Intake Seals and RTV & VOES Questions

[Traveler733]

Anyone had luck with RTV silicone sealant on intake to cyl. heals seals.    Maybe use it as a lube on installation.  Then wait 24 hours for it to cure, after the bolts are torqued.   It seems like once a year, I have to reseal them because of a vacuum leak.
That and the VOES leaks. I may just toss the VOES and ground the wire that goes to it. Any thoughts?
I'm running the S&S HI-4 ignition. It's a Bagger with S&S stroker bottom end. SE heads Hi-lift, cam. I think I can dial out any knocking with the dials on the ignition unit in the nose cone.

[Ohio HD]

Does your motor use stock length cylinders? S&S sells different width intake manifolds. Maybe you're just on the edge of being wide enough. I would accurately measure the narrowest width between the heads at the intake ports. Call S&S and ask them what width your intake should be.

I wouldn't use RTV. It's just a patch.

[Ohio HD]

Also heads being milled effects the manifold fit. But taking material off the heads should make the intake tighter to the heads.

[JW113]

Just for fun, try setting the intake manifold against the two intake ports in the head (without the clamps), give it a good eyeball both inside and out to see that the ports line up with the holes in the manifold, and that the manifold sits flush against the head. i.e. no gap on the top or bottom. If the ports don't line up nicely, or you have gaps against the heads, you have some fitting of the manifold to do.

As stated, don't use silicon rubber on the seals. I do use "Sil-Glide" (a high temp silicone grease) on the seals so they can move around and find their happy spot while tightening down the clamp bolts. And on that note, also make sure the carb is installed on the manifold and mounted securely before doing final tightening of the manifold bolts.

-JW

[thumper 823]

3M 5200 is the better option if you are concerned

[JW113]

The design is not intended to be glued. Speaking only for myself, if I was out in the middle of nowhere and needed to get back home, yes I'd do that. But back home, I'd look for the actual problem and fix it.

-JW

[Ohio HD]

The design is not intended to be glued. Speaking only for myself, if I was out in the middle of nowhere and needed to get back home, yes I'd do that. But back home, I'd look for the actual problem and fix it.

-JW

[thumper 823]

IF, if you have raised ports you need to inspect carefully.
Do you?
If you do,  sometimes the front and rear flange have to be swapped to make it fit right.
   

[Traveler733]

Thanks for all that replied!
Some good information that you have written.
Some good ideas of what to check!
Cylinders are stock length. SE heads are as out of the box.
I'll follow your suggestions and see where that takes me.

[Burnout]

Intake seals last more than one year, you have something messing it up.

Verify fit of intake between the heads with no rubber or rings.
Check upper mount? Is there any base gasket leakage?

[kd]

A common cause is the mounting.  If the breather base doesn't fit right up to the head after the manifold is mounted you must shim the mounting posts.  S&S sells rubber coated shims for this purpose.  If there is a gap and you draw it down with the breather bolts it WILL eventually shift the manifold on the heads and result in a leak. 

BTW, the same is true if thwere is a gap at the car or throttle body and usually a gasket will fill that gap.

[Traveler733]

Again, thanks to all, for sharing your knowledge!
Most of the replies are sure helping.
I have S&S stuff on order, along with a Dunlop D402F WWW tire, that seems to be in short supply...
Riding season is almost over here, so I will start the repairs, soon..

[Ironheadmike]

I use dawn dish soap . It works great .