Which N/A efi motors?

[SummerObsession]

This subject has come up more than once among a few of us out here in the sticks.
If you were going to pick some naturally aspirated motors with efi, which ones would you use? It seems a lot of builders are offering products along these lines now.
A friend was just telling me about GT 588" efi motors making around 750hp, no reliability issues so far.
I would eventually like to convert my Peto 580" motors (most of the parts are the same or close) to something like these.
These are just a few engines I know of:
Sterling-750 n/a efi available
TMP-750-800hp efi
Zul-several diffent packages, don't know about efi
GT-750hp 588ci
Sonny's ( ;) ) up to 813ci, efi on any of them
Anyone have any experience with these or others?

[Steamin' Rice]

Pfaff makes a nice 600HP and 700 HP EFI that is N/A.....

[SummerObsession]

I forgot Pfaff.
He builds great stuff from what I know...have not heard about his efi though.

[Whipped Caliber]

Pfaff's EFI stuff is great!! i have one of his 565ci Q-rotor EFI motors and it starts 1st time each time!!! 45 hours on it so far!! ;)

[Havasu Cig]

I have been told that Pfaff is ahead of the curve when it comes to EFI motors.

[SummerObsession]

Thanks for the info guys.
Anyone know about GT?
I had someone recommend them, but I don't see much of his stuff out here.

[Charley]

J
Give those things back to Larry and give him a HP # to get.... Larry is awesome and will do it with out emptying yer wallet

[DogHouse]

You've got good parts in those motors. All you need is more compression and cam to get you up in the power range you're talking about. If you want to spend the $$$ on EFI, that's easy enough as well. Your Dart single plane manifolds can be converted for use with injectors very easily. From there you'd just need the throttle bodies, injectors, ECMs, high pressure fuel system (pumps, regulators, rails, etc) and other assorted EFI hardware (sensors, wiring, etc). Charley is right about Peto, great work, fair prices. He's not up to speed yet on EFI though. Wally (Heavy Hitter on the boards) helped set me up with the EFI hardware and we dyno'd and tuned at Larry's shop. If you step up your motors a little, you would be in the same ballpark as mine. If you want to run Electromotive EFI and direct fire distributorless ignition, you could start with my EFI program and tune from there.

[bigkatboat]

GT spends YOUR MONEY ON YOUR MOTOR! No hype, no BS, just good parts, the correct knowledge, and PURE RELIABLE POWER. He once ran a blown gas drag boat motor ALL season, with just a valve spring change. He won his class in IHBA that year! You can "buy a name" or you can "buy a motor", GT MARINE delivers, at realistic prices.

[SummerObsession]

You've got good parts in those motors. All you need is more compression and cam to get you up in the power range you're talking about. If you want to spend the $$$ on EFI, that's easy enough as well. Your Dart single plane manifolds can be converted for use with injectors very easily. From there you'd just need the throttle bodies, injectors, ECMs, high pressure fuel system (pumps, regulators, rails, etc) and other assorted EFI hardware (sensors, wiring, etc). Charley is right about Peto, great work, fair prices. He's not up to speed yet on EFI though. Wally (Heavy Hitter on the boards) helped set me up with the EFI hardware and we dyno'd and tuned at Larry's shop. If you step up your motors a little, you would be in the same ballpark as mine. If you want to run Electromotive EFI and direct fire distributorless ignition, you could start with my EFI program and tune from there.
Thanks for the offer! You're right about the parts. However, I do want to swap out the cranks. 4130 isn't always the SAME 4130 if you know what I mean. :wink: To get reliable horses, I would eliminate the weakest link. Everything else is top notch!
The reason for efi, IMHO, is NOT for power. Carbs will make just as much or MORE at WOT. Idling, dock manners, a clean transom, etc. etc. are the main drivers for me. I am looking into a program that would allow an easy change between 91 octane and 110 octane fuel as well. A little timing and a fuel curve change and it might run pretty well at the shootout and on other special occasions! :eek: :wink:

[SummerObsession]

GT spends YOUR MONEY ON YOUR MOTOR! No hype, no BS, just good parts, the correct knowledge, and PURE RELIABLE POWER. He once ran a blown gas drag boat motor ALL season, with just a valve spring change. He won his class in IHBA that year! You can "buy a name" or you can "buy a motor", GT MARINE delivers, at realistic prices.
I've heard that as well.
I don't know if I trust ex drag racers though. :eek: :eek: :D :D

[DogHouse]

Thanks for the offer! You're right about the parts. However, I do want to swap out the cranks. 4130 isn't always the SAME 4130 if you know what I mean. :wink: To get reliable horses, I would eliminate the weakest link. Everything else is top notch!
The reason for efi, IMHO, is NOT for power. Carbs will make just as much or MORE at WOT. Idling, dock manners, a clean transom, etc. etc. are the main drivers for me. I am looking into a program that would allow an easy change between 91 octane and 110 octane fuel as well. A little timing and a fuel curve change and it might run pretty well at the shootout and on other special occasions! :eek: :wink:
I've got a Scat crank in mine as well. Haven't had any issues at all, and it regularly sees 6k+. We dyno'd to 6500. If you're going to cam up such that you need to spin higher than that, you won't be idling low enough to keep those Bravos happy while shifting!

[SummerObsession]

I've got a Scat crank in mine as well. Haven't had any issues at all, and it regularly sees 6k+. We dyno'd to 6500. If you're going to cam up such that you need to spin higher than that, you won't be idling low enough to keep those Bravos happy while shifting!
Hence, the efi. :wink:
I'm not going to twist it hard enough to need mechanical lifters. I don't like adjusting valves that well. Been there done that too many times after each 1/4 mile.
It just needs to breathe with a little more compression.
Scat's are OK for most things, but pressure the extra rod length puts on the the crank with 580 cubes is the worry.
Puls, I run WOT for miles at a time at LOTO.

[DogHouse]

Uh, I'm running a 598, 4.5" crank, 6.8" rods, reeeeeeealy short pistons, 800+ hp. I run mechanical rollers but only because they allow for cam profiles that make more power, not for the rpm potential. I check/adjust every 20 hours or so. Yes the EFI helps with idle because you can really fine tune and run IAC, but still if you run too wild a cam, you're not going to get it to idle well enough to make a Bravo drive happy. If you stick to hydraulic rollers, you won't have enough duration to even worry about idle quality, it'll be fine. It's when you get into the high 260-270 range @.050 that idle turns to sh!t, and hydraulics usually don't go that high.
Assuming your motor is balanced well (mine's internal), really, you have no worries with the Scat crank. But hey, it's your $$$, spend 'em if you like!
:D

[SummerObsession]

I agree with you regarding the cranks. I really don't lay awake at night worry about them, but when it hits rebuild time, I will probably replace them. By the time you sell the old ones and buy new, it's not that much. Might go with a few more cubes anyway. :D

[TYREPEDDLER]

My new boat's heeded for GT's monday. 588/efi 750 I haven't here anything bad. I'm a long ways from ca if i have problems.

[Jrocket]

My new boat's heeded for GT's monday. 588/efi 750 I haven't here anything bad. I'm a long ways from ca if i have problems.
What boat will that be?

[TPI]

GT spends YOUR MONEY ON YOUR MOTOR! No hype, no BS, just good parts, the correct knowledge, and PURE RELIABLE POWER. He once ran a blown gas drag boat motor ALL season, with just a valve spring change. He won his class in IHBA that year! You can "buy a name" or you can "buy a motor", GT MARINE delivers, at realistic prices.
BKB,
Thanks for the encouragement, but I think these guys are referring to Gary Teague "GT". Who happens to be a very good guy. I think I am going to have to change my ID to TPB. My site has some good motor info also: www.TPBOATS.com.............. Only for CA residents though. I like to service/maintain my own motors.............