Front "China wall" sealing issue on SBM

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Yeah. It's pretty tough. But if you want something to STICK, it works.
Use the"Monkey Snot" on the part you can remove the gasket with power tools. You never stick a valve cover gasket to the head, you always stick it to the cover and you can scrape it off and finish up with a wire wheel on a bench grinder. Don't you know that? Like a t-stat gasket, stick it to the housing not the intake.
 
Use the"Monkey Snot" on the part you can remove the gasket with power tools. You never stick a valve cover gasket to the head, you always stick it to the cover and you can scrape it off and finish up with a wire wheel on a bench grinder. Don't you know that? Like a t-stat gasket, stick it to the housing not the intake.
Don't "I" know that? Yeah, I think after forty plus years I do. Who said anything about sticking anything to the head? Other than you? I always use a razor blade scraper to remove it. Usually it gets right under it and cuts it right off.
 
Don't "I" know that? Yeah, I think after forty plus years I do. Who said anything about sticking anything to the head? Other than you? I always use a razor blade scraper to remove it. Usually it gets right under it and cuts it right off.
Post #13 above

"If you use anything use something like 3M yellow weatherstrip adhesive and glue the cork to the block with nothing on top of the cork."
 
Post #13 above

"If you use anything use something like 3M yellow weatherstrip adhesive and glue the cork to the block with nothing on top of the cork."
I was talking about the cork intake seals. Not valve cover gaskets.
 
That engine either has a ton of blow by .. 'let me clarify...no breather or pcv' or you can just simply spray some brake cleaner where it leaks and squirt some more RTV into the crack
 
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I would like to out that the intake china walls do not exactly match the block. Second, what could be an intake leak might actually be an oil sending unit, the threads that it screws into leaking, or fittings used to mount the feed line to a manual gauge.
 
If I did go with the cork gaskets I wasn't planning to put silicone on the whole thing, just some globs in on the edges where the heads/block/intake meet.

Next time I run the engine I'll pull the PCV valve and breather from the valve covers and watch for how much blowby it has once it's warmed up. I'd hope not a ton, the short block I assumed to be high-mileage since it came out of a smashed-up 2000 Ram pickup at a junkyard but the cylinders still had significant cross-hatching left with no ridge to speak of at the top. The oil also looked and smelled fairly fresh and there was no sludge buildup anywhere inside so I'd like to think it was maintained well.

I'm thinking it needs a better (higher-flowing) breather as the one on it now seems kind of restrictive, it's one of the cheaper ones with the foam and a 1/2" or 5/8" fitting to go the air cleaner. Speaking of which I also need a proper air cleaner base with the fitting for the PCV breather, the current one just has a hole I've covered up with heavy tape and the breather is just open to the engine bay.

@dano the leak is only coming from the front china wall, not the rear. Fortunately the upper rear of the engine is dry as a bone.
 
Nothing new to offer... I use Black RTV (by permatex) "Max Oil Resistant". 3/8 bead across the china walls, and a heavier dab in all 4 corners. Never a leak.
 
Nothing new to offer... I use Black RTV (by permatex) "Max Oil Resistant". 3/8 bead across the china walls, and a heavier dab in all 4 corners. Never a leak.

I've put together a good few SBMs and never had this problem before which is why it's annoying. The 360 in my truck has a Performer intake and that hasn't leaked at all in the 3+ years it's been together but that has factory iron heads. The weird thing is both times I've sealed this 5.9/360 it leaks from the exact same spot, the passenger side of the front china wall.

To further address the blowby concerns the engine runs like an absolute champ, I had it chassis dyno'd back in Colorado and it made 286 HP to the rear wheels uncorrected which is pretty spot-on for this combo. After getting it re-tuned for lower altitude here in Georgia it now spins the tires all the way through 1st gear and will break them loose even from a roll until I either let off or shift to 2nd and that's with 3.55 gears, fresh Sure-Grip and 275-wide ultra-high-performance Continental tires. It frickin' rips and I need to have my wits about me before flooring the gas pedal.
 
Even if the engine has some blow by the PCV system should handle it. It look like you have a lot of pressure inside the block to push that much oil out, that high in the block. You might want to see how much vacuum you are getting from the PCV. The inside of the block should ideally have a slight negative pressure from the PCV system, at which point oil wouldn't come out even if there was a slight leak in that seal.
 
Even if the engine has some blow by the PCV system should handle it. It look like you have a lot of pressure inside the block to push that much oil out, that high in the block. You might want to see how much vacuum you are getting from the PCV. The inside of the block should ideally have a slight negative pressure from the PCV system, at which point oil wouldn't come out even if there was a slight leak in that seal.

Noted, again though it only leaks when I'm hammering on the engine repeatedly at high RPM, like above 4,000. When cruising around or even occasionally stomping on the gas and running through the gears very minimal oil leaks out. It happened the most at track days when I'd be going around a tight course in 1st gear (2.94 rear gears back then) and go to redline (5,500-6,000) at WOT on the final straightaway; I'd get back to the staging lanes and notice a small puddle of oil on top of the timing cover.
 
Like @George Jets said in reply # 23, I cut those tabs off at deck height so the RTV will be able to get all the way in the corners. Clean, clean, clean it all good before you start back together with it and hopefully the 'Right Stuff' will solve your problem.
 
I wouldn’t use cork at all. They always leak. Just use right stuff and it will seal.

Exactly what I did just last night. After every couple passes at the track enough oil would seep out from the front and sit on the top of the timing cover to need to dab up with a paper towel.

Took some right stuff, gooped it on and spread it smoothly across with my finger. After cleaning with brake clean and getting it dry
let it sit and hour and a half, pulled car back in my bay. It sets up that quick.
unless you have a big gap and serious figment issues, this stuff should fix you up. Love it, but not cheap, 3 oz tube was like 18 bucks
 
Well thanks to a fellow FABO member @416stroker it's obvious now why I couldn't get it to seal. It's not a simple issue of my methods being wrong because like I said I've swapped intake manifolds on small blocks at least 10 times and only ever had a sealing issue on this engine. It turns out the underside of the intake manifold on that passenger side front corner doesn't have a wide enough "flange" to seal up against the block and head in that area with this specific combo of parts. The pics he shared with me explain it all...

block area.jpg


intake area 2.jpg


Intake area.jpg


What's odd is I once ran an RPM Air-Gap on a 360 LA block with factory iron Magnum heads and didn't have this issue but maybe I just got lucky or didn't notice it as much lol. Oh well at least now I know!
 
Well thanks to a fellow FABO member @416stroker it's obvious now why I couldn't get it to seal. It's not a simple issue of my methods being wrong because like I said I've swapped intake manifolds on small blocks at least 10 times and only ever had a sealing issue on this engine. It turns out the underside of the intake manifold on that passenger side front corner doesn't have a wide enough "flange" to seal up against the block and head in that area with this specific combo of parts. The pics he shared with me explain it all...

View attachment 1716089170

View attachment 1716089171

View attachment 1716089172

What's odd is I once ran an RPM Air-Gap on a 360 LA block with factory iron Magnum heads and didn't have this issue but maybe I just got lucky or didn't notice it as much lol. Oh well at least now I know!
I would contact the manufacturer and show them what's up. With that design you aren't the only one with the issue. Possibly they caught the issue and made a production change to correct it. You could have bought a early manifold.
 
I use cork, RTV in down on the block and let it set up overnight. Then RTV the top of cork and I lightly put some on intake and don't forget the corners.
 
Lol
Never had cork leak after an intake install. Best cork versions were the Felpros with the.....never mind^^^^^^^^. In lieu of that some spray adhesive works if the gaskets don’t have the adhesive (block side only) China walls need to be degreased thoroughly before affixing. Then RTV black in the corners. There’s a difference between correct (sparingly) use of the RTV and over application in some cases.

Don’t go cutting the end of the tube off and using your elbow to spread it. (Just an expression we used in my construction days using caulk doing siding, kitchens and baths) :eek:
You mean a Virginia Joint. Leave 1/2" fer caulk in yr stain grade millwork!
 
Speaking of which I also need a proper air cleaner base with the fitting for the PCV breather, the current one just has a hole I've covered up with heavy tape and the breather is just open to the engine bay.
the pcv should be connected to manifold vacuum not the air cleaner. the breather from the other valve cover goes to the air cleaner base.
 
Lol

You mean a Virginia Joint. Leave 1/2" fer caulk in yr stain grade millwork!
Exactly. I learned early on all about laying down one smooth thin bead vs. a bead that looked like a long lumpy weld. One exterior wood trim company crew I worked with we used to fill up big *** knot holes on the boards, that was what we called “schmoo it” and we also used to sing this song when an installer asked if he should caulk big gaps or holes. As our dear leader often says “Not A Joke”....

 
I used that on a cork oil pan gasket on the first 383 I built. When I had to tear it back down later I had a heck of a time getting the remains of the gasket and cement off the block. I haven't used in the 45 years since.
If you think that cork was hard to remove, wait until you get ahold of an engine assembled with the right stuff, honda bond, or similar gasket maker. Damn near need an air chisel to the the stuff back apart.
 
If you think that cork was hard to remove, wait until you get ahold of an engine assembled with the right stuff, honda bond, or similar gasket maker. Damn near need an air chisel to the the stuff back apart.
Yep.
 
Stuff is great until it needs to be disassembled. Had to take a stiff sharp putty knife and a hammer to get the oil pan and timing cover off of a blueprint stroker motor I tore down. It was the first time I had come across it and thought it might have been windshield urethane until I checked into it.
 
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