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#1
08-08-2005, 06:03 PM
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How to stop/fix intake crossover cracking??
I have two Performer intakes that are cracked in almost the identical place. The first is mine that I have had for almost 16 years and the other I recently got as part of a carb/intake deal. The intake I got in the recent deal had been repaired (welded) and was cracking again in the same area. What can I do to fix the current cracked intakes (welding, JB weld, etc).
Also, how can I keep from cracking my current Performer and Performer RPM manifolds that are still in good shape? Is filling the head with lead the only solution? I have a 400 and a 455, live in the northwest where it does get a little cold a times. I use an electric choke quadrajet on both cars and would like to prevent any further problems without pulling off 4 heads to fix any future cracks. Any thoughts or ideas are appreciated! Thanks Michael |
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#2
08-08-2005, 08:24 PM
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DO NOT fill the head with lead. You get that baby hot and your looking at lead all in your motor. Put something in the port that has a high resistance to heat the way you want it to block off. Find an old junk aluminum piston and melt it using a cutting torch and fill your port with it.
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#3
08-08-2005, 09:25 PM
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Thanks for catching that!! Lead vs aluminum......too dang hot outside to think straight right now and let my mind and fingers catch up with each other to let you know what I actually meant!!
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#4
08-09-2005, 07:56 AM
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Overtightening causes cracking. The alum intakes takes ALOT less bolt torque than the stock intake. Install the intake & run the engine/drive the car. When it is cold, re-torque the bolts. I just snug them. Drive the car for a few days & check the bolts again when cold & then leave it.
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#5
08-09-2005, 09:32 AM
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Where is it cracked at? I bet on the bottom where the heat crossover is, right? Then its not from overtightening, but from heat and maybe a poor design. Filling your head may be the only permanent solution. If your not using the heat from the crossover you should be ok. The only drawback is that your car may be a bit coldblooded after startup.
__________________
North Dakotas fastest REAL GTO 10.10 @ 131 MPH in the 1/4 Hoping to get it back together some year. www.jandjrepairandrestoration |
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#6
08-09-2005, 10:45 AM
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Yes, both cracks are on the underside of the intake on the heat crossover side or "edge" where the crossover passage meets the rest of the intake. I believe it is from many many heat cycles that ultimately did my and the other intake in.
What I am concerned about is that they both cracked in pretty much the same place on the intakes to begin with but on different engines driven in different parts of the country. One has been welded (likely for pretty good money) and it cracked again in the welded area. Just want to prevent it on my good intakes and possibly fix the cracked intakes if possible. Someone in the past mentioned JB weld or other fixes that might work. Any ideas? It is all under the intake and cannot be seen when on the motor so only I will know what has happened. Thanks |
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#7
08-09-2005, 10:51 AM
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please dont use lead!!!!!!
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#8
08-09-2005, 11:40 AM
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Cracking is due to a faulty design and high heat.
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#9
08-09-2005, 02:32 PM
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Ok, as I said, I was thinking aluminum but wrote lead. My mistake....won't be using lead.
 So heat is the killer of my intakes, what can be done to stop it from cracking my good intakes and what can be done to fix my cracked intakes if welding doesn't seem to work??? I don't want to crack more intakes and it would be nice to fix the cracked intakes correctly for use later on or to sell. Is filling the head the only fix/cure? Are the RPM and HSD intakes as prone to cracking as the performer? Thanks |
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#10
08-12-2005, 07:35 AM
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The manifold cracks where there is the greatest concentration of stress. As I said prieviously, overtightening causes cracking. Poor design may well contribute to the problem, but I use the same intakes & they don't crack??? Because of the different expansion rate of alum & iron, you have to allow the intake to 'move' & you do that by not overtightening. I have been installing alum intakes for 30 years with no problems.
This is what the Edelbrock instructions said with one of their intakes: CAUTION: Do not over-tighten as warpage or even breakage can occur. After engine has been warmed up, run, shut off & after having set overnight, RETORQUE WITH ENGINE COLD. [ 25 FT/LBS]. |
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