FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: PaulProe on July 22, 2021, 11:21:04 AM
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I am assembling a MSD/Holley Dual Sync distributor into a Borla/Rousch EightStack manifold atop an FE. The distributor uses a tapered gasket to seal the joint between it and the manifold. I am finding it to be EXTREMELY tight, to the point you have to use a deadblow to get it to go down. Take the gasket out and everything slips together fine. Doing some research:
1) a number of threads on the hole being too large, nothing on it too small.
2) checking the Ford drawings, the hole is supposed to be 1.97 (don't know the tolerance range). The hole in the manifold mic's at 1.965
3) Checking gaskets (Felpro), I find two different sizes, one slightly smaller OD than the other. Even the smaller one is much tighter than you would expect.
4) looking at alignment of the shaft and the hole, it seems to be pretty well centered. Using gauge pins, it's maybe .002-.004 off center. We used the distributor to position the manifold when we torqued it down.
Anyone else run into this. I know the tighter it is, the less it will leak, but this makes it extremely difficult to adjust the timing. With everything in place, it takes two hands to rotate the distributor.
Ideas or comments? Should I try to reduce the taper on the gasket?
Paul
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My guess is that the seal groove in dist. housing was not cut to the proper depth. I've had this show up a couple of times when using an aftermarket dist.. In the free state, the seal should simply float within the confines of the groove; clearance both above and below the sea and approx. .010 to .015 between the seal I.D. and inner groove O.D..
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Mine was pretty tight with new bbm tunnel wedge and ice ignition rubber grease helped. this may sound silly is it a new engine block? If it is fresh build be sure to check the cam bearing is not interfering with fit.
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. . . this may sound silly is it a new engine block? If it is fresh build be sure to check the cam bearing is not interfering with fit.
It is a new block, new build but don't think the camshaft bearing is an issue. Without the gasket, the distributor drops in just as it should. It is definitely the gasket that is causing the issue.
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. . . this may sound silly is it a new engine block? If it is fresh build be sure to check the cam bearing is not interfering with fit.
It is a new block, new build but don't think the camshaft bearing is an issue. Without the gasket, the distributor drops in just as it should. It is definitely the gasket that is causing the issue.
Cool seems like your on the right track then
mine was tight but not tight enough to have to mill anything.
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Had the same thing with my blue thunder 2x4. I razor bladed a sliver off the outside of the gasket. Mine was more than tight.
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Seal groove minor diameter 1.551".
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I wonder if the hole in the manifold is tighter then usual? I know this year I found that mine was leaking oil pretty bad. The seal on the distributor was a bit stiff from age/heat. I run a vintage Dove TW and with a new seal it is now oil free. It must not have taken much to go from "leak free" to "leak like the Exxon Valdez"...literally. I was expecting worse, but a new rubber ring dried it right up. ???
The gasket fits loosely on the distributor(old Mallory) which makes me wonder if all the "new" stuff is made much tighter to help eliminate the typical issues of leakage on the older stuff.
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Tnanks for your help, guys. Kind of confirmed the MSD distributor was machined incorrectly. Your dimensions helped me to figure correct amount of squeeze and then modified gasket. All is well now.
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silicone grease ( die electric grease ) is like magic on rubber or viton o-rings. Engine oil, WD-40, regular grease,lithium grease etc may help a little, but silicone grease is so much better you won't believe it, till you try it.
old ford injector o-rings used to fit so tight guys would break the injector or bend the fuel rails, a little silicone grease and they would slide right in.cant tell you how many techs i showed that trick to that just said " holly sh!t, you weren't kidding " .
may not solve your problem but might give it a try.
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silicone grease ( die electric grease ) is like magic on rubber or viton o-rings. Engine oil, WD-40, regular grease,lithium grease etc may help a little, but silicone grease is so much better you won't believe it, till you try it.
old ford injector o-rings used to fit so tight guys would break the injector or bend the fuel rails, a little silicone grease and they would slide right in.cant tell you how many techs i showed that trick to that just said " holly sh!t, you weren't kidding " .
may not solve your problem but might give it a try.
I agree. I run into the occasional tight distributor and some assembly grease and some twists going in always seats it. It also seems like once they get some heat in them, they loosen up as well.
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X2 on the silicone grease, works on radiator hoses also. Aftermarket FE alum. water pump, inlet oversize impossible to fit, just a bit of said grease and like magic wiggled it right on!
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Yup...some Sil Glide is always on the shelf ready to help things fit!!!