I have a 72 Buick 350 in my 66 skylark coupe, i had it running good for over a year before i decided to tear it apart and clean it up, i got a new set of iron heads and so thats as far as i tore it down but now i have a huge issue i jist cant solve. The car will start up as soon as you touch the key, it idles and revs fine and it quiet but it freely flows water into the oil pan. Ive pulled the intake 4 times now and reinstalled it, same problem each time. The last time before i started it i let it set for two days with water in it and it stayed full but as soon as i actually fired up the car the water level drops under the intake as it flows into the oil pan.. im lost and beyond frustrated...please send help
. sounds like your new iron heads are the wrong year . 72 is a crossover year and it seems people go by casting numbers that are too general. . There are coolant holes in later 72 - 80 heads and cannot be used on early 72-68 blocks but general casting numbers shows that head covers those years . Go get your old heads back.
Here's a pic of 2 heads and your possible coolant leak. Notice the center two coolant holes on one that the others don't.
So i found the leak, turns out one of the intake water ports is pitted from corrosion just enough to not form a proper seal to the head
I cant fix it ive tried everything including three new intake gaskets, im not sure the pitting was the issue but the gaskets arent at all stopping the water, it flows out of the oil pan no matter what
The gaskets ive used are the valley pan style and at first i was using rtv, that made it worse, it would flow out just as fast as i could put it in then, now it it just a steady stream out of the oil pan
Once the water level gets just under the water ports on the intake it stops leaking, and i can see each time i pull the intake back off that the water is flowing down the valley pan
What I would do is start with a razor blade to trim off any old RTV and gasket material and then if you have pitting then use some JB weld to built it back up. Then I would use the TA composite intake gaskets instead of the steel valley pan. The composite is WAY easier to get a good seal vs the steel gasket I find. I would use a SUPER thin skim of "the right stuff" sealant on both sides of the Composite intake gasket. Super thin skim though not much. I use the stock valley pan just to cover the underside of the intake but I cut off the parts that actually seal the ports and use the better TA composite gaskets. Try this and I'm sure you will be leak free...
Thanks for the help, im gonna get the parts on order tonight hopefully, ill let you know what happens
If you have feeler gauges or some precise calipers then measure how thick the steel pan gasket is? Or maybe call TA and ask them which thickness is the closest to stock gaskets. I normally go a little thicker as they squish down a lot more than the steel gasket and that's why they seal so well in my opinion. Another tip is to clean out the threads is the heads where the intake bolts go. I use an old bolt with a slot cut into it and run that in and out with some wd 40 or something to remove the gunk from the threads. Then I wire wheel the bolts quickly to remove crap from them. Then use engine oil to lubricate the bolts when you go to torque it up. I bolt it up to 15 foot pounds and let it sit overnight and then the next day I torque it to spec. Be sure to follow the correct sequence of bolt tightening. The reason I let it sit before fully torquing is so the front and rear bibber seals don't spit out when you tighten the bolts. Some people don't like these seals and prefer a THICK bead of RTV instead but I prefer the rubber chunks they don't leak if done right. Another tip is to trim down the height of the rubber seal as so Erinyes it's too tall. And if the heads are milled a lot then it is better to use the RTV as the rubber seals won't fit well.
