L24 horsepower

[zeiss150]

Ok, this is what I have. 72 240 with e88 head,and a stock cam. Head has been rebuilt with new seats and valves(no polish and port) I rebuilt the bottom end, new rings, bearings, cylinders honed (didn't need boreing). I put a 6-2 header with a 21/2" exaust (dynamax flowmaster). I still have the old point distributer and Im still using the origanial round top SU's, I've taken off all smoge "stuff". So, that is what I have. what can I do to get more Horsepower out of this L24 engine. I am thinking about putting a light weight flywheel on and chaning to an electronic distributor. I've also read about putting in "SM" carb needels (how much are thoes?) ... What kind of rearwheel horespower can I expect to get. This is my first car engine experiance, so forgive my ignorance, any info. would be Great!

Thanks !:stupid:

[beandip]

the large 21/2" plumbing will loose you low end power and torque. That coupled with the header . As for the SM needles I bought mine from Z-therapy and they were $30.00 if I remember correctly. The electronic ignition will provide you with much better performance and the engine will be smoother running. I went with a '79 280 ZX ignition. If you find one at the bone yard be sure to get the adapter that the dist. bolts on to , that attaches to the block . The 240 part will not work right and y ou will have trouble with the timing. I also picked up the coil and its hold down mounting . This is a 12v coil not the 8v of the 240 and it is larger in dia. . Go to the page geocities.com/zgarage.2001/engine.html scroll down and you will find instructions on how to do the install. One thing it states that you cannot use the stock tach this is incorrect if the tach does not work just reverse the wires. My 240 tach has been working fine for over two years . One thing with the SUs , they are capeable of suplying all the the engine can use and then some , even a stroker engine. This is with the correct needles. I dont know if your stock engine will benifet from the richer mixture . There are others here I am sure that have tried them on a stock L-24

[zeiss150]

thanks for the info ... But what kind of HP can I expect out of my L-24 setup?

and will the lighter flywheel help at all?

[beandip]

not really but it will allow for quicker shifts as the rpm will die off faster between gear changing. I personall do not like it but this is just me. Probibly the most felt change will be the ignition , now when I made the change on my engine the old stock 240 dist need new points , but I couldent believe the difference it made in the driveability . This and the use of 20w oil in the carbs.

[zeiss150]

Beandip, what your saying is that the best think I can do for my L24 is go with electronic ignition. But how much horsepower will that give me, or will it just make the car run smother? I really amy trying to get a 200 horsepower L24... is that possible?

thanks for your info beandip.

[Phred]

I dyno'd a fresh L-24 That was ITS prepped. It had 165 HP at the flywheel, and it was a front runner. Without headwork, cam, and other trinkets, you won't see 200 HP from a L-24.

Phred

[beandip]

This guy know what he is talking about . Thanks Phred long time no see.

[zeiss150]

Phred, What is ITS? Sorry still learning. What kind of mods did the l24 have and do you know what kind of rear wheel HP that 165 flywheel HP translates to. one last question... what kind of 0-60 can I expect from a 165 flywheel HP. Thanks guys your info is invalualble.

Matt-

[SteveK]

zeiss150

Expect to loose about 25% + through various HP sapping things like gearbox, diff, tyres etc -- rolling resistance.

A few months ago I put a fresh L24 into my Z with stock ignition and SM needles (gives a more linear fuel delivery I found) the head had been reworked i.e. flattened, ported and polished and had new stainless valves and hard seats, new stock cam, springs, followers etc, 6 into 1 header and K&N's

All in all giving a compression reading of 170 bang on across all 6,

plugs out, dry.

We got in excess of 120+ at the wheels equating to 150+ or so at the flywheel --- (lightening of which does not increase HP of the engine it just means less is wasted)

I have read several items on the web regarding the stock L24 one guy took a number of tests on various stock L24's and averaged them out and this came to about 110 BHP at the wheels stock.

So to sum up, headers, mild headwork, K&N's got me 10 or so BHP, Pretty poo really for £700, but good foundation work when I do get the head skimmed and a new stage 2 cam.

On other vehicles (RS2000's MG, Mini Cooper, Triumphs etc) the same amount of work has netted me 20 or 30 BHP, indicating that the stock engine needs more significant work than just a bolt on jobbie.

Its all about getting the engine to "breathe better" and as it goes, for a single OHC the L series do quiet well, in order to get significant gains you need more drastic surgery

Head skim (you can get away easily with 30 thou before shimming the towers)

Decent head gasket

Cam, followers, lash pads etc

And lots of tweaking

Ignition systems wont necessarily net you more HP, but they will help you get a more consistent, stronger spark up to a higher rpm, which is vital.

Throwing money at a set of triples will not get you anywhere without the others first (if it does you were either running flat tops or there was something else wrong), as was mentioned the stock round top SU's perform very well, a friend of mine (with his own Dyno) spent several days tweaking a set of triples on a stock L24 and only got a few (under 10) BHP more and he runs 2 650 HP mustangs for fun on track days (yes we have got some HP figures like that in the UK)

If you want bang for bucks -- go to the breakers yard spend a couple of hundred, get a low mileage L28, put a P90 head on it, cam it, put triples on it, decent headers -- that will get you into the 200 BHP region.

[Phred]

SteveK,

Good post, I agree.

Matt,

The only other unanswered question you had was about ITA.

The Sports Car Club of America, SCCA, is the major sanctioning group for road racing in the U.S. A group of classes is called Improved Touring. Broken down into individual classes A, B, C, and S. So ITS is where Zcars race. The rules are very restrictive as far as the allowed modifications. Basically, stock components must be used in the engine, but you can balance, adjust cam timimg, ign timimg, and carb tune as well as run headers. So these engines represent the peak HP that can be had with a stock engine.

Phred

[2ManyZs]

Hmm, only 165 at the flywheel Phred? I would have expected a tad more than that.... what head was he using? I would have guessed it closer to 180 at the flywheel......

Gee, then I guess that goes to show the Bimmers do have a huge advantage.... I saw a dyno sheet on one 325 that was pushing better than 200 to the rear wheels....

[Victor Laury]

Originally posted by 2ManyZs then I guess that goes to show the Bimmers do have a huge advantage.... I saw a dyno sheet on one 325 that was pushing better than 200 to the rear wheels....

It's going to need it to haul all that power windows, locks, seats, mirror, autosuck, sunroof hardware around!