406sbc motor: Block #3951511
 

Just bought a 9:1 motor #1511 block, 406, 4-bolt, with 3 freeze plugs. Bought from Richard Willis in Hennepin, OK. Super guy. Question: What head gasket thickness should I use to bump the compression a little? I am not sure what gasket is on motor now. Also, for a street motor, what type should I use: mls, copper, etc? Thanks, Richard!!!

Don't know that you could bump the compression much with the gasket, but Felpro 1003 is a .041 tk with wire ring @ bore size 4.166, and the 1010 is a copper wire ring @.039, that the 2 most commonly used on the 406" engine with compression up too 12.5, you don't need MLS, or copper for the 9 to 1 engine unless it's turbo or supercharged.

JMO


Zip.

careful what you do that 4 bolt block is the weakest of the 400 blocks.
at least girdle the mains which could help.

i have owned three 406 ci....1st one made 611hp 11:1 Compression
2nd one 13:1 compresison pair of 750's..made 700 hp range.. ( pushing it but no issues)

3rd one and still own it..460hp...10:1 static compression...fixing to put a 142 b&m blower on it at 5/6 lbs of boost and run some 110 octane..looking for 550hp maybe a tad more ( street driven)


as rabiddawg said the webbin is weak in these 400 blocks...i personally would not recommend over 600hp range without hardblocking it..otherwise i would run it and not worry at all.

406sbc motor: Block #3951511
 

I am only running this on the street. Will only be pushing 400- 425 hp. What is the cost to girdle the mains? Motor is not installed yet, still on cradle. Thanks. Mike P.

Re: 406sbc motor: Block #3951511
 

$93.60 here,

Zip.

http://procompelectronics.com/index....ategory_id=830

I have a 511 casting 400 block. It is bored .040 and made 738 hp on the dyno. It is filled to the water pump holes though. I run it on Alky due to the fill, but was told this would be good to go. No girdle on the mains here.

Just my .02.

I posted the site for a main gurdle, because someone suggested it. I too have 2-400 blks, a 2 bolt main 377" on alcohol, that has been welded 3/4" below the deck on one side about 4" lg. it's filled to the bottom water pump bolts. It's in the car right now, i don't know how much HP, but it runs mid 6's 1/8 and mid 10's in the 1/4 @3250lbs. I also have a 4 bolt that ran the same #'s at 406" on gas, in the same car no filler. I donot have a gurdle on either of these engine, and the 2 bolt has hundreds of passes on it, the 4 bolt broke a rod and shortened it's life, but the blk was still o'k and i'm rebuilding it for the street. I've probably ran 10 of these blk's in the last 20 yrs. no gurdle, with pretty good success.

JMO

Zip.

406
 

YOU COULD HAVE THE HEADS MILLED, MIGHT ADD A LITTLE COMPRESSION, 400-425 HP ON THE STREET SHOULD NOT NEED A MAIN GIRDLE, BUT IT NEVER HURTS TO HAVE ONE.

:idea: Zip, interesting opinion(s) on the 400 blocks. Many say don't even to bother building one, due to cap walk, then the real examples of how long they have lived get posted.

Do you "think" that your longevity results are due to the block filling, mostly, or just attention to detail in block preparation ? For those who have machining finished and are just about ready to assemble, block filling appears to be a no-no, due to cylinder warpage/movement, from the expansion of fillers used. Others say don't do it ! When engine warms up, block/cylinders must be able to expand equally & filler won't allow this to happen.

Then we have the choices between f&r cap straps vs. a complete girdle assy. Your posted site doesn't have any pics of the girdle(s) available. Would be nice to see one & be able to compare with other brands of girdles.

As always, thanks for any info you can supply, you haven't misled or let me down yet.