l24cam into l28 n42 head

[jimbo]

i have a 72 auto w/l28 motor & n42 head the cam does,nt cut in till 3000rpm.I have orignal standard l24 motor with stock cam in good condition. will i get better acceleration with l24 stock cam if i swap it over. I am not interested in 125 mph top speed, but better lower end performance....Thanks... Jimbo....

[sjcurtis]

Jimbo, did you install the l28, is the n42 and cam the original set up for that l28. Was the l28 a center sump, rear sump or front sump l28 before it was fitted . Are you running tripple carbs, twins carbs or injection. Are you running electronic ignition. do you know what diff ratio you are running and what is the wheels and tire combination. Sorry about twenty questions. It may help.

steve:classic:

[2ManyZs]

You won't realize much if any benefit by changing the cam to the L-24 version as the cams from the L-24, L-26 and L-28 were very similar.

You might be better in the long run to go with a performance grind cam that will give you the low end power you are looking for.

Perhaps part of your lack of acceleration is due to the automatic, your torque converter may be slipping, or your trans bands may be worn and slipping. I think I would explore the transmission possibilities before you go tearing into the engine as the stock cams were all designed for a wider torque range than most specialty cams would be.

Actually, most of the L series are a bit weak in the lower rpm's, but that is due to the smaller displacement and the lower torque of the engine itself. Most all the cars seem kinda weak until you hit 2500 rpm's or so.

But, like sjcurtis said, the rear end ratio, tire and wheel package and your induction/ignition system can make a huge difference as well..

[jimbo]

thanks for the replies,i had the l28 motor installed but did not know it had a lumpy cam in it. it does not cut in till 3000rpm. i am looking for more bottom end performance.

My l24 motor is in good condition, only changed it over so i could run unleaded petrol(i,m in aust) the cost of the l28 was about the same change over price as was to convert my l24head with valve seats ect. the bottom end performance of the l24 was good.

My 240z is a 72 auto(happy with that)standard model 3.54 diff ect, 14inch wheels,twin S U,s

the l28 is standard except for cam that does,nt cut in till 3000rpm & has electronic distributer.Its a 78zx model n42 bottom end & n42 head.

What i am asking will the stock grind l24 cam if installed in the l28, cut in well below the 3000rpm of the l28 & give me better bottom end performance.

[sjcurtis]

It sounds like you have a bulk stock L28 with a stock polution cam. Even with the government reducing the octane rating in standard unleaded without consenses your 240Z /72 engine in standard form was produced in a configuration that could deal with the current crop of fuel in oz. The L28 will deal with all your fuel concerns but will only ever be pedestrian unless you tweek its tits off it ( inject it boost the compression and fit a 68 degree cam). The L24 ran so much better because it was designed to provide maximum performance from its configuration. My 12/71 L24 auto with twin hitachi carbs goes like a cut snake I get a little bit of ping from the useless fuel but thats it. I recomend do not tamper with the cam configuration until you are sure both cams are self oilers as the 240Z L24 engines did not all have self oiling cams, so it could be a bit more than a simple cam swap out. The L28 can be a magnifcant engine if you can get a good upgrade package to work for you. Where do you live in Oz as there are some realy good people around that could help you with this problem.

regards

Steve :classic: