeDatsun]

Definitely the L28 is a top choice if my mechanic

friend still has my old L28 i left him I would gladly pick it up and build it up and when the time comes I could swap in.

 

I want to give the L24E a chance pretty much anything I do to the L24E can be transferred to the L28 in the future.

Edited April 9, 2013 by ArchetypeDatsun

[madkaw]

Good to see someone else sticking with the little l24. Gollum has some great info. With my mild modifications-stage 2 cam and unshrouding and l28 valves I mustered 155 at the rear with SU's. That's enough for some good fun. Now whether the stock FI will deal with that, I don't know. I would sure love to have MS FI with my motor now.   

[ArchetypeDatsun]

I like to give it a chance the engine hasn't shown any problems that would suggest I swap it out. I don't know the limit of the L24E computer unlike the L28E.

 

Would you know why the early 810's had 154hp instead of the later models 125hp that's 29hp difference.

 

 

[rejracer]

In 1979 they changed the way HP is measured from SAE gross to SAE net.  It's roughly a 20% difference.  They did the same thing on the Z cars as well.