Re: Switch from 10-30 to 20-50 pressure change?
[Re: Cab_Burge]
#1659158
08/25/14 08:03 PM
08/25/14 08:03 PM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
OP
super stock
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OP
super stock
Joined: Mar 2010
Posts: 984
Tennessee
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Quote:
If it was square on all four corners, the exact same measureemnt on the top and bottom on both sides I would try the .090 If it wasn't square, especially if wider on the bottom than the top, I would have the intake cut on a angle so the bottom is tighter than the top by .0015 to .0030 I've had to have that done many times on lots of Mopar V8 You might want to put the intake on the motor and then use seveal intake bolts(not real tight, maybe 20 to 30 inch lbs) to hold the manifold in place so you can get aggressive on using the feeler gauges to get it measure the best you can before proceeding You can loosen them and try moving the intake to get it center also before deciding what measurements are where We don't calll these motors Hemiriods for nuthin, if it was easy all of them would be perfect Good luck
Yea, you are right, I can just imagine the poor guy that lays out the $$$$ for one of these and has to take it to a "shop" to diagnose and fix a problem like this. No wonder I am often the only HEMI at a 250+ car cruise in! So you are advising that I take a .030 cut from the top to .000 (where it is not sealing)to put more clamping force on the gasket? and use a .090 gasket? I am considering "Gorilla snot" sealer around the ports as well. No more "let the gasket do the work" for me! Just imagine what the vacume is at 3,000 rpm on the freeway with a 4,200lb. car when you close the throttle to exit! It reads 17" @ idle! It must be over 50" on deceleration!
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Re: Switch from 10-30 to 20-50 pressure change?
[Re: dwayne welder]
#1659159
08/25/14 08:08 PM
08/25/14 08:08 PM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
OP
super stock
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OP
super stock
Joined: Mar 2010
Posts: 984
Tennessee
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Quote:
Doe's the intake sit on the china wall when bolted down? Is there a gap for a bead of silicone? Just thinking of anything to check!!!!
Thanks for trying to help! No there is a good .200" of gap from the bottom of the intake to the china walls. I have a great imprint of the head on the gasket, (torqued to 70in.lb. on center and 48 in.lb. on ends). But the oil is flowing past the gasket just the same!
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Re: Switch from 10-30 to 20-50 pressure change?
[Re: Hemi ragtop]
#1659160
08/31/14 01:52 PM
08/31/14 01:52 PM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
OP
super stock
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OP
super stock
Joined: Mar 2010
Posts: 984
Tennessee
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Well, I hope everyone else is having a great Labor Day weekend, mine is a bust. Just to review, I discovered that I had oil wicking THROUGH my paper composition intake gaskets. Sealed to both intake and head with silicone but POURING THROUGH the paper! So I installed .060 Superformance gaskets dry except for the end rails as instructed. Result, oil pouring AROUND the gasket even with clear imprint showing good compression into the gasket! Over a quart in 70 miles! That was two weekends ago. I started talking to old time engine builders, racers etc. First comment, NO ONE runs dry intake gaskets with high rpm or large cubic inch, (over 500) engines. A good friend and former HEMI super stock racer agreed to help if I would listen to him. No one else offered to step foot in the garage so I took him up on his offer. He used .060 and .090 wire to space the manifold up and check for matching intake/manifold angles (also double checked with angle finder). This also showed a little better port alignment at .090. He suggested that .090 would also allow more gasket crush/bite. Next he told me to stud the intake. That way all the torque would be crushing the gasket vs. being used to thread into the heads. Lastly, he told me to buy "Honda Bond" to use as a sealer. It is now Thursday night, long weekend, and the two largest car shows of the year coming up back to back. The second one requires a drive of almost three hundred miles round trip. I started ordering parts Red Label. I know better, something always goes wrong when it JUST HAS TO GET HERE BY FRIDAY! In order to make up .090", I had to order two sets of Superformance gaskets, one 030 and one 060. Then studs, McMaster Car was the only place I could find that had 1/4-20 studs 3-1/2" long with 1" thread on either end. That was discovered on Friday so I had a "Saturday" next day air on those! all told, over $135 just on shipping! Saturday morning was spent at the track watching the Pro Mod race. Several of the racers are friends. One runs an all aluminum 8-71 blown HEMI. I talked to ALL of them, they confirmed that they had to use either 3M weatherstrip adhesive or "import silicone" on the intake gaskets or they would have to pick them out of the exhaust ports! So I go home and get started waiting for my SS buddy to arrive. First I install my studs with a drop of Blue Locktight to "refusal" (as deep as they would go as per instructions). My buddie arrives and final inspects everything, one more wipe down with laquer thinner and he opens the gaskets on a clean work bench,,,,,,one is clearly market 060 with part#, the other is clearly marked 030 with DIFFERENT part#, and ALL FOUR GASKETS MEASURE 030"!!!!! CHECKED WITH A MICROMETER!!!!!!! I AM TOTALLY SCREWED!!!!!!!
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Re: Switch from 10-30 to 20-50 pressure change?
[Re: Hemi ragtop]
#1659164
08/31/14 02:20 PM
08/31/14 02:20 PM
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Joined: Mar 2010
Posts: 984 Tennessee
Hemi ragtop
OP
super stock
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OP
super stock
Joined: Mar 2010
Posts: 984
Tennessee
|
Here is one of the real problems, there is no room for a mike so I used calipers, there is just .150" of material in this area to seal the HUGE vacume in the port! I bought the rotating assembly new, freshly machined and balanced at Diamond Elkins, from a long time friend of Dan Manchini, Butch Elkins, and a long list of famous Mopar racers/builders. In discussing this with him, he relayed stories about racing in the "High Roller Club". This group would race, flat out from Detroit to Chicago, stop, then race back! His HEMI Charger would see 6,800-7,200 rpm for hours! Oil consumption was a problem! One of his buddies, installed a small "O" ring around the stud in this area to prevent the gasket from taking all the abuse!
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