Engine Stringer Spacing (width) Specifications ???

[tpenfield]

Greetings,

I have an inquiry on my Mercruiser engines that I am selling. The person is planning on upgrading their twin engine 5.0L cruiser to my engines ( 6.2's). They are wanting to know if my 'new-style' engines will fit where their current 5.0 engines are. The key thing being the width between the engine mount stringers (I assume).

So, I Google searched for a while yesterday and looked through the various service/installation manuals that I have, but could not find anything definitive (drawings, etc). Also looked in the Adults Only section, but nothing jumped out at me. I did come across a post by @achris from quite some time ago indicating 22-1/2" for small block engines.

I measured the spacing as best I could on my engines and seemed to come up with 22-1/2" as well.

Anybody got any links to a Mercruiser Spec for stringer spacing? I assume that the 5.0 and 5.7's would be the same, and perhaps the big blocks (7.4 and up) would be slightly wider? Just don't know for sure.

I'd like to send the person a spec or 'official' drawing for the distance between port & starboard engine mounts, for both his engines and my engines.

T.I.A. for any info

 

[Pmt133]

On mercs site they give you the installation drawings for the reman 4.3 and 350. (Click reman and scroll down to the section and it gives pdfs) Center to center on the mounts is 22.5" (have it written down from redoing my stringers and 4.3 and 5.7 should be the same for that.) The 6.2 stuff is more difficult to find but I really doubt it would be changed considering boats were available with both power for a period of time without redesign...

Merc site

 

[Scott Danforth]

Your 'new-style' block is nearly identical to the older SBC. The crank, rods, and pistons are GMPP SBC parts in a Mercruiser supplied block

You are overthinking it

 

[tpenfield]

On mercs site they give you the installation drawings for the reman 4.3 and 350. (Click reman and scroll down to the section and it gives pdfs) Center to center on the mounts is 22.5" (have it written down from redoing my stringers and 4.3 and 5.7 should be the same for that.) The 6.2 stuff is more difficult to find but I really doubt it would be changed considering boats were available with both power for a period of time without redesign...

Merc site

The 4.3 link opens, but not the others . . .

I'll just go with 22.5"

 

[Pmt133]

The 4.3 link opens, but not the others . . .

I'll just go with 22.5"

I can confirm a 350 fits on the same pad width as a 4.3.

 

[Scott Danforth]

The 4.3 is an SBC. The LS is technically an SBC (just Gen 3/4), the LT1 is an SBC (Gen 2 and 5). The Mercruiser 4.3/6.2 is technically an SBC

 

[tpenfield]

Yes, 22.5" is the number . . . I was just hoping to send the person a Mercury published drawing that confirms what I am telling him. But . . I measured the spacing on my engines and he will do likewise.

Maybe, just maybe, this person will buy the engines . . .

 

[Fun Times]

Merc has an installation jig to help place the motor mounts while building the boat… looks like this,

CP Performance - Installation Jig 91-806794A02

Installation Jig 91-806794A02

www.cpperformance.com

There at least used to be a website that had/has the lines with engine inches in a diagram… can’t find it at the moment on the phone but maybe later tonight I can locate it if it still available online… let you know.

 

[Fun Times]

Though possibly older engine models, I found what I was thinking about when I saw your topic... I'd say they should be pretty much near the same sizes give or take an inch or two probably on how far the other engine mounted items stick out..., Exhaust, etc..
You'd be looking over the "Installation Drawings for reviewing specific dimensional differences (open is separate windows)" links within the followings,

https://static.perfprotech.com/files/store/app_themes/ppt/images/product-specs/57l.pdf

https://www.perfprotech.com/blog/articles/470-repower#

https://www.perfprotech.com/blog/boat-and-engine-technical-tips/marine-engines/454-496-repower

Or all of them under the marine – Re-Powering (General) listings halfway down the page, https://www.perfprotech.com/blog/articles/marine-part-technical-tips#patent

 

[tpenfield]

Though possibly older engine models, I found what I was thinking about when I saw your topic...

Thank you. These are the types of drawings I was looking for.