hacker-pschorr

+1
I've been tempted to make this thread a sticky........

If it's the stock ignition components controlled by a new brain we know it's good for 650-700rwhp.

But I agree, this much work I would opt for a more modern COP system.

If Greg, Mike or Andy are interested, I'm sure Todd would share the specs on how he modified the coils he's using on the twin turbo.

James Bailey

As it sits now on the dyno cart it uses two stock ignition "exciters" , secondard stages. I do not think they intend to rev this engine much over 7,000 RPM but as I have stated I KNOW nothing ! But it sure is PRETTY !

GregBBRD

Yes, we are still using the stock igniters and coil, controlled by the Link brain. We intend to try something else, once we get the thing tuned, to see if we are limited by ignition.

I love the reliability of the stock igniters and coils. I've had many problems, over the years, with aftermarket ignition systems, which has made me very conservative.

GregBBRD

We might need that. Thanks for the offer.

One of my big backgrounds is airflow. I've had a flowbench since I was old enough to drive. Over the years, I've cut and ground on a rather big variety of heads....but I've dedicated the past 6 years or so, to the 928 head. One of the really cool thing about airflow measurements is that you can take total airflow numbers and pretty accurately figure out how much horsepower a given engine with a given head is going to make.

I've ground 928 ports until I see them in my sleep....I'm talking about 100's of hours grinding and flowing these heads. I've got several "practice" heads that I've cut in many, many different shapes and sizes. I've tried big valves, small valves, sunk valves, smooth valves, and rough valves. I think I've tried every "reasonable" port shape that can be done, without welding.

I'm to the point where I can walk up to a 928 head, look and touch the ports, and tell within a few percent of how much airflow there will be.

I've yet to see an intake port that has enough airflow to make 700 flywheel horsepower, from a naturally aspirated engine. Although these heads combine the features that make these ports flow the most amount of air I've done to date and every port was individually measured and equalized, they are not an exception to this.

If this thing makes over 650 flywheel horsepower on this engine dyno, I'll be dancing the night away....and I predict that Andy will break every piece of the drivetrain that he could possibly break.

m42racer

Sounds to me the Ignition is not the problem here......yet.

jorj7

I have no doubt that you'll be dancing on this one. And maybe we should send
Andy to the Kibort school of driving, I hear that learning to control the power is
the key to success. Just don't let him tell you how to build the engine...

James Bailey

Considering that Andy plans to go REAL FAST that might not be the right school

AO

dr bob

The Good News is that this won't leave a mark...

blown 87

Can that even be done with just a hammer and a dremel tool?

Rick Carter

Looking forward to the oiling solution.

m42racer

Yes, I agree this engine will easily make 650 HP. If it is making 530HP at 5500 RPM, another 120 HP is very achievable with another 2000 RPM. Start dancing Greg.

Without spilling the beans, can you enlighten us to what the problems were on the dyno. Some here have suggested the Oiling problem causes Rod bearing failures. But reading your posts, you say the engine is still on the dyno cart. So whatever the problem is is did not hurt the engine. If this is the case, loss or lack of presuure cannot be the problem as this is still wet sump nor can it be sealing issue. The only thing I can think of left must be a breathing problem. Looking at your photos it shows the Valve covers with breathers going to the Intake box. Just guessing, but did the engine stop breathing and push all the oil out the breathers? This is an old time issue with wet sump engines. The stock pumps cannot keep up with the excavation of the sump gases and they are really liquid movers not air movers, the sump pressurizes and the oil pumped up into the Heads cannot return to the sump. The heads fill up and is pushed out the breathers.

Tell me how I know this. I been there before. It was solved by doing several things. The sumps (2 engines in my boat) were sucked dry with a scavenge pump and the stock pumps were left to provide the Oil to the engine. The oil sent up to the valve train was restricted and the heads were scavenged with their own pumps. This was used for sometime until I spent the money and the engine dry sumped properely. This was the cleaner way, but the other way did work. The engine was disassemebled after sometime with the first fix and the Piston pins showed some scoring due to the scavenge pumps working alittle too good. This was fixed by limiting the vacuum, but it had to be tested and adjusted.

Hope this is not the case as it cost me a small fortune and the time to do and recheck was costly. I suppose this is the cost of breaking new ground. At least you are doing it on 1 Porsche 928 engine. I was doing it 2 Lambo marine V12 engines.

Good luck. I love the work and the engine looks great. Maybe I need to look into these engines for the boat. At least the cost would be lower. Love to hear from you via PM on what it would cost to build 2 of these for marine use.

blown 87

That is a statement you will not hear often, when going to two "Built" 928 engines will be cheaper than another engine.

I shudder to think what a pair of marine V12 Lambo engines would cost.

The_Remora

This is a VERY cool thread, congrats to all involved, beautiful work. Sounds like it could be a huge leap forward for the entire 928 community as well!

James Bailey

Ah yes...."I shudder to think what a pair of marine V12 Lambo engines would cost. " full on race versions appear to be around 90,000 Euros .........EACH !!