Originally posted by Gav240z The guy who helped me out is running an L28 that is pushing just under 300HP non turbo on SU carbs.

Nice! That'd be crazy!

I'll have one too thanks. ;-)

yeah it's a fair bit of work to do but I have a fair idea of what parts I'll need and am currently looking for these parts.

I will do my best to document the set up and all processes involved and try and make it as understandable as possible and hopefully publish it to other Z owners.

With permission of course from the person who shows me how .

Gav,

Any chance you could give me a brief run down on the basic specs of this motor?

To my knowledge so far it's like this.

P90 Head

F54 Block

L20B(4Cylinder) Rods.

LD28 Crank.

260z Gearbox

4:11 Diff.

SU's

Ok for the work involved.

The P90 head will be pretty wildly ported.

Flat Top Pistons installed.

30 thou overbore. ~ 3.1 litre with LD28 Crank.

Remapped Distributor(Revs out to 8400rpm).

The SU's have their throats ported and the intake manifold is heavily ported.

Not sure on Camshaft Profile.

Valves still not certain.

Comp ratio probably 10:1

Not sure on treatment of bottom end of motor in the way of shot peening, balancing etc..

As I said I'm getting a rough idea of the specs of the motor I know he's willing to help me out with it just gotta save the money.

The car should pull low 13's possibly high 12's with this set up.

in a 240z anyway 260z with some weight loss probably the same.

I'm not engine building expert however hopefully I will learn alot about it soon.

There's quite a few pages around on building a 3.1L stroker, which is what you're talking about with that combination Gav240z.

It's just a matter of looking, here's a couple from a 2 second search.

http://www.geocities.com/row4navy/engine.html

http://zhome.com/rnt/3.1Cobb/3.1engine.htm

I also found a really good one a few months ago but I musn't have bookmarked the sucker. Oh well.

Another 2 stroker links:

http://www.zhome.com/rnt/3.1HanveyProject.htm

http://www.geocities.com/inlinestroker/

Sounds like an awesome package Gav!!!

...and speaking of sound....8400rpm! How good is that gonna sound!

Good to see the power being made with the SU's too.

Thanks for the links my friends, I have read a couple of those previously the more I read them the less there is to it.

It's just sourcing the parts really.

I have the flat tops the F54(2 actually) P90, I can get the l24 rods or even l20b rods pretty easily.

The SU's are used on the set up currenly(Which I love) , but it won't supply fuel till 8400rpm gotta really use the webbers for that it currently goes flat around 7000rpm.

So he's tinkering with the idea of putting those on or even tripple SU's like the old jags.

I will definately try take pics of his car next time i see it, it's really a beautiful Z.

Whats the expected fuel economy out of interest?

My 280zx does a good 10L/km freeway driving, but is very bad city driving, and thats with injection.

My L26 260Z's I have owned never stayed on the road long enough to go through a full tank so im not sure on those, they seemed thirsty though.

If its not your daily driver then its not a worry but mine are/will be so i keep it in mind. These cars cost me a fortune in fuel compared to my old 4 cylinder, much more fun though.

My basically stock L26 averaged around 11L/100km on the drive up from brissy. Around town I'm now doing 14-15L/100km which is sorta hard to afford as a daily driver. I suppose I could do another liter better if I babied it everywhere.

Yeh, thats why i stopped my L28ET build, a lot of people in the know were telling me fuel economy was terrible.

A 3.1 L28 with triple carbs that does 13's I imagine would just be pouring fuel into the motor. Personally I'd use injection and port the plenum and use a 65mm throttle body.

The only reason my 280zx uses so much fuel is its rough running condition, its anyones guess how many cylinders im firing on at any one time :stupid:

It drives great after i service it though, but it needs the plugs cleaned/replaced every 5000kms, my guess is rings being the cause.

I sound like an old man talking about fuel economy but only since i started driving around 400km's a week to work have i valued petrol so much...