cam selections triple webers

[s14280zx]

I am changing my 79 280zx fuel injection to a triple weber 40 dcoe carb system. My setup will be as follows: F-54 block, N-47 head, stock flattop pistons, triple weber 40 dcoe 151 series carbs, motorsport header, 3"custom exhaust system,magnaflow muffler,ACT street clutch,extreme pressure plate,Fidanza aluminum flywheel. I want to upgrade the cam, and valvetrain, and I wondered if anyone has any suggestions on what brand, and size would be the best for my setup. I would like to keep a fairly smooth idle if possible, and keep a fairly broad powerband, since my car will be a street machine, mostly on weekends. Any advice would be appreciated. THANKS

[Dtsnlvrs]

Your best bet would be to call Ron Iskenderian @ Isky Racing Cams. If you are patient and willing to spend the time to talk to him, he will do a custom grind for you based on what you want the motor to do and what your setup is. However he will want to know everything about the motor ie exact comp ratio, etc etc. FWIW the 40DCOE151 comes with 32mm chokes which should work fine for your application, but be prepared to spend some money to get the jetting just right. It is a matter of trial and error to get the idle circuit and accell jetting right to match the motor. BTW where is Winber, PA...if it is not too far from DC, when you get the setup complete and installed, I could come up and help with the final tuning, I have a huge jet selection at my disposal, as well as different chokes if needed.

[Dtsnlvrs]

FWIW the webers will work well with a stock cam if you choke the carbs down to 30mm. Makes for a very smooth running engine that pulls like a beast down low. Just curious, are you ditching the stock FI due to performance issues (ie not enough power) or is it just not running right?

[beandip]

I am not a injection guy , but have you looked into a Mega-squirt . The 280 guys in my area are going that route and seem vary happy with the results. Just a thought.

[s14280zx]

Your best bet would be to call Ron Iskenderian @ Isky Racing Cams. If you are patient and willing to spend the time to talk to him, he will do a custom grind for you based on what you want the motor to do and what your setup is. However he will want to know everything about the motor ie exact comp ratio, etc etc. FWIW the 40DCOE151 comes with 32mm chokes which should work fine for your application, but be prepared to spend some money to get the jetting just right. It is a matter of trial and error to get the idle circuit and accell jetting right to match the motor. BTW where is Winber, PA...if it is not too far from DC, when you get the setup complete and installed, I could come up and help with the final tuning, I have a huge jet selection at my disposal, as well as different chokes if needed.

I live 10 miles away from where flight 93 went down on 9/11, just east of Johnstown, PA. I'm trying to have it ready by the end of summer hopefully, and I would appreciate it if you would help me set the jetting. That is another area where I will be needing help with,since I never messed with carbs before. I have been tuning my late model 240sx's for the last few years,and I thought I'd try something different. I got the weber setup for $200 off of a local wrecked 280z, so the price was right. All I need to get is a fuel pump,a linkage kit,the clutch,and some air cleaners. I'm planning on pulling the motors in the next month or so.The f-54 is on my parts car, and I'll be using the n-47 head off of my origional motor. Thanks for all the advice. When I get it ready to run, I'll have to let you know, and maybe we can set something up. THANKS

[s14280zx]

I thought about that route, but I already have most of the parts I need for the conversion, so I may as well try the webers. It should be a fun project, since I never messed with carbs much. I have two s-14 240sx's I've been tuning for the last several years, so this will be a new experience for me.

[s14280zx]

My stock engine runs good with the fuel injection, but with the domed pistons, it just doesn't have the power down low, I thought about a turbo kit, but since I got the weber setup so cheap, I figured I'd go that route. I realize it will probably cost a little more to set up, but I already have most of what I will need, and I almost have my 98 240sx paid off, so I'll have a little more $ to work with soon.

[4381821]

just a note of caution,

The cam I put into my L28 motor with Mikuni 44's was an ISKY Stage II cam. Now the motor has to rev up past 2000 rpm before it can get any real power. Although this could be a product of my diff ration beeing stock still... Keep this in mind if you are going to drive it on the street. The stock cams are better suited for the stop and go action of the streets.

[jmortensen]

I don't know what Isky's stage II cam is, but I ran a .490/280 which is about the equivalent of MSA's stage IV on the street with my 44s and had no trouble at all in stop and go traffic. I also had a 12 lb flywheel and an ACT clutch too, and 2.5" exhaust. No problem. I think the difference was that I had a 3.70 diff and a ZX 5 speed. Now I've finally stepped up to a 4.11 diff which I think will make it even better, but it won't be on the street anymore.

If you want to run triples, everything should be set up for triples. They're made to make more power at higher rpms, so things like close ratio trans, lower diff gears, and shorter tires help quite a bit.

If you want it to idle like a kitten and have grunt at 1200 rpm, forget the triples. But you can't have it both ways, and the stock cam runs out of steam at 5500 to 6000 rpm.

[s14280zx]

Thanks for the advice. Rough idle doesn't really bother me that much. This car won't be a daily driver. There are alot of winding mountain roads in my area that are fun to fly up and down. I'd take more power over smooth idle any day. I have my F54 block ready to pull out of my parts car, and have an engine stand ready. I'm not sure what diffs I have, I'll have to check into that. I've been taking the bumpers off and doing some bodywork the last few days when I get time. I got the paint last Friday. The one parts car was owned by an autoshop teacher in virginia. It's an F54 in a 79 zx,so I'm not sure what all was done with this motor. It came with a xenon front bumper, and custom moulded fiberglass wing and ground effects that were made by this teacher.