tomcat

Following the lead and advice of some of our customers, we are going to approach Holley about including their multi-point injection in an Rtech supercharger/supercooler system. On top of a 540 with good heads this system would produce 1000 HP @5700 RPM. Engine building specs would not differ from normally aspirated marine, with the possible exception of head gaskets. ECU would likely be FAST due to the experience of our customers.

Target retail price is $10K. I can't say for sure whether this deal will fall into place, but is it worth pursuing?

You could get the same power by modifying Merc EFI, but the only thing you could reuse is the intake manifold and even it needs milling and porting work. The Holley single plane was meant for this application and is available for tall decks.

The Math:

Air

540 X 5700/3456 x 1.00 V.E. = 890 ACFM (use 1000 CFM TB)

890 ACFM X 1.55 Density ratio = 1380 SCFM

1380 SCFM X 0.075 lb/CFM = 103.5 lb/min

103.5 lb/min X 9.8 HP/(lb/min) = 1014 HP

Fuel

1014 HP X 0.6 lb/hr = 608 lb/hr

(608 lb/hr)/8 cylinders = 76 lb/hr per cylinder

(76 lb/hr)/0.8 duty cycle = 95 lb/hr injectors (the largest Holley sells)


We have produced 1000 HP @ 6200 RPM using a 498 stroker with a Nickerson carb, Dart intake, ported GM cast iron heads, solid roller cam and Stainless Marine exhaust manifolds. The density ratio is based on the intercooler effectiveness measured in that dyno test, and a boost level of 8.5 psi. The volumetric efficiency of 100% is from AFR test data.

We are basically using a 540 with better heads to allow the use of a hydraulic roller cam and lower RPM. What do you think?

Turbojack

Tom are you figuring on getting your 1.55 density with 8.5lbs of boost? Your injector size I think is correct since I am using the 96's & see 80% dc with I think A/F ratio at 11:1 or 11.5:1 Second question is desktop dyno shows a centrifugal blower motor will make more HP with a 2000cfm verse 1000cfm being the only difference. Why do you think that is?

tomcat

Hi Jack:

Yes, 8.5 psi is enough IF the intercooler takes most of the heat out. This does depend on cooling water temperature so if water is warmer you need to start with more boost. Still think 9 psi would be maximum, mainly because those heads flow so well.

I know that Desktop Dyno always shows an increase, even when the carb size is way beyond what is necessary for a certain engine. I don't have the real dyno results to confirm or deny. Maybe I'm using an old version, but do their supercharged simulations make sense to you?

Airpacker

WHAT! 800 hp of drive smasher wasn't good enough for ya Tom?

cobra marty

What is the price for a Holley EFI manifold, fuel rails, 1000 or 2000cfm throttle body? Is it all less than $1000?

How much for injectors? 85lbs?

Fountainclimber

Tomcat,

Clean your inbox.

Fountainclimber

tomcat

Housecleaning done.

Hardcore

Hey Tomcat. Way to go! Now when I want that EFI setup I know where to come.
Of course, if the Holley people are smart, they'll want to offer a marinized 540 -572 cid engine package based on Lunati lower end parts, Holley heads and topped off with a an R-tech Supercooler & fuel injection system. Can anybody imagine Mercury Racing SC1000 power and reliability (and then some) for about half the price...