Vacuum Leak on my Daytona

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Steve Meltzer
Posts: 866
Joined: Mon Sep 06, 2004 10:31 am
Location: with Barney the Beagle boy and Enzo 8995

Vacuum Leak on my Daytona

Post by Steve Meltzer » Mon Nov 11, 2013 6:44 pm

I've been struggling with a vacuum leak on my Euro '71 Daytona Spyder conversion. I just had Pierce straighten out (literally and figuratively) my carbs and he also inspected the intake plenums, which he reported to be straight. (I"ll recheck them tonight.)
Every intake port leaks at the juncture of the intake with the cylinder heads. If you spray brake cleaner in the joint, the engine revs up like crazy, so I know that the diagnosis is accurate. I had this issue on my coupe and solved it by putting in a fatter O-ring, but even the newer plumper O-rings can't seem to stop this vacuum leak. The O-rings are just held in place with grease, no RTV.

Any thoughts here? I've heard this is an uncommon problem and also that the intakes should only be lightly tightened, which I did to 20#, carefully and evenly with a torque wrench. As always, thanx for your advice. steve
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

Steve Meltzer
Posts: 866
Joined: Mon Sep 06, 2004 10:31 am
Location: with Barney the Beagle boy and Enzo 8995

Re: Vacuum Leak on my Daytona

Post by Steve Meltzer » Tue Nov 12, 2013 10:58 am

I got a good look at the intake on the new "fat" (5mm) o-rings and then set the intake down on bare metal-to-metal: the visual difference, without any measuring, was dramatic. Then I put in some correct, thinner (3mm), o-rings and the intake set in place like it did with no o-rings. Maybe the problem was iatrogenic! I'll button her up with the thinner o-rings and we'll soon find out. If this works, thanx goes to Mike Pierce for his ideas. s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

Michael Bayer
Posts: 699
Joined: Mon Nov 04, 2002 7:22 am

Re: Vacuum Leak on my Daytona

Post by Michael Bayer » Tue Nov 12, 2013 7:48 pm

Fingers crossed for you Steve!
Michael J. Bayer
330GT s/n 9727
365GTC4 s/n 14943
Dino Spider s/n 1193

Steve Meltzer
Posts: 866
Joined: Mon Sep 06, 2004 10:31 am
Location: with Barney the Beagle boy and Enzo 8995

Re: Vacuum Leak on my Daytona

Post by Steve Meltzer » Tue Nov 12, 2013 8:26 pm

thanx Michael! i need all the help i can get. s
steve
meltzer, "“With a Ferrari, whatever it is, it’s a $1000. If that’s what it is.”"
'66 330 GTC, '72 Daytona-red, did they make any other colors?

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