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gamedawg03 01-14-2013 06:47 PM

brodix ik200 question
I am about to get my 406 built. I have brodix ik 200 heads from my 383 do i need to get steam holes drilled in them thanks

vinniekq2 01-14-2013 07:26 PM

are you using a GM block?

gamedawg03 01-14-2013 07:31 PM

Yeah dont no casting numbers rite off top of my head but its factiry 4 bolt main already machined and .30 over

lmsport 01-15-2013 08:58 AM


Originally Posted by F-BIRD'88 (Post 1635045)
You can call Brodix direct to get specific advice on drilling your Brodix heads corrrectly for 400SB steam holes.

When I did my 406, with vortec heads, I did not drill for the 400 steam hole.
Instead i simply connected the water pump bypass hose to the water port outlet on the drivers side rear of the block (by the distributor). This is your heater hose. It most be connected heater core or not.
Connecting it at the back of the intake manifold instead of at the front, near the thermostat really helps the colling system function. Eliminates all thermostat open close fluctuation and resulting water temperature spiking on any SBC during warm up and idling. and your 400SBC. My 406 never overheats.

If your intake manifold has the extra water ports at the rear, by the distributor:
I highly recommend you do this simple mod even if you do end up drilling the steam holes in your heads.
many intake manifolds have the extra water ports on the rear of the intake manifold just for this improved cooling system function. GM originally routed the water pump hose just like this on old 60's era engines prior to the emissions era, when they then wanted to the make the chevy engine generally run hotter in an attempt to aid emissions control at the time.

Its pretty simple and it works.

Why the connection on the drivers side versus the more common pass side connection?

gamedawg03 01-15-2013 01:13 PM

I have a victor jr now but im getting a super victor im not sure if it has it in the back of the manifold also i have a weind water pump but there no place in it or the victor jr for for alternator bracket

vinniekq2 01-15-2013 01:34 PM

If you are upgrading to a super victor,we are talking serious power and high RPM? Are the heads ported a lot? I would probably drill the steam holes,or if you are making big power,think about an after market block.

techinspector1 01-15-2013 01:48 PM

Here is an outline of the procedure if you decide to drill the holes.....
Technical Articles at Greg's Engine & Machine
In my opinion, I wouldn't run a 400 without them. GM engineers found a need for them at low rpm's. Steam pockets would form at the blind corners of the water jackets as a result of the cylinders being siamesed. These pockets of steam would heat that little area and either cause pre-ignition or would cause the motor to spit out the head gasket. I am unsure as to whether or not the engineers tried running a hose from the back of the heads to the water pump, but if they did, it apparently didn't work as well as drilling the steam holes because I know of no factory bypasses, only steam holes. No steam holes are needed if the motor is to see duty in the higher rpm range, such as in a racing application. The speed of the water through the water jacket due to higher water pump impeller speeds will wash away any steam pockets that may try to form. It's only a problem at lower rpm's.

vinniekq2 01-15-2013 05:10 PM

Sounds like instead of steam holes drilled in the heads,that we all know about;you could also look for an antique intake manifold that GM made or a very old cast aluminum intake that was designed for engines that not only preceded the 400 small block,but also preceded the 350 small block.

gamedawg03 01-15-2013 08:14 PM

Im looking for a serious street and strip motor. This is my first serious motor being built, i have had all the machine work done to it i have been looking at rotating assemblies in cnc notorsports website. The one i looked at says its 11.6 cimpression with 64 cc heads .im getting my heads port matched and bowl blended and putting 2.05 valves in them my question is what would be the best way to go for cam for best power on street and strip a retrofit roller or solid roller

1Gary 01-15-2013 09:03 PM

Let's break down the steam hole question.

We know we bore/hone 400's with torque plates mainly because the design of the 400's bores move around alot.

We know the 400's where never designed for high performance use.They where never intended for high compression use.I.E.:76cc heads

We are very sure with increased output=increased heat.

Now I worked at the Chevy engine plant as a engine tester when the 400's where new.Also my racing operation over the yrs in 9.90 cars of 17 last count cars used 7 400's of various size.All of them with steam holes drilled.

We know mainly because of the well documented issues the OEM 400 blocks have is the reasons why the aftermarket blocks where designed as they are.

The summation of this is if not for the leakdown sealing issues the 400's have,there isn't a sound reason not to have the steam holes drilled.

As a side comment.Any suggestion not to drill those holes is confusing as the reason.Or to run bypass hoses.At best that is very dated.At the worst it is to draw attention to themselves knowing it is argumentative post.Certainty drilling the steam holes is a proven preventive method.

If your asking which cam type would be the king of the hill given your SCR,a roller solid lifter with a rev kit is the way to go as long as you don't mind setting the valves.Certainly you have to have the springs for it and check the clearances.

vinniekq2 01-15-2013 09:12 PM

when your heads are finished,have them flow tested.Then what 1gary said,the solid roller that matches your cylinder head flow will be the better choice.

1Gary 01-15-2013 09:18 PM

Had me back tracking here.Long before you buzz this 406 up,need to know that the rods you have/rod bolts can cover that kind of stress.Also IF you go solid roller lifter cam/kit,most are going to leave something on the table on the lower rpm ranges.Almost all are going to need a loser T/C and gears.

BTW-love that brand name heads.We have used them(maybe not this model,but)have had nothing but good results.

gamedawg03 01-15-2013 09:27 PM

I was looking at the lunati voodoo 60132 and 60133 cam i think they have complete kits to its going in a 87 monte carlo ss 7.5 10 bolt 4.10 gear but looking for ford 9in

1Gary 01-16-2013 03:41 AM

For the record from Wiki:


The only 400 cubic inch size of this family, 400 cu in (6.6 L) small-block, was introduced in 1970 and produced for 10 years. It was loosely based on the 'medium' journal 350 and had a 4.125-inch (104.8 mm) bore and a 3.75-inch (95.3 mm) stroke. The 400 differed from other small blocks in that the cylinders were cast siamesed, used a 2.65" 'large' main bearing journal, and oftentimes had one more core/freeze plug on both the left and right sides of the block. Initial output was 265 hp (198 kW) and was only available equipped with a 2-barrel carburetor. In 1974 a 4-barrel version of the 400 was introduced, while the 2-barrel version stopped production in 1975. 1976 was the last year that the 400 was used in full and mid-sized Chevrolet Passenger car, available in both A-Body and B-Body lines. While popular with circle-track racers and drag racers, the engine could be prone to cooling problems if cylinder heads without added steam holes were used.

And from E-question:

Engine HP Specs for 1970 to 1980 Chevy 400s
Written by moss strohem
Engine HP Specs for 1970 to 1980 Chevy 400s

The Chevrolet 400 CI small-block engine was introduced in 1970 and remained in production until 1980. It was an "in-between" engine option, fitting in the middle of the 350- and 454 CID Chevy engines.
Design and Applications

Based on the original SBC platform, the 400 engine used a crankshaft stroke of 3.75 inches (1/4 longer than the 350 SBC) and a 4.125-inch cylinder bore. It was -- as a large-displacement, small-sized engine -- used in Chevy full-size cars and light-duty pickup trucks. High horsepower was never the intention for the 400 SBC. Rather, the increased torque from the greater displacement made it suitable for heavy vehicles.

Standard Performance Output

The highest rated output for the 400 SBC occurred in 1970 -- 265 horsepower. Horsepower declined throughout the 1970s due to a combination of increased emissions requirements as well as measuring the output at the rear wheels (net) as opposed to at the engine flywheel (gross). At its lowest, output was rated at 150 to 180hp.

You can search any number of reliable sources,myself included,that advise drilling the steam holes.In my professional opinion drilling steam holes in non 400 heads has no relevance to the thin OEM 400 block decks.

1Gary 01-16-2013 04:27 AM

Curious as I always have been,I had to go search for the Turbo-Fire 1970's 400's spec.Honestly I didn't find the compression ratio,maybe it would be in a repair manual.Still,a two barrel 265hp engine in what would be at best a 3500lb car running 13 seconds in OEM trim,I am having a hard time wrapping my head around that.That is 43 yrs ago.

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