Is the general consensus still to push the rubber seal for the spark plugs INSIDE the cylinder tin (so it seals) under pressure?

-Aaron

mine have a groove that slips into the tins, positive seal at all times

What are those, Mort? That makes the most sense...

I push mine down thru the hole. Positive seal under pressure.

Do you see any difference when there pushed inside. Mine are just resting on the outside not tight at all

I've been looking for just that type of seal system. Where did you get yours?

Looks like a new product idea for 914rubber??

I use the regular seals and just push them through the holes with a screw driver.

Corvair engines had a plug seal that snapped into the tin. I wonder if they could be adapted.

Nick

Let me check I may have one that would work nicely.

Something like this. I'm not sure of the hole size of the in Corvair's tin and if it will work for the 914 tins.

Looks like it's worth a try. I think I'll order some.

Nick

Checked my grommets, and the one that would work nicely was a little too small.

beru set from partsgeek, about $24.00

Beru is exactly the same, it's an in or out also. I have a set in my hands.

If you push the seals down on the barrel of the connector prior to pushing them onto the plugs, they seal just fine (as designed by the factory)

Yes, it looks like they will hold some tension. But not a "grommet" type of fit if that's whats wanted.
Mark

You're correct, Mark. Grommet fit is the goal.

There isn't that much pressure under there!! The idea that pressure will push the rubber against the underside of the tin hard enough to seal is a misnomer. A pretty ridiculous one.

Use all the gauges you want, try it both ways. You won't notice a difference in head or oil temps. Sometimes we get way out of reality with ignoramus details.

Just push them until they seat firmly from the outside. That's all you need to do.

The Corvair spark plug boots can be made to work. They fit perfectly in the tin but must be modified by cutting off the inside and outside nipples and enlarging the hole to fit over the connector. I recall that they were easier to install in the tin on a Corvair.

Nick

Nice to know.

What style of motor tin did you fit test on 1.8 or 2.0?

It's hard to tell what tin I have. The case is from a VW 411 so it's likely a 1.7. I ordered a couple extra Corvair seals and I'm glad I did. I cut the center hole too big in the first one I modified.

They're a bear to snap into the tin but they sure seal up nice. Now I guess I should fix the other air leaks in the tin.

Nick

I have run mine on the inside. I have run mine on the outside, I have run mine with none. Dyno showed no improvement nor did the oil temp, or the head temp.