Inliners International Forums General Discussion Hi Performance Mercruiser 470 3.7 timing-chain & also bore limits

I am building a 3.7 Mercrusier. As most of you know this is a 4cyl derivation off the Ford 460, [whereas the 3.0/181 is a variantion of the GM Iron Duke/ChevyII 4cyl).

I am looking for answers on two questions-
1/ Can you put a 4.44 bore (.080 over) in the factory cast in liners? As far as I know, no test exists to separate what the thickness of the cast-in liner is vs the aluminum of the block. Basically bore it and shine a bright light looking for "shadows". My block (and I am "land-locked" so it's the one I would prefer to use, rather than having another shipped in) is already at 4.39 and has deep scratches in one of the bores. I think .050 will clean it up. I'd like to know if
anyone has experienced boring one or more of these stock blocks to .080 over.

2/ A tech copy that Phil sent me from a 1999 newsletter mentions the timing chain used by the writer is one for a "Line bored Windsor".
Now, that statement gives me more questions than answers. I am not clear as to whether that means just the chain, because the cam "pulley" is definitely a lot more like a Small block Chevy, so obviously you can't swap on a Windsor set. Something a lot of people don't know is a Windsor chain and a SBC chain are identical. Maybe it's a Chevy Cam gear and chain with a Windsor crank gear? or Maybe the cam gear is unique to these motors?
The factory set-up is a chain with a really added-on looking sliding tensioner. By going with a chain for a "line bored"- so 10-20 thou shorter (5-10 thou per side), do you eliminate the need for that tensioner?
Furthermore I am interested in going with a wet-style belt drive, such as the Comp 5100. I feel anything that can be done to eliminate the harmonics of a big four, should be done, and that this may help.
Pics of this item, here: http://www.summitracing.com/parts/CCA-5100/?rtype=10

Have you contacted our tech adviser, Sarge Nichols, on these engines? I'm sure he could answer you.

How do I do so? I am not a paid member...

tell him Armond sent ya! (501) 646-0790 There are benefits to joining, beyond this.

eliminate the harmonics

That will certainly help prevent them from reaching the cam, but AFAIK the most effective practical method is reduce the rod angle and get as light a piston as you can afford.

I'm up in Canada... without knowing time zones and whether he works during the day, maybe an email is best...?

And yes, Panic, Groden rods (as an experiment) and Diamond pistons.

Sarge is in Fort Smith, AR and is available in the afternoons. He is good at getting back to folks as well. We have talked about these engines at length, as I have a couple of them as well as a Ford Motorsport head. Tough engines! Wish they were a little lighter though.