Sbc 350 vortec heads coolant out of cylinder 6 exhaust.

I'll make this brief and as detailed as possible. I drove 60 miles no problem then at a stop light waiting for the light to turn green my exhaust is spewing white smoke. Steam train amounts. Did compression check and got:

1-185. 2-205
3-188. 4-205
5-165. 6-210 with coolant out exhaust port while cranking
7-165. 8-205

My question is how can the be so far off from driver to passenger side? Also how is cylinder 6 still holding compression?

The heads have about 1k miles on them and the engine rebuild has about 500 miles. I used the normal felpro head gasket 7733pt-2. Initial timing is at 10* and total is 31* all in around 2.8k rpms. Car never overheated and everything was great up until now. Wideband read 12.1 at wide open. Thanks for your help.

I had this happen to me but some how I wound up with a 305 gasket and never caught it. Until it blew. Good luck in finding it before reassembly

First off, Welcome to CHR!

Bummer of a post - could be a couple things that would not affect compression. It may be a bad intake manifold gasket or a cracked intake manifold. I'd check there before pulling heads.

Thanks guys. I'm gonna rip it apart and report back.

Sorry I missed it being your first post Welcome to CHR enjoy your stay

Coolant in cylinder 6. It still held 210 compression. It's still odd the there is a big difference between the driver and passenger side. I'll send the heads out to get them checked. I've also read that cam timing could cause the huge difference in compression. Does that sound logical?

Was the block magnafluxed when it was rebuilt? For your sake I hope it's a bad head and not the block. BTW, welcome aboard.

What does the gasket look like?

Quick update: My wife is right, I'm an idiot and this is proof. When I did my first head swap I used the felpro 7733pt2 with great results. When I rebuilt my current block I ordered a sbc gasket kit from a no name brand from Amazon. I just wanted to use the valve cover gasket, oil pan gasket, exhaust gasket and other non critical gaskets to save some money. The entire kit was $30. As I was assembling the engine, I guess I carelessly thought "what the hell, I'll try these gaskets because they looked pretty durable." Man was I wrong. The gasket failed not at the metal ring around the piston but at the compressible orange sealing surface. When I removed the heads I can use my index finger and smear that sealant off. It pretty much flakes right off. I'm gonna try to upload a pic but the website is giving me an error. Am I pissed? Not really because it's an easy fix. However, dont cheap out on the head gaskets.

Lots of cheap new junk for sale out there. Seems like most guys try them because they look good. Im kinda a slow learner with that stuff.

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Originally Posted by Grillhands

The entire kit was $30.

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And there was a reason for that. :mad:

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So I flushed the engine with 12qts of oil and took the car around for a nice drive about 2 days ago. Today, my friend came over and he wanted to hear the car run. I started it up and within 1 minute the car turned off. I thought maybe I forgot to turn the fuel pump on so I tried to kick it over again but the solenoid only clicked. I checked the volts going to solenoid and everything was good. Turns out MY ENGiNE CEASED!!! I cant even turn it over with a breaker bar on the crank. I drove this car for 600 miles after my rebuild without any problems and it decided to crap out at idle. I had oil pressure and I used my drill to prime the pump to 50 psi with my dewalt drill just to be sure. I removed the starter to be sure it wasnt binding to the flywheel. All valves and pushrods are fine. I didn't open the engine yet because my frustration level is at astronomical levels. How could this have happened? I'm at a lose. Can anybody please provide insight? I rebuilt the engine with all clearances in spec.

Sorry. Its seized not ceased. I'm too angry to edit

pull the plugs then turn it over . my guess you'll have coolant come out of #6 hole. coolant dont compress .

Plugs are out and still doenst move a inch. I drove it yesterday too.

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Originally Posted by DennyW

Can you rotate the engine CCwise? Have you tried it at the flywheel ? Either way ? Any give at all ?

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Tried CW and CCW. It doesn't budge. I drove the car 600 miles before this. I haven't tried at the flywheel but when I tried to start the car my external ford soleniod got extremely hot.

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Originally Posted by Grillhands

So I flushed the engine with 12qts of oil and took the car around for a nice drive about 2 days ago.

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By your statement above, I'm assuming coolant got in your oil and circulated with the oil through the motor. Bearing surfaces and coolant do not get along, before I tried to spin the motor anymore, I would pull the pan and check the bearings.

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Originally Posted by 36 sedan

By your statement above, I'm assuming coolant got in your oil and circulated with the oil through the motor. Bearing surfaces and coolant do not get along, before I tried to spin the motor anymore, I would pull the pan and check the bearings.

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When the head gasket went I only drove it about 1/8 mile at 20mph. I made sure the oil circulated to sweep out any coolant. I guess it wasnt enough. I just cant wrap my head around that I drove it about 5 miles and nothing happened.

Looks to me like you didn't drain the block before removing the head so the fact that there is antifreeze in the cylinder is false info looking for a cause

Sounds like the gasket wasn't the only problem. Perhaps a bad cylinder or head crack.?.?

Bottom of piston 4 came apart.

I'm glad you pulled the pan. Now, you need to discover what caused the piston skirt to come apart. In your picture of the cylinder, is it a shadow making the clearance around the piston appearing to be substantial?

I think it the way my light was angled. I checked clearance for the rings and they were within spec.

The little tab that hangs down is what broke

The bottom part of your piston is the skirt. Was this bored and new pistons, or just new rings? Was the cylinder taper measured? Looking at your cylinder picture again, #2 & #4 piston tops appear cleaner than #6 & #8, was your gasket blown between 2 & 4? Cylinder wash and hydraulics (water in the cylinder) can break pistons. You need to find what caused the piston to break before you put it back together or you'll be doing it again.

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Originally Posted by 36 sedan

The bottom part of your piston is the skirt. Was this bored and new pistons, or just new rings? Was the cylinder taper measured? Looking at your cylinder picture again, #2 & #4 piston tops appear cleaner than #6 & #8, was your gasket blown between 2 & 4? Cylinder wash and hydraulics (water in the cylinder) can break pistons. You need to find what caused the piston to break before you put it back together or you'll be doing it again.

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Block wasnt bored but it was honed. I reused my old pistons and just changed bearings. The old gasket shows it gave out between 6 and 8. I didn't taper though. I'm picking up a remanufactured jasper hopefully this week. I'm gonna swap my 906 heads over and maybe my cam if it's not damaged. I'll slowly tear this one down to see where its jammed. Thanks for the help everyone. This site is a gem! If I missed anything that I should check let me know please.

So are the heads modified in any way????? milled, ported? And did you use any sealer on the head bolts?/ If the heads have been ported( and those port walls look thinner than normal and close to the bottom) the porter could of went thru the wall near the bolt boss that is between the two ports which will cause a pretty drastic coolant leak, especially if the bolt threads into block aren't properly sealed---happens a lot with Chevys because the block deck bolt holes go thre and aren't blind like most other manufactures---------

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Originally Posted by jerry clayton

So are the heads modified in any way????? milled, ported? And did you use any sealer on the head bolts?/ If the heads have been ported( and those port walls look thinner than normal and close to the bottom) the porter could of went thru the wall near the bolt boss that is between the two ports which will cause a pretty drastic coolant leak, especially if the bolt threads into block aren't properly sealed---happens a lot with Chevys because the block deck bolt holes go thre and aren't blind like most other manufactures---------

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The heads have a mild port. They are not milled. I use Indian head on the arp head bolts. I had these heads on another engine and it didn't give me any problems. The heads maybe have 1k miles on them.

I think maybe you also have a problem with your compression guage-maybe filled with the coolant?????????There isn't any way that those pistons on stock heads/block would have that much compression

I tore down the engine and a piece of the side skirt came falling out. Once it dropped everything spun freely. To my surprise there are no marks or scuffs on the cylinder walls what so ever. I was expecting some really nice gouges but its smooth like when I first honed it. I'm glad the block is not ruined however I'm still gonna pick up the jasper.

You still need to determine what caused the skirt to break, they don't normally break on their own.
JMHO, but I suspect too much taper wear at the bottom of the cylinders.

Take a look

JMHO, looks like ring blow-by and uneven skirt wear. I would check the ring lands for wear and cylinders for taper.
Again just my opinion, but it's probably time for boring and new pistons.

Were the cylinders measured for wear / taper before the "rebuild"?
Or did you just hone and set in new rings?

350 short blocks are cheap. scrap it and start over .

Skirt tabs on cast pistons are very easily cracked/broken just handling the pistons while on the rods-the flip side to side against shank of rod will very easily crack and/or break off the amount of the tabb that you see in these pics-----while there are only a few pics in this thread, I see several no-no's but have received no comment back from poster

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Originally Posted by 34_40

Were the cylinders measured for wear / taper before the "rebuild"?
Or did you just hone and set in new rings?

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I honed and set new rings.

Quote:

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Originally Posted by jerry clayton

Skirt tabs on cast pistons are very easily cracked/broken just handling the pistons while on the rods-the flip side to side against shank of rod will very easily crack and/or break off the amount of the tabb that you see in these pics-----while there are only a few pics in this thread, I see several no-no's but have received no comment back from poster

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What's the purpose of that tab? I have another set of pistons doesnt have them

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Originally Posted by DennyW

Take a look at this article first.

Full-Round vs. Strutted: Piston Forging Designs and Skirt Styles Explained

Explained: Symmetrical, Asymmetrical, and Full-Round Piston Skirt Design

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That's was an excellent article!

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Originally Posted by DennyW

(Indian head)
This gets hard. Not good for that use.

Instead, use this on the threads. Works WAY better. And, it stays flexible.

High-Temp Red RTV Silicone Gasket Maker 81160

Attachment 70395

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You had good experiences with the rtv?