L24 horsepower

[Phred]

2manyZs,

I built and dyno'd several 240 ITS engines, and the most I ever saw was 172. This was on a SuperFlow computer control dyno.

This particular engine won the Oregon Region Championship. I'm sure other engine builders have gotten more HP out of the L24. Up here in the Northwest we have what we call California Horsepower. Someone comes up from Ca. and says his dyno shows 185 HP. Then gets pulled down the straight by one with 170. This was similar with the formala ford engines. We would build one with 114 hp, go to the runoffs and pull a guy down the straight who claimed to have 118. In all fairness, dyno's in different parts of the country use different correction factors. Thats why you should not get too optimistic when you hear someone throw out some big HP numbers. Dyno's are great tuning tools, and give you a good reference point on how a particular engine is going to work. But its all relative. If you get beat down the straight, you need more!

Phred

[moyest]

I have to agree with the comments on Dyno variation.

When I bought my stock standard L24 powered 240Z with 2.5" exhaust, the Dyno sheet showed 131 horsepower.

Now, that CAN'T have been at the rear wheels, so I assume it was at the flywheel. But the L24 in this part of the world is rated at 151hp at the engine!

Anyway, I went ahead and did porting/polishing, re-profiled cam, and triple weber carbs on TWM manifold (port-matched) with better spark plugs.

Result was 133hp at the rear wheels, a nice curve on the Dyno chart, and I can really feel the difference on the road! That makes me think the original 131hp figure must have been at the engine (which makes the 151hp rating a bit of a mystery!?).

So there you have it. :classic:

But perhaps any of you boys can recommend how to get more out of my engine set-up? e.g. electronic ignition (would that require re-tuning the carbs again, and more tinkering, or is it just a straight "swap-n-drive" scenario?)

MoyesT

[Bambikiller240]

Originally posted by moyest

.................But the L24 in this part of the world is rated at 151hp at the engine! ....................................

MoyesT

Back when 240Z's were being built and sold as new cars, the HP rating listed in the brochures and Data tags was calulated in what was called GROSS HP meaning the engine was on a test bed with no accessories like an alternator, EGR pump, (and probably not even a water pump driven by the engine). The figure was nice for advertizing, but was certainly NOT a real world number with validity for the buyer. Somewhere in the mid to late 70's (in the USA) the gov't mandated the use of SAE NET horsepower figures which meant that the engine HP rating had to be measured on an engine equipped with all accessories found on the production automobile.

[Ben]

And even those figures were optimistic, as a control fuel wasn't used & the OEM exhaust was also not fitted (among other things)....

A fresh, stock, L28E will turn the rollers on a Dyno Dynamics dyno at around 68kW via the factory auto & a 3.9:1 R180. In comparison, my DR30 Skyline, fitted with a fresh (stock) 145kW FJ20ET will turn the rollers at ~110kW via a 5-speed & 3.9:1 R200 LSD. The run in the auto was done in 2nd (to enable manual gear selection) and the manual in 3rd.

There is a local driver with a full-race L24 that turns a DynaPak at ~160kW @ ~8500rpm. That car MOVES.

Anything above 120HP is good for an L24!

(but if you factor in the 'different' readings that a DynoJet gives as opposed to a Dyno Dynamics, then the figure is more like 140HP).

[beandip]

I don't know where your part of the world is as you decided to not include this in your profile. But your expectations seem a lot high with your L-24 .:tapemouth

[frank13]

BMW? CIS or CISE. Both of which are mulitport fuel injection systems. My cousin had a 86 325E 5spd, posi. Real nice car. He couldn't get around to pass my POS '80 Audi 4000 1.6L VW motored 4 spd. Some engines have lots of revs but no torque. Some have lots of torque with no horsepower. The Z has both. Low numbers or not. When you can get in a 30 year old car and have that old engine slam you head back as you take off, that is not too shabby. If you look at cars just a few years ago, there was alot of talk for the cars like mitsu, mazda, honda, about having 150 ponnies. Wow it only took like 30 some odd years. They also do not tell you if it's at the flywheeel are drive wheels. So don't get down on the numbers. The Z is A lite car. It uses it's ponnies well. Remeber most new ( last 10 years) Asian cars (read economy here) are in the lower range than the Z. And weigh more. :devious:

[Mr Camouflage]

Do how do you get more power from the L24?

Different cam?

EFI?

Bore and stroke to L28 specs?

Turbo?

All of the above?:classic:

[kmack]

Originally posted by moyest

I have to agree with the comments on Dyno variation.

When I bought my stock standard L24 powered 240Z with 2.5" exhaust, the Dyno sheet showed 131 horsepower.

Now, that CAN'T have been at the rear wheels, so I assume it was at the flywheel. But the L24 in this part of the world is rated at 151hp at the engine!

I had my '73 L24 engine dynoed last July. Motor has 200k+ miles, bad valve seals and worn rings. Burns about a quart of oil every 1500 miles (more if out on the track, a lot more!). Here is a copy of the Dyno Chart .

The chart is at the bottom of the page. 127 hp w/ 127 ft-lbs of torque, at the wheels! And it was running rich. Not bad I say. '73 L24 block, E88 head, stock points, cam, '71 SU's, 6-2 header, 2-1/4" exhaust.

btw - if anybody is interested, this motor is for sale. $100 obo.

[moyest]

Beandip,

I'm in the "Australian" part of the world, and I think my expectations for horsepower have proved fairly reasonable. 133hp at the wheels has made a HUGE difference from a driver's perspective, and I hope I can squeeze a bit more out by improving the ignition (electronic).

Based on all the other comments, I think I can summarise as follows:

151hp is GROSS HP for a standard L24 (nothing more).

Kmack's Dyno results of 127hp is probably at the flywheel.

My result of 133hp at the rear wheels seems pretty good, but bring on the "160KW" figure!!! That's INSANE!

P.S: Kmack, I make that comment because my previous Dyno (standard engine like yours, reconditioned with headers and exhaust) showed nearly 130hp - that figure CAN'T have been at the driving wheels, because now I'm pushing 133hp at the driving wheels (after fairly extensive modifications) and it has made a HUGELY noticeable difference. If you're churning out 127hp at the rear wheels then you're nearly keeping up with my current engine set-up: mild cam, ported & polished head, non-standard headers and exhaust, port-matched TWM manifold, and and triple DCOE45 webers!

The L24 sure is a mighty engine! Mine's back at the mechanic though, with torn O-ring / soft-mount on one of the carbies! :sleepy:

Back tonight.

[Bambikiller240]

Originally posted by moyest

Based on all the other comments, I think I can summarise as follows:

151hp is GROSS HP for a standard L24 (nothing more).

Kmack's Dyno results of 127hp is probably at the flywheel.

YES, 151 HP is GROSS with nothing attached to the engine.

NO, kmack's figures are at the rear wheels as he indicated in his post.

[kmack]

Originally posted by moyest

Kmack's Dyno results of 127hp is probably at the flywheel.

P.S: Kmack, If you're churning out 127hp at the rear wheels then you're nearly keeping up with my current engine set-up: mild cam, ported & polished head, non-standard headers and exhaust, port-matched TWM manifold, and and triple DCOE45 webers!

Yes that hp figure was taken at the wheels. On a chassis dyno. Follow the link to the webpage and you'll see the pictures.

What you need to keep in mind is this: all chassis dyno's can and will produce different hp figures based on level of calibration, height above sea-level, maintenance programs for the dyno, etc. All this using the exact same car. Now take into account the fact you have a completely different car and engine. That alone is a big factor.

6hp is a fairly big step up from my car which, aside from headers & exhaust, is basically bone stock. But with the mods you have you really should be running a little bit more, IMO.

Use the dyno to your advantage. Take some time and plan to spend a day on the dyno making changes to your engine. Tune it up some, adjust the timing, mixture, etc. The only way to fully tell if you are getting the most out of your motor, is to make minor adjustments while using a dyno. The hard numbers will tell the tale.

As for me, I'm getting ready to make plans for another trip to the dyno again in the upcoming months. I have my '71 motor rebuilt and back in my car. E31 head, Fel-Pro gasket, K&N filters, headers/exhaust, electronic ignition. I'm hoping to hit at least 130hp (at the wheels!) and then the mods will start from there. I have to establish my baseline first, though.

[kmack]

Originally posted by kmack

127 hp w/ 127 ft-lbs of torque, at the wheels! And it was running rich. Not bad I say. '73 L24 block, E88 head, stock points, cam, '71 SU's, 6-2 header, 2-1/4" exhaust.

Talk about reviving an old thread....

This is an update to the dyno information I got last year.

Last September I had the opportunity to rebuild my 71's original engine. '71 block, E31 head, new rings, gaskets, seals, Felpro head gasket, no machining to block or head, '71 SU's, 6-2 header, 2-1/4" exhaust, stock distributor, points, K&N filter in stock airbox.

So this past Saturday, I finally had the chance to put the engine on the dyno to see what kind of difference it has compared to the old '73 engine.

Man! What a difference it made!!!! 136.8 hp at the wheels!!!!

Now keep in mind this is on the same dyno that was used last year, so the results will be fairly accurate.

I couldn't believe it myself when I first saw it. I was only expecting to just break 130. But it's still running rich like it was last year. So on a subsequent run, I removed the k&N and airbox all together. 139.2 hp at the wheels!!!! That's almost 2.5 hp alone being trapped in airbox! I'm gonna be hacking that thing up for sure now!

I haven't had the time to scan the dyno sheet in yet, but I will soon. Proof is in the paper!

FWIW, San Antonio is at about 800-900 ft above sea level. Temp. was about 95* F and humidity was in the 80% range.

Also, does anybody know what the rated hp figures are the JDM Fairladys w/ the L6 2.0L? We had one one the dyno also, but it only pulled 88 hp at the wheels. Seemed kind of low to everybody. Owner said he does regular maintenance on the engine and has had no signs of problems with that engine. It is a daily driver, too.