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Discussion Starter #1
After a long hiatus from the boating forums, I'm getting back into the swing of things.

I built a mild blower motor about 7 years back. A recent leakdown showed that it was getting to be time for a valve job, so I tore it down last weekend.

I'm running Dart 345's on an o-ringed block. My question has to do with head gasket options. When I put this thing together, I was advised that the height of the o-ring had to be 20% or less of the copper head gasket overall thickness. Since my o-rings(.041 dia.) are above the deck .018"-.020", I went with .093" thick gaskets. I had a hell of a time getting the gaskets to hold water. Yamabond was used extensively and then there are the quench issues....

Anyway, I'm looking for suggestions here. Can I get away with a thinner copper gasket? What about pulling the o-rings and running one the new fancy mls gaskets? What else can I do?

What say the gurus???
 

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My block was o-ringed by the PO. I went NA and didnt need it. Running cometic gaskets with no problems.
 

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Have you measured your o-ring protrusion? That is out pretty high for .041 wire.
Do you have receivver grooves in your heads?
Wags
 

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Discussion Starter #4
That dimension is the measured protrusion. No receivers in heads. That is how block was when I got it.
 

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Well, not going to get water to seal with no RG. Not easily anyway.
This has been debated over and over again. You will get guys saying not necessary then bittch about water sealing. You will get guys saying they don't run em and all is fine. Then there is the right way to run them.
Wags

Oh, I ain't joining this thread this time.
IMO (well, and the opinion of Forcell and Clark) receiver grooves must be run (because it is the protrustion of the copper into the groove that actually seals) and use silicone sparingly around water holes, no issues.
 

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o rings

my engine was the same. orings in the block, and no reciever groves. i have been running cometics MLS. last year it was a 509, with nothing in the groves and MLS. ran it at 15 lbs boost with no issues. this year its a 540. only thing different, is we added wire to the grove, that sat flush with the deck. filled the grooves just for the hell of it, prob not necessary. running 10 lbs this time. seems people are running as much as 30# on MLS gaskets
 

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Well, not going to get water to seal with no RG. Not easily anyway.
This has been debated over and over again. You will get guys saying not necessary then bittch about water sealing. You will get guys saying they don't run em and all is fine. Then there is the right way to run them.
Wags

Oh, I ain't joining this thread this time.
IMO (well, and the opinion of Forcell and Clark) receiver grooves must be run (because it is the protrustion of the copper into the groove that actually seals) and use silicone sparingly around water holes, no issues.
And then there is what always worked for me. Prolly about 25 in all from blown alcohol to blown gas.
I 0 ring the block only and I do it with the old hand tool from Isky. I don't use copper wire (as isky supplied) but use Piano wire...but then later years I used just plain wire from a hardware store.
I have never used a head gasket thicker than .060. Many times I used a .040.
If the block was a chevy block I used ultra blue silicone on the heads studs. Darts are blind so I don't.

I then using ultra blue silicone seal....bead around all water areas....the block....then put the gasket on.....now silicone on the gasket (head surface side).
I let the silicone dry for a couple days if possible before putting water to the motor.
I have run 25 lbs of boost and never had a head gasket problem.
I did have a water leaker once but we used a different brand silicone....at a race and in a hurry (sleeving a block) but later that was solved by using Permatex Ultra Blue.

Currently with the advent of the new gaskets.....I have two out there blown gas at about 15 lbs with no O ringing and using the Fel Pro MLS gasket. Got a couple unblown deals that push 15 to 1 and they use same gasket or the cometic.

Yeah the silicone is a pain in the ass. But I get real gun shy going against something I know works.
 

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And then there is what always worked for me. Prolly about 25 in all from blown alcohol to blown gas.
I 0 ring the block only and I do it with the old hand tool from Isky. I don't use copper wire (as isky supplied) but use Piano wire...but then later years I used just plain wire from a hardware store.
I have never used a head gasket thicker than .060. Many times I used a .040.
If the block was a chevy block I used ultra blue silicone on the heads studs. Darts are blind so I don't.

I then using ultra blue silicone seal....bead around all water areas....the block....then put the gasket on.....now silicone on the gasket (head surface side).
I let the silicone dry for a couple days if possible before putting water to the motor.
I have run 25 lbs of boost and never had a head gasket problem.
I did have a water leaker once but we used a different brand silicone....at a race and in a hurry (sleeving a block) but later that was solved by using Permatex Ultra Blue.

Currently with the advent of the new gaskets.....I have two out there blown gas at about 15 lbs with no O ringing and using the Fel Pro MLS gasket. Got a couple unblown deals that push 15 to 1 and they use same gasket or the cometic.

Yeah the silicone is a pain in the ass. But I get real gun shy going against something I know works.
I too have done this same exact method for many years, however the last 2 motors (1 blown, 1 turboed) I used the new style silicone coated (entire gasket surface both sides) copper head gaskets from FLATOUT GASKETS with my o-ringed block. Works excellent and no messy silicone to apply. As far as MLS gaskets.......I just can't bring myself to run them on a boosted deal, even though many guys are have good luck with them. Jocko

https://www.flatoutgroup.com/factstips.aspx
 

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Yeah I think someone else mentioned those coated gaskets before worked for them also. I thought it was Wags but maybe it wasn't.
 

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I use cometics on my piece. But I only run 20# at the Cove. Around 12 or 13 every place else. No issues. They will handle blown gas stuff. I will never be that hard on gaskets. (I hope)
So, I have used copper w/ wire and receiver grooves, and cometic. That is all (on boosted stuff that needs to seal better than a regular 1027 fel pro, etc)
Wags
 

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flatout

i have used the flatouts. they worked real well. in fact, i was planning to use them this go arround, but could not find the right one for what i needed.
 

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Flatouts are the only gasket to use, NEVER have had one leak, stainless orings with .005 reciever groove in head, 44psi..
 
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