572 camming/build questions
 

Just curious what cam vs compression you guys with 572's are running and where you are spinning. Currently this thing has a 242/244 @ .050 112 Lobe sep. 108 Intake CL and .612/.637 lift. Im spinning 5200-5300. Breathing through ported 345 merlins. 9.2 compression, 36 deg total advance, barry grant 1050. Been looking for some more power and felt the cam may be a bit small for these cubes and I'm sure the heads could use an upgrade (Especially if a larger cam is installed that wants to pass air more efficiently). Only upside right now is the docking attitude is great but for all I know I can increase in camming and not lose much. Let me know your thoughts/experiences. Thanks -Chris

chris,that is a lot of camshaft for a normally asperated engine,what boat is it in,what gear ratio,and what prop are u running?i think u should prop it to max at app 6200 rpm.

1.36 gear with 26 pitch. 28' Eliminator eagle. Last known dyno had peak power in the 5300-5500 range (Fairly flat). Cam doesnt seem that big to me with 572 cubes. I'm running a 244/248 on a 112 with 633 lift in my 408 strip car spinning to 6700. Both are hydraulic rollers but thats 164 less cubes. For some reason when I seen the cam card I expected a bit more duration and lift even though we're spinning much lower.

Seems small to me, are you running a 4.5 crank ? The 572 GM crate motor with a 4.375 crank peaks at 5500 and runs a 254 / 264 cam.

Talk to C Straub. Nuff said...

Chris, I have a couple cam grinds I use on 572's and they are both in the 647 to 657 lift range and 258/266 @.050 duration with 114 lobe separation. I personally use different heads than you are but these cams make good power to 5800 with hydraulic lifters. I run Brodix -4 on 572's with very good results. Rob

That cam is only slightly larger than a stock 525EFI cam for 502ci. Its too small for a 572ci.

That was the first thing I thought too, awful small, leaving some hp on the table. Maybe Chris Straub will chime in with a cam suggestion, just kidding, but I do seriously think cam is too small. I am running 10 degrees more duration in my 540 and its only 8.2-1 comp, Smitty

Ok, so its not just me then. Thought it seemed pretty tamed. Yes, its a 4.5 / 4.5. I think a bigger stick and some good flowing aluminum heads with a 9.5:1 static would liven the beast up. Built up good (Callies crank, oliver rods, teague drive ect) Shouldnt have no problem with the added power and spin. I've been talking to JimV and hes going to get back with me on some thoughts on heads. I'm thinking the cam should be replaced along with the heads. I doubt I'll get my moneys worth out of good heads without decent camming. I think the Dart intake will be well enough. The Barry Grant 1050 may bottle neck some but I've seen much higher spinning 514's run the 1050's with no problems. Guess it will be fine after some rejetting.

i run a pair of 580cu motors (572 30over) with 8.6:1 comp and dart pro1 335cnc heads with 8lbs boost 1100hp,,,,,cam is a 250 258dur 625 629lift on a 113....of your going to stay NA id change the lift to 640 650 ish

The 1050 is plenty. I tried the next size up dominator (sorry brain fart can't remember size) couldn't get the boat to idle well and was just too much carb. I used bb3 with some work done to them.

Built a set of 572's last year that made 754 HP 720 TQ with Bob Madara cam, lift was around .750 (thats all the info you get without calling Bob).Compression is 10 to 1 with AFR heads and Pro Sytems 1150's. They idle like a 500 EFI making power to 6000+ RPM's.

10:1? wow I'm afraid to go anything over 9.5 with this fuel around here. Usually it is around 91 octane. Some pumps advertise 93 but I wouldnt count on it. Is that RMbuilder? How do you contact him?

Rm builder 585-654-8583

I think thats a good call,you'll get it right the first time with the right parts.

my 598ci N/A is at 10.25:1 running pump gas.

.647 lift, 255/263 @.050, 112 LSA.

Whats the top rpm your getting?
Friends 572 with 254,266,ls112 is getting 5600rpm in his 1989 38 top gun #3 drives.Can't remember the prop pitch but the boat origanally had cobra 750's.They changed cams and gained another 300rpm,81mph now.Not too bad for a tank.

Good stuff.

I love the all black look. Just my style.

Spinning it 5800rpm with a 32p Bravo 1 and just over 6000rpm with a 30p Bravo 1. Doesnt like the 32p very much, a bit too much prop at summer heat and a full boat.

Still ran 96.5mph today. It has a few more in it for sure.

Thanks Smitty. I'll get in touch with him and see what he has to say. :drink:

Man, your valves aren't spending much time over .500 lift
Give that baby more lift and more duration. It's a 572.

Better heads are always key to making power, but you also have to get those valves open fast and hold them open. You're probably already propped past your HP peak.

MC

Whats yours guys feelings on the Merlin III aluminum CNC 345heads? Seems like a reasonably priced upgrade as far as heads go. Stock port locations. Flow numbers look good for not having a 6" pipe (like afr does on their flow testing). I'd be going from the Iron Merlins with same port locations so I'd likely be able to go back without making changes to my CMI's or dart intake.... Some hand porting would likely take them even further if possible with these

i have a similiar bbc with afr 357's. i changed from a .632/.632 244/254 at .050 to a .690 266/268 and picked up 80hp at 5900 on the dyno. boat ran 8 mph faster.