View Full Version : 351W Head Gasket

06-10-2009, 01:50 PM
I'll never meet George Reid, author of "Rebuilding your Short Block Ford", but if I did I'd kick him straight in the junk repeatedly. George is pry a nice guy, it's just that I consulted his book as I rebuilt and upgraded a few things on my 351w (heads/cam/intake) George's head bolt torque specs are WAY OFF. :mad: On or about pg 50, he says 65-72 ft lbs of torque on head bolts in sequence, brought up to the final spec in 3 steps. A quick google search shows 100 ft lbs to be the concensus for 351w head bolts. I assume this is for stock engine in a car/truck.

Now I'm no physicist, but it sounds like a long damn way from enough torque to hold the heads down. I would imagine the pressure to increase exponentially as torque goes up... So i'm not off by 30%, but pry a helluva lot more than that. :confused: maybe not, but i don't know....

At any rate, I'm still trying to get the milkshake sludge out of the oil pan. Any tips on dissolving that crap? been running diesel thru the lifters, pan, pump, etc. The engine's cleaned up pretty good, but still takes a while to completely drain the pan. I may have to remove the pan to double check that its clean, but trying to avoid that unless its necessary.

I'd like to take off a main cap and inspect a bearing or two, but don't really want to pull the engine, again unless I need to. I drained the oil/water immediately when I got home when the engine was still hot, so I'm hoping most of the water drained out or evap'd. The next day, I put a gallon or so of diesel in it and turned it over quite a few times.

At this point, my main concern is the lower end collecting enough rust/corrosion to cause a bearing failure further down the road. Any thoughts? I want to make sure its done right. I'm pretty tired of working on the damn thing instead of being behind it, but I can't imagine having to tear into again for a crank bearing, or worse.

What's the torque spec on these engines? Is it different for marine?

Also read to torque the "corners" to 110. Or should they all be the same?

06-10-2009, 02:19 PM
65 to 72 would be typical for an aluminum headed engine. 100 ish is typical for any cast iron headed V8 and the corners should never be different unless the bolt size is different, some performance books will list a different torque for studs vs bolts...........but 65 to 72 lb sounds super light.

I usually take mine up in steps of 20....... torque it in order to 50 70 90 and then the final torque.........and re check it once its been warmed up once.

With aluminum heads you need to check the torque a few times.

06-10-2009, 02:23 PM
for the sludge removal try Marvel Mystery oil it does the trick. put a quart in let it get warm at idle and then shut it down and drain it........then fill it back up with the regular oil.........on some engines it takes a few tries. Ive used it on quite a few head gaskets failures.

In General small amounts of moisture are not a problem and will go away on there own as the engine is heated up, its typically large blockages of water oil mix that cause problems.

06-10-2009, 04:44 PM
Make sure you are not reading the torque spec for a 289/302 with 7/16 head bolts which is a lot less then the 1/2 351w bolts. Be aware that in many cases aluminum heads are torqued to different specs (often lower) than cast-iron heads. Just make sure you are reading what you're reading.

06-10-2009, 05:05 PM
Cameron, thanks for the MMO tip. I'll go grab some on the way to the house. it looks like the lifter are getting clean diesel so I'm hoping its not that big of a deal.

Tim, ya know now that I think about it, I'm almost positive they were rebuilding a 302. I never thought to double check the damn book!

So, if this were your boat, would you slap on a new gasket and button it back up? or think about going deeper into it?

06-10-2009, 05:25 PM
I had a faulty torque wrench ruin a weekend at Parker one year. I'm not sure how long your ran the motor but when I heard the head gasket blow I look back and could see the water pushing out the side. This was on a twin turbo big block Chevy.

All we did was put on new gaskets and drain the oil. It sounds like you have gotten a lot of the milk-shake out of your motor already. I would say put gaskets on it and then change the oil at the end of the weekend until you are sure its clear. Even oil with some water in it has a lubercating effect which is what you really want to happen when you do blow a head gasket.

On a side note, which I don't think you should ever do. I blew a head gasket while on my way to a street race back in Southern Calif a long time ago. I let the motor cool off and still did the race for some cash. Went home and change the gasket and oil and she still ran for a long time after that.

06-11-2009, 02:36 PM
Checked the book last night. They were building a 289 with 7/16" bolts. The book also says it covers everything from a 221 up to a 400M, including the windsor. Just a tad confusing. Oh well, lesson learned. Never use just one book. Should've bought Pat Ganahl's too.

I felt it in the throttle, but couldn't tell what was going on under the motor box. Ran it for maybe 20 minutes after that, about 1/2 of that at idle. 30 minutes tops. It was enough time to get pry two gallons of water in there.

When i pulled the head on that side, I can see where the gasket on cylinders 2 and 3 were getting weak. I'm not going to pull the engine or oil pan. Hopefully, I can get new gaskets here pretty quickly and get back on the water. Putting <20 hours on your boat in year will make ya a little crazy...

BTW if anyone wants a pic of any of this, just let me know.