full stagger vs. short stagger - again
 

I searched the archives and found a thread on this, but I am looking for a little more clarification.

1) Can someone please describe the difference between full stagger and short stagger and possibly provide a diagram showing the difference?

2) How much longitudinal (aft-to-bow) space is saved with a short stagger?

3) Any reason to use the short stagger besides a desire to save longitudinal space?

4) Compared with an engine compartment in a single-engine boat with a big block Chevy, how much more length at minimum would be required to achieve a staggered configuration for two big block Chevys? I'm talking about cramming them in there on a 30-33-foot boat without designing a gigantic engine compartment with lavish space observed on high-30s foot boats.

5) In particular, I don't understand this statement from the other thread: "Full stagger is normally 18 inches, short stagger is 24."

Thanks in advance!

fixx
 

5) In particular, I don't understand this statement from the other thread: "Full stagger is normally 18 inches, short stagger is 24."



this means how far apart the crankchaft centerline is or how far apart the prop shafts are...24'' the engines are real close to eachother,pretty much rear statboardengine port valve cover almost touching the port starboard engines valve cover and a 24'' center to center..a full staggar the drive shaft pretty much goes under the header on the other engine and are 18'' center to center and need twice the engine space..

staggered
 

heres the web site to search on.

http://www.mercurymarine.com/repower...gs/?category=1

heres the page for bravo staggered.

http://www.mercurymarine.com/media/m...gs/500bull.pdf

what kind and length boat are you thinking of staggering.

staggered
 

heres a link for exhaust.

http://www.cpperformance.com/t-custom_tailpipes.aspx

i have some installation drawings from mercury for staggered TRS thru #5 that i've held onto since 1987 in case you or some one else are going the transmission way.

i could scan and email if anyone needed it.

Dan pm me your address the t shirts came in and I owe you one, and if you don't mind I'd like to get those scanned drawings if you get a chance. No rush

A short answer to the first three questions on V bottoms.
A full stagger puts one engine completely in front of the second engine, putting the engines as close to the centerline of the boat as possible and the drives as close together as possible. A short stagger moves one engine slightly forward of the other to move them closer to the center but not as close as a full stagger. Usually a partial stagger is done so as not to cut into the cockpit space as much or based on a predefined engine bay.
Figure a single engine or twin side by side engine bay needs the length of an engine plus room for accessories and transmissions. A full stagger boat doubles that length where a partial stagger will only require 50-70% more length.
In general, the closer the motors are to the centerline and the deeper set into the boat, the better the balance. Also, the closer the props are together, the better the forward thrust. The same boat staggered Vs. side by side should be up +/- 10% faster, all things being equal otherwise.

My boat is a full stagger and the engine compartment is quite large. The first two pics are my boat, the other two are similar Donzi's.

This is a short stagger in an older 36 Apache. I believe the 37 Outerlimits had a short stagger as well.

http://www.offshoreonly.com/classifi...o45201-en.html

Thanks for that.

Just how are the engines getting closer together port-to-starboard of they aren't ahead of each other? How many inches closer to the keel is each one as compared with side-by-side?

With the short stagger, one motor sits just far enough ahead of the other so you gain the width of the headers to pull the motors closer.

Without having exact numbers and roughly speaking, 1/4 width of each engine hangs over the keel on a full stagger, engines sit flush to the keel with a short stagger, and side by side they sit about 1/4 of an engine width off the center keel.

Hello,
I am rebuilding old race boat. Would it be possible to scan information regarding staggered engines with TRS drives. Really appreciate any help.
[email protected]
248-495-5516
Thank you, George