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2bbl To 4bbl Conversion Advice/Help
https://www.slantsix.org/forum/viewtopic.php?t=52696		 Page 1 of 1
Author:  Captain Caravelle [ Thu Jul 11, 2013 6:29 am ]
Post subject:  2bbl To 4bbl Conversion Advice/Help
Hello all,
New territory for me....
Just got my hands on an unused Offy 4bbl intake and want to convert my Super Six
Can you guys please direct me to any threads already out there where this has been done? Or give me some input as to what I'll need and how to do it?
It's going on my 78 Caravelle Super Six.
Again....new territory for me.
What I need help on is....
What's the best carb to use?
What do I do about the linkage setup?
Exhaust...
My fantasy plan is to use a 383 housing and drop my Super Six pie plate on top
I heard this would fit/work...the idea being to keep it looking stock.
Ideas on that?
I'd also like to run straight exhaust as apposed to duals.
Is that a do able idea?

Sorry for all the questions...like I said...new turf for me.
Thank you very much in advance.
Author:  Captain Caravelle [ Wed Jul 17, 2013 4:20 am ]
Post subject: 
No takers, eh?
Kinda figured somebody here would have had done this one......
Author:  Matt Cramer [ Wed Jul 17, 2013 6:40 am ]
Post subject: 
The carb is going to depend on the rest of the engine, but a 390 cfm Holley seems to be the usual choice. You can probably make it work with the stock Super Six throttle cable. Offy four barrels will bolt to the stock exhaust manifold, too.
Author:  Joshie225 [ Wed Jul 17, 2013 10:22 am ]
Post subject: 
Quote:
No takers, eh?
Kinda figured somebody here would have had done this one......
It may be that we've discussed this 8 ways from Sunday and are getting old, tired and cranky. An Edlebrock 500 will likely make you happier than the 390 Holley, but it's really a waste to go from a perfectly functioning 2bbl to a 4bbl without taking care of the other, more significant, restrictions in the system first such as the cylinder head and exhaust system.
Author:  Reed [ Wed Jul 17, 2013 10:40 am ]
Post subject: 
Ditto what Josh says. On an otherwise stock motor the two barrel Super Six setup is actually better than a four barrel.
Author:  Captain Caravelle [ Wed Jul 17, 2013 12:20 pm ]
Post subject: 
Thank you very much for the replies guys.
I kinda figured this had been covered a few million times
New turf to me though and I don't know where to look.
If anyone has any links that I can read up on I can leave you guys alone on this one.

I was thinking of doing the intake, carb and headers.
I was thinking that would be better than the stock setup.....no?

Either way...thanks for the input.
Much appreciated.
Author:  Reed [ Wed Jul 17, 2013 12:35 pm ]
Post subject: 
Use the search button on this board to find two and four barrel conversion as well as every other conceivable slant six modification discussed ad infinitum.

Short answer:

For a street motor, a two barrel carb, Dutra Duals rather than headers, increased dynamic compression ratio, possibly a bigger cam, possibly bigger valves and/or head porting, increased diameter free-flowing exhaust, HEI ignition upgrade, recurve the distributor, is a good basic starting point.
Author:  Captain Caravelle [ Wed Jul 17, 2013 3:02 pm ]
Post subject: 
Quote:
Use the search button on this board to find two and four barrel conversion as well as every other conceivable slant six modification discussed ad infinitum.

Short answer:

For a street motor, a two barrel carb, Dutra Duals rather than headers, increased dynamic compression ratio, possibly a bigger cam, possibly bigger valves and/or head porting, increased diameter free-flowing exhaust, HEI ignition upgrade, recurve the distributor, is a good basic starting point.
Once again....
Very much appreciated.
I've been a slant junkie for a while as you can see by my cars...just love them
But this is a new undertaking.
I'll do my searching....
And thanks so much all of you for helping out the newbie. :D
Author:  Reed [ Wed Jul 17, 2013 3:06 pm ]
Post subject: 
We've all been there. We are just getting a little crusty is all.
Author:  Captain Caravelle [ Wed Jul 17, 2013 7:23 pm ]
Post subject: 
Quote:
We've all been there. We are just getting a little crusty is all.
Understood.....
Getting a little ornery myself in my old age.... :D
Author:  DusterIdiot [ Wed Jul 17, 2013 7:51 pm ]
Post subject:  IMHO..if you gotta do it.
Quote:
1980 Plymouth Volare 2 Door 225 Super Six
I think if you were going to pick one of your rides to be the hot rod, this would be the better platform.

You'll need a rear axle swap to better gears 3.21:1.
You'll need to score a Lokar kick down setup if an automatic.
The offy is fine, save up for dutra duals.
Land an Edelbrock AVS 500cfm.

I'd look hard at rebuilding the engine for a mid-9:1 static compression ratio
and an 8:1 dynamic CR. I'd grab an 819 grind from OCG for the build and dial for a 102 intake centerline for lowend torque to haul the heavy late model car.

That should work as a baseline to get your easter eggs together, before considering the swap.

-D.Idiot
Author:  Captain Caravelle [ Thu Jul 18, 2013 5:15 am ]
Post subject:  Re: IMHO..if you gotta do it.
Quote:
Quote:
1980 Plymouth Volare 2 Door 225 Super Six
I think if you were going to pick one of your rides to be the hot rod, this would be the better platform.

You'll need a rear axle swap to better gears 3.21:1.
You'll need to score a Lokar kick down setup if an automatic.
The offy is fine, save up for dutra duals.
Land an Edelbrock AVS 500cfm.

I'd look hard at rebuilding the engine for a mid-9:1 static compression ratio
and an 8:1 dynamic CR. I'd grab an 819 grind from OCG for the build and dial for a 102 intake centerline for lowend torque to haul the heavy late model car.

That should work as a baseline to get your easter eggs together, before considering the swap.

-D.Idiot
Thanks greatly D! :)

Just curious....
Isn't my two door Caravelle essentially the same thing?

Either way...thanks for the info.
A bit of it is still a bit french to me but I'm sure my buddy who builds race engines..
The one helping me will decipher what I don't get.

I very much appreciate all of your advice and help guys.

Thanks!!!
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