L26 Performance?

[260pos]

Okay thoughts here; I have a 260 if I use the Maxima's n47 head, and some .040 over 240 flat-top slugs and a standard head gasket. according to lengine I should get a 10.4 compression ratio. A bit high for today's fuel, but the aluminum head thing. I'm not sure of what the voodoo is, but I'm under the impression that you can run higher CR's with aluminum. would I have to run a cam with alot of overlap to run this CR? I know that I'm going to get a lashing about the L26, and that I should drop in a blown 7 liter sbc v8 with a 2-speed air shift transmission, but I'm just trying to get a little more power and fuel mileage out of the car for now. (okay, a bit of an exaggeration but I will be told to use a l28, won't I?) As a non-US L26 puts out about 165-170 horse gross, what kind of power do you think a this would put out with a mid range cam, and the ports matched and polished? (Yes I should be in bed dreaming of MS L28et's VS. dreaming up such madness.)

3am in Vegas & I'm going to sleep...

Thanks,

Jim

[JMortensen]

A bigger cam with more overlap would definitely be a good idea. Not only will it make the car less likely to ping, but you'll also get a heck of a lot more power out of it. I wouldn't go any smaller than a "Stage IV" Schneider, but really I'd suggest that you have your cam reground. Also look out for coil bind in the valve springs and the valve spring retainer hitting the valve stem seal, Both happen with lifts above .470 or so. Search and you'll find solutions to both of those problems.

 

The thing about the aluminum head vs iron head is a V8 thing. You can't get an iron head for an L series unless you're going deisel. The aluminum heads we use aren't really that good, and so we are limited in the compression ratios we can run when compared to newer engines.

 

As far as what power you're going to get, it's really tough to say exactly. I would guess that if you were running SU's, had everything tuned right and had a decent exhaust system you could expect in the 175 whp range. That's a SWAG, so you may come out + or - from that number.

[piper5177]

I am running that setup with triple Webers and a Schneider stage 3 cam with an E31 head. I am running through a 79 five speed and r200 diff and get around 165 to the wheels on 91 octane. I can squeeze another 10-15 HP with more aggressive timing on 110. My limitation is the head flow. With a good port and polish, big valves, a stage IV or V and dyno tuning 190 at the wheels should be doable. For the street I don't know if revving that high to get that power is going to benefit you though, not to mention the cost of the head work to get there. My setup works pretty well for canyon/mountain driving and autox. I keep up with my buddy's 1993 Carrera on everything but the freeway and I can take him when the road gets crooked, but that may just be driver ability.