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How much horses will L28/P79 combo make?


Zoldman

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So I'm looking at what kind of V-8 swap to do, and reading up on Z's in general.

 

I start to see that a well prepared L28/P79 motor with good cam and head work looks to be a pretty stout combo.

 

My question is, how stout? I have looked all over the web and cannot find any horsepower/torque/0-60/1/4 mile times. I know its not a V-8, but this combo may be all I could ever want or need.

 

Anyone have some help to offer? I'm looking for a very streetable package that will still light up the unwary. I prefer carbs and lean in the Weber direction.

 

I was going to post this first on the V-8 forum, but I already know what those guys will say. I like going fast in a straight line too, but there are limits to my needs, and I love the way a Z handles.

 

Thanks

 

Bill Boyd

1972 240 waiting for me to make up my mind

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That is like asking how much power will a Chevy 350 with vortec heads make? It depends on so many different factors, there is no correct answer.

Do a search of this forum and you will see lots of answers to your question. Bottom line, anywhere from 150 to 300 hp, depending on head work, how big the cam actually is, and carburation/state of tune,(and type of piston, flat, dome, compression ratio, etc..)

-Bob

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Yep, it depends on an array of things, but generally with a well thought out setup and a semi-large cam, you could probaly expect a peak of 275-300 HP on street gas, thats pretty much a top dog motor too. 250ish HP should be alot easier to achieve.

 

For the money though, and I'd argue ease because I'm a V8 guy, you'd get more torque and driveability with a V8 and a T56.

 

I am still debating on using my F54 flattop or not.

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Robello has put out at least one 287 crank HP, big SU car, but your clarification is helpfull because hardly anyone puts out these numbers, they are definately wishing for the best.

 

I dont know many people running 13.5:1 or whatever on the street though smile.gif There is a guru (pro race engine builder), who insists things like this can be done with Evans NPG. Alot of people debate it, and I for one was pretty much right along with them. He put his case forth though without arguing, he's done the testing not most of us who disagreed.

 

Evans is used as de-icer I believe in the airline industry, and supposedly is much cheaper.

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Guest norm[T12SDSUD]

Well, just to give you an idea of the potential of these motors.

I run a 2.8L with the diesel crank installed for a total displacement of 2.9L.

I have an N42 head with 10.6:1 CR and bored out dual SU carbs.

The car is my daily driver.

The last time I ran the car with slicks two years ago I ran a 12.88 @ 105.8 mph.

 

My best run with street tires last year was a 13.29 @ 106.6 mph with a terrible 2.156 60 ft.

 

A few months later with those same street tires at a well prepared 1/8 mile track surface, I pulled a 1.81 60 ft. time, so as you can see the car would run high 12.9's on street tires under the right track conditions.

 

That's allot of performance out of a cheap old junkyard dog L series engine!

 

If you can afford the V8 conversion then do it, but if can you settle for an L series engine combo, you will still be able to run with some pretty fast competition.

 

later

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Since the subject has been brought up (again), I may as well mention that John's 305hp race motor, Norm's 12.88@106 street motor, and my 235rwhp street motor, all have N42 heads. Where are the big P79 numbers? (just askin', I don't think the n42 is the livin' end, necessarily, and of course the heads on our motors have been tweaked a bit)

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True, but gas costs money, even for crappy stuff smile.gif $5 a gallon doesn't make a street car IMO, but that depends on the goals I suppose. I ran 11.4:1 with a reverse cooled LT1, but that allows for some more compression (rev cooled). I still though wasn't able to be as aggressive with low end timing as I wanted, I had it pulling MADLY off idle but was getting pinging and had to back it off. I could not find a magic cell to work with without the ping :( 91 MTBE, garbage.

 

I think I'm going turbo, if I have to run race gas on the track its no big deal, intercooler should be fine on the street with street gas.

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looking for a very streetable package that will still light up the unwary.
You guys are getting a little off topic.

 

I would give you a definitive answer, but I don't know. My 2.4L is still smog legal.

 

But, from what these guys (and others in the past) have said you can get 300 HP out of the L6, but it will be pushing things. For a "streetable" engine (a very subjective measure), lets say 225-250 HP.

 

But keep in mind that while 300 HP in a non-turbo L6 is on the high end, a 300 HP V8 is downright mild. The V8 will be a much more pleasant engine on the street and will be much less prone to breaking something. And if done right the car will still be able to corner in a way that exceeds most peoples ability to drive it.

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I had a bit less than 500 HP (with an ignition miss) in my LT1/T56, and it was streetable with 3.42s in a 3450 pound car. Put that thing in a car weighing a thousand pounds or so less, and it will rock AND be streetable.

 

I think the poster is leaning towards a V8, and if your not doing the work yourself then you'd spend so much on a hot NA L6 that a V8 would look quite delicious IMO, hot L6 can be very, very pricey.

 

Turbo or V8 for 'real' power, not that even 225 is a slouch in a 2200 pound car! For those of us though that think fast is 11 seconds or better...

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Thanks to all who replied to my post. I'm leaning pretty heavily toward V-8 swap now, as build up of L-28 to HP I want will cost mucho bucks and give me a real peaky motor.

 

When I get to going on this, I'll be back on the V-8 board for more pearls of wisdom.

 

Thanks again

 

Bill Boyd

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