'And the Fun Begins!'

[bulldurham]

I seem to remember that the intake manifold gasket does not provide a water port on the rear and it was suggested to me by someone to not open a hole in the gasket to allow water thru that port. " It is just another opportunity for the gasket to leak". Jose, was it you w/ whom I had that discussion??

 

[V6 JOSE]

Hi Doug,

I don´t remember what I ate for breakfast, so I don´t know if it was me, but I have advised others not to cut on the gasket at all. The only thing I do recommend is, removing the lower part of the gasket, which seals the front and back of the manifold mating surfaces, and putting a 3/8 " bead of silicone sealer across there, especially at the corners. I have found that you get a better seal doing that.

Jose

I seem to remember that the intake manifold gasket does not provide a water port on the rear and it was suggested to me by someone to not open a hole in the gasket to allow water thru that port. " It is just another opportunity for the gasket to leak". Jose, was it you w/ whom I had that discussion??

 

[Mike Armstrong]

Hi Doug,

I don´t remember what I ate for breakfast, so I don´t know if it was me, but I have advised others not to cut on the gasket at all. The only thing I do recommend is, removing the lower part of the gasket, which seals the front and back of the manifold mating surfaces, and putting a 3/8 " bead of silicone sealer across there, especially at the corners. I have found that you get a better seal doing that.

Jose

I'll remember that this time around

 

[bulldurham]

I have that same problem, Jose. Poor memory is a blessing w/ regard to some things but putting an engine together is not one of them.

 

[Mike Armstrong]

I had suspected so but I think I've confirmed why my radiator fill neck blew off. I had ordered a new radiator cap from RockAuto. On their website a 66 Sunbeam Alpine 1.7L requires a Stant 10206 Radiator Cap with a depth of 1". However, the radiator cap that was on the radiator when I bought it was a Stant 10229 Radiator Cap with a depth of .75" , retracted it's about .5". Fully retracted the Stant 10206 is approx. .75" leaving no room for the pressurized radiator coolant to vent past it

Page 255....

http://www.stant.com/files/9314/0979/5335/2012_Passenger_Light_Truck_Catalog.pdf

Are any of you guys using a Stant 10206 Radiator Cap on your SV radiator? If not, which are you using?

 

[gordonra]

Hi Mike,

If you built enough pressure to blow the neck, chances are good it also pushed it's way past the gasket into the intake manifold.

It's possible that you lucked out with minimum damage.

Rich

I had suspected so but I think I've confirmed why my radiator fill neck blew off. I had ordered a new radiator cap from RockAuto. On their website a 66 Sunbeam Alpine 1.7L requires a Stant 10206 Radiator Cap with a depth on that one is 1" . However, the radiator cap that was on the radiator when I bought it was a Stant 10229 Radiator Cap with a depth of .75", retracted it's about .5". Fully retracted the Stant 10206 is approx. .75" leaving no room for the pressurized radiator coolant to vent past it

Page 255....

http://www.stant.com/files/9314/0979/5335/2012_Passenger_Light_Truck_Catalog.pdf

Are any of you guys using a Stant 10206 Radiator Cap on your SV radiator? If not, which are you using?

 

[Mike Armstrong]

Hi Mike,

If you built enough pressure to blow the neck, chances are good it also pushed it's way past the gasket into the intake manifold.

It's possible that you lucked out with minimum damage.

Rich

Hi Rich.

Didn't think of it that way but that may well be true. Enough pressure to bow out the tanks on the radiator, geez, that's gotta force coolant in the opposite direction somewhere, perhaps as you said, into the intake manifold.

Not sure if I need to pull the manifold now. maybe if the gasket has been compromised it has to be re-sealed. If anything that leak i noticed from between the carb spacer and manifold has to be addressed.

 

[Tom H]

Mike, I'm not making any sense out of your radiator cap discussion. If the cap you installed was 3/4" long vs 1" required, it would not have sealed at all. You are basing the required cap on an assumption that you have a standard 66 Alpine radiator. But from earlier posts it is clear that this radiator has been rebuilt. It seems more logical that the neck actually is SHORTER than original and the cap used was shorter than stock but not short enough. If a 3/4" cap is put into a 1/2" neck, it is already compressed and will not release, but a 3/4 " cap into a 1" neck will not seal.

Tom

 

[Mike Armstrong]

Mike, I'm not making any sense out of your radiator cap discussion. If the cap you installed was 3/4" long vs 1" required, it would not have sealed at all. You are basing the required cap on an assumption that you have a standard 66 Alpine radiator. But from earlier posts it is clear that this radiator has been rebuilt. It seems more logical that the neck actually is SHORTER than original and the cap used was shorter than stock but not short enough. If a 3/4" cap is put into a 1/2" neck, it is already compressed and will not release, but a 3/4 " cap into a 1" neck will not seal.

Tom

Hi Tom,

Your right, that's a good point. I'm basing it all on it being a 'stock' SV radiator, which, after being triple cored, it no longer is! Will the cap neck length required typically change after being triple cored? The radiator is currently at the shop so I can't measure what the actual depth is (probably should have before jamming a cap on it in the first place), but it not retracting enough to allow for bypass seems a likely cause of the failure.

 

[Tom H]

Re-coring would not necessarily require a different neck, but who knows what changes they did while re-coring.

Tom

 

[Mike Armstrong]

Re-coring would not necessarily require a different neck, but who knows what changes they did while re-coring.

Tom

True, I'll be sure and measure the depth when I get it back.

 

[kmathis]

Hi, Mike:

I am running a Stant 10329, which is for a stock 1974 Mustang II, I haven't had any over heating issues with it. I didn't look up the 10229, however the 329 has been working for me.

Hope this helps,

 

[Mike Armstrong]

Hi, Mike:

I am running a Stant 10329, which is for a stock 1974 Mustang II, I haven't had any over heating issues with it. I didn't look up the 10229, however the 329 has been working for me.

Hope this helps,

Thank you buddy.

I'm just going to have to measure the neck on my radiator and make sue that the cap I get is long enough to seal yet retracts far enough to relieve pressure.

Edit: pic of the old cap that was on the radiator when I bought it and the new RockAuto replacement cap. Note the .75" vs 1" neck depth difference.

http://s1362.photobucket.com/user/EighteensTen7/slideshow/Radiator caps

 

[Mike Armstrong]

Tore down the engine a bit to reveal the intake manifold gasket. I took a few pics so you guys could see it still in place as it was when I lifted the manifold off. I'm sure it's obvious to some of you guys that a couple 'modifications' were made that might have contributed to coolant entering the manifold. If you do see where the problem is could you chime in please? Thanks

http://s1362.photobucket.com/user/EighteensTen7/slideshow/Gaskets

I'm assuming the intake manifold gasket stays in one piece when it's installed. I don't recall now why it was so difficult to get it in place but I seem to remember that some of the manifold bolt holes did not line up with the holes in the gasket so i had to elongate some of the holes (which could have been a sign that it was the wrong gasket or it was being installed incorrectly). Also, there is about a 1" gap on one end of the gasket that didn't seem right. There was also a small pool of oil on the middle of the gasket that assume was just from the crankcase.

I also included a pic of the spark plugs. Their lined up as i took them out with number 1 cylinder plug at the top left. None were clean as jose suggested looking for. Kinda weird but I did notice that all the plugs on the number 1 cylinder side of the engine are darker than the other side of the engine for some reason. ?

Thanks

 

[Mike Armstrong]

I added a couple pics of new vs old manifold gasket and the gasket removed. You can see the two passage ways I cut out on the old one, probably not a good idea Also, I haven't laid the new one in there yet to see how it fits/differs but you can see from the pic how I had to elongate a couple of the holes in the old gasket to pass the manifold bolts through.

http://s1362.photobucket.com/user/EighteensTen7/slideshow/Gaskets

 

[Mike Armstrong]

I taped over all the passageways on the intake manifold itself.

Poured water into the opening for the radiator hose housing, no leakage into the carburetor part of the manifold, poured that out. Poured water into the opening for the carburetor, no leakage into the coolant passageways. So the intake manifold is intact.

The only thing I can think of that allowed coolant into the fuel/air passageways of the intake manifold would have to be poor sealing where open coolant passageways are next to open manifold passageways (two up front, two in the back). So I'm going to assume I installed the manifold gasket incorrectly.

If a head was cracked or a head gasket blown I would think the presentation would have been different, like white smoke billowing out the exhaust.

EDIT: It was a bit concerning to see such a difference in the look of the spark plugs, one side with all three looking black, the other side with all three looking white'ish. But after filling the intake manifold with water I now think I know why. I didn't know till then that the two sides of the manifold are separate. I poured water into one side but the other side remained dry. So in looking at the plugs I think it's now obvious that only one side of the manifold had the leakage (from the coolant mixed in with the fuel/air).

Now would that be the side with the dark plugs or white'ish looking plugs?

Either way, I'm gonna replace the whole gasket of coarse. I think I installed it dry last time with exception to the ends. Maybe this time around I'll use sealant around all the passageways.

 

[Mike Armstrong]

Picked up the repaired radiator, the mechanic did a great job on it and didn't charge me even though he thinks it is was one of two things that caused it blow, I either had the wrong radiator cap on it with a neck that was too long to allow it to retract far enough to bypass the pressure or there is a leaking head gasket that's forcing exhaust gas pressure into the cooling system faster than it can be relieved at the radiator neck. He suggested to run the engine and remove the cap to look for bubbling which would suggest exhaust gas escaping from a leaking head gasket.

I measured the neck on the radiator, it's exactly .75". If that's the same as when it was stock then I would think the cap with a 1.00" neck that Rockauto lists for a 66 Alpine 1.7L would be incorrect because it couldn't retract far enough to allow pressure to bypass.

However, what concerns me now is which one of the several caps I have accumulated was the one actually installed on the radiator back when it blew? If it was the 1.00" Rockauto one I can understand what happened, but if it was the one that looks like it was on there at the time then it may not have been the cap because that one is 13LBS with a .75" neck, same specs as the one Kelly is using.

 

[pcmenten]

Hey Mike. Thanks for all the follow-ups on your progress. It's informative to see your process.

I'm a little surprised and impressed that you're using a 13 pound radiator cap. That's a relatively high value. Good things happen when you allow the engine to run as hot as is practical, things like lower piston/cylinder friction, better fuel atomization, etc.

I'd be sure to have some synthetic oil mixed into the crankcase. I don't recommend straight synthetic but having a quart or two will really help things.

And, yes, the stock intake is divided left and right. So, yes, that does explain the left-right difference in plug colors. I'd say that the side that was not dark had the leak, so I'd carefully examine that side of the gasket.

 

[Mike Armstrong]

Hey Mike. Thanks for all the follow-ups on your progress. It's informative to see your process.

I'm a little surprised and impressed that you're using a 13 pound radiator cap. That's a relatively high value. Good things happen when you allow the engine to run as hot as is practical, things like lower piston/cylinder friction, better fuel atomization, etc.

I'd be sure to have some synthetic oil mixed into the crankcase. I don't recommend straight synthetic but having a quart or two will really help things.

And, yes, the stock intake is divided left and right. So, yes, that does explain the left-right difference in plug colors. I'd say that the side that was not dark had the leak, so I'd carefully examine that side of the gasket.

Thanks.

After the experience of having the radiator blow up I'm very skittish about radiator caps in general. I'm going back to 7LBS like the original with a .75" (max!) neck. I'll compress it to make sure it can fully clear the opening to the radiator tank to bypass.

Synthetics are great. The only thing I worry about with synthetics is that I've heard they will seep out of the slightest potential leak area. Royal Purple is super popular around here.

That was my guess to, the side with the lighter shade plugs probably had the leak. Whether the gasket wasn't seated right or torqued down correctly, I'm going not leave it dry but install a bit of sealer around each port to make sure the leaking doesn't occur again.

It would 'appear' that the engine was worked on some time in the past. There is an edge of a newer looking Fel-Pro head gasket exposed that I don't 'think' was installed in the factory. So I'd like to think it was rebuilt at some time.

http://s1362.photobucket.com/user/EighteensTen7/slideshow/Head Gasket

 

[pcmenten]

Regarding use of synthetic oil; I switched oil in a 2004 Ranger with the 4.0 SOHC engine. The rear main seal started to leak. Switched back to mineral oil and the leaking stopped. I was surprised and disappointed that the original Ford seal was not tolerant of synthetic oil.

Synthetic oils can cause neoprene seals to shrink, but a mix of synthetic and mineral oil will prevent the shrinkage.