3.1L Dyno results...Thoughts?

[AZGhost623]

Once you get an O2 sensor installed which you said was in the works it will definitely shed light onto you fuel system. I would run F11 tubes if it were me which are great for top end... F2 tubes are good for very large main jets or alcohol based fuels. I would also go up in your main jet, and then adjust from there with air correctors. Say a 160 main jet, with 200 or 210 air correctors and keep adjusting if needed only on the air corrector to richen/lean out the fuel. Its very expensive to start playing with changing out jets since you have to buy 6 of each every time... read/checkout the weber faq list on here... order from piercemanifolds.com or pelicanparts.com.

[t-tom]

I got my Jets from Jason at Warehouse33.net  He is a Weber Redline authorized Dealer. He does not have all the Weber parts listed on the website but call or email him he can get everything they make. Mention HybridZ and a get 10% discount. 

[Tony D]

Could be the 40s choking off the breathing. Spent $$$ in the wrong place? No...Just didn't spend 2 grand on headwork knucklehead.

That's a terrible retort, no class.

 

And that engine is down on power for displacement. It's making less than my bone stock L28. More torque, but terminal HP is really low.

 

My 2/2 ran consistent 15.50's at San Antonio Dragway (26 passes) weighing 2695# with me (255#) in it -- if I transposed the numbers (2965# as most people insist for a 2/2...) the HP calculation is just ridiculous. 89.95 mph trap speeds.

 

The power is in the head, it's not breathing. In fact, Scott Burkhardt's SU-Powered L28 spun over 200 at last years MSA, and the following year added slightly more with the Triples on it...without forged pistons and the ability to pull beyond 7,000 you will always be down on power. But Scott's engine was cast pistons, and peaked around 6,500 as I recall.

[steve260z]

Well, with the video and the dyno graph what's your gut feeling regarding the motor cutting out past 5K?

 

I'm going to double check all the connections on the Crane unit and try another distributor I have on hand.

Steve

[steve260z]

One the way...Can't wait to see the results.

Innovate MTX-L

 

[Xnke]

You are probably very rich past 4k, which is close to peak torque for a 35mm runner diameter. once past the torque peak, fueling demands start falling and if the carbs are too rich you see power falling off.

 

I stand by what I said, however. Spending Money on the bottom end is not going to help horsepower until you've spent the money in the head.

[steve260z]

Yeah, I didn't mean to be a dick. Its just that I wanted a stroker not a ported and polished 2.6L.

I can still get head work done. Realized that before starting the project but wanted to get a baseline performance of

the stroker and go from there if needed/wanted.

 

What if anything do you make of the motor cutting out on my dyno video. Car was run to 6k on the video.

Thanks

steve

[Xnke]

I would check plug gaps, and do some plug chops during the breakup to see what is happening in the chamber, since you don't have a wideband yet.

[ozconnection]

Tony D said this a long time ago....power is in the details.

 

Some stock L28's put down 100 rwhp and others 140 or so....accuracy and precision will make the difference. Its funny that two of your key components are the same as mine: a stage 2 schneider cam and 10 to 1 compression. Mine is a 100 thou  over bored L26 block, so capacity is almost 2.8. It has a tiny L20A head, tiny valves and ports and runs 131 rwhp....through an auto trans!! The point i'm making is that your engine does have a better (bigger) head and the p90 flows nicely stock, so look carefully at cam timing. Carbs can be off quite a bit, so get your wideband ASAP!!! It's a fantastic tuning tool that works for you every time you start your car! Ignition timing will make a difference to the midrange and my maximum timing figure is 32 degrees with premium fuel and NGK BP6ES stock plugs.

 

I recently bit the bullet with my other engine in my other car, took off the P90 head on the 2850cc L28 bottom end and put on a very developed, closed chamber E88 with a massive cam. That's just what ya gotta do to get GOOD power, all you have to do is make sure everything else on there can support it. Sounds like you've got the bottom end ready, time now just to finish it all off.

 

Good Luck  

[madkaw]

Still surprised that the dyno didn't have an O2 sensor to give you AFRs on your run. Every dyno I've seen has that.

[steve260z]

yeah, it was a mobile Dyno at the track. Wished they had one too. Either way I needed to get the wideband anyway. Trying to convince my neighbor to drag his welder unit into my garage today and get it hooked up.

 

Here's a guy with a stroker, stage 3ish cam and 40s.

Laid down 220 HP and Torque at 5,550rpm.

 

Edited May 4, 2014 by steve260z

[roger280zx]

zredbaron spun a dynojet to 264, a bit more compression (12:1), deduct about 3% for the reduction in compression and you have 256.  This is what an optimized head/cam will do on a quality 3.1 with a very good header and theoretically too small 40mm carbs.  The power is in the head, always has and always will be.

[Xnke]

3.1L should produce 300-320HP from a properly optimized head and cam, with a very good header, properly sized carbs, and a good tune. 100HP/L is a perfectly doable target for an aluminum-headed, 2-valve modified wedge combustion chamber. Cut 20% in driveline losses and you should look for 250RWHP to point out a good combination.

 

Not that 250RWHP would be where I stopped looking for power, but it gives you an idea of where you are in the scheme.

[steve260z]

Is that HP goal acheivable with a stock p90 with no porting?

[Xnke]

I suspect not, although PMC racing engines does produce 370+HP stroker engines, and he has some photos and explainations on this site too.

[roger280zx]

A stock p90 head, no porting, and 15psi makes 250 all day.

[rturbo 930]

What I'd really like to know is how streetable that 100+ HP/L motor is, and how long it'll last between rebuilds. Zredbaron's 3.1L, for example, is definitely not a street motor, but he also didn't build it for the street.

[ozconnection]

Jump into someone's car that has that spec. You'll want to know where to 'sign the check' soon after LOL

 

'Speed costs money, how fast do you want to spend'

[Tony D]

300HP Datsun 3.0L were all over Japan in the 80's. It was the larger ones that had problems with cylinders not staying round.

The saying was, once you make a 3 Liter L-Gata, you wrecked your car, and you gave it to a friend, who wrecked his car, and gave it to a friend, who wrecked his car....

 

Point being, the L-Engine properly executed will outlast the car it's in even at 100 hp/L. If you read the "Super Samuri" stories of the 70's the longevity and lack of wear in a dominating car was shockingly legendary.

 

Keep the valve train stable, without stupid lifts and ramps, with proper geometry, and the valve guides don't wear. They go a LONG time.

 

What was "unstreetable" with carbs is MORE than well-mannered with port fuel injection. Our 8,000+ power peak Bonneville Engine was surprisingly tractable once we put a heavier flywheel on it and FI. With a single four barrel it wouldn't idle below 2,200 rpms, and with 45 DCOE's 1,700. 45 TWM ITB's idled at 450 rpms if we wanted, and did 750 rock steady all day long.

 

With a 5.38 rear gear, WATCH OUT on the street! (Welcome to 'Streetable Japan-Style'!) No different an rpm range than an A210 if you think about it...before anybody makes any comments!

[1vicissitude]

I suspect not, although PMC racing engines does produce 370+HP stroker engines, and he has some photos and explainations on this site too.

 

I love reading Peter's posts, but have yet to see this site you speak of.

 

Would you care to either post it or pm me with the url?