Z24 intake manifold coolant passage sealing

[OlDatZMan]

I'm starting to put the intake manifold back on the head before putting on the head. I figure its easier to get at the int man bolts with the head on the bench. Exh man on after head on the bock. Surfaces are clean and I'll clean them again. I looked all over and find there is NO consensus on how to seal the coolant passages anywhere I looked. The blue RTV that was on the old gasket was loose and wet, and I don't like RTV anyway. I have my old std Formagasket #2 I've used for 45 years and some new Gaskacinch I've never tried. So far I've seen these suggestions: no sealant, Indian Shellac, aluminum paint, silicone, absolutely no silicone, grey, black, and blue rtv, Permatex copper, the titanium version of JB Weld. I've searched Ratsun and haven't found a thread though I bet there is one somewhere. My gut says use Forma #2 on the all mating surfaces of gasket/head/manifold water passages, but let it tack for a while (30 min?) before assembling, and then let it sit overnight at minimal torque with the mating joint horizontal before final torquing......and Gaskacinch all the other mating surfaces. The blue rtv that was on the old gasket was uneven, loose, probanly had leaked some, and looked like it wanted to be somewhere else. What's the latest word/opinion?

 

Head gasket set is Felpro HS9210-PT1. I gotta say the int man gasket is uninspiringly thin even though in a perfect world with no differential heating I hear it said that a gasket shouldn't even be necessary.

 

And while I'm on the intake manifold, exactly how much does coolant in the runners really matter for gas when you already have another coolant heat source under the carb that's gonna radiate into the runners to meet up with block heat coming the other way at some point? Heat may keep gas in vapor form. If I ever find a ASME 20 gal LP tank I'm putting propane on this engine. I ran lp10 or 20 years in my 68 GMC 250-6 and it LOVED it, whereas on gas now it is nervous and unhappy. Unfortunately the 50 gal tank I had on the GMC on the 720 is so large that it would look like a truck carrying a big hot dog.

[datzenmike]

Clean the surfaces and put the gaskets on dry like the factory did. Thin gaskets are fine because the parts are well machined. Sealers are only useful if you don't have a gasket or you're putting together a GM or Ford. 

 

NEVER use anything on a head gasket, this isn't the 1950s. Clean both surfaces thoroughly, the bolts and the threaded bolt holes. Torque all bolts to 20 then 40 then 60 ft pounds in this order from the center out...

 

R A D

8.....7

4.....3

2.....1

6.....5

10...9

 

If this is a Z24, once a year on a COLD engine loosen one bolt only and torque to 60 ft lbs. Then move to the next bolt. As only one bolt is loose at a time you can do in any order you like. On a Z24 this will prevent early blow out of the head gasket.

[OlDatZMan]

Thanks Mike. I had already already found what you wrote elsewhere and put in in a doc, especially the head bolt loosen/retighten stuff. I do pay attention. But I hadn't specifically found any mention of the int man coolant passages. Every place I looked yesterday and today, probably at least 40 people's accounts or preferences, used some kind of sealant, mostly blue rtv. OTOH virtually all of those were V8's or 6's. I didn't find a single inline engine account. Ok dry it is.

[Lockleaf]

I've installed 3 or 4 fel pro gaskets dry on these intakes and been leak free for years at a time.

[datzenmike]

I don't know if it's GM or the people that drive them or some mass hysteria about sealing gaskets, maybe some urban legend that sealer has to be used on things that don't need it but go into any wrecking yard where some red neck had dumped his Chev and it will have intakes, exhausts, thermostats, water pumps fuel pumps are covered in that blue RTV shit. Every bit you see on the outside has an equal amount squeezed into the inside. Rads and oil filters plugged with it.

 

Pulled this blue RTV 'worm' out of a KA head cooling passage. Must have been a GM owner too. If it has a gasket for it put it on dry... the maker did. Why would you think sealer would make it better?

 

[seattle smitty]

Well, OlDatZman, here's one lonely salute from another old guy who started his mechanical life using good ol' Permatex #2 to another.  And I STILL use it for some things, however politically incorrect it seems to be nowdays ("Oh no, are you still using that tarry, messy old black guck?!!  Haw, haw haw!!).  My regular application site for this or the "Aviation" brush-on version is the necks for radiator hoses, and other water hose fittings.  On old cars these surfaces are frequently pitted, so the #2 might help with sealing, but the main reason is that down the road that appliation of #2 will make the hoses a lot easier to remove.  

Another incorrect thing we used to do is "save" some gaskets if they weren't all torn up and getting or making a new one seemed like more trouble.  You'd ether wet down the gasket in a light oil (3-in-1 oil was the light oil we had before WD-40 came along) to make the old gasket swell a little, or you'd goop it up with #2.  Yup, I'll still do this, too.

[datzenmike]

I often take stuff off or replace before going to the store. No problem, I just cut my own gasket from a cereal box. Ball point pen, knife, scissors and a small hole punch. My thermostat housing was some left over gasket material but, thermostat cover, water pump and at least one of the fuel pump gaskets are home made from cereal box .... and no sealer whatever.

 

[seattle smitty]

 

 

 

 

But WHICH cereal box, Mike?  Captain Crunch would surely be a bad choice  .  .  .

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

b

[datzenmike]

I've had no problem with regular Cheerios but balk at the use of Shreddies. They just don't sound very reliable.

[seattle smitty]

When I was young and handsome, I raced outboard hydros (incl. once at Lac la Hache, B.C., and just missed a chance to race on Lake Cowichan, which might be near you),  and my preferred block-to-case gasket material for my 250cc Konig was the paper used to make airline schedules.

[datzenmike]

The L series oil pump gasket looks like waxed paper.

 

I don't remember ever being young...

[distributorguy]

I learned the hard way that applying a bit of #x sealant to water ports, even on a head gasket, is ok.  

I assembled a TR6 motor a few years ago and didn't do this.  On the pushrod side of the motor, despite both the head and the block being resurfaced, the gasket leaked oil.  Disassembled it all and had to remove a triple Weber setup, glued the gasket back in place, and it sealed.  You can say don't use #2 on a head gasket, which is fine, but there are times it would save your butt if you do and there's no down side, other than clean-up during the next rebuild.  But at least you won't have to clean up after all the leaks.  

[seattle smitty]

On 6/27/2018 at 4:25 PM, OlDatZMan said:

 So far I've seen these suggestions: no sealant, Indian Shellac, aluminum paint, silicone, absolutely no silicone, grey, black, and blue rtv, Permatex copper, the titanium version of JB Weld.

This line is still cracking me up.