Major problem sealing an intake manifold

[MarsChariot]

Today was my third attempt at running my new Ford crate 5.0 (GT-40 aluminum heads) and for the third time I had to shut down due to a coolant leak into the intake on the passenger’s side (clouds of billowing white vapor on the passenger side exhaust).

I’ve done many an intake manifold and usually get the water passages sealed, if there is a leak as there can be with Edelbrock Performer 289 aluminum intakes. (Incidentally I am running a carb until I finish cobbling together the remainder of the efi components, so that is in the works.)

Nothing I do seems to fix this one: I have read all the previous threads for insights on sealing issues; carefully thought through all the likely places things could go wrong with the particular head-intake combo; used the Ford Racing gaskets, the Fel Pro 1250 gasket; used hi-temp silicon on one side of the water passage, on both sides of the water passage; always torqued things in stages as per specs for the aluminum heads and intakes and re-torqued after a few hours just in case; all the usual gasket adhesives, including thick beads of silicon and thin beads of silicon sealer; used studs to carefully lower the intake into position; let it sit for day and let it sit for a couple of hours before adding coolant; checked to make sure the intake is “key stoning” into its seat squarely; checked to make sure the gasket adhesive is doing its job and that the gaskets are not moving or out of place; drained the oil and refilled with new filter to avoid contamination each time; and even got a new intake just in case there was a warp, crack, or machining problem with the previous one.

In short, I have carried out a pretty thorough program of experimentation for obtaining what I hope will be reproducible results. From try number one to try number three I have succeeded in getting the sealing problem to move from both sides to just the one side. But it still leaks. The last attempt was done with all the care of brain surgery. I am aware of how tricky intake sealing can be, but I think that I have used up all the likely options. More important, if this one is that tricky, I worry about ever removing it in the future for fear of not getting the magic sealing incantation back. If my program of analysis was not good enough by this point, I confess to being a little stumped.

I guess I am looking for some thinking outside the usual box.

 

[bronco italiano]

I am sure you did not use the front/rear cork gaskets. I must say that I too am perplexed as you have done just about everything. Did you try the gray gasket maker or ultra blue on the water passages? Did you use a cleaner tap on the intake threads? Did you check the cylinder head for squareness to the manifold? Please post your final results. It will be interesting to know. BI

 

[ken75ranger]

Your not the first one to have this problem. Mine was a vacuum leak though. See if you can find a local shop that carries Hylomar sealer. If not you can find it on line. The blue one is the one you want. Put it on both sides of the gasket and drop the manifold on it while it's wet.Torque it down and you should be good to go. Best damn sealer I have ever used. It never through hardens like RTV. It you do have to change gaskets the old stuff cleans off with laquer thinner. I think we have 3 members here had issues sealing up gt40 heads and Hylomar worked for all of us. I do prefer plain Mr Gasket intake manifold gaskets but any plain one should do. If you can't find the Hylomar local this is a good place to get it.
http://www.roverparts.com/Parts/901.cfm

 

[knack]

Since you mentioned that these are new parts - here's one more possibility: porosity in a cylinder head casting. There may be a unplanned for connection between the water jacket and an intake port. If the hole is big enough you might be able to see it or feel it.
Hope I'm wrong.
knack

 

[NMBronco77]

Any chance that your new equipment is just different enough that your bolts are now bottoming out, and when you torque them, you are actually just tightening them up against the bottom of the threaded holes? Just a thought.

 

[MarsChariot]

Thanks for the comments. I had assumed that Hylomar was not available. I have ordered some up and will give it a try. Is it used as a bead or is it spread on gasket surfaces? Yes, I usually use Mr. Gasket, but went with the Fel-Pro on try number three. Maybe I will also go with Mr. Gasket on try number four just to make sure I change multiple variables at once, in keeping with general practice(!).

Compression seems o.k. across the board, so I am assuming for the time being that the issue is between the water jacket and the intake. But if things keep going as they are, I will go deeper. The intake bolts are ARP stainless (wife said not to be cheap on a new crate engine) and I did check the installation depth. Yep, I have been very thorough, which is why this is more frustrating.

Another trip is coming up next week, so I will not be able to try again until after March 2. But I will post the results. This engine has been sitting since December all pretty and ready to go. The ’73 is atrting make noises with 6 months of continuous use, so I need to get the Chariot back in action.

Finally, when all is said and done, you have worry about why there is such a problem. No one seems to complain about the stock efi manifolds not sealing. Are the surfaces of the stock efi lower intakes machined very different than the carb aluminum intakes? I sure would like to know what that difference is. I hope that when I go efi in a few months, the problem will go away.

 

[Broncobowsher]

I'll attack this a little differently...

Have you pulled the plugs yet? can you idintify which cylinder(s) are eating coolant? I would find that interesting and it may change the direction that I search.

But on the hunt for the intake leak, it is a coolant problem. Have we tried to pressureize the cooling system and see where the coolant goes? Leave the carb offand peak into the runners. Sometimes you can get a fairly good fiew of the port and maybe the problem. Maybe it is a bad head gasket or mating surface?

If you already have your EFI intake, and are still questioning your coolant leak, try installing the EFI lower and pressurizing the coolant again. It has a better view of the ports. If the leak stopps with the EFI intake then you know it is the intake.

On older aluminium intake I have seen the aluminium eaten away on the inside and leak coolant into the engine. Could be the problem as well. Also known aluminium wheels the leak air through the porous casting.

If you are doing a misquito killer fog machine, it should be fairly easy to find the leak anter you pressurize the cooling system.

 

[ken75ranger]

Just spread the hylomar on real thin with your finger. Not a bead but a thin coating. I kind of like the flex you get with the plain Mr. Gasket add the stickyness of the hylomar and you can seal up almost anything. If you ever need a head gasket for those heads let me know I have a good one for you.

 

[76 bronco J]

--- I have some info on the subject & you are not alone plenty of people have had problems ,but seems more often when using the smaller stock style intakes such as the performer & even more so on the "X" head motor with it's 178cc intake runners versus the 160cc runners on the "Y" heads,,,,,I am also on my 3rd set of intake gaskets with the Y headed motor & the performer 289 intake,,,,fun ...fun right,,,,,, I have about 15,000 miles on the Y headed 5.0 motor so the #1250's didn't exactly fail immediately & I don't baby the motor,,,,, I didn't have coolant leaks ,but the more common problem according to ford & other people with the soft stlye gaskets shifting around or getting blown out from valley pressure or sucked in from vaccum ,,,,,since 2002-03 range ford has revised it's recommendation & say's now MUST use intake gasket part #M-9439-A50 with the X303 or Y303 heads,,,,,, I' ll list some part #'s to explain more-- following gaskets are made by Fel Pro(ford racing part #M-9439-A302 , ford racing#M-9439-B302, self branded #1250,& slightly bigger#1262) <these are all similar construction being 0.050" thick with black soft composite bodies & the printo seal beads,,,,,the previous gaskets mentioned were recommended by ford for years for the Y heads & for a short time when the X heads first came out ,,,,plenty are still using them however & 9 out 10 people still recommend them being unaware of ford's revision ,,,,the new gasket ford says to use part #M-9439-A50 has the following construction< 0.070 " thickness ,redesigned for improved port location and allows mild porting,teflon coated & steel reinforced with the printo seal beads,,,,, this new gasket produced by Fel Pro for ford specifically for the X & Y GT40 head applications appears to be a stock style hard blue gasket with larger almost 1262 openings & the printo seal beads usually only found on the soft black style gaskets & I couldn't & still can't find a part # directly from Fel Pro,,,,this gasket fits the head better than any other gaskets for the Y & X heads,but not really so much for the smaller performer 289 intake with the printo seal bead barely exposed however it has not had a leak for the last few thousand miles & has not shifted around or split being steel reinforced core,,,,,ford racing has a manifold part #M-9424-A321 which appears to be a really a edelbrock performer,,,,reason mentioned> ford racing has always not really recommended it for with use the Y heads ,but for some reason they have in quotes "does not fit GT40 "X" heads",,,,,, I like many used the performer 289 for throttle responce & I figured the E cam runs out at about 5,500 rpms anyway ,,,,, from research though it seems bigger runner manifolds such as the GT40 fuel injection,performer RPM,victor JR etc. really fit these heads better & the smaller runner manifolds are a always a compromise fit,,,,,, for installing here's my method-- place the manifold down on dry gaskets to view the gap at the each end of the intake valley to determine the bead thickness needed,,,,,I use latley a very very small amount of the "the right stuff " sealant around the coolant ports & use it for the valley end seals instead of silicon,,,the rest of the gasket has no additional sealant besides a little permatex to hold in place,,,if you put hylomar as suggested around the fuel/air ports be aware of the many overlaps & mismatch between gaskets & ports because the sealant can migrate everywhere including the backs of the intake valves & in the lifter valley,,,,between the fuel & vaccum situation no sealant around the fuel/air ports is really the better way to go,,, the new gaskets hold themself in position good with little sticky stuff in the middle area of the gasket when used with the torque to yield graphite head gaskets ,,,, to place down straight every time I like to use 4 long carb studs screwed in intake bolt holes while it placing down then removed after the intake is in position,,,, for the bolts I use permatex non-hardening sealant to allow repeaded retorques without breaking the seal,,,,speaking of retorque ,the factory ford production graphite head gaskets(really Fel pro's) that come on these aluminum 5.0 crate motors are used in conjunction with the ford factory production torque to yield bolts & are not supposed to be retorqued after running the engine,,,,,,,I'm still really not sure of the solution with all the conflicts ,but do some searches with the new gasket part #'s & putting in X ,Y headed 5.0 crate motor intake leaks etc. & maybe get to some discussions like I did ,,,,,,below are some pics 1. last #1250 that split 2 & 3. shows how new gasket is sitting 3. shows truck running today at around 900-950 rpms with 15 to 16 pounds of vaccum < this is normal with the "E "cam on a 302 & anyone with one can confirm that ,,,,,pic shown running to show even with the less than ideal printo seal beads showing there is no vaccum leak for some reason,,,,,side note> the E cam requires a minimum of 14 to 15 degrees intial timing while the total timing remains the same as stock & needs a quick ramp up to the 3 grand range,,,,, what does all this mean ,,,hell I don't know ,but like plenty I'm sick of constantly cracking open the motor,,,, the less than ideal look of the current gasket is staying for now since it's not leaking ,but like I said it seems the smaller runner intake are always going to be compromise fit on these heads...... anyway some food for thought above......................tired of typing will submit & edit later

 

[MarsChariot]

Thanks for the thoughts.
Broncobowsher: The plugs were fairly mute on which intake was offended with coolant. But my best guess last time was number 1, 4 and 8. This time I am suspecting number 1. It is a brand new intake, so I should not have any corrosion issues. If it is a bad head gasket (compression says otherwise) then FR is going to hear about it! And they will not need to be on a telephone.

ken75ranger: I will wait until the Hylomar arrives and try a dab on whatever gasket I try next. I always used Mr. Gasket before. Maybe that is next up to bat.

76 bronco : Thanks for the summary of your analysis. Well I am in for it now. As it happens the M-9439-A50 gasket is precisely the gasket I used on attempts number 1 and number 2, precisely because it was 0.070 thick- the thickest of the lot as far as I can tell. The picture you show shows exactly the same thing that I noticed: the top of the blue bead is exposed on the P side of the intake-head seal. When I looked at the seal line after I had disassembled it, there were microns of gasket between the intake and open air. So that is why I decided to ditch the M-9439-A50 and go with the 302 Fel-Pro Printo-Seal since the openings matched the Performer better. I have to say the that the M-9439-A50 certainly came off a lot easier. The Fel-Pro was a pain, half of it stuck as shredded paper to the head and causing about 45 minutes worth of extra work to get it off. Off as in “kind of’, too.

So now I am thinking of going back to the thicker M-9439-A50 ($33 a pop though as opposed to $18 for the Felpro) and slathering it with Hylomar and giving that a try.

What worries me is that even on the cast iron heads, the Performer gaskets would crap out unexpectedly, sometimes after a couple of years. Once after I had re-torqued it, the other after I hadn't. It was fortunately always when I was close to home or on crank up in the garage. My big concern is that it might suddenly decide to go belly up when I am to hell and gone in the middle of nowhere. When I think of some of the places that I have been…..

Which leads me to my Plan B: If try number four is unsuccessful, then I may ditch the carb and Performer and plow through to the EFI manifold. This thing has got to be dependable. That’s why I got the new engine, since I was always in fear of the tired old 302, which was making noises and leaking like a sieve, giving up when I am really out in the boonies.

Looks like my next attempt will be after March 2.

 

[kwspony]

Does your intake gasket have the small slits on the ends near the water jackets? I had the same issue on my 351. I had to go to a different gasket that only had openings for the runners and water jackets. It would leak either in the front or back depending on how I placed the gasket. The intake just wasn't long enough to cover the slits on both ends.

 

[bigmuddy]

I will through out using the great stuff sealer, never had a leak since using it with some good Fel-Pro gaskets.

Ben

 

[ken75ranger]

I agree with almost everthing 76 has to say except for the excess hylomar. There won't be any excess if you put it on the gasket. His pics of the motor looked exacty like mine when my 5.0 sucked air like Rosey O'Donnell suck doughnuts! I did swap my cam about a year after doing the intake with hylomar. It was nice to pull the intake off and just clean it up with a rag and some thinner.

 

[MarsChariot]

Kwspony: That doesn’t sound like any gasket I have tried…yet, if I understand correctly, so I guess the answer is no.
bigmuddy: The Fel-Pro certainly did a better job last go-around. But man I like the way the FR gaskets clean up.
Ken75ranger: So I will apply the Hylomar directly to the gasket next time. That was pretty much how I did the silicon and the gasket adhesive last time. And it seemed to help.

I am sure it will all become perfectly clear a week from now when I have another window of opportunity to work on this problem.

 

[MarsChariot]

As promised, upon return from my trip today I made attempt number four to crank and run my new 5.0 GT-40 aluminum head Ford racing crate motor. This time I went with a new Performer intake, new FR M-9439-A50 intake gasket (third set at 30 bucks a pop), and, Hylomar sealer all around. On the intake gasket this time I also trimmed 2 mm on the lower edge of the passenger side to bring the intake bead within the intake sealing surface (see pictures in post above).

On start-up there was no substantial change from the attempt number 3 (itself an improvement over attempts one and two), with white vapor exiting from the passenger side exhaust, and steadily increasing as the engine warmed up rather than going away. The drivers side was vapor-free. The aluminum x-head 5.0 crate just does not seem to like the aluminum carb intake. Even when successfully made to work, the word is that the intake seal appears to be tricky and temperamental. If anyone has ever gotten a Performer to mate up with an XE3M crate engine, now is the time to speak or forever remain silent.

So also as promised, after the fourth attempt, I am aborting efforts to use a carb and Performer intake on this engine and continuing through with EFI. The EFI-specific intakes are not known to have sealing problems with this engine, but the Performer does. So that’s it for the carb.

Meanwhile I have a brand new MSD Street (with vacuum advance) Pro-billet distributor with a new steel gear that will go up for sale to help fund the TFI distributor that I will need to replace it with. Likewise with two perfectly good Performer intakes. And a set of new Ford Racing aluminum valve covers, too. Look for those on the “for sale” area in the near future.

The engine looks pretty, but it just doesn’t run.

 

[ken75ranger]

Wow, that really sucks! I'd bet you have a head gasket problem at this point. Before you go to the EFI at least throw a straight edge across the mating surfaces. I'd hate to see you bolt up all the efi stuff and have to pull it all off again.

 

[needabronco]

Mars...,
I don't know if anybody has asked this yet, but I suppose that the block/heads were possibly shaved down to get the compression up, which could correspond to the need to have the intake trimmed the appropriate amount to match the mating surface. I know that you have a crate engine and everything is 'new', but it's an idea???

 

[DonsBolt]

Well I know what you mean about the performer intakes being a bitch to seal up to a Ford Racing Crate Motor. I also have a X headed crate Motor, and went through a simillar nightmare as you.

The real problem is no one makes a carb intake that matches up to the runners on the GT 40 heads. The older heads have a runner length of around 1.82-1.85 where the newer heads have a runner length of 2.11

I was able to get the performer 289 heads to seal of my X heads but it was a real pain. I never had the coolant sealing problems you had, but I had a hard time with vacuum leaks, and sealing the intake runners.

What worked for me was getting rid of the intake manifold bolts, and getting a set of ARP intake studs. Then using a set of gaskets with the smaller intake runner dimentions, I was able to get it to seal. I tried the Holimer sealant, but it didn't work well for me. I ended up using the gray RTV coating both sides of the gasket, around every hole. The studs allwed me to keep the gasket in place better, and also the studs torque a lot more consistantlly.

I wish you all the best, and know what your going through