intake leak

[sixty9cobra]

I have a Victor intake that was ported to match Survival cnc ported heads. While he was porting them, he broke into the pushrod tubes. He then I assume reamed the pushrod tubes and inserted steel tubes with epoxy.  I have been having oil consumption issues the past few years, initially it was good. Last yr i thought it was a gasket issue. This year I blanked off the carb with a plate and a Shrader fitting. I removed all the rocker arms. I then pressurized to 15psi, and it seems I'm getting leaks (bubbles) on two of the tubes. I know this is only half of the possibilities because I can't check the valley side with it on the engine. End result it has to come off and be repaired or replaced. Is epoxy a reasonable repair?  I have a 35yrs background in UHV vacuum and Particle Accelerators bla bla. I'm not sure how epoxy holds up an engine. My first feeling is remove it clean up the areas pull a vacuum on it and let it suck in the appropriate epoxy. Vacuum in UHV world gets baked to 200c we are only talking 200f here. Advice from the experts please. My other option is to replace the manifold. To toss this manifold would be tossing a lot of $. I have videos of the leaks but its just bubbles.

[jayb]

Harry I think epoxy would be fine for that, but I would use JB Weld, not some other brand.  I've had really, really good luck with JB weld over the years, even fixing fuel leaks in blocks and fittings.  Not sure the standard hardware store stuff would be up to the drill.

[sixty9cobra]

Is the different JB weld than the hardware store brand? Or are you talking about hardware brand 5 min epoxy? i know they make high temp 5 min epioxy i used it on my snowmobile heated grips.

[Barry_R]

I've used JB Weld or Splash Zone marine epoxy for that task many times with good success.

[fekbmax]

+3 on JB weld or splash zone.

[sixty9cobra]

I found splash zone and a bunch of JB weld. Is this the right JB weld? looks like splash zone is 80 bucks for a quart. JB weld 8.99  I am not worried about the price at this point just getting the right stuff.

[70tp]

From my experience, most or all quick set epoxies don’t set up as hard and strong as the slow set ones .   And also, over time, the slow set seems to soften also. 

[fekbmax]

I have done several intakes with the tried and true original JB weld over the years. I have an old port O sonic that I did 8 pushrod tube's in over 30 years ago, ran it hard for 5 years or so and wouldn't hesitate to put it back on an engine now.

[My427stang]

I am a JB Weld fan as well, just the old original 2 tube stuff as above.  Get it really clean and put it together.

[Joe-JDC]

First, don't use steel in an aluminum intake manifold, it does expand and shrink at a different level from the aluminum and will separate after a bit of time.  I always use either aluminum tubing or brass tubing for pushrod tubes.  Clean the pushrod hole completely with a rough grit sandpaper roll and give it a texture to hold the epoxy.  I bevel the top and bottom of the hole to pond a bit of epoxy at both ends of the new tube.  Clean the tube exterior and rough up the exterior with a coarse sandpaper.  Clean the pushrod tube with acetone or lacquer thinner and the exterior of the tube you are going to insert.  Coat the complete interior of the pushrod tube hole and coat the exterior of the tube with the JB Weld, and twist the tube as you insert it into the pushrod hole so that it gets a complete coverage of the tube and hole as it slides into place.  Place the manifold in a position so that the tube is level with the table/floor and let it set up/dry in a level position.  When it is dry, clean the interior of the tube where the epoxy may have spilled over, and blend the ends to the manifold.  The bevel you did at the beginning should have a good bed of epoxy to seal up both ends and there should be no leaks in the future.  This method has worked for me for over 30 years using JB Weld epoxy.   Aluminum tubing comes in .035 wall thickness, brass can be had in .015" wall thickness and diameters within 1/64" of the pushrod hole diameter.   Joe-JDC

[Stangman]

Which JB weld do you use Joe.

[sixty9cobra]

I wonder if it’s worth it to remove the steel tubes and have someone tig weld up the runners where the pushrod tubes are broken thru. A  few people including my wife say just get another manifold. Joes point about the expansion rates bothers me. Another option is to take out all the tubes and replace with aluminum or brass. I think this option has the potential to become a disaster. The last option is to just fix the leaky tubes and run it. Manifold was done in 2018 it lasted 4 or 5 yrs before it started consuming a quart every 2 or 300 miles. there is wet oil in the tailpipes.

[Joe-JDC]

Are you sure it is a pushrod tube leaking?  What intake gaskets were you using?  Hopefully not the Fel Pro Printo-0-seal.  They deteriorate after a few years and leak terribly.  Also, did you do a leak down test, compression test, to be sure it was not guides, or ring seal?   A leaking pushrod tube should cause the engine to run rough and sound like a vacuum leak if it is leaking that much oil.   The Victor can be ported to match the Survival heads without needing tubes and still flow close to 500 cfm.  Joe-JDC

[sixty9cobra]

    Hi Joe I had the manifold off last year and replaced the intake gaskets which were pintoleaks with Barrys black gaskets that he has made. That did solve some oil consumption on DeCell. This year I took off the carb, put a plate on with a Shrader fitting. Removed the rockers and pressurized to 15 20 psi. Applied leak tech to the tube and saw at least 2 leaking on the valve cover side of the manifold. One has a bubble every few seconds the other has constant bubbles in a few places. I have no idea what's happening on the underside yet. No leak down motor is fairly fresh less than 7k miles. There could be other issues but this is the first i found.

[sixty9cobra]

     I have an update I got all 16 tubes out they were only epoxied on the ends. They are .625 O.D. and .555 ID 3.5 inches long.  Should I use 6061 aluminum?  72 inches is 48 bucks delivered.