I just got a set of heads from my builder. Casting number 3973370. Cut 2.02 valves, cut for springs, fully ported, and gasket matched. Even did my intake too. All manley parts. Tripple springs, and Stainless steel valves and the whole nine yards. My builder says he never drills steam holes on 400 heads unless they are everyday motors. On weekend cars or track only he nevr drills them. So what do you guys think about this. I have to go with what he says that way if something happenes i can take it back to him!
Ed

I have not heard of anyone not running them. I do not see any good that could come from it, only negatives. I would run the holes.

You need to run the steam holes. The 400 SBC was designed to use them. Taking a BIG risk. It may of been done, but why take the risk.

the old heads i had on there didnt have them, and i didnt have a problem. Fel-Pro makes 400 gaskets with out them...and some with them. I called a guy form L&M engines. Local guy that is very reputable, he said they are not neccessary unless its driven daily. Learn something every day huh. I dunno what to do
Ed

If its a weekender street/strip deal you can get away with not running them. Mine are actually plugged off at the deck (helps prevent cracking from steam hole to head bolt hole). I run mine on the street probably 150miles/month and haven't had any problems. My water temp stays 170dg and I run the extra manifold cooling lines from the front of the intake to the rear.

I have run mine now for over 2 years and they are not drilled either... Trickflow's/ Airgap and a 4 core radirater (pun from work). However I am also running a modified thermostat and a no-bypass waterpump from Stewart... I'm sure all that upper aluminum is one BIG heatsink too~ :D

the only time i know of when drilling steam holes is neccessary is when you run 327 or 350 heads on a 400 block.don't all factory 400 heads already have steam holes?did i miss something?

For a street engine I would most definatly
have the steam holes drilled. For a 1/4 motor
you could probably get away with not drilling them
but why risk it?
All 400 heads from the factory came with the
holes drilled but there are very few aftermarket
heads that come drilled.

my daily driver 406, I didn't. The machine shop had a tech tip from Brodix that said just use a 350 head gasket. So on my Pro 1's, they didn't get drilled and I drove the truck daily and it nevr hit over 210 in 105 degree weather...

dont run the steam holes on any of my 400 motors and use the gaskets without the steam holes .all my motors are for bracket racing .i hope you didnt use a 350 head gasket on a 400 if you did its going to blow.i was told by a perty smart machine shop man that the steam holes were there to relieve pressure at idle so a street motor would surely need them

Thanks Guys, i'm going w/o the steam holes. Was told they are for just street motors that have to idle for a duration. No i didnt use the 350 gaskets. Cant because of the .060 overbore. I need a gasket thats 4.185 or more. I got the one w/o the holes and i'm just going to go for it. Thanks for the help
Ed

I run the steam holes unless it's an oval track motor. The issue is that steam can collect in the area between the cylinders, there's no gap between the cylinders to let it go to the top and get flushed out. This is essentially the story from GM, but I never understood the need for the top row of holes. Anyway, it's been shown to my satisfaction that in race car that's at RPM all the time there's enough water velocity through the jackets to flush the steam pockets. In a street car I'd run at least the lower row, I just wouldn't feel comfortable not doing that. my own 406 Chevelle has upper and lower steam holes.

Tom

Digging up an old post....

Today I was told today by a machinist that running the steam holes is asking for cracks in the deck. His advice was to plug/pin them in and run a 400 head gasket w/o holes.

Wolfplace, Tom Parsons, or Billk have any input on this?

Thanks.

Steam holes are for 400s that operate below 3500 rpm because of steam pockets that develop. If you see any street time, i.e. driving to/from the track, then steam holes are a must.

If the engine operates primarily above 3500 rpm, then you may go ahead and plug them.

On my e-tech 200 heads on my 400 ,Edelbrock says to only drill bottom steam holes

If it's a stock block & for the street use the holes especially in the center. The outboard ones are not a real concern to me.
Aftermarket blocks do not have the steam pockets & don't need them but we always bring water out of the back of the heads on these.
As has already been said drag race & circle track where you keep the RPM above about 3000-3500 are not normally an issue but I still use the rear water hoses.
Just because you don't see the problem on a temp gauge does not mean you don't have one, it is a localized issue & may never show on the gauge,, at least not until you blow the head gasket or crack something :D

FOR THE STREET WITH A STOCK BLOCK USE THE HOLES & CORRECT GASKETS

Originally posted by gasgzlr:
Steam holes are for 400s that operate below 3500 rpm because of steam pockets that develop. If you see any street time, i.e. driving to/from the track, then steam holes are a must.

If the engine operates primarily above 3500 rpm, then you may go ahead and plug them. I am running an electic water pump. It runs at about the same as belt pump would be at 3500 RPM all the time, even when the engine is at idle.

Wouldn't take care of the stream pocket problem that a street car/engine would have with a belt driven pump?

Cable, I run a Mezierre 55gal pump on my 422 which has the holes plugged in the deck. I've never had any issues with cooling from the lack of steam holes. Of course, I don't run an oil cooler and with my short filled block I can only go around 15 miles in any one direction (in the summer time) before my oil temp gets out of my comfort zone (above 250). I did break a ring magnet on the pump once and ran into some cooling issues very quickly.

Originally posted by JOHN WILSON:
Cable, I run a Mezierre 55gal pump on my 422 which has the holes plugged in the deck. I've never had any issues with cooling from the lack of steam holes. Of course, I don't run an oil cooler and with my short filled block I can only go around 15 miles in any one direction (in the summer time) before my oil temp gets out of my comfort zone (above 250). I did break a ring magnet on the pump once and ran into some cooling issues very quickly. That's good to know, thank John.

Man, I wish I could find some 3.875" forged stroker pistons in a 4.145" (0.020" overbore), use a 6.0" rod and cost under $600.

If I could, that is what I'd build instead of just a 406.

On the 400 blocks we plug the steam holes by the head bolts cause if you look there is a big hole next to that where there is a place for the steam to go, With the angle of the deck if there is steam if present it will get out. I always figured that was one hole that didn't need to be there if you think about it.

Originally posted by CNC BLOCKS N/E:
On the 400 blocks we plug the steam holes by the head bolts cause if you look there is a big hole next to that where there is a place for the steam to go, With the angle of the deck if there is steam if present it will get out. I always figured that was one hole that didn't need to be there if you think about it. =
All I can say is we have solved a number of "problem children" by putting the center two steam holes in 400 engines that were used on the street. ;)
The last one was a few months ago after a customer put a set of Ede heads on a 400. It ran only a "little hotter" but took out the head gasket on one side in the center. The other side was pretty ugly.
Only change was the addition of steam holes in the center,, problem solved.
My understanding is, with a stock block, a steam pocket will develop behind the center head bolt & in the lower 'crevice" between the cylinders where water cannot circulate adequately without the holes, if the engine is used on the street hard & them allowed to run at slow speeds.
Once a steam pocket develops you will have no cooling at this point. This is not a good thing.
On a street driven 400, my recommendation is to use the holes in the center of the block where you have excessive heat due to valve placement.
Again, in my opinion, in any application where low engine speeds can be avoided this is not a problem.
This is also not a problem with the aftermarket blocks or the BowTie with blind head bolt holes especially if you remove water from the back of the intake instead of forcing all the hot water back through the heads.
Another option is to modify the head gaskets per Brodix's recommendations for optional cooling which works very well with their heads in lieu of steam holes.

Originally posted by Wolfplace:

Again, in my opinion, in any application where low engine speeds can be avoided this is not a problem.
Just to confirm Mike. Is the problem with plugged stream hole w/street engines the low engine speeds or low water pump speeds?

The reason I ask because of the electric water pump question mentioned above.
Thanks.

Originally posted by bluerebl:
</font><blockquote>quote:</font><hr />Originally posted by Wolfplace:

Again, in my opinion, in any application where low engine speeds can be avoided this is not a problem.
Just to confirm Mike. Is the problem with plugged stream hole w/street engines the low engine speeds or low water pump speeds?

The reason I ask because of the electric water pump question mentioned above.
Thanks. </font>[/QUOTE]=
It should keep the water flowing enough to alleviate the problem but I can't answer the question directly as I have never tried it.
Why not go here & post the question to Jack. He is pretty sharp regarding cooling systems.
Stewart Pumps (http://www.stewartcomponents.com/cgi-bin/yabb/YaBB.cgi)
I think you will find a single 55 gal pump is not recommended if you are going to do a lot of street driving.
In my opinion it is not going to flow enough water at higher speeds to cool the engine properly for any length of time but like I said, I haven't tried it.
I do know Stewart does not recommend their 55GPM electric pump as a stand alone deal for the street.

I'm running Brodix RR200 cylinder heads on my 400. Brodix tech said that because of revised coolant passages in their heads, they do not recommend drilling steam holes. They have a tech bulletin that shows what gasket to use and what holes to enlarge on the head gasket. So far my motor actually runs cooler than the previous 383.

Originally posted by Wolfplace:
Another option is to modify the head gaskets per Brodix's recommendations for optional cooling which works very well with their heads in lieu of steam holes. What mods are need for head gaskets using Brodix heads?


Originally posted by HiTech5:
I'm running Brodix RR200 cylinder heads on my 400. Brodix tech said that because of revised coolant passages in their heads, they do not recommend drilling steam holes. They have a tech bulletin that shows what gasket to use and what holes to enlarge on the head gasket. So far my motor actually runs cooler than the previous 383. Do you have a link for a writeup about this info?

Thanks.

Originally posted by bluerebl:
</font><blockquote>quote:</font><hr />Originally posted by Wolfplace:
Another option is to modify the head gaskets per Brodix's recommendations for optional cooling which works very well with their heads in lieu of steam holes. What mods are need for head gaskets using Brodix heads?


Originally posted by HiTech5:
I'm running Brodix RR200 cylinder heads on my 400. Brodix tech said that because of revised coolant passages in their heads, they do not recommend drilling steam holes. They have a tech bulletin that shows what gasket to use and what holes to enlarge on the head gasket. So far my motor actually runs cooler than the previous 383. Do you have a link for a writeup about this info?

Thanks. </font>[/QUOTE]They don't have it online but if you are interested it is in their catalog.
Just call 470 394-1075 & they will send you one.
If you have DSL you can download it from their site but it is like 53 pages so it might take a while on dialup like we got up here in the sticks :(
Brodix (http://brodix.com/)