SB to BB swap

[onesubdrvr]

I've asked this before, but don't recall getting an answer, and I couldn't find it in my search, so please, excuse me for being repetative.

If one were to want to remove a SBC and install a BBC would moving the motor mounts be required?

How much Longer is a BB? Wider? Higher?

What else would be different (I imagine you're exhaust would shift outboard slightly).

Thanks
Wayne

[Cuda]

I'm pretty sure they use the same mounts, as for the other questions, I don't know.

[onesubdrvr]

I'm pretty sure they use the same mounts, as for the other questions, I don't know.
Same mounts,...but in same location?

Wayne

[Pismo]

Goto offshoreonly.com and search

[Cuda]

I'm pretty sure they bolt right in. I think the only concerns are top and side clearances. Makes sense seeing how they use to put BBC's and SBC's in the same model cars.

[mrfixxall]

I've asked this before, but don't recall getting an answer, and I couldn't find it in my search, so please, excuse me for being repetative.

If one were to want to remove a SBC and install a BBC would moving the motor mounts be required?

How much Longer is a BB? Wider? Higher?

What else would be different (I imagine you're exhaust would shift outboard slightly).

Thanks
Wayne

1/2" wider X 1/2 forward

[smokediver]

wayne , go to the merc site ... compare the dimensions between the 2 . i am sure it is wider , longer , and taller ...

[MOP]

Out in our shop there is a 350 and a 454 sitting side by side, I did not have a tape handy but using a crude string to compare the BB is about 4"s wider and about the 3"s longer plus about 2"s taller. I was pretty sure there was a big difference but wanted to confirm it, the motor mounts look to be in the same place. If your exhaust exits through transom the tips will need to be moved.

Forget it Wayne put a Pro Charger on instead!

Phil

[onesubdrvr]

Out in our shop there is a 350 and a 454 sitting side by side, I did not have a tape handy but using a crude string to compare the BB is about 4"s wider and about the 3"s longer plus about 2"s taller. I was pretty sure there was a big difference but wanted to confirm it, the motor mounts look to be in the same place. If your exhaust exits through transom the tips will need to be moved.

Forget it Wayne put a Pro Charger on instead!

Phil

:idea: :biggrin.: :wavey: :bonk: :eek: ,.....kind of a natural progression huh?

And come to think of it, I do have this laying around,.....

Wayne

[blackhawk]

Not sure about Merc, but a Volvo Penta 496 is 4.4" wider, 3.4" longert, the same height and 218 lbs heavier than a 350. I'm sure Merc is close to that.

[onesubdrvr]

Not sure about Merc, but a Volvo Penta 496 is 4.4" wider, 3.4" longert, the same height and 218 lbs heavier than a 350. I'm sure Merc is close to that.
Thanks, between your's, Phils and Smoke's input, I'm sure I could fit one in there, only thing I'd have to do is run remote oil filter because I think with the added width, I'd no longer be able to get to it,....and I'd have to pull it to change the starter,... that sucks!!

It's just a thought I have, I would say it'll be winter before we know it, but, this is Florida,....

Wayne

[MOP]

Wayne keep friggin around and you will either hurt yourself or you sweetie will kick your butt!! :shocking: :shocking: :biggrin:

[onesubdrvr]

Wayne keep friggin around and you will either hurt yourself or you sweetie will kick your butt!! :shocking: :shocking: :biggrin:
The only reason this system isn't on yet is
1) I need new exhaust manifolds,.... Glenwood's
2) The turbo's are sized for a Big Block, and Medium boost. I'm going to a Turbo shop tomorrow and see what kind of deal I can't work out for two slightly smaller units,... then,...WATCH OUT!! :eek: :party: :bighug: :checkered

If I have to spend too much more money, the system goes up for sale.

I've done a fair amount of research on this set-up, and besides the obvious HP / Torque gains, I think it will be surprising in other ways!

Wayne

[Cuda]

Don't do it man! The boat already runs great and sounds great.

[MOP]

Qoute: !!!

I'm going to a Turbo shop tomorrow and see what kind of deal I can't work out for two slightly smaller units,... then,...WATCH OUT!! arty:

Wayne I remember an article on when Audi was running their real hot 4X4 race car that the officials had then reduce the venturi size in the turbo, maybe that can be an option on those.

Phil

[MOP]

Qoute: !!!

I'm going to a Turbo shop tomorrow and see what kind of deal I can't work out for two slightly smaller units,... then,...WATCH OUT!! arty:

Wayne I remember an article on when Audi was running their real hot 4X4 race car that the officials had them reduce the venturi size in the turbo, it was done with a simple plate in the inlet maybe that may be an option for you.

Phil

[Cuda]

Wayne, you are becoming dangerously close to Phil's signature line. :eek:

[onesubdrvr]

Wayne I remember an article on when Audi was running their real hot 4X4 race car that the officials had them reduce the venturi size in the turbo, it was done with a simple plate in the inlet maybe that may be an option for you.

Phil
That is deffinately a possibility - The other is to make it a single vice twin set-up. For what I'm wanting to run (5psi or so boost) - striving for about 35% increase in power one is fine - infact good for up to 7psi. But, that's where exhaust plumbing gets to be a big issue. This system (being complete), would most likely be done easiest by modifying the housing from an E10 to an F80, or like you said, using a restricting plate. The biggest issue is how much boost to run with my C/R, for that I think the trick is to install fuel / air monitors until everything is fine tuned.

I was going to save this for my next project, but, who knows.

Wayne