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Cometic Intake Gasket

5K views 31 replies 10 participants last post by  luv2rock 
#1 ·
I bought a second set of cometic intake gaskets after having my first set fail. It develop a vacuum leak that was throwing the AFRs haywire and oil was being sucked in as well.
Now, these gaskets state that retorque and additional sealants aren’t required, except in a street application a slight RTV around the water ports is recommended. So I didn’t retorqued or used Gasgacinch, but I did use some RTV. I tried to retorque after driving for a while, but it actually got worse.

Has anyone used them successfully? Should I use Gasgacinch and retorque even does it says is not needed?
Thanks in advance for any input.
 
#2 ·
Use Explorer gaskets or Fel-Pro 1262-S3 intake gaskets. Use a small amount of the Right Stuff around the water ports and in the corners where the heads meet the end rails. I Gaskesinch my intake gaskets in place first. It helps to keep them from moving around. You definitely need to retorque after some heat cycles.
Also; check lower intake fitment to heads. Is there more gap one one side or the other? What are you using on the end rails? Cork gasket or the Right Stuff?
 
#3 ·
Lower fitment to the heads is perfect with these gaskets. Thicker than average and helps with the port alignment. I just use RTV ultra black at the end rails, which is what the engine builder recommended.
 
#4 ·
I had bought an Edelbrock rpm intake a few months after they had came out and done everything by spec when I installed it,including a retorque after the first heat cycle.Weeks later,my coolant level began to drop,but external leaks were not present.I checked the oil and sure enough,it looked like a milkshake,so I assumed I must have done something wrong during the installation.I drained the oil and reinstalled a new intake gasket along with a new oil filter and oil.Once again,weeks later,the coolant level began to drop and after checking the oil,the milkshake was present again.So I knew I couldn't have done a bad install twice,so I pulled the intake and took it to the machine shop.Turns out,a couple of the passages were out by 0.90" on both banks of the intake & coolant was escaping around these areas.This was a brand new intake too.So before you install a new gasket,make sure to check the intake with a straight edge at least.Im not sure of the maximum allowable amount an intake can have,before leaking will occur,but it wouldn't hurt to give yours a quick check.Was it obvious where the leak occurred once you got the intake removed?? What did you use at the end rails?? Cork,rubber or rtv?? Another thing I like to do for an intake install is to buy 6 bolts that are the same thread and pitch as the intake bolts,but much longer in length (3") I screw them into place,1 at each corner of the intake and 1 in the middle on both sides.Then lay the gaskets in place over these bolts,lay whichever type of end rail gaskets you're using in place and lower the intake into place.Install all of the oem size bolts in every empty bolt hole,then remove 1 of the 6 long bolts,replace it with a oem size bolt then do the same to the remaining long bolts.This will prevent the gaskets from moving around.If you're using the original intake bolts or cheap bolts,I recommend that you replace them with ARP or something similar.Ive had numerous broken intake bolts from reusing them more than once.
 
#5 ·
It was obviously leaking within the ports on the lower part. I believe it was due to not retorquing the bolts within a couple of heat cycles. The bolts were loose when I finally check them, but it was too late. I use rtv on the end rails and I’ve never had an issue on that area. I was using arp bolts and now I’m switching to studs.
I read about the long guiding bolts before. I’m going to check with a straight edge.
 
#6 ·
you guys do know that car manufactures put bar's leak tablets in these cars straight from the factory

the parts were new then, just think what kind of warpage these inatakes have being used
 
#9 ·
I’ve been reading other threads about intake gaskets leaking and I’m starting to believe that over torque is one of the main reason the gaskets fail. Edelbrock and FRPP recommends only 18 ft pounds max. AFR recommends hand tight with a 1/4” ratchet if possible. However, most torque specs flowing around suggest 22-24 ft pounds. The later is what I used and when I retorqued I could see the gaskets creeping down and the leak got a lot worse. So this time I’m going to try 18 ft pounds max. One good heat cycle and retorque again. I may even do another retorque after a couple of weeks.
 
#12 ·
I re-ringed my engine at 112k. When i assembled it, I used 1250 S3 gaskets that I had on an kenny bell boosted engine with different heads and a different intake. After assembly, and a few miles, coolant was leaking from the intake and pooling on the timing cover. I dropped in some bar's leak, and today it is still not leaking with 196k...Besides the water pumps I have put on anyways
 
#16 ·
I bought the gaskets from Ed at FTI. I think I’m going to see him tomorrow or Saturday at the NMRA event so I’m going to ask for his advice. Unless someone else has any experience with them.
 
#17 ·
I've been using Cometics for several years now. No issues and certainly a huge improvement over FelPro 1262.

For your issue, I'd check the angle of the intake port face and heads and make sure they're parallel.
 
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#19 ·
What torque spec do you use? I haven't been able to find a spec for the cometics. It's what I'm using, and no issue so far, but I am curious.
For reference only, here's the part number I used. Cometic C5652-060
 
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#21 ·
In order of what I do, VERY thin coat of ultrablack around water port, either on gasket or head, your choice. 3 dots of 3m adhesive, place on head with hand pressure for 30 seconds, VERY thin coat of ultra black around water port on gasket. Lay down the needed bead of ultra black on end seals. Place intake and tighten. You will need to tighten the intake bolts 3-4 times after heat cycles due to the gasket becoming compressed with heat cycles. 90% of leaks are because the gasket compressed and the bolts were never tightened after the initial time.
 
#23 ·
Awesome. Thank you so much!

I did check the mating surfaces for warp and laid the intake on the heads without gaskets and it was perfect with no gaps.

So you recommend retorque 3-4 times after initial install? Meaning removal of the upper plenum 3-4 times or going through the torque sequence 3-4 times after some heat cycles?
 
#26 ·
I can see that. I’m going to do a good heat cycle and retorque the next day after a good cool down.

Any input on doing the torque again after say a couple of weeks?

Thank you for your help! I know you have a busy shop to take care of.
 
#32 ·
I use to curse and sling tools everytime I had to remove the upper when I bought the first rpm intake Edelbrock came out with.You had to remove the side cover to install a bolt on the inside of the intake.Long curved needlenose pliers were helpful,but it was still a pain.
 
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