Re: New Engines: 557 or 572
 

Which bore 4.5 or 4.6 has less head gasket issues?

Re: New Engines: 557 or 572
 

4.5

Re: New Engines: 557 or 572
 

Its a gen 5 merc 93 or 94 I forget . 502 390hp merc.

Re: New Engines: 557 or 572
 

If it's the light weight block you might not want to use it.

Re: New Engines: 557 or 572
 

Is the 4.25 the stock crank and I would change the stroke and pistons only. to get 548?

Re: New Engines: 557 or 572
 

Hey that's my saying. :D :D

Re: New Engines: 557 or 572
 

The stock stroke is 4 inch.

Re: New Engines: 557 or 572
 

Out of one of my 598's.Just a small leak in a header is a real bad thing. :D

Re: New Engines: 557 or 572
 

wow :eek: and thanks for the the ED :D

Re: New Engines: 557 or 572
 

I heard that the cometic gaskets have eliminated most head gasket issues.
What RPM's are most builders comfortable with on a 4.5 stroke 1000+ hp motor. For sustained length runs.

Re: New Engines: 557 or 572
 

the cometic and the new fel-pro are great and for me they have just about done away with headgasket problems

Re: New Engines: 557 or 572
 

6300 to 6500 with real roller lifters

Re: New Engines: 557 or 572
 

solid :evilb:

Re: New Engines: 557 or 572
 

904 or bigger

Re: New Engines: 557 or 572
 

yep :D

Re: New Engines: 557 or 572
 

I must be doing something wrong, head gaskets have been a nightmare for me.

Re: New Engines: 557 or 572
 

studs or bolts also head gasket problems can be the result of other problems, tune or weak deck or weak head

Re: New Engines: 557 or 572
 

i think i saw a block that matched those in your shop... :drink: :evilb:

Re: New Engines: 557 or 572
 

Big M, ARP pro studs, Big Duke heads, dark plugs,

Re: New Engines: 557 or 572
 

what kind of headgaskets and how much timing

Re: New Engines: 557 or 572
 

Felpro 1077, 32 on 114 octane. and 12lb of boost.

Re: New Engines: 557 or 572
 

What rod lenth is that, and is it the same as a Merc 900 or sterling 1050. Trying to stay with the conventional head stuff. :D

Re: New Engines: 557 or 572
 

6.635 is a good rod length for that combo

Re: New Engines: 557 or 572
 

those work great for us!

Re: New Engines: 557 or 572
 

That with a good Isky tool room gold stripe spring eliminates the bullsh1t 50 hour service.

Re: New Engines: 557 or 572
 

These 557s that make 1100HP went 178 hours since i built them with the big lifters and Isky springs.And they got murdered too. :cool:

Re: New Engines: 557 or 572
 

the 1077 is the mls gasket i have had good luck with them, are they leaking water or are you blowing them and if so where

Re: New Engines: 557 or 572
 

Finish on the block has to be to the specs that Fel-Pro want for that gasket.It says it on the case that they come in.

Re: New Engines: 557 or 572
 

you are right just got to hope he had that right hell i like that gasket better then the cometic

Re: New Engines: 557 or 572
 

I don't like a sq or over sq motors.the thrust angle and the big slug your trying to sling..

Remember back when the Nascar guys were destroking there motors making more power.

Also why do you think Sterling is running that cube, they have people spending $$$.I bet the experimented on a few costumers :rolleyes: I would think they figured it by now whats the best combo, again there looking at max hp in a race application and usually have a higher RPM peek hp .I would think The bigger the ci the lower the RPM.


CI cal

http://www.itpapulling.com/ci_calc.html


http://www.ajdesigner.com/phpengine/...lacement_b.php


piston speed

http://www.csgnetwork.com/pistonspeedcalc.html

http://www.thedirtforum.com/pistoncalc.htm

rod ratio
http://www.mustang123.com/calculator...Calculator.asp

Re: New Engines: 557 or 572
 

No water problems, just leaking between a couple of cylinders.

Re: New Engines: 557 or 572
 

ROB,

What would make you think that they are interested in low maintance intervals and overall motor longevity???????

Otto

Re: New Engines: 557 or 572
 

They are well worth it. They are no trouble if the valve adjustment is done properly.

Re: New Engines: 557 or 572
 

I would have to disagree with this statement. A square engine verses a oversquare has nothing to do with harmonics. If your having troubles with harmonics get a new engine builder that knows how to balance! If every component is balanced correctly and accurately the engine will have ZERO vibration in it.

Re: New Engines: 557 or 572
 

That depends on how long of a rod length you choose.

Re: New Engines: 557 or 572
 

This is one way to achieve 572 cu.in. ( the most common)

Re: New Engines: 557 or 572
 

Dean what CI are these, I forgot what you told me.

Thanks Bro excellent job!

Re: New Engines: 557 or 572
 

which one would hold up better 572 or 598 both with the same rod length?

Re: New Engines: 557 or 572
 

Are we taking with a 4.5 stroke on both? If so Both packages are capable to go the same amount of hours if built right. The 572 combo will have a tad better seller between cylinders due to the smaller bore diameter.If your talking supercharged I would go with the smaller bore engine for this reason. The other objective to use a 4.500-4.530 bore diameter is to allow more rebuild life in the engine and again better head gasket seal being SC. I like to build life into the engine instead of maxing out the bore on a brand new Dart Big M or Merlin block. As far as ring seal goes between the two combos, on N/A packages both will hold up the same. SC combo ring seal may go away a tad sooner with the larger bore area 598. A ton of other factors come to play with longevity as you already know.....machining, assembly,and of course tuning!

Re: New Engines: 557 or 572
 

557