Rtech's Secret Weapon - 1600 HP "Big Gun"
01-08-2004, 09:37 AM
#1
Rtech's Secret Weapon - 1600 HP "Big Gun"
We have had three separate requests for a supercharger system that can make 1600 HP on large displacement marine engines. Two of these requests are for "supercats" and one is for staggered engines in a big vee. Two of the three boats are attempting to set speed records.
Initally the engine builders have looked at certain classes of drag racing where a single blower can make 2000 HP in a Mustang. But this racing class is a much different application, where limited displacement (<400CID) and "stock design" heads require enormous boost pressures to deliver the required air flow. Reliability is not a major concern and blower drive failures are common due to overspeeding.
In a large displacement marine engine with the best possible heads, you need big flow at relatively low pressure. There is currently no single blower available that can deliver the required pressure/flow, although Vortech's V-20 prototype introduced at PRI looks promising.
Looking at the Vortech compressor maps we selected two smaller blowers that are just about perfect. These rough drawings give you an idea of what we're doing. We're staying with the proven supercooler design, but it is a double decker with upper and lower plenums.
Unfortunately the twin blower setup will not work on staggered engines in a narrow vee hull, so those guys will have to wait for the V-20.
Love to hear from the big CID guys as we build the prototype, so we can address as many design issues as possible.
Initally the engine builders have looked at certain classes of drag racing where a single blower can make 2000 HP in a Mustang. But this racing class is a much different application, where limited displacement (<400CID) and "stock design" heads require enormous boost pressures to deliver the required air flow. Reliability is not a major concern and blower drive failures are common due to overspeeding.
In a large displacement marine engine with the best possible heads, you need big flow at relatively low pressure. There is currently no single blower available that can deliver the required pressure/flow, although Vortech's V-20 prototype introduced at PRI looks promising.
Looking at the Vortech compressor maps we selected two smaller blowers that are just about perfect. These rough drawings give you an idea of what we're doing. We're staying with the proven supercooler design, but it is a double decker with upper and lower plenums.
Unfortunately the twin blower setup will not work on staggered engines in a narrow vee hull, so those guys will have to wait for the V-20.
Love to hear from the big CID guys as we build the prototype, so we can address as many design issues as possible.
01-08-2004, 10:11 AM
#3
You just couldn't hold it in and wait for the boat show to unveil your Big Gun kit, or is it Top Gun. I can hear it now playing in the backgroung.
I would guess a given is a dominator flange manifold and carb.
And why not eliminate the belt slippage and needing a 8-10 or 12 ribbed or cog belt and set it up for a chain drive. There are tons of motorcycle applications which might work and probably cheaper. I'm liking the chain drive more and more. Unlimited sizes and ratios. There are plenty of manufactures out there to make them.
For that kind of power do you need dual carb on a sheet manifold? Is there room on the side of the carbs between the exhaust to put the intercoolers on each side?
Or on your design why not just dump the two discharges into the same plenum and then flow thru one solid double height intercooler instean of two separate plenums and intercoolers.
I allways thought that the self contained Prochargers would be cool if they were mounted down low on either side of the crank pully.
I would guess a given is a dominator flange manifold and carb.
And why not eliminate the belt slippage and needing a 8-10 or 12 ribbed or cog belt and set it up for a chain drive. There are tons of motorcycle applications which might work and probably cheaper. I'm liking the chain drive more and more. Unlimited sizes and ratios. There are plenty of manufactures out there to make them.
For that kind of power do you need dual carb on a sheet manifold? Is there room on the side of the carbs between the exhaust to put the intercoolers on each side?
Or on your design why not just dump the two discharges into the same plenum and then flow thru one solid double height intercooler instean of two separate plenums and intercoolers.
I allways thought that the self contained Prochargers would be cool if they were mounted down low on either side of the crank pully.
01-08-2004, 11:32 AM
#4
Yes, it's hard to keep a secret, but it stimulates discussion and that's why I come to this place. I appreciate your brainstorming.
The intake is a single plane with Dominator flange, but we are thinking it should have a 2000 CFM throttle body for this setup. I haven't asked Dean if he wants to try and modify a Dominator carb for this application. At this point we are working with an EFI expert on the injection system. Leaning towards eight injectors in the runners and four in a thick spacer under the throttle body. The ECM we are looking at can handle two maps simultaneously so it should be possible to run the eight injectors as though the engine was naturally aspirated and run the four injectors according to density increases.
One of the reasons that two blowers are good is you are dividing the blower HP load across two driven pulleys. I don't expect belt slipping problems and don't need the HP capacity of a chain. By the way, one of the drag racers I know is breaking the chain drive on his centrifugal blower. HP required to spin the blower goes up as the cube of blower speed.
There is room for two long thin intercooler cores above the valve covers, but getting into them without restriction and distribution problems is a problem. We may use one tall intercooler in the plenum if we can still get good water distribution. But I will still split the plenum itself in two because it's easier to control the distribution of air flow that way.
I like the compressors above the valve covers for a clean inlet path. Tapping the valve cover for a drain is easier than tapping the pan. But self contained could be mounted where you suggest and still have a decent inlet except for the engine mounts.
We toyed with the idea of using reverse rotation blowers that have the blower inlet facing forwards. This is now popular with the drag racers, but you run out of room between the engine and the back seat in most boats. The advantage was the extra room for a thicker intercooler core and deeper plenum.
I am hoping to have this prototype down in time for the L. A. show; definitely for the Miami show.
Thanks for your comments,
Tom
The intake is a single plane with Dominator flange, but we are thinking it should have a 2000 CFM throttle body for this setup. I haven't asked Dean if he wants to try and modify a Dominator carb for this application. At this point we are working with an EFI expert on the injection system. Leaning towards eight injectors in the runners and four in a thick spacer under the throttle body. The ECM we are looking at can handle two maps simultaneously so it should be possible to run the eight injectors as though the engine was naturally aspirated and run the four injectors according to density increases.
One of the reasons that two blowers are good is you are dividing the blower HP load across two driven pulleys. I don't expect belt slipping problems and don't need the HP capacity of a chain. By the way, one of the drag racers I know is breaking the chain drive on his centrifugal blower. HP required to spin the blower goes up as the cube of blower speed.
There is room for two long thin intercooler cores above the valve covers, but getting into them without restriction and distribution problems is a problem. We may use one tall intercooler in the plenum if we can still get good water distribution. But I will still split the plenum itself in two because it's easier to control the distribution of air flow that way.
I like the compressors above the valve covers for a clean inlet path. Tapping the valve cover for a drain is easier than tapping the pan. But self contained could be mounted where you suggest and still have a decent inlet except for the engine mounts.
We toyed with the idea of using reverse rotation blowers that have the blower inlet facing forwards. This is now popular with the drag racers, but you run out of room between the engine and the back seat in most boats. The advantage was the extra room for a thicker intercooler core and deeper plenum.
I am hoping to have this prototype down in time for the L. A. show; definitely for the Miami show.
Thanks for your comments,
Tom
01-08-2004, 04:15 PM
#7
Charter Member #655
Charter Member
I saw a Pro Charger M5 the other day looks big enough for that kind of boost ever done any work with them and the Rtech?
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01-08-2004, 08:16 PM
#8
Looks can be deceiving. You need to see a compressor map and Procharger does not provide them. One of the engine builders looked into this quite a bit and could not get Procharger or others using the M-5 to confirm that it would work.
I can't recommend something for a very expensive engine project unless I'm SURE it will work. Even though Procharger and Vortech rate their blowers for maximum HP potential at maximum blower RPM, you do not want to run them at the limit.
Finally, we have the experience of an OSO member who dynoed the M-5 on his 598 CID. He got 1125 HP @ 12 psi spinning the compressor at about 38,000 RPM. At the maximum compressor speed of 46,000 RPM he might see 1300 HP @ 16 psi.
Switching to Big Chief heads would drop the boost and allow the blower to breathe better, but I don't think it would ever reach 1600 HP and be reliable in the marine environment. Blowers are rotating air scoopers; you reach a point where you just need a bigger scoop.
But I know for sure that two smaller blowers can deliver the airflow without overspeeding the blower. That's why the design is the way it is right now, until Vortech starts producing their new prototype blower in standard rotation.
I can't recommend something for a very expensive engine project unless I'm SURE it will work. Even though Procharger and Vortech rate their blowers for maximum HP potential at maximum blower RPM, you do not want to run them at the limit.
Finally, we have the experience of an OSO member who dynoed the M-5 on his 598 CID. He got 1125 HP @ 12 psi spinning the compressor at about 38,000 RPM. At the maximum compressor speed of 46,000 RPM he might see 1300 HP @ 16 psi.
Switching to Big Chief heads would drop the boost and allow the blower to breathe better, but I don't think it would ever reach 1600 HP and be reliable in the marine environment. Blowers are rotating air scoopers; you reach a point where you just need a bigger scoop.
But I know for sure that two smaller blowers can deliver the airflow without overspeeding the blower. That's why the design is the way it is right now, until Vortech starts producing their new prototype blower in standard rotation.
01-08-2004, 08:35 PM
#9
Registered
Just curious are you trying to do this on pump gas? If not the compression and cam may need to be experimented with so the motor builds some of its own cyl pressure. Now the blower doesn't have to run so hard to make the power. I really don't know blower motors very well so forgive me if my thoughts are a bit out there. What firing order do you recommend on these bigger motors? I have heard a 4/7 swap is worth some some power and durability especially in large high HP motors. Cool research!! Someday I will build a blower motor.
Craig
Craig
