Big Bore for an MS461?

[B440]

I have searched the internet, and I'm coming up with no answers. Is there a big bore kit for the MS461? Is there some company selling a P&C kit larger than the stock 52mm?

Or, can the 661 top end (56mm) be used and turn it into a hybrid (like the 044/046)?

And lastly, is there a longer crankshaft that could be used? I believe it is a 36mm stroke.

 

[drf256]

Highly doubt it bud.

Swapping cranks from model to model will be super frustrating as well. Not sure which bearings the 461 takes, but the 046 takes 6202 sizes and the 064 /066 (also 52mm-54mm) takes 6203 sizes I believe. I’m not sure which the 461 takes.

The 044/46 swap is relatively easy because they are variations of the same model, so same stroke and same basic geometry.

The 461 and 661 are different model lines with different bores and strokes.

If you find an AM big bore, it’s likely to not run any better than the standard bore. Usually it will run worse despite the increased displacement. The transfer area gets encroached upon by the bore widening, making filling the increased bore with the smaller case even more difficult.

Sorry to rain on your parade.

 

[T.Roller]

Yeah I wouldn't swap a oem topend for a Chinese big bore. Youll be going backwards.

 

[J. Loe]

Well...

ms 461 woods port race thing
https://r.tapatalk.com/shareLink?sh...461-woods-port-race-thing.11407/&share_type=t

 

[mdavlee]

Crank is the same as 460. Easy swap to get a little longer rod is a 372 rod.

 

[Wonkydonkey]

Well...

ms 461 woods port race thing
https://r.tapatalk.com/shareLink?share_fid=1392778&share_tid=11407&url=http://opeforum.com/index.php?threads/ms-461-woods-port-race-thing.11407/&share_type=t

What you need/we need is those numbers,,, that treemonkey crunched out. And some porting mods like mastermind did to the 461,
Put it in a blender and see what you get...

 

[B440]

Thanks everyone. I'm not sure porting is my way forward. Has anyone placed a 661 cylinder on top of the 461 case to see if it lines up? Looks like they both use the same style under-exhaust transfer port.

 

[T.Roller]

Thanks everyone. I'm not sure porting is my way forward. Has anyone placed a 661 cylinder on top of the 461 case to see if it lines up? Looks like they both use the same style under-exhaust transfer port.

Why not send it to one of the builders here to port?

 

[Deets066]

Crank is the same as 460. Easy swap to get a little longer rod is a 372 rod.

Would that be same stroke as a 64 then?

 

[drf256]

Thought an 064 had a longer stroke than an 046. 85 vs 77 cc with same bore.

 

[Deets066]

Thought an 064 had a longer stroke than an 046. 85 vs 77 cc with same bore.

It does

 

[Deets066]

Now that I think about it, it can't be as much stroke as a 64.

 

[paragonbuilder]

Crank is the same as 460. Easy swap to get a little longer rod is a 372 rod.

Would that be same stroke as a 64 then?

Same stroke, just a longer rod Keith. Mike does the whole crank swap over?

 

[mdavlee]

Never looked at the whole crank swap.

 

[paragonbuilder]

Never looked at the whole crank swap.

How hard is it to pull the crank apart to swap rods?

 

[mdavlee]

How hard is it to pull the crank apart to swap rods?

100 ton press maybe

 

[paragonbuilder]

100 ton press maybe

Wow that’s a big press!

 

[mdavlee]

Wow that’s a big press!

Better to have extra if you don't have heat

 

[Redfin]

What am I missing? I know you fellas are not suggesting swapping rods to increase stroke.

 

[T.Roller]

Kinda what I was thinking.