trigear nose mount hole in firewall.

Just getting ready to install engine mount. Having trouble wrapping my head around having to drill holes in the firewall for the nose gear leg attach bolt. When we are so worried about the need to make the firewall as safe as we can and sealing up the holes we need with all sorts of special things, this just seems goofy/poor design that we must cut/drill a hole when from first look it seems that if the bolt went in the other way it would work. Anyway of not drilling this hole? Just one of those things were i would rather see if there is a better way or idea as i am not 100% happy with the plans and how that will look etc.

Any suggestions or just drill and move on and get over it?

I built my 6A before any of the talk of drilling a hole in the firewall surfaced. I put the bolt in from the bottom, and use one of those all metal, small hex locknuts. The bolt needs to be partially slid through and out of the mount, then start the nut, then tighten. No big deal at all. You might need an extra washer on the bottom to keep the tip of the bolt from contacting the firewall, I don't recall and they are probably all a bit different.

Correction!! I mistyped above. I meant the bolt from the top, nut on bottom. Didn't catch my error until I saw the picture! Sorry.

What do you guys do to plug the hole?

Bob Collins said:

What do you guys do to plug the hole?

Click to expand...

Van's included a stainless plug in the kit. I installed and then siliconed it in too.

I did the same as Alex and installed the bolt from the bottom and metal lock nut on top without any problems.
Squeak
RV7A

Thanks

I talked to a builder and will follow his advice. I am NOT drilling the hole. Seems goofy. Several people that drilled the hole as per plans have been able to remove the leg for the service bulletin without needing the hole. Maybe a little awkward but i feel much better then an extra firewall penetration. Thanks all AGAIN.

Besides having to drill the hole in the panel, you may need two people to service the bolt. I understand the heater diffuser panel would also need to be removed. Seems like a no brainer to put it in upside down. I've heard some need to beat a little dent in the firewall, but that is no big deal either.

LifeofReiley said:

Van's included a stainless plug in the kit. I installed and then siliconed it in too.

Click to expand...

They did? In the finishing kit? Hmmmm... wonder where I put that?

Firewall forward kit

I believe the plug comes in the FF kit.

AlexPeterson said:

I built my 6A before any of the talk of drilling a hole in the firewall surfaced. I put the bolt in from the bottom, and use one of those all metal, small hex locknuts. The bolt needs to be partially slid through and out of the mount, then start the nut, then tighten. No big deal at all. You might need an extra washer on the bottom to keep the tip of the bolt from contacting the firewall, I don't recall and they are probably all a bit different.

Click to expand...

It's not about being able to assemble it, it's about being able to maintain it.
In a few years after the bolt has possibly rusted in, you may need to remove it for some reason. It is a very simple task if installed as specified...if not ...I guess you can always un bolt and remove the engine mount.

On my -6A...

...I installed the Plug as shown on the FWF plans...except I needed to us the next size larger plug.
With the "as called out" hole drilled in the firewall, and the engine mount in place, and the nose gear leg installed, the called out bolt direction (insert from cockpit side of firewall) would not quite fit.

The problem (for me) was that although the bolt shaft would just clear the SS firewall material, the bolt head could not make it through. And if I turned the bolt around and tried to put the nut/washer next to the firewall, there was not enough clearance between the gear leg weldment and firewall to allow the nut to fit.

Also, it just seemed that if I ever did need to remove the bolt, it would be much easier if the bolt were installed in Van's recommended direction, as I could "tap" it out (through the removed hole plug). Not as easy to do from the cockpit side of things going the other way.

When I first started looking for the called out SS plug, I could not find the one that was in the build kit of parts. I did find a non-SS plug, but not the SS plug (check with a magnet, the SS part should not be attracted, a ferrous compound part will be attracted). An email off to Van's was replied with ..."well, we never had anyone actually check, but you are right, they are not SS. We will just need to change our description of the part. What you have is correct."

So, off to the hardware store I went, in search of a SS plug to go with my SS firewall. I did not find any, ended up with a chromed steel plug (next size larger) and after attaching the nose gear + bolt / nut, I prosealed the plug in place.

Fel-Pro Anti-Seize

I installed the bolt from the bottom and metal lock nut on top without any problems. No holes in the firewall. Just use a little Fel-Pro Anti-Seize Lubricant on bolts and the gear legs and when you need to remove them it will be no problem. I turned wrenches for a living in a Power Production Plant and have removed bolts that were under water for years and they could be removed if Fel-Pro had been put on the threads.
Squeak

RV-7A

I installed the bolt from the top with the nut on the bottom, no hole in the firewall.

If the NG strut has to come off , I can get a wrench on the nut to turn the bolt out. Had the same arrangement with the Subby engine and did remove it a couple times.

If you don't have the FWF kit, you can pick up a chromed metal spring clip plug in the hardware department of Lowes. They have them in different sizes. Pop it in, if you like seal with proseal or RTV and you are good to go.

hmmm... timely this discussion has come up now. I figured patching this hole was something that was just left to the builder's imagination. I cut a circle of aluminum big enough to cover teh hole, and prosealed the heck out of it. It's just glued on with proseal. What's the melting point of proseal?
Now I'm thinking I should remove this, and get a piece of stainless and rivet it over the hole, and then more proseal...

RickWoodall said:

... Anyway of not drilling this hole? Just one of those things were i would rather see if there is a better way or idea as i am not 100% happy with the plans and how that will look etc.

Any suggestions or just drill and move on and get over it?

Click to expand...

I chose not to drill the hole in the firewall per plans. I shaved the bolts threads at an angle and clocked the bolt for positive clearance. A few years later getting a wrench on the nut to remove the nose strut for rework to comply with the SB proved a non-event.

I didn't drill a hole in the firewall either (early early kit).. Bolt installed from the top and used a thin self lock nut.. no problem... Be sure to use some kind of anti-seize on the bolt.. I also used it on main gear mount bolts and engine mount bolts.. any bolt that you might need to remove later that goes through steel....

I did put the hole in the firewall, came in handy when I removed the gear leg to send in for the modification.
I used two beveled stainless steal washers ,one on either side of the firewall with a 3/16 or 1/4 in. bolt to clamp them together. I think they were called fender washers.
Gerry 7A 70188

IMHO, I think following the plans in this area is critical... just in case something happens to go wrong down the road. If your insurance company finds out you deviated from the plans and had some sort of nose wheel incident... you might have an issue to deal with. And Yes, I know it makes more sense for the bolt to be installed opposite of the plans.

Umm not sure.

LifeofReiley said:

IMHO, I think following the plans in this area is critical... just in case something happens to go wrong down the road. If your insurance company finds out you deviated from the plans and had some sort of nose wheel incident... you might have an issue to deal with. And Yes, I know it makes more sense for the bolt to be installed opposite of the plans.

Click to expand...

I appreciate all the feedback. We bolted the engine mount on, and are sure we will be fine with no holes. As for concerns/liability not following plans, i am no engineer, but...one less hole in the firewall seems good to me. I did find one of the claims that the vans plug isnt even stainless interesting. In Canada, its mandatory that even the heat vent has to be stainless. Sooo, i will plug away, happy with my decision to have one fewer holes in my firewall. Getting close to needing a big expensive io320. Uggggh.

rvbuilder2002 said:

It's not about being able to assemble it, it's about being able to maintain it.
In a few years after the bolt has possibly rusted in, you may need to remove it for some reason. It is a very simple task if installed as specified...if not ...I guess you can always un bolt and remove the engine mount.

Click to expand...

Scott you are correct. However, I did not write correctly in my earlier post - the bolt head is up, the nut down in mine. Duh. I didn't think clearly when I originally wrote it, the picture posted jogged my memory! I've had the nose gear out about every other year for inspection.

I guess the question is why doesn't everyone install the bolt as shown in the picture, without a hole in the firewall?

LifeofReiley said:

IMHO, I think following the plans in this area is critical... just in case something happens to go wrong down the road. If your insurance company finds out you deviated from the plans and had some sort of nose wheel incident... you might have an issue to deal with. And Yes, I know it makes more sense for the bolt to be installed opposite of the plans.

Click to expand...

IF you have an accident, the insurance company will look at a lot of stuff, but they don't look to find deviations from the plan or none of us would ever collect. What they want to see are all documents with regard to being a pilot, and all certification documents and log book entries with regard to the airplane. If the pilot and airplane are legal, they will pay.

Been there, done that. My Subaru powered RV was about on the other side of the moon from Van's plan. AVEMCO paid with a smile.

Unbolt the engine mount?

rvbuilder2002 said:

It's not about being able to assemble it, it's about being able to maintain it.
In a few years after the bolt has possibly rusted in, you may need to remove it for some reason. It is a very simple task if installed as specified...if not ...I guess you can always un bolt and remove the engine mount.

Click to expand...

Scott,

I hear what you are saying and my guess is you speak from a good deal more experience in these matters than I have. I need little convincing that good access is always a desirable thing. However, I chose not to install the firewall plug because to access it in my older design, I would have to disconnect and remove the battery and its box from its per plans location between the rudder pedals. My feeling is "IF" in the future and for whatever reason I can't remove that nose gear bolt as already described in my earlier post.....and long before I would even consider un-bolting the engine mount as you opine, a far easier alternative using little more than a right angle drill and a rotary file is to cut in a hole at that location and go with a firewall plug per plans from that point on.

Bolt direction.

AlexPeterson said:

Scott you are correct. However, I did not write correctly in my earlier post - the bolt head is up, the nut down in mine. Duh. I didn't think clearly when I originally wrote it, the picture posted jogged my memory! I've had the nose gear out about every other year for inspection.

I guess the question is why doesn't everyone install the bolt as shown in the picture, without a hole in the firewall?

Click to expand...

I might be wrong, but I thought that the direction of the bolt was chosen so that if the nut came loose the bolt could not drop out of the gear. It would be blocked by the plug in the firewall.

With the bolt going the other way and you did some inverted flight the bolt might drop out.

Kent

Larger hole

noelf said:

...I installed the Plug as shown on the FWF plans...except I needed to us the next size larger plug.
With the "as called out" hole drilled in the firewall, and the engine mount in place, and the nose gear leg installed, the called out bolt direction (insert from cockpit side of firewall) would not quite fit.

Click to expand...

I had the same problem (I suspect EVERYONE must have the same problem).

My solution was to enlarge the hole in the firewall slightly and fabricate a simple flat circular stainless steel cover plate. The plate is secured with 3 off #8 screws. I have nutplates on the engine side of the firewall and the cover plate is sealed using a custom cut piece of high temperature fire resistant Koolmat.

Quite easy to fabricate and dead easy to remove. I now have very good access to that nose gear bolt.

If you use this approach make sure to orientate the three nutplates so that they do not conflict with the engine mount in that area.

Picture of cover from cabin side attached.