Spoolin

iTrader: (8)

Has anyone heard of or read about any company designing Direct Injection Heads for LS motors?

96 Comp T/A

iTrader: (8)

GM is rumored to be working on these for production, or do you mean DI like Sprint cars run? FYI, Sprinters just run the nozzle through the back side of the head, but the fuel is still introduced before the intake valve. A true DI setup would probably something that is best left to the OEM's at this point, as the fuel pressure required to run one of these is outlandish, and the injectors needed to run at that pressure level and cyclic rate at the volume required to make real power is probably out of the realm of capability for most aftermarket vendors, and outside of the spend of most consumers. Interesting tech though.

Whistler

iTrader: (46)

You'ld probably have an easier time converting a Duramax to gasoline and spark ignition.

I guess you could probably have a front timing cover that could accomodate the mechanical pump and drive it off the cam in block, similar to the distributor-drive covers out there. That'd probably be just as much work as engineering a head with an injector hole in it.

I'd buy it in a second if they made it. DI is awesome.

Spoolin

iTrader: (8)

Thought of that, and in addition to the problems you suggested would be running a fuel system under the required pressures. Most fuel pumps on the market would not last very long or be able to do it in the first place. It's possible to maybe run three pumps inline but that's more or less a temporary solution.
A friend of mine suggested running a set of ecotec heads on each bank!

Whistler

iTrader: (46)

I really doubt you'ld get any electric pump to make 20,000 psi.

87silverbullet

iTrader: (11)

20,000 psi is not needed for direct injection. Its roughly about 1700 psi but thats at wot on GM 3.6l motor. Diesels are a little higher somewhere between 2000-2500 psi.

You are still correct though. No electric pump will get to 1700 psi or 20,000 psi

Whistler

iTrader: (46)

I thought it was higher, just checked my GM books.. max SIDI FP is 2176. The Duramaxes run well over 20,000 though, up in the 23,000-25,000 range.

Spoolin

iTrader: (8)

I'm pretty sure it is higher as well. I recall reading that it was in the 20,000 psi range but I'm no expert. I know that the cylinder pressures of a diesel with it's 18:1 compression is really high prior to the combustion cycle.

FSAE_Junkie

Can't speak for direct injection in SI engines, but CI engines use fuel rails operating at absurd pressures. I have a friend who works with Cummins fuel injectors. He routinely talks about dealing with 3000+ bar rail pressures.

Thats roughly 44,000+ psi. It's not easy to do.

Spoolin

iTrader: (8)

I was searching around on the internet and gave a call to a company called Coates Engineering. Their heads are still in R&D but holy crap that would be awesome to have the first prototype of their heads.

I couldn't find any other video clip than this one so please ignore all the "be happy go Green" crap and focus on the nitty gritty of their head design. Pretty cool.

http://www.youtube.com/watch?v=pDsRa4eT7co

87silverbullet

iTrader: (11)

Alot has changed since I left the dealer. I remember working on the old non-intercooled 6.5 diesels and the injector pump pressures (iirc) were around 4-5000 psi back then and the compression ratio of those motors were 22.5:1.

You are right and I am amazed at the pressures that these motors run at. This is what I found at "the diesel place" for duramaxx's


Cylinder block casting and machining changes strengthen the bottom of the cylinder bores to support increased horsepower and torque.
Upgraded main bearing material increases durability.
Revised piston design helps lower compression ratio to 16.8:1 from 17.5:1.
Piston pin bore diameter increased for increased strength.
Connecting rod " I " section is thicker for increased strength.
Cylinder heads revised to accommodate lower compression and reduced cylinder firing pressure.
Maximum injection pressure increased from 23,000 psi to more than 26,000 psi.
Fuel delivered via higher-pressure pump, fuel rails, distribution lines and all-new, seven-hole fuel injectors.
Fuel injectors spray directly onto glow plugs, providing faster, better-quality starts and more complete cold-start combustion for reduced emissions.
Improved glow plugs heat up faster through an independent controller.
Revised variable-geometry turbocharger is aerodynamically more efficient to help deliver smooth and immediate response and lower emissions.
Air induction system re-tuned to enhance quietness.
EGR has larger cooler to bring more exhaust into the system.
First application of new, 32-bit E35 controller, which adjusts and compensates for the fuel flow to bolster efficiency and reduce emissions.
The Duramax 6600 also has a new intake air heater to reduce smoke and emissions during cold or light-load driving. The system features a 1000-watt grid heater located in the air intake duct, which is triggered automatically by the engine controller. It heats up the incoming air to speed warm-up of the engine.