640 WHP 7 litre 928!

[rhjames]

interesting comments---

the injector flow on the video seems to be suggesting that at the rpm ramp up (while the plates are at WOT) the fuel flow is intermittent, not steady. at least, that's what I see. I'm not complaining about this, just curious why the dyno didn't "see" it..? In other words, the naked eye should not be able to pick up a reduction or stoppage of fuel flow above idle rpm. The injector appears to have, dare I say, hiccups through the video. It would be equally interesting to me, to see a slow motion video of the injector action. In slo-mo, I would expect to see the injector pop regularly, not flow off and on erratically as in the video..... just thinking out loud here---

as for the non-OEM fuel delivery, you're not the only one (in the 928 world) who has said they would not use anything but Porsche parts----another curiosity of mine. considering that fuel pumps have come a long way since the OEM parts were put in these cars, I would think that the BG or Aeromotive pumps would be more than enough to supply your engine. 428 cubes @ 7500 rpms is not much to feed, compared to some of the monsters we have in drag racing these days. We have been using a BG 400 on the Quick 16/32 car for over 5 years now, without any issues what so ever. That's one pump feeding a 1000hp 540 cubic BBC, weekend after weekend of racing. I would be more concerned about an OEM pump not supplying enough fuel (leaning out) or just plain failing, than today's modern pumps. One guy has even gone to the extent of using 2 OEM pumps (in parallel--3 pumps total) as a safeguard, but in my humble opinion, that too is unnecessary. Besides, the BG pumps are easily rebuildable--

I'm still curious about the rods--you're picture appears to show a rod/piston offset that would be standard Chevy rod offset?

--Russ

[Danglerb]

Whats the highest, "safe" pressure at the fuel rails?

Messing around with placement and angle of the injector sounds like it could be fun. I was thinking closer and pointed more directly at the valve.

[Barbapapa]

I'm not sure that's intermitent fueling in the video. I think it's the light from the flashlight moving along with other conditions, the camera, airflow, vibrations etc. I've looked at that and another video in their higher resolution form and have a hard time telling what's really going on.

The non-oem parts I avoid are fuel pumps and ignition parts. It's because oem stuff has to be proven to be reliable. I use a Walbro pump which is oem on some GMs. I avoid fuel/ignition stuff like BG, MSD etc because I consider it unreliable.

[Barbapapa]

Originally Posted by Danglerb

Whats the highest, "safe" pressure at the fuel rails?

The concern is overall fuel delivery capacity at the higher pressure and sealing and atomisation at part throttle when manifold vacuum is high. A full vacuum is equal to 15 psi more pressure if not compensated in the regulator. I prefer not to compensate at the regulator to keep things simple.
The proper solution is to buy bigger injectors and use them at the pressure they are intended for

[Danglerb]

Originally Posted by Barbapapa

The concern is overall fuel delivery capacity at the higher pressure and sealing and atomisation at part throttle when manifold vacuum is high. A full vacuum is equal to 15 psi more pressure if not compensated in the regulator. I prefer not to compensate at the regulator to keep things simple.
The proper solution is to buy bigger injectors and use them at the pressure they are intended for

I'm not much of a machinist, so all my tinkering would be in the control system, which I likely would not keep simple.

I see a fair amount of success on other platforms with higher fuel pressures, up to about 90 psi or so. My impression was that as pressures go up, atomization gets better.

Guessing that idle quality at the track as long as it starts and doesn't die isn't too critical?

[Herr-Kuhn]

Great work. I'm unclear on why everybody thinks the driveline is going to break. Torque breaks parts, not HP. Your car is running a nice, solid 500 ft-lbs which should be easy to deal with. These drivelines can handle more torque than that, but not likely for long duration. I've seen my car lay down 635 ft-lbs on the dyno without blowing up. If you keep that trans cool you should be able to cope with that torque, even on a track.

It is easy to see you have the cams and intake setup for the higher powerband range, which for a track car, is what you really want (in most cases). The individual throttle bodies do cost you some in the midrange, but they flow more upstairs and since the car is light you will still have plenty of power midrange to pull it as hard as you want. I also assume there is some overlap on the cams to get it to sing out past 7K like that.

Nikasil...I say that is a good idea, because you will make the engine last longer and lower the friction of the system as a whole. If the sleeves can be pulled easily then you can always have them re-plated if they get damaged. Motorcycle and snowmobile guys do that all the time to freshen them up. Same can be done on a plated aluminum block, assuming you can deal with the tear down.

Some questions:

What cams are you running?
What is the bore size?
Speed density or MAF controlled?
Batch or sequential?
Knock sensors installed?

[Herr-Kuhn]

RH...The big Aeromotive A1000 pump isn't that great a pump. Yes, it outflows the Bosch 044 at low pressures, but above 50 psig, the Bosch 044 actually outflows it, pretty substantially. When sizing pumps, you always have to look at the overall flow at the fuel pressure you want to run. I wanted to go A1000, but it just didn't add up given the pressure I wanted to run. The nice part is one could size a really big injector and then turn fuel pressures down to get proper atomization to really take advantage of the flow characteristics of a given pump. So many variables...

[Barbapapa]

Originally Posted by Herr-Kuhn

Some questions:

What cams are you running?
What is the bore size?
Speed density or MAF controlled?
Batch or sequential?
Knock sensors installed?

Hi John.
The cams are my billet blanks ground to 250ish duration with 12.7mm lift intake and exhaust. The lobes are optimized for the 35mm bucket size. That much lift takes some clearancing in the heads and is about the limit possible.
Bore=109mm
The Motec uses a combination of TP and MAP, a Bosch TPS and GM 100kpa Map sensor.
The injectors and COPs are both sequential. I use the oringinal S4 ref and sync sensors. The ECU sends its signal to a Motec ignition expander for the multiple coils. The coils are ignited by a pair of Bosch 4 channel ignitors.
I'm testing a standalone knock sensor and looking at having the ECU takes its signal. There's work left to do for that.

Funny you should mention removing sleeves to repair damage. I've already had the pleasure of doing just that! This engine had a valve break at the keeper groove a while back. It did some damage and nicked a cylinder. I didn't like the original honing finish anyway so I had the sleeves replated/honed and now keep an extra on hand.
Originally I honed the block with torque plates mounted but I've changed that. I now have an individual fixture to hone and install the sleeves finished. The advantage is that I don't have to bore the block deeper than the piston travels to allow honing. That keeps more meat in the block. I feel the tradeoff is well worth it, I don't seem to be giving up bore roundness anyway.
You might like my sleeving method. It's a long way from the old days of simply boring a hole and stuffing in a tube. I've developed some details which I'm very pleased with and that part of the engine is not something I worry about anymore.

Thanks for the transaxle ideas. It does take away from enjoying the car to worry that something is going to break and knowing you've put over 600 ft/lbs into one gives me hope

[BrendanC]

Hey Mike. Awesome stuff.

Those are cayenne coils? How are they?

[shmark]

Mike that is just phenomenal, congratulations! I know you've worked on this for a long time, totally worth it. And if everyone is impressed with the engine, you should see the rest of the car. I got to see it up close when he was still building things and then engine is just the start of it. Custom suspension, exhaust, CCW wheels and Alcon racing brakes you could serve a party on. Amazing machine, way to go!

[Danglerb]

How does MAP work with the ITB?

[BrendanC]

Originally Posted by Danglerb

How does MAP work with the ITB?

Carefully.

[lizard928s]

Mike,

What would the price on a set of billit cams be?

And what mods did you have to do to make them fit. I am also curious as to what your lobes looked like.

TIA

[Louie928]

Hi Mike,
Congratulations!! Your project is unbelievable in all respects.

If you can keep your tranny cool and be a bit easy with shifting it should last a while. The torque isn't quite to the level to cause trouble.

Great design and execution.

Louie

[icemang17]

Mike
Amazing work.....especially making a BIGGER displacement engine that makes less torque down low then some "convential" strokers....a great way to save the driveline... I did a little dyno comparsion between yours and Louies 603whp run....its interesting that Louies motor makes considerably more torque below 5500rpm....but yours make more past 6k, as Louies is dropping past 5500rpm.....

So looking at the torque curve comparsion....it must be a combo of the cams-larger valves and probably shorter ITB runners that shifted the torque curve so much higher....

So what size diameter ITB and how long of a runner? My guess is 52mm+ and maybe 6 inches

[Barbapapa]

Originally Posted by icemang17

Mike
Amazing work.....especially making a BIGGER displacement engine that makes less torque down low then some "convential" strokers....a great way to save the driveline... I did a little dyno comparsion between yours and Louies 603whp run....its interesting that Louies motor makes considerably more torque below 5500rpm....but yours make more past 6k, as Louies is dropping past 5500rpm.....

So looking at the torque curve comparsion....it must be a combo of the cams-larger valves and probably shorter ITB runners that shifted the torque curve so much higher....

So what size diameter ITB and how long of a runner? My guess is 52mm+ and maybe 6 inches

Hi Brian.
My dyno chart made Louie's results even more impressive because I have 30 more cubic inches, more cam etc but only made 30+ more hp.

I had no idea I was missing low end torque. Driving the car on the street isn't very practical because putting your foot into it at any speed or rpm range induces wheelspin, at 5200 it then shoots towards the redline quickly.

The throttles are 54mm. The intake track length is about 9". The ports are bigger too.

BTW, how is your car? I heard you got some nice results from some practical mods.

[Barbapapa]

Originally Posted by lizard928s

Mike,

What would the price on a set of billit cams be?

And what mods did you have to do to make them fit. I am also curious as to what your lobes looked like.

TIA

Hi Lizard.
Here's a pic, you might see how I machined the head to clear the taller lobes. It was a simple machining operation for a 3 axis CNC mill. The base circle is a wee bit smaller too in order to keep the oil channels matched between the head and tappets. I don't think I had to reduce the base circle though.

I think I've sold a set of unground cams for 1800. They would be nitrited after finsh grinding. I like making stuff like that and am about to start on some more.

BTW, you can see the modular sprocket on the intake cam. That's because my grinder didn't get the relationship correct I had to cut away the integral sprocket and make that to get the timing correct.

[icemang17]

Originally Posted by Barbapapa

Hi Brian.
My dyno chart made Louie's results even more impressive because I have 30 more cubic inches, more cam etc but only made 30+ more hp.

I had no idea I was missing low end torque. Driving the car on the street isn't very practical because putting your foot into it at any speed or rpm range induces wheelspin, at 5200 it then shoots towards the redline quickly.

The throttles are 54mm. The intake track length is about 9". The ports are bigger too.

BTW, how is your car? I heard you got some nice results from some practical mods.

Mike
Its still doesn't run :>( But I did gain 8whp from Carls intake spacers

It should be running next week, & I plan on tracking it again end of the month...

I did blow a rod bearing back in April...got really lucky since I caught it early enough to save the motor.....did LOTS of mods to improve oiling, just about everything you can short of a drysump like yours....(which looks great BTW)

Taylor cross drilled crank
"loose" rod bearings .0025" or looser
3/8th pan spacer + windage tray
GTS baffle
Improved breather routed to catch can (two on both sides)
new oil cooler in bumper, not radiator
Accusump with 55-60psi EPC valve with switch to prevent idle oil dump

I hope its enough to surive a few racing seasons... everything else is stock 5.0L S4 stuff.... I've been thinking about new cams with lightweight lifters as a next step....but thats down the road.....

I would love to see your machine run...heres a link to mine on youtube

http://www.youtube.com/watch?v=386X2Wehh5I

You bring up good points about the engine being "too much".....Louie has made similar comments about his..... I'm having a blast out there with 300whp-3100lbs & very few cars can catch me on the straight

[Barbapapa]

Originally Posted by Danglerb

How does MAP work with the ITB?

Mr. Glerb!

Each throttle as a hose barb below the throttle. A hose from each goes to a little "resevoir" and one hose from that goes to the MAP sensor.

You would think it's important to do something like a resevoir with internal baffling, valving or something fancy but in reality this setup always seems to work very well no matter how simple you keep it. I suppose you could also run a vaccum booster but I've never done that.

[icemang17]

Also when you decide to make some more billet cams...let me know as I'd like to put a set in the widow version 3.0.... Not 100% sure what duration-lift to run just yet