how do you make a 406SBC? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

68_GMC_910 · 09-12-2002, 08:56 PM

dang... I feel like a dumbass asking this because I know that it's common knowledge...

but I'm guessing it's a 400 bored out... 0.30 over?

I wish I had some formulae to calculate this stuff...

Eddie H. · 09-12-2002, 09:08 PM

You are correct, a 400 bored .030 yields a 406 .
I've got a 404 in mine. It's bored .020 over.

tom hand · 09-12-2002, 10:13 PM

Engine Cubic Inch Formula: BORE x BORE x STROKE x .7854 x NUMBER OF CYLINDERS

Johns70 · 09-12-2002, 11:24 PM

ok but how do you get a 406 stroker?

68_GMC_910 · 09-13-2002, 12:48 AM

Thanks, guys. That was exactly what I was wanting to hear!

68_GMC_910 · 09-13-2002, 01:01 AM

oh, and what's the difference between the 400 and 350 blocks other than the bore diameter? I know water jackets and heads are a little different, but basically what I wanna know is can the 350 block, (with the help of the 400 crank) go as big as 406 or do i need a 400 block to go big-bore???

oldyeller · 09-13-2002, 03:54 AM

you will need a 400 block to build a 406, all your doing to it is increasing the bore size to .030 over, but a 350 block with a 400 crank and a few other mods will make a 383 stroker.

bigjimzlll · 09-13-2002, 09:59 AM

the biggest you can go on a 350 block(safely) is 388ci. which is .060 over and 3.75 crank..you can use a bigger stroke crank for more cubes.. but then it gets costly.

Eddie H. · 09-13-2002, 10:26 PM

If you're willing to spend the cubic dollars, I have seen small block 400's stroked to make a 427. PAW used to sell a stroker crank kit. For the same money , though, you could probable build a good Big Block, so why bother.

PanelDeland · 09-14-2002, 12:20 AM

Chevy now offers a 383 crate engine that has a 4.00 bore but uses a special 3.80 crank.This gives a 383 without an overbore.That would make a 393 (I think).
So in conclusion lets say you can get cubic inches but they cost cubic $$$.
BTW one of the magazines did a 454 smallblock but I think they used a special aftermarket block and could have built a nice BB and most of the rest of the truck for what they spent.

09-12-2002, 08:56 PM	#1
68_GMC_910 what would Neal do? Join Date: Sep 2002 Location: Winnipeg, Manitoba, Canada Posts: 150	how do you make a 406SBC? dang... I feel like a dumbass asking this because I know that it's common knowledge... but I'm guessing it's a 400 bored out... 0.30 over? I wish I had some formulae to calculate this stuff... __________________ 1968 GMC 910 Long Step 250/3onTree 1969 Chevy C10 longfleet, 350/350

09-12-2002, 09:08 PM	#2
Eddie H. Registered User Join Date: Mar 2001 Location: Paradise TX USA Posts: 1,200	You are correct, a 400 bored .030 yields a 406 . I've got a 404 in mine. It's bored .020 over. __________________ "Negative people always seem to have a problem for every solution"

09-12-2002, 10:13 PM	#3
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	Engine Cubic Inch Formula: BORE x BORE x STROKE x .7854 x NUMBER OF CYLINDERS __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

09-12-2002, 11:24 PM	#4
Johns70 Registered User Join Date: Dec 2001 Location: Spring Creek, nevada. U.S.A. Posts: 456	ok but how do you get a 406 stroker? __________________ 69 chevy short wide box project 70 GMC jimmy project

09-13-2002, 12:48 AM	#5
68_GMC_910 what would Neal do? Join Date: Sep 2002 Location: Winnipeg, Manitoba, Canada Posts: 150	Thanks, guys. That was exactly what I was wanting to hear! __________________ 1968 GMC 910 Long Step 250/3onTree 1969 Chevy C10 longfleet, 350/350

09-13-2002, 01:01 AM	#6
68_GMC_910 what would Neal do? Join Date: Sep 2002 Location: Winnipeg, Manitoba, Canada Posts: 150	oh, and what's the difference between the 400 and 350 blocks other than the bore diameter? I know water jackets and heads are a little different, but basically what I wanna know is can the 350 block, (with the help of the 400 crank) go as big as 406 or do i need a 400 block to go big-bore??? __________________ 1968 GMC 910 Long Step 250/3onTree 1969 Chevy C10 longfleet, 350/350

09-13-2002, 03:54 AM	#7
oldyeller Captain CAAAVVVMMMAAANNN! Join Date: Mar 2002 Location: Anna Texas Posts: 726	you will need a 400 block to build a 406, all your doing to it is increasing the bore size to .030 over, but a 350 block with a 400 crank and a few other mods will make a 383 stroker. __________________ 72 LWB Fleetside C10 Custom 350/350 97 GMC Yukon 4X4 SLT Anna, Texas check out the project old yeller

09-13-2002, 09:59 AM	#8
bigjimzlll Senior Member Join Date: Dec 2001 Location: Redding,CA...USA Posts: 4,736	the biggest you can go on a 350 block(safely) is 388ci. which is .060 over and 3.75 crank..you can use a bigger stroke crank for more cubes.. but then it gets costly. __________________ It's called "drag racing" if they called it "tic..tic..WHAM!..BANG! F*&K!!!", they'd have to keep the magazines under the counter with the other men's publications click the clicky to join the site.... http://67-72chevytrucks.com/vboard/payments.php 67 lwb..first hotrod in 25 years..540 best ET is 9.45 @ 141.44 Anderson,CA

09-13-2002, 10:26 PM	#9
Eddie H. Registered User Join Date: Mar 2001 Location: Paradise TX USA Posts: 1,200	If you're willing to spend the cubic dollars, I have seen small block 400's stroked to make a 427. PAW used to sell a stroker crank kit. For the same money , though, you could probable build a good Big Block, so why bother. __________________ "Negative people always seem to have a problem for every solution"

09-14-2002, 12:20 AM	#10
PanelDeland I am a Referee of life. Join Date: Jun 2000 Location: Greensboro N.C. Posts: 13,993	Chevy now offers a 383 crate engine that has a 4.00 bore but uses a special 3.80 crank.This gives a 383 without an overbore.That would make a 393 (I think). So in conclusion lets say you can get cubic inches but they cost cubic $$$. BTW one of the magazines did a 454 smallblock but I think they used a special aftermarket block and could have built a nice BB and most of the rest of the truck for what they spent. __________________ The 47-present Chevrolet and GMC Truck Message Board Network,it's owners,moderators,members,and associates of any type should not be held responsible for my opinion. You can't fix stupid,not even with duct tape. "My appearance is due to the fact that "GOD" does punish you for having too much fun!" Barrett-Jackson has perfected alchemy,they make rust into gold! "You can lead a horse to water but you can't saddle a duck" "Cleverly disguised as a 'Responsible Adult' "Sometimes your Knight in shining armor is just a retard in tinfoil"



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