Im taking my 406 to the machine shop next w/e, They want to know exactley what they need to check and balance abd that nice stuff..

Im not a newbie but im no expert either..What are the main things i need to have checked and machined for the 406 to be ready to be built?

-Anybody have a 415/420 stroker motor set up here?..
might be interested in that too if theres not a whole of changes to do to the block.

heres what i have so far-

edelbrock rpm air gap performer l 750 holley Dp l forged 5.7 rods l forged weisco pistons l 1.6 roller rockers l full arp engine bolt kit l dbl roller timing chain l deep sump oil pan

what i need-

heads (going 200/64) l cam (need opinions)l crank l oil pump (standard or HP/HV) l water pump (standard or HV/clockwise-counter clockwise..using 91 ta serp assy)

This is mostly going to be a street -w/e car..but will drag once in a while.l'd ike to see 11 flat.

 

If you've already got the rods & pistons, then there's no changing the stroke.

In a stock SBC block, the deck height( distance between crank centerline and deck surface) is 9.025", more or less. So:

½ the stroke + the rod length + the piston "compression height (distance from center of pin to top of piston) + "deck clearance (how far down in the hole the piston is at TDC) = 9.025".

Nothing you can do to the block, really, that will change the numbers. Except buy an $$aftermarket tall deck block$$.

You need to be looking out for a 400 crank. With the 5.7 rods, and assuming of course that the pistons are for 5.7 rods (1.425" compression height, as compared to 1.56" stock), the only stroke you can possibly run, is 3.75". But, it might be possible to internally balance the motor, with the longer rods.

 

Additionally:

If you're running a 91 belt system, you need a "reverse rotation" water pump.

Use a Mellingi M55 pump; the Mr Gasket 26 spring; a Meliing IS-55E pump drive shaft; and a Melling 55S screen. You won't need a HV pump, unless you make some alteration or other to the oiling system that causes it to flow ALOT more than it would with worn-out stock bearings.

Heads: go for flow. I have no direct experience where I can tell you that Brand X is better than Brand Y; but, with a moderately large motor like that, you need all the flow you can get.

A cam with .050" duration in the 235-240° range on the intake is about right for that size head on that size motor. Exhaust lobe specs will depend on what heads you get. The lower the exhasut/intake ratio, the bigger you'll want to make the exhaust lobe. Aim for a peak lift at or just above the heads' "port stall" lift. Don't cheap out on the valve train: it's what makes a motor turn up RPMs.

 

I thought the reverse rotation were on the LT1's. I guess you learn somthing everyday.

 

you're thinking in different terms. he means the waterpump pumps water the opposite direction. the LT1's reverse cooling means it cools the engine opposite of a traditional SBC, heads before block.

 

ok..so i'll need a counter clockwise water pump.

As for the checking & machining goes..

-checking deck height
-rod clearence
-balance rotating assy.

Are these pretty much the only things that need to be checked?
-Thanks Rick

 

Its a machine shop right? They should know what needs to be checked and clearanced on a block if they are a valid shop. Are you putting new cam bearings and freeze plugs in? Is the machine work already done? If they are the ones boring the engine, I would imagine they will check everything, hot tank the block, and install the freeze plugs and cam bearings. Are you using the stock crank? That should be checked, and probably turned, and the rods should be re-sized checked for flaws, and have new quality bolts installed. A quality machine shop will know all of this and more, and shouldn'r be asking you if they are building it.

 

i would recommend AFR heads it you have the cash. they are awsome.

 

I Agree ,, If they don't know the drill, get your block out of there! Never put any time or money into a block or head until it has been magged and pressure tested..

 

The block has been hot tanked, bored .030 over, cam bearings installed,and new freeze plugs have been replaced as well.

I didnt have it magged beacause i bought the engine while it was running and had never overheated or gotton beat on (friends motor) ..Came out of a 73 truck, Just towed crap around.

Yea its the best machine/performance engine shop around.
i just dont want them to check a bunch of stuff if they dont need to...it'd be a waste of money, and i wanna get by as cheap as possible.

The rods, pistons and crank will all be brand new.