New Engines: 557 or 572
 

I am thinking of build a couple of spare engines and can't decide which stroke to go with.They will have convention 24* heads and whipples with a solid roller. I have 598's now and I really like the torque of these, but it seems all of the big name builders are going with The 4 3/8 stroke 557. Will there be much difference with this over the 4 1/2 572.

Re: New Engines: 557 or 572
 

220-221, whatever it takes! :drink:

Re: New Engines: 557 or 572
 

LOL

You may want to watch this, they could be your back ups as well? :evilb:

Re: New Engines: 557 or 572
 

How about some 557's from Mercury... :D

Re: New Engines: 557 or 572
 

The smaller Stroke is suited for sustained high rpm.


557,s love to play in the upper 6000 rpm range.


557,s are my platform of choice.
But then again I like Budlite. :drink:

Re: New Engines: 557 or 572
 

Now send me the 5.0 whipples your getting and I will put them on these 557,s with these CFE chief heads, solid rollers.

This is my next setup.

Re: New Engines: 557 or 572
 

I smell a bargain in the works. :eek: :D










You may as well go ahead and price those old junk quad whipples to me as well... :evilb:

Re: New Engines: 557 or 572
 

Just go 1075's and forgeettaboutit! :drink:

Re: New Engines: 557 or 572
 

So that would be a vote for 557, :evilb: smartest thing I've heard today, just wish I could afford them. :(

Re: New Engines: 557 or 572
 

I would highly suggest 4.375 stroke. I have built 1600 horsepower with a PSI on carbs and gas. A 557 will handle 6800-7200 RPM with ease.

Re: New Engines: 557 or 572
 

Isnt 557 there norm ci for them ???

Re: New Engines: 557 or 572
 

Yes

Re: New Engines: 557 or 572
 

I am guessing because they can RPM it?

Re: New Engines: 557 or 572
 

Are the solid rollers really worth the trouble?

Re: New Engines: 557 or 572
 

572's are kinda boxy no?

Re: New Engines: 557 or 572
 

Due to harmonics....always build a square engine...they are happier and
they will last significantly longer

Re: New Engines: 557 or 572
 

Your saying a the bore and stroke the same??? :eek:

Re: New Engines: 557 or 572
 

Thats the old showpower slogan, how do you know that???

Re: New Engines: 557 or 572
 

588cu in :cool:

Re: New Engines: 557 or 572
 

it's from Mr. Mom..... :drink:

Re: New Engines: 557 or 572
 

572 4.5 X 4.5

Re: New Engines: 557 or 572
 

what trouble, once they are broken in and adjusted once nothing should change if it does, you will know you have a problem before the big bang happens

Re: New Engines: 557 or 572
 

yeah forget about it...top end every 50/60 hours, total rebuild every 100/110 hours...forget everything but your check book! also you will want to get another boat so you'll have something to run when your motors are being freshened up mid season :eek:

Re: New Engines: 557 or 572
 

Can someone confirm or deny but I understand the 572' has a less than optimum rod-to-stroke ratio.

Re: New Engines: 557 or 572
 

that would depend on rod length, i do not like a square engine

Re: New Engines: 557 or 572
 

yes Rob !

Re: New Engines: 557 or 572
 

bingo...... Panther!!!!

Re: New Engines: 557 or 572
 

I believe a 6.535 is std. on a 572 with off the shelf parts and gives it a bad rod/stroke ratio, no?

Re: New Engines: 557 or 572
 

yes that is 400 long but you can go longer

Re: New Engines: 557 or 572
 

Great thread! Keep going, I'm learning.

Re: New Engines: 557 or 572
 

I run a 6.70 rod in mine but we needed to order custom pistons cause we couldn't find a dished piston to bring down compression for the blower. Lunati said we could have ordered a flat top piston for a 6.70 rod but we would have needed to mill a dish into the piston and I didn't want to do that.

We also had to go .030 over due to some tapers in the bores so I'm actually at 580 cu in.

Re: New Engines: 557 or 572
 

there is more to running a dish piston then just for compression with a blower motor you did the right thing

Re: New Engines: 557 or 572
 

The only thing we did wrong was totally miss the mark on the cam.... ohhhh, I've learned so much since then and have also switched builders..... :eek: :drink:

Re: New Engines: 557 or 572
 

Wouldn't the growing popularity of the 557 vs 572 be a piston speed issue ?
4.375 stroke equalling more durability & reliability ?

Re: New Engines: 557 or 572
 

So MC: What did we learn from this experiment? It's always good to have extra motors on E Dock!!!!

Re: New Engines: 557 or 572
 

it could be but rod length also efects piston speed

Re: New Engines: 557 or 572
 

I have run 4.600 bore -4.500 stroke for over 8 yrs with no less
than 6800 chips. It all depends on the height of the block,length of the rod,and pin placement in the piston.
I will run my power for how long it takes.If you want to run a larger enough cam solid rollers are the only option.
I don't get it some times and I know it drives engine builder's
nuts.Power boaters will spend days or big $ on detailing ,but taking a couple of hours to run through the valves or at least an inspection is out of the question.Its cheap insurance in my book,I like to pull the valve covers after every hard run.
Big """ would be my choice just depends on the combination
your looking for. Good luck I'm a little envious that your building spares.

Re: New Engines: 557 or 572
 

MAY I please ask a question I have a 502 30 over so it's a 510? or 509? next time I freshin up what would be a good stroker set up what size crank and rods? I HAVE MERLIN 310 R M HEADS ON IT . CAN IT BE BUILT TO 540 550CI'S. THANK YOU ART :D

Re: New Engines: 557 or 572
 

you could run a 139cc head to knock the compression down. I run a 4500 bore 4500 stroke 6.700 rod flat top piston on a 139cc head 60,000 copper gasket never had any problems 9lbs of boost.

Re: New Engines: 557 or 572
 

What block are you running? probably shouldn't go over 4.25 crank with 6.385 rods, 4.53 bore, 548 cid.