another one bites the dust (intake gasket failure)

Foghorn · #1 (**permalink**) 05-08-2011, 07:24 PM

First session on day two of the spring meeting of the Cobra Owners club at Willow Springs. Lots of white smoke from the right sidepipe....

Initial inspection upon pulling the right valve cover, it appears to be that side intake gasket. More to follow after I remove the intake tomorrow evening.

Racer_X · #2 (**permalink**) 05-08-2011, 08:42 PM

What type of gaskets? Fel-pro?? Alum. heads, alum. intake? Was anything shaved or changed from factory "as delivered" configurations?

JDwithSC · #3 (**permalink**) 05-10-2011, 07:25 PM

Very curious myself as I have a Keith Craft aluminum Pond 482 with about 4,800 miles on it. Most are telling me that if nothing has happened yet, don't mess with it. I hope it works out without any major internal damage.

4pipes · #4 (**permalink**) 05-10-2011, 07:46 PM

What? No hydro- lock? Amateur.

Rick Parker · #5 (**permalink**) 05-10-2011, 08:11 PM

Based on 4pipes comments ....count your blessings.

RON N BKFLD · #6 (**permalink**) 05-10-2011, 08:52 PM

Yeah, my dash camera got you being towed in as I was getting off the track. (in the Bondurant mustang). Glad you figured it out and it wasn't the head gasget............Ron

Foghorn · #7 (**permalink**) 05-10-2011, 10:47 PM

Started the investigation this evening. No oil in the coolant, and no coolant in the oil. Coolant in several cylinders, not limited to one side. The #1 cylinder pumped the more coolant out than any of the others. I pulled all the plugs, squirted all the cylinders with Marvel Mystery Oil, and turned the engine several times by hand, pumping the MMO out through the plug holes. I repeated this process three times. That is as far as I made it tonight. Tomorrow, my goal is to get the intake removed and see if I can locate the actual failure.

I have drained the oil (no water!). I am planning a flush by running the oil pump with a drill and draining it again. I am hopeful that I didn't hurt the bottom end. FWIW, the gasket failed between shifts, so I wasn't full throttle. That may have made the difference. Or just caused enough damage that it will run fine for awhile and really make a mess when it goes.....

Racer X: Don't know what brand gaskets. Shelby block, e'bock heads, Blue Thunder hi-rise dual-plane intake. It's a KC crate engine, built in the summer of '07, although I didn't get it running until June of last year (properly stored, turned occassionally by hand & primed before the initial start-up). I have 1500 miles on it with no more than 100 heat cycles. Three oil changes. The hottest it has ever been was 95C. During the track day, it was holding a steady 80C and 60-80 psi oil pressure all day Saturday.

More to follow.

FWB · #8 (**permalink**) 05-11-2011, 06:08 AM

sounds like the gasket failed at the coolant passage in the front, letting water seep into #1 runner, get a good set of replacement gaskets from keith and use motorcraft diesel sealant on them and you should be good to go.
been there....this will be a good time to check to see if any pushrods are rubbing the intake too........this was causing issues with mine.....16 sticks pushing on the intake doesn't make for a good seal......

fred

Keithc8 · #9 (**permalink**) 05-16-2011, 09:05 PM

Yes we have had a few problmes with the Fel-pro gaskets from a few years ago. It seams that the pressure and the anti-freeze cause a problem at the end ports like 1,4,5 and 8. Used these for 10 years with no problem and then over about a 2 year period we had prbomes with them. I know that some things were changed in the anti-freeze and it seems to eat on the gaskets and make them soft and even push out.
We have special gaskets made by Cometic to fit the heads better and that will hold up to the anti-freeze. The Victor intake gaskets seem to work pretty well but do not match the heads very well.
I am sure the gasket moved and let water into the intake port and then it put it through out the engine. Give Tony or Lance a call and we will get you some of the new gaskets. We have also been used distilled water with anti-freezes made for aluminum blocks and heads. We have found in some of our race engines that even the tap water eats on the head gaskets as well. The chemicals vary in the water from area to area. The new gaskets have been working great since we have started using them about a year or so ago.

Thanks, Keith

Foghorn · #10 (**permalink**) 05-17-2011, 01:16 PM

Finally removed the intake manifold last night. The intake gasket was the culprit - it failed on the right side between the front coolant passage and the number one cylinder. I have pictures, but my computer is not downloading them - I will post them as soon as I solve that problem.

Disclaimer: What follows is NOT an indictment of Keith's ability to build a quality engine, nor an indictment of his business practices. However, it IS an observation based on findings from disassembling my engine. I do not engage in the practice of "throwing my trash in the street" or publicly slandering an individual or business. Any dissatisfaction I have with the engine that I bought from Keith will be addressed with Keith in person and not online in a public forum.

The intake manifold gaskets Keith used in assembling this engine are horrible. The dimensions of the gaskets don't match the heads / intake. The locations of the bolt holes in relation to the intake tract holes and coolant passage holes are not dimensionally accurate causing the gasket to shift when the intake manifold is installed. The gasket material between the #1 cylinder and the front water passage is approx. 3/8" wide, yet only about 25% of that was actually sealing (this characteristic is the same on the left side, but it had not failed - yet). The rest of the gasket material was blocking the #1 cylinder intake tract. I don't know the gasket manufacturer (the material appears to be graphite impreganted paper) but whatever template they used to manufacture this gasket is incorrect in several of its dimensions. This gasket would have failed at some point, regardless of how the engine was operated or coolant used.

More to follow.

car4jim · #11 (**permalink**) 05-17-2011, 06:07 PM

Same problem with my K.C big block. Follow Keiths advise and get the gaskets he recommends and you'll be gold!

olddog · #12 (**permalink**) 05-17-2011, 06:42 PM

Just realize that the size and shape of the gasket now, may not be the same as it was when it was assembled. Things shrink, stretch, and extrude.

Foghorn · #13 (**permalink**) 05-17-2011, 10:06 PM

Olddog: touche'!! a very valid point...and hence why I don't "throw my trash in the street". we all know what observations and opinions are like...

That said, here are the pictures that I spoke of earlier:

I couldn't get quality pictures of the gasket while the intake was still installed (poor lighting, iPhone camera), but it was obvious that there was fitment issues. I would have to say a combination of poor manufacturing and slippage once installed. The holes in the gasket for the bolts were elongated and the unclamped portions of the gasket between the ports was bowed away from the head.

I have spoken with Keith's boys, and will snag a set of the Cometic custom gaskets as soon as they're available.

RICK LAKE · #14 (**permalink**) 05-18-2011, 03:31 AM

Foghorn I make a living working on cars, not building motors. I have done well over 300 motors in my last 28 years as a double master tech for GM. I am old school. KCR builds some of the most power per dollar HP motors in the FE family. 15 years of racing both with the cobra, and 1/4 mile cars with friends. Some motors are aluminum heads and iron blocks, some are all aluminum. I am sure the KCR does a gasket match before assembly of the motor.
Here where we differ,ALL my gaskets get either 1 or 2 coats of a sealer like HIGH-TAC, COPPER SEALER, and RTV on both sides of the gaskets and allowed to skin before installing and get 24 hours to totally set. Down side is if you are pulling heads or intakes alot, ( can't see why ) then I only coat 1 side of the gasket for sealing. The cleaning of surfaces takes time and is a pain. If using the correct tools to remove the old material like plastic looking razor blades and the correct 3m discs, (blue) you should have little to no damage of surfaces when done cleaning. IMO glueing gaskets stops 95% of the heat cycle problem. Gald KCR has gottin you new gaskets, who they seal better than the old ones. I think that the reason the gasket blew in was because of high coolant pressure from racing. Gald no damage was done to motor except for this. Weakest link in the chain goes first. Rick L.

MOTORHEAD · #15 (**permalink**) 05-18-2011, 04:53 AM

Foghorn:
The FE intakes present a unique fitment problem because the intake bolts enter the head at a 90* angle as opposed to vertical as are the small blocks. Thus when tightening them, the bolts are pulling the intake toward the heads and in opposite directions, one side to the other. With intake bolts going down vertically, the intake is drawn tighter as you tighten them, as the angle of the intake and head interface causes a "wedge" effect that squeezes the gasket tightly.
Barry R at Survival Motorsports has a book available that covers FE assembly, and has a lengthly procedure about measuring the intake to head fittment prior to assembly so that the chance for leaky gaskets ( or cracked manifold) is minimalized. It's a must have for anyone building an FE. (IMHO)
Ted

Dons427 · #16 (**permalink**) 03-23-2012, 08:22 AM

Quote:

Originally Posted by Foghorn

Finally removed the intake manifold last night. The intake gasket was the culprit - it failed on the right side between the front coolant passage and the number one cylinder. I have pictures, but my computer is not downloading them - I will post them as soon as I solve that problem.

Disclaimer: What follows is NOT an indictment of Keith's ability to build a quality engine, nor an indictment of his business practices. However, it IS an observation based on findings from disassembling my engine. I do not engage in the practice of "throwing my trash in the street" or publicly slandering an individual or business. Any dissatisfaction I have with the engine that I bought from Keith will be addressed with Keith in person and not online in a public forum.

The intake manifold gaskets Keith used in assembling this engine are horrible. The dimensions of the gaskets don't match the heads / intake. The locations of the bolt holes in relation to the intake tract holes and coolant passage holes are not dimensionally accurate causing the gasket to shift when the intake manifold is installed. The gasket material between the #1 cylinder and the front water passage is approx. 3/8" wide, yet only about 25% of that was actually sealing (this characteristic is the same on the left side, but it had not failed - yet). The rest of the gasket material was blocking the #1 cylinder intake tract. I don't know the gasket manufacturer (the material appears to be graphite impreganted paper) but whatever template they used to manufacture this gasket is incorrect in several of its dimensions. This gasket would have failed at some point, regardless of how the engine was operated or coolant used.

More to follow.

WOW! you have just described the exact same issue that I had with my 428 FE with 600 miles on it!
I had vanilla pudding on the underside of the valve covers and the intake manifold.
This was awful to deal with and the fear of rod or main bearing wash-out.

Dons427 · #17 (**permalink**) 03-23-2012, 08:25 AM

My engine builder; bill carlquist has a method of measuring the thickness of used gaskets, tp to bottom; so he knows if the angle milled on th eintake is a correct match to the cyl. heads



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