mild build up

[Eric]

i'm lookin to build my stock l28 a bit. i'd like to hit 250hp but i'm not sure if what i want to do will get me there. i'm thinkin stroker crank(just the crank, no boaring), port/polish, 60mm tb, cam, flat top pistons, and header. will that get me close to my goal? i'm goin to be doin this on a tight budget so the less mechineing the better.

[ww]

Don't do the LD28 crank if you're not going to go overbore.

 

I think you need to get new pistons anyway in order to get the right pin and deck height and I don't think the pistons that work are available in stock diameters so you have to bore the block at least a some to get them to fit.

[TheNeedForZ]

well the stock L28 is rated at 170hp, you are looking for 250hp. That is 47% increase in output from an N/A engine, you are going to spend a fair chunk of change.

 

You'll need at least a stroker motor to get 250hp. The diesel crank alone almost doesn't do anything. If you don't want to spend that much in a fully build stroker, then like ww said, forget the LD crank. I'd spend money on the TB, porting, 3-angle valve job, cam, and more CR....

[AK-Z]

well remeber that the 170 hp numbers were what was stated 20-30 years ago so it would be more like 150hp. I would say that short of a full rebuild, 200 hp is pushing your expectations. You will problably be able to reach 250hp if you get a valve job, cam, and a aftermarket computer, and have the whole thing tuned. those 20 year old stock computers are crap.

[Eric]

well then, sounds like i need to rethink this. any idea of what it would cost to get it board over for the stroker kit? what about a valve job?

[Eric]

and a aftermarket computer, and have the whole thing tuned. those 20 year old stock computers are crap.

what about the z31 ECU and MAF upgrade? would that be of much help?

[Mack]

quick recipe for some easy HP.

 

put flat top pistons in your block, get a Maxima N47 head (11.4:1 compression w/flattops), have it ported mildly, a camshaft in the 270 to 280 range with at least .450" of lift, header, 2.5" mandrel bent exhaust, and get an aftermarket intake manifold!!! the stock ones SUCK, or go carb'ed. There has been much talk on Zcar.com about an aftermarket intake that someone is selling for like $550. check it out. I think the posters name is spork.

 

oh yeah, and ditch the stock FI crap, a Z31 system is VASTLY improved over the flapper door. Or say screw it and go MegaSquirt.

 

all this should get you in near the 200rwhp range, if done properly. and that is probably 250 at the crank.

 

Im pushing somewhere in the 160 to 170rwhp range and I dont have a FULL 2.5" exhaust, or a header or an aftermarket intake manifold or a cam, or a Z31 FI system. Ive got a 1980 280ZX 2+2 with everything still in it and its low 15 sec capable.

[olie05]

for reference,

 

1mm overbore, flat top pistons (10.3:1cr) Cold air intake, Stock exhaust manifold, 2.5" mandrel bent exhaust, 3.9 rear, and ALL STOCK electronics got my car down to 14.8 1/4 mile. 2,500lb's...

 

 

just for reference.

[v80z]

Eric

 

I ran LD crank

30 over f54 block

p90 head with plenty of porting

forged venolia dome top with full float pins

13.5:1 C.R.

weber 40 with 36 Chokes

stock dizzy with electonic conversion

30-32 degrees total advance

cam 613 lift ~ 300 duration most topend profile from schneider

nismo big header and cannon intake

 

car weighed in at 2250 without driver. I could run to 7800 rpm in 4th gear with a 4.11 rear end = 134 mph

Would not make any power below 4000 rpm

but from 4k to 8k you had to be quick.

 

Things it needed

 

Definately EFI aftermarket

Crank trigger ignition

 

if not EFI IT needed bigger carbs say 50 mikunis. IT definately needed to breathe bigger at the high end.

 

Dry sump oiling

 

Of course I ran 110 - 113 Sunoco

 

All this said it made 270 280 hp at the crank. The best back in the day were race motors setup for one race that dynoed at 312 hp.

 

I guess what I am trying to say is that your goals for an N. A. L28 motor does not constitute a "mild setup"

[Mack]

there have been advances made since "back in the day" Im not trying to be a dick, although I know I may be coming off as one here.

 

There is a guy on Zcar.com, Briann510 not sure if he is here or not...... He had Rebello build him a motor for a street driven 240Z, He has put down 278rwhp, with more on tap. he is running MILD compression in comparison (I.E. I dont think he is running race gas) and he also has a streetable cam. He has been beting the piss out of it for a few months now, and it has shown no signs of slowing down.

 

Of course, this is a 3.2L with head work. but its not an all out motor either. I shudder to think what this thing would put up on an engine dyno. I have heard reports of a drag racer somewhere in AZ that puts down 370rwhp on an NA L6, but have not confirmed it. running in excess of .750" lift.

 

 

250 at the crank is do-able in a daily driver for not ThAT much cash. I would say you could get by for under 3K if you spent it WISELY. hell, Im under 1K, car cost included and Ive shaved 3 seconds off of my 1/4 mile time, for a heavy 280ZX 2+2. yeah I know, i went from low 18's to low 15's, lol but you gotta admit, thats not bad.

[JMortensen]

I guess what I am trying to say is that your goals for an N. A. L28 motor does not constitute a "mild setup"

I bet that setup would have made A LOT more hp with bigger carbs.

Here's what I have:

~11:1 compression (needs 95 octane)

E31 with 280 valves, ported and polished, valves unshrouded (lots of work in the head)

L28 with block notched to match the head where the valves were unshrouded

.490/280 cam, Schneider springs and retainers

44 mm Mikunis

Cannon manifold (longer straighter runners than the Mikuni manifold)

ITG filter

header and 2.5" exhaust

ZX EI and MSD

 

That yielded whp somewhere in the 240's. Gtech said 108 mph in the 1/4 at a weight of 2635. Do the math and cut a few mph off the trap speed because the Gtech didn't average the last 100 feet (or whatever it is) like the drag strip does and it shows something like 248whp.

[PUSHER]

Your best bet is to put together some combo of a head and a block to have higher compression than stock.(not starting a block/head war) Use the search to best decide which head and block to use. Get a cam that is best matched with the compression and performance in mind. Use worked SUs or tripples with a header and exhaust. Be happy with a 160-200hp mild build. I say this only because this is pretty much a mild build, not much machining, not much money, then again not much hp/tq but you have to make sacrifices.

[Eric]

i guess i might be giving these engines a bit too much credit. i thought i could do 250hp for alot less than it's turning out to be. i'll just push the limits of my budget and call it a day. whats the best price for a stroker kit? MSA's is like 2k i think. anything cheeper?

[PUSHER]

Junkyard/ebay/etc. sourcing all the parts yourself. Im pretty sure its flat top pistons on 240z rods and a diesel crank in a bored out block with some headwork. Found some reading for you

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

[JMortensen]

Strokers are good and all, but they'll only give you an increase proportional to the added displacement. For example, a 3.2 is 12.5% larger than a 2.8. So if your 2.8 makes 250 whp, then your 3.2 will make 281 hp. Is the 31 hp worth the several thou it costs? That's up to you.

 

We've had several people lately build strokers and put down less than 200 whp. IMHO it was because of the cam and head that they had. One guy (zredbaron) got a different head from Sunbelt and added 40 hp. Then he did some carb tuning and got some more. He's on 40mm carbs, I think theres more to be had with 44's or 45's.

[thehelix112]

Nice interesting discussion on sonic choke on ozdat forum recently: http://ozdat.com/forum/viewtopic.php?t=6286

 

Was proposed that an increase in displacement will only change at what RPM the sonic choke occurs. If you want more power you have to get the head to flow more air, either through less restrictive valves/ports/manifolding, or forced induction.

 

 

Dave

[NZeder]

Just spotted this thread - also I noticed the question "does anyone sell the stroker under 2K?" Well I found this link today also.

wow under $1100 for new stroker kit

 

at the price I am sure a number of these will go?

[briann510]

Yes briann510 is on this board also

 

yes our stroker is a mild one putting out approx 280 rwhp. runs on 91 octane with 9.6:1 compression with a mild custom ground cam. we were thinking of raising compression and changing cams to get over 300 rwhp, but just havnt done it yet.

 

doing a lsd, coilovers, different 5 speed and yz flare kit first.

[pjo046]

Just one thing though. Are you absolutely set on having a N/A engine?

You say you are on a budget, and don't have too much money to spend. The cheapest way to get 250hp is definately to slap on a 280ZXT turbosystem. You get all the parts you need for cheap on ebay, and you could invest in a bigger hybrid turbo and a good intercooler. You already have a L28, and I guess you have a CR somewhere in the early eights? That is perfect for a responsive turbo L6 with low lag.

 

My previous Z was a 260Z. I bought it when it was already done modified. The PO had done all the modifications, and the reason I eventually sold it was I wanted more power, and needed a bigger platform(L28) to start a new and better build on. The 260Z had a STOCK L26 engine with no internal mods(CR around 8.3:1), which had been converted to turbo by using a small Rajay turbo(Some crappy thing, the Garrett would have been much better), injectors, ECU, harness, AFM, distributor, intake etc all from a 2.4 Maxima, two extra injectors controlled by a piggyback and a Saab 900T IC. It produced around 250hp and was very responsive. But still, if you started out with your L28 and got yourself a good hybrid turbo, you would do MUCH better than that.

 

It seems like if you are going the N/A route you will spend several thousand dollars just to get a bit over 200hp?

 

But of course I understand that a N/A and a turbo are two different things to drive and all, and that if you are decided on the N/A setup then you will go for it. I am just suprised no one has asked you about this, and that no one has mentioned the turbo-option.

 

I see you are a newbie to the forum, so perhaps you haven't thought of this solution? If I am totally wrong, then forgive me for bringing the turbo-option up. I just thought I'd mention it for you just in case.

[Eric]

thanx for all the input. i've desided to do it a pice at a time. it'll be easyer on the walet that way. the MSA performance pistons when i run the quick rebuild in a few weeks, then later i'll do head work, intake, header. i have thought about turbo, but after the last turbo project i did, i'd like something that wont involve changing the harness and ECU.