Coolant in cylinders; fresh 400 sbc build

I recently finished a 400 sb build that someone else started. The heads were machined and ready to go when I got it and the block had yet to be torn apart. I took it apart and inspected and all looked real good as if the engine had very few miles. It didn't even have any ring ridge. So I build it and put it in and fire it up.

First thing I notice is smoke from bank 2. Was blueish white. Second thing is the engine get warm Fast! And the coolant will not stay in radiator as if combustion is getting there. So I turn it off and go do something else as I scratch my head to figure out where I went wrong. Topped off the coolant after it cooled down and walked away again. Came back the next day and the coolant was very low again with no external leaks. Desided to try to start it and it would only turn an inch. So now I pull the spark plugs to see which cylinder is hydro locked. #4 poured water. Turned it over to pump it out and #6 had a little as well as #1 and 8. I think 1 and 8 might be because I forgot to put sealant on the intake and the coolant is getting into the intake ports (I hope). #4 And 6 is definitely a problem.

Heres the question. Before I take it apart, I will check all cylinders with my compression gauge. Is there a way to determine if the block is cracked or just the head gasket could be the problem BEFORE I take it apart? I will also check the head for warp-age.

I just walked back out to look at it after typing this post and #4 was full of water again after just sitting there for a few minutes. This means it is flowing there pretty fast. Turned it over and water pumped out of #4 only. This tells me it is likely a head gasket but I want to be sure before tearing it down again

more likely is a cracked cyl. block or head

lets say its a cracked head. I have a set of 305 heads sitting around. What would be the out come of 305 heads on a 400? The only upgrade is a 0.442 int./0.465 exh. cam.

Just foating some thoughts, but the question was is there a way to tell whats wrong before I take it apart? You know, like if you put oil in the cylinder you can determine bad rings or a valve.

sounds like you got leaks all over---could be wrong head gasket for 400 block and also the 400 blocks crack pretty bad from the steam holes to the bolt holes to the cylinder---400s have 2 small steam holes between the cylinders to feed water from the block to the head---if you have the wrong gaskets or the wrong heads can be a problem---also these blocks are syameez bores and they crack from those steam holes to the bolt holes to the cylinder---cracks may not show up until the bolts are torqued

Should I have put oil or sealant on the head bolts? I put oil as I always have but I just read in Alldata that thread sealant is used. Something just tells me that I did something wrong when putting the heads on. I'm gonna check compression tomorrow, remove the head bolts and clean them and reinstall them (maybe about 5 ft lbs over torque) and recheck compression to see if it changes. I build this in the backyard with now shelter so I dont think I paid as good attention to what I was doing as I would in the shop

Sounds like you should pull the heads and check hole alignment with the block and gaskets. If water is flowing in that fast, there has to almost be something else wrong. I don't think a crack will send water into the cylinders that fast with the motor being cool. Probably no other way to tell except pull the intake and heads.

like Jerry said... .there is a crack or something not line up gasket or water port holes to fill up that fast its big . as for head bolts the threads need sealer on them but even with no sealer they will not fill up the cylinder. last one that fill up one that fast.. that i look at had it bad spot in the ex port ....weak casting

Last one I had do that had a crack in cylinder wall about 2" long half way down.I don't think it would leak that fast even if you left a bolt out.

Did you drill the heads for steam holes?
Technical Articles at Greg's Engine & Machine

No I did not. The block is in stock form

It's not the block that gets drilled, it's the heads. Did you look at the link I provided for you?

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Originally Posted by techinspector1

It's not the block that gets drilled, it's the heads. Did you look at the link I provided for you?

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No sorry haven't had time. Here are my compression numbers...

#1 = 175 psi, 3 = 150, 5 = 140, 7 = 170

#2 = 142 psi, 4 = 168, 6 = 166, 8 = 157

#4 is the one that water flows out of. 1, 6, and 7 only have a little when I turn it over.

The heads were done by a machine shop before I got this mess. I can only assume that they are fine.

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Originally Posted by techinspector1

It's not the block that gets drilled, it's the heads. Did you look at the link I provided for you?

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I just skimmed through your post and remembered that they said that they tried to rebuild the stock 350 that came in this truck. (78 K5 Blazer) They found that the 350 block was cracked and then found a 400 to build for it. The heads were already done and I think it could be possible that the heads were off the 350. So, with that in mind and the compression specs I posted, is it possible that my problem is that water is entering the cylinders through these non-existent steam holes??

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Originally Posted by Bigbzc

No sorry haven't had time. Here are my compression numbers...

#1 = 175 psi, 3 = 150, 5 = 140, 7 = 170

#2 = 142 psi, 4 = 168, 6 = 166, 8 = 157

#4 is the one that water flows out of. 1, 6, and 7 only have a little when I turn it over.

The heads were done by a machine shop before I got this mess. I can only assume that they are fine.

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Not if they don't have steam holes drilled in them.

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Originally Posted by NTFDAY

Not if they don't have steam holes drilled in them.

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so with no steam holes I can have coolant going directly into the cylinders?

The water out of the block will find some place to go

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Originally Posted by NTFDAY

The water out of the block will find some place to go

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Guess I'll find out when I pull the heads back off

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Originally Posted by NTFDAY

The water out of the block will find some place to go

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Yep, and if it can't go, it will generate a hot spot where the gasket can let go or pre-ignition/detonation can begin.

How can I identify the heads?

Well – here’s my two cents worth on what may be your problem. The 400 block starts life with a 4.125 bore (verses a 4.00 for a 350). You didn’t say if the block was bored but if it was, the bore would now be between 4.155 and 4.185. In any case, the head gaskets for a 400 typically are sized for a larger initial bore size and they have steam holes. The 400 block requires specific head gaskets with matching steam holes (Fel-Pro PN 17031).

The 350 heads are intended to be used on a smaller bore and they do not (in their stock form) have steam holes. 350 head gaskets do not have steam holes. Many well intended hot rodders have put 350 heads on their 400 blocks in anticipation of upping the compression ratio with the smaller chambers only to have a real disappointment in a very short time if steam holes were not drilled and proper gaskets not used.

When using heads without steam holes, the pressure immediately builds and more often than not, compromises the gasket. When that happens, water in the cylinders is common. I think you’ll find the gaskets have been compromised – as evidenced by compression being significantly lower in #2 cylinder.

I’d recommend pulling the heads, making sure you have steam holes and correct gaskets and reassembling.

Good Luck,
Glenn

I said the block was stock. Never been machined.

http://img_0096 (640x427)(5)-windowslivephotogallery

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Originally Posted by jerry clayton

http://img_0096 (640x427)(5)-windowslivephotogallery

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I got a blank post Jerry

OK--couldn't get it to post but do have a pic in my gallery of the steam holes in a 400 block---however these have been blocked as is sorta common mod for some guys---you can see how the one hole is cracked over to the head bolt hole and toward the cylinder however this block has been sleeved because of the crack into the wall---hope it gives you an idea of what to expect or look for. It is the first pic that comes up.

If anyone would like to post it to the thread I would appreciate it---Maybe Looey can take care of it.

Thanks

Jerry

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Originally Posted by jerry clayton

OK--couldn't get it to post but do have a pic in my gallery of the steam holes in a 400 block---however these have been blocked as is sorta common mod for some guys---you can see how the one hole is cracked over to the head bolt hole and toward the cylinder however this block has been sleeved because of the crack into the wall---hope it gives you an idea of what to expect or look for. It is the first pic that comes up.

If anyone would like to post it to the thread I would appreciate it---Maybe Looey can take care of it.

Thanks

Jerry

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Post the pic in PhotoBucket and copy the URL. Then reply and click the "Insert Image" button at top of window and paste the URL

http://i706.photobucket.com/albums/w...zc/BadA400.jpg

Block before assembly

http://i706.photobucket.com/albums/w.../bareblock.jpg

So did you look at the photo in my gallery?

I know that the photos can be posted here and I'm not going to do photobucket--too many pics of my stuff are by magazine phtogs and copywrite type stuff can be involved whereas just posting on a single post is ok

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Originally Posted by jerry clayton

So did you look at the photo in my gallery?

I know that the photos can be posted here and I'm not going to do photobucket--too many pics of my stuff are by magazine phtogs and copywrite type stuff can be involved whereas just posting on a single post is ok

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Yeah, I see that. I'll look real close at the block this weekend when I get time to pull the heads off.

Just wondering if you read post #21. All this is mute not having pulled the heads yet

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Originally Posted by cffisher

Just wondering if you read post #21. All this is mute not having pulled the heads yet

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Yeah I read it. I will pull the heads after the tornados pass over. I should know something by Sunday and will post then

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Originally Posted by Bigbzc

I said the block was stock. Never been machined.

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You seem to be fixated on the block. We're not talking about the block. It has steam holes already in the decks from the factory. As Glenn told you, the heads and the gaskets must also have steam holes to match up with the holes in the block decks.

Guess I'll have to go out in the garage and take some pictures of my stock 400 heads so he'll know what we're talking about.

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Originally Posted by techinspector1

You seem to be fixated on the block. We're not talking about the block. It has steam holes already in the decks from the factory. As Glenn told you, the heads and the gaskets must also have steam holes to match up with the holes in the block decks.

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Yeah I got that plain and clear. I was responding to the post above that which said that I hadn't said whether the block had been bored over or anything and I believe somewhere in the begining of this thread that I mentioned that it was all stock and did not need work as it had very low mileage and no ring ridge. I think you are right about the heads being off a 350 because that is what was in it before I got it. How can I ID between the different heads? By the way, thanks for your help so far

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Originally Posted by NTFDAY

Guess I'll have to go out in the garage and take some pictures of my stock 400 heads so he'll know what we're talking about.

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I know exactly what you are talking about

I have to drill steam holes in heads between cylinders, a total of 6, got it.

I'll know after the storms blow over and I can remove heads to see if they are 400 heads or not.

Production Chevy heads have the casting number under the valve cover. It's 6, 7 or 8 digit number. Use an awl or something sharp like that to scratch around on the numbers. Many times, there is dried crud on them and a 3 might look like an 8.

Here's what 400 heads look like (steam holes circled)

Ok, I pulled th heads and there are no steam holes so I can only assume that they are 350 heads. the casting number is...
462624. Please tell me what kind of 350 heads they are.. (double hump) or what?
http://i706.photobucket.com/albums/w...c/SUNP0001.jpg