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Should steam holes be drilled in cylinder heads used on a 400SBC

  • Yes

    Votes: 14 82.4%
  • No

    Votes: 3 17.6%
  • what ya talking bout Willis?

    Votes: 0 0.0%
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Discussion Starter · #1 ·
Ok...I have read conflicting advice on this....so I want the straight poop

If I build a 400SBC do I have to drill the steam holes in the head Yes or no....

Back in the day the answer was yes...but today its not so clear cut
 

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My neighbor has them drilled for his late model dirt track stock car! I really don't know the answer myself, but I figured I could let you know of a racing engine that has it. He has over 30K in the engine.
 
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i have an instruction sheet from "Bill's II" i can send ya Duane... if ya want ;)


Bill told me Yes.... i was gonna follow his advice on this one...
 

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Discussion Starter · #4 ·
SHIFTY4 said:
i have an instruction sheet from "Bill's II" i can send ya Duane... if ya want ;)


Bill told me Yes.... i was gonna follow his advice on this one...
Well as I said back in the day the answer was always yes but I have heard a few say there didnt drill the holes (I think Nova SS(from steves site)was one of them that has built them both ways with no problems)...but anyway I was just wondering...thanks John I would love the instructions....if you could send them off to my hotmail account that would be cool:)
 

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It is still clear cut. You need the three steam holes on the bottom of the head to allow steam pockets which could form to escape. They do not always form, especially above 2,800 RPM, but when they do they do form they do not generally go away. Once formed the steam pocket doesn't conduct heat so the area of the block heats up and you can get into detonation.

The production heads had six holes (three 0.250" and three 0.125" holes) in the head, you only need the bottom three 0.250" diameter holes (exhaust side). They are not bored straight down, but at a 40° angle sloped towards the exhaust ports using the head gasket (Fel-Pro 1014) as a template.


Big Dave
 

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Discussion Starter · #8 ·
SHIFTY4 said:
seems ta come out small... dunno why... i'll send it to ya
thanks...:)

but in my experence it always come out small...even though it went in big ;) :D
 

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if your still not 100% sure call jeff brotherton of brodix heads, he personally hand picked my heads and knows everything in the world on heads, i guess he should since his last name is part of the company name..lol

just an idea
 

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Discussion Starter · #11 ·
Here are the instructions from Johnny

 

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Discussion Starter · #14 ·
DriveWFO said:
Run a gasket without the steam holes, fill the block and run it WFO :D
No I wont be running hardblock in this motor...now I have another project on the back burner at the momment that I will be running that stuff in...oh ya..a 1/8" overbore and some hardblock to the welch plugs to stabilize the block and we will be good to go;)
 

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This was discussed a lot at Camaros.net (http://www.camaros.net/forums/showthread.php?t=82265&highlight=steam+holes) and it is still a 50/50.

I did not drill mine, and am running aftermarket steel heads. The consensus is if its a daily driver and see a lot of idling, then yes, if it is a performance car and see 3000+ normally, then no.

I'm at 10.17: 1 comp, motor stays on the cool side, and no problems.
 

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I run Brodix RR200's on my 377, and i was told not to drill the holes in them, this came from Brodix. when i had stock heads on my car, my builder didnt drill them either...he said hes never had a problem with it in 30 years. Unless the car was gonna be 100% street, like a stock build 400...then he would drill them.
 

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If the engine will be street driven, then YES drill the steam holes. If you don't know how to do it, take the heads to a machine shop and have it done.

Good Luck! :D
 
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