l28e performance?

[Guest 7mc123]

i got a 74 260z l28e p79 heads , dual webers ,headers dont know who makes them. i purchased this car not too long ago. would headwork make a difference or would it be better too swap heads. im looking for the best combo for my set up . i also would like too know what 5 speed i would need too find.

[RTz]

i got a 74 260z l28e p79 heads , dual webers ,headers dont know who makes them. i purchased this car not too long ago. would headwork make a difference or would it be better too swap heads. im looking for the best combo for my set up . i also would like too know what 5 speed i would need too find.

 

 

If it were me, I'd start with fuel delivery. Almost ANY system would be better than downdraft Webers. Buy the best you can afford, preferably something you can grow with.

[zeiss150]

how much WHP do you want? If you want over 200 then you should think about turbo charging. If you don't want to deal with the turbo stuff then loose those webbers and ether go with an after market FI system or 72 or earlyer SU's. The P79 head is a great head and I don't think you need to replace it in either case. Head work alone wont get you a ton of power. More Wheel Horse Power comes from a comprehensive system of engine components.

 

You can use any Z 5 speed ... but , the stay away from the turbo 5 speed I've read threads about 2nd gear blowing really easy. also keep your 4 speed shifter so you don't have to modify your 260 body.

 

good luck

[BRAAP]

Ditto everything that zeiss150 said. Your P-79 is one of the more ideal heads for the L-series with flat top pistons. (FWIW, here at Rusch Motorsports, we feel that the P-79 is on the top of the list of ideal heads for mild to fairly hot N/A street L-28’s). As zeiss150 said, head work alone wont gain you a ton of power. On a bone stock L-6, head work might not gain you much of anything, but custom head work does compliment many other mods such as big cam, free flowing induction and exhaust etc, it is at that point that you will see and feel realistic performance gains from custom cylinder head work.

 

Depending on your budget and how you approach satisfying your quest for more power, you could build the power train all at once, or just do minor changes here and there as your budget allows till you get it where you want. If you are new to the Z, I strongly recommend the latter route, and enjoy the ride… (pun intended…)

 

First off, get rid of those down draft carbs and if carbs are what turn your crank, (again, pun intended), the early SU’s that zeiss150 mentioned are readily available and capable of great performance AND economy or for that ultimate in exotic carburetion, a set of triple carbs. Aftermarket EFI with a custom intake is also an option. Also, something that you can get started on right now is to get your ignition system up to snuff. Make sure it is at least electronic from a later 280 Z or ZX, good quality wires such as Magnecor or Nology, don’t buy wires because the color is just right, i.e. Taylor, Accell, MSD, wires are merely a mediocre wire, not a true performance wire. Also, use a quality coil.

Now for the easiest and least expensive mod you can perform right now, and this sometimes results in the single biggest gains, play with your ignition timing, (this applies to bone stockers with factory or worse settings). You’d be amazed at how much more power is available just by advancing the ignition timing over the stock settings. A good starting point for unmolested dizzys, (this is for the guys that don’t have a dial back to zero timing light), set your initial ignition timing between 15-22 degrees. If the engine rattles like Detroit diesel, you went too far for the fuel grade you are using so back it down till the rattling goes away. If you must take your car through a DEQ smog check, be sure to turn your distributor timing back to stock when the time comes….

 

Hope this helps and keep us posted on your progress….

 

Paul Ruschman