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Weird cyl-head water leak
1 Attachment(s)
Ok small block gurus, lend me a hand.
I have noticed a water leak from my 351w stroker with edel Vic jr ally heads. I finally tracked it down to the head/block joint, just above the oil filter. The pic below shows where it is coming from. 8000 miles on the motor. here are the symptoms: 1/ No overheating or cooling system pressurisation 2/ No water in the oil 3/ definitely not running downwards from the inlet manifold sealing area 4/ only get about 10 drips from it as it cools and is nearly cold after a run - doesn't leak when hot or stone cold. 5/ no biggy - water level staying relatively stable 6/ engine has never been overheated, but gets regularly thrashed So - my guess is that it is coming from the head gasket - probably the forward connecting passage betwen the block and the head. I have some options: 1/ it ain't broke enough to warrant fixing it 2/ it should get a new head gasket and check head for warping. 3/ dump some coolant system sealer stuff in there and pray. what do you reckon? PS - leak/leek - I heard it already. |
Hi,
There is a possible leak from the lower[short] head bolts as they go into the water passage. Did you put sealer on them as the heads were put on? You could try draining the rad and taking out the lower bolts and putting thread sealer on them and re-torquing them. Good Luck, Perry.:cool: |
I would vote for #3.
Rick |
New head gasket
Wilf,
I know you like things right and orderly. Pull the head, check it for flatness and then do what is necessary to fix it properly. Even if the head is flat you need to change the gasket. If the head proves to be warped I would pull both heads and make the necessary corrections. Just my 2 cents. Summer is just around the corner. Good luck, Harris |
Wilf,
Just a suggestion as I am sure you have already checked this. I fought the very same type leak for a year and finally in desperation I got my torque wrench out and checked the head bolts along with all others. I found several that had backed off as much as a pound. I retorqued all of them and that was about 2 years ago and I have never had a drop of water leak since. However I now go over the car on a regular basis and check the bolts to see that they are staying tight. Ron :) |
Thank you for your replies guys, there seem to be some options that are easier to do than others, so I guess they will get tried first.
Harris - yes, nice and orderly is the english way!! LOL However, I have recently fallen under the bad influence of some colonial types, reckon I must be getting lazy. Or old, or both. I can see that head coming off in the near future tho'. |
Don't forget grammar and spelling correction. :D
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Wilf,
I forgot to ask you in my previous post. Are you guys still doing "floggings" at the Tower of London? My wife and I are coming to England this year and having her watch a flogging would straighten the old gal out. Keep your heads tight! Harris |
Harris - sorry, the only floggings still happening take place behind closed doors for ex public-school members of the House of Lords.
Public attendance strictly frowned upon - we english like to keep our perversions private! Of course - you could always take the lady to Saudi Arabia, no shortage of public flogging there. |
Wilf,
Had the same problem with my 351/victor jr. setup but it happened earlier, actually first time I ran the engine. Problem was the head bolt torque wasn't high enough. It seems that I had too many values, Edelbrocks numbers, ARP's numbers, and Ford's numbers not to mention dry vs. lubricated. I think I initially used ARP's numbers for lubricated threads and had to add another 5 ft/lbs to get the water jackets to seal. I ran the motor for a while (couple of hours) and then went back and retorqued all the head bolts. Added 5 more ft/lbs to be sure and haven't had any more water leaks. If I think of it I'll check the final numbers tonight when I get home and repost. h dog |
Hey Guys....
If you "re-torque" heads do you just check tightness or do you loosen them one at a time and re-tighten to whatever torque spec you are wanting??? Thanks, Jack :confused: |
Jack,
You must back off the bolt 4 or 5 pounds and then come back up to final torque without stopping along the way. Breakaway torque is always higher than the "sliding surface" torque value, so just checking the current torque won't tell you anything. |
Umm, just a thought guys, are we sure that any of the head bolts enter the water jacket on a 351W? I know they do on a 302, but I am not sure about a 351.
I am also torqueing to 105lbs ft on the short bolts, 115 on the long. Sound right? |
Wilf,
The lower outside bolts go into the water jacket. Roscoe |
Thanks Roscoe - I couldn't remember for the life of me.
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I'm building a 393. I've run a tap down every headbolt hole and looked in each one with a light. The holes are all blind, none go into the waterjacket.
My block is a 351 D9AE (1979). I torque all my ARP bolts at 105. Ed |
Wilf,
It is a common practice, at least among circle track engine builders to put a thin layer of clear silicone around all the coolant passages on both the deck and the head. They also put it around the studs and under the washers, even on blind holes since the coolant could migrate across the deck from the passages to the studs. This used to be something the Sprint Car and Late Model engine builders would do on their aluminum motors since aluminum moves so much during warm up and cool down, but now they’re doing it on iron block/alum head motors too. Actually the only gasket they don’t use silicone on is the carb. Scott |
Wilf,
Did you make your alt. braket or buy it aftermarket. I have not been able to find one for my 351. After you get your water leak problem fixed could you take a close up of your alt. bracket. TomS. |
Wilf,
I have the exact same problem with my big block. Slightly different location but the symptoms are identical. Does not overheat or leak when warm and running, only leaks after completely cool, not mixing with oil or combustion chamber etc. If you find a simple solution- post it. My problem is having enough clearance in the engine compartment to remove the head. |
TomS - alternator bracket came from my engoine builder, will ask him for the source.
Plan now is: stage 1: retorque all head bolts if no cure: stage 2: remove the 2 short bolts from around the affected area and refit with more sealant. Not doing this at stage one since I feel that completely removing any single bolt whilst the others are tight is intrinsically "bad" from a strict engineering viewpoint. if no cure: stage 3: pull head, check for straightness, replace cyl head gasket and use some luvverly silicon sealant. Any particular grade of silicon I should be using? I have also heard that header gaskets seal better with that stuff. |
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