I alluded to this in another thread. Figured I'd get off my butt and post it up.


If you ever remove the intake manifold of a Shovel motor it’s a good idea to check how it aligns with the spigots on the heads. If it doesn’t align well, you’ll probably end up with a leak sooner or later. The best method is to loosen the heads and adjust their position to match the manifold. Once the head bolts are loosened, you’ll notice you can actually rotate the heads a bit.
One method is to put your manifold in place between the spigots and then start tightening the head bolts. Look at the gaps between the head spigots and the manifold to see if it's aligned correctly. Adjust the heads as needed.
Another method is to install the manifold without the o-rings. Install the clamps and tighten them, and the loose heads will align themselves to the manifold. Now tighten the head bolts in the standard crisscross pattern to 15 or 20 ft. lbs. Remove the manifold and finish tightening the head bolts to the proper torque specs.
You can make a leak tester to check your work by fabbing some type of cover for the front of the manifold. A piece of metal with holes drilled to match the holes of your manifold, and another hole for some method to connect an air line, works fine. To test your manifold-to-head connections pump about 5 psi into your contraption. Yeah, you gotta make sure both your intake valves are closed! Use some leak detector or make some with soapy water. Slosh it on the head-to-manifold joints and watch for bubbles.
When you are installing those dang o-rings, roll ‘em up onto the head spigots, but make sure they don’t twist when you slide them into the gap. Then before you put the clamps on, take a wrap or two with some electrical tape around the o-ring. Use some good tape, not the el-cheapo crap from the bargain bin. I like either Scotch 33 or Scotch 88. 33 is thinner and more flexible.
Some folks don’t like the tape routine. It does goo things up as the tape gets warm. And that is one reason it helps seal things. The next time you pull the manifold off, it easily cleans up with some good ol’ gasoline.
You folks with later model Shovels don’t have to mess with the o-rings; you’ve got those nice wide sissy bands. But things’ll still last longer if’n you align the heads and intake manifold.

 

Thanks for taking the time to post this.

Another thing to consider if running an S&S would be to install the carb and air cleaner backing plate and mount to the carb and bracket to the front cylinder rocker box to get the alignment set.

If you have the early o ring type seals you can also upgrade to the rubber band type with a hard spacer to fill the gap where the o ring fits and use the larger clamps and rubber band seals. I use this configuration on my 68 and it seals the intake up nicely.

 

I'll resurrect this old thread cause I've now ruin into two shovels over the last few months in which the S&S intake is just too wide and needs to be shaved - I assume this happens when prior machining took material off the head surface or the jug surface - rotating the heads/jugs will not change the gap but will change the angle - my angle is dead on - I have a gauge for the angle - seems like the only way to get a good seal is to custom fit the manifold then go to the band seals - I've been tempted to re-machine the manifold as well but that is a lot of work

As for the tape - all the O-rings I've used do not "roll up" onto the head port - I'd like to see a pic of this technique - cause maybe I'm missing something

 

 

to add what we do to this and everyone is almost doing the exact same thing

1 -- o rings we roll them onto the manifold set in place and slide into the spot, then USA 888 hi heat electrical tape in applied, around the head/intake and on top of the o rings -- set clamps in place ( aircraft type ) then install the carb and air filter to get the exact spot its going to live in tighten all of it

2 - they make a custom kit that replaces the o ring with a plastic square O ring replacement - much easyer with a new head install but you can do this after - at the same time we only use the Red silicone flat rings - not the black rubber ones -- aircraft type clamps install carb and air filter and holding bracket for the works - tighten - additional piece to this is the silicone flat rings and the aircraft clamps can and do slide around on one another so we glue the clamps to the flat rings hi hear silicone - let dry 24 hours

 

JZ - you are using two piece clamps then? I can't see the path to glory using the tape with a band clamp

 

no aircraft clamp is a one piece that works well with an plastic stop nut on it 1/4 - 24

 

so you are opening the band completely then? whenever I've tried to open those bands I always eff then up - I always place the seals and bands on the heads - then push and rotate in the manifold - use vacuum grease and have never had issues with sealing - I've never used the tape cause I could never figure out how to get the tape under the band - just could never get the bands to open without bending them - to fix my current problem I re-machined the manifold to fit - then used my standard protocol with vacuum grease

 

vacuum grease is a new one for me don't know exactly what it is -- type / brand name ???

 

vacuum grease is a high silicone content grease that is superior in sealing and lubricating and it takes very very high temperatures without running - Dow Corning makes it - it is expensive but some shops will through it out when jobs are complete or a new job is started under an ASTM standard - I've had the same tube for 30 years