Baffle and Horizontal Induction Snorkel Questions

Hey - I am working on the ever-so-fun baffles and am running into some issues with figuring out when to stop working on the left front baffle and shift towards the horizontal induction snorkel installation.

What I am struggling with is do I bend up the left front ramp to match with the cowling before I fit the snorkel?

One of the first instructions for the snorkel is to measure down 3/8" from the left front ramp and draw a line that you trim the snorkel to. If I bend this ramp to match up with the cowel inlet, the cut on the snorkel will not be straight. I also am struggling a bit with seeing how the filter will lay flat on top of the bent ramp.... it may be the correct way to go, but wanted to check with those that have gone before me before I screw up yet another part.

Thanks,
Jason

Don't bend

There will be a bunch of advice from others but first, don't bend that left ramp or you will waste more that a day straightening the thing out later. Look closely at the snorkel directions, there is no mention of bending the ramp. The bend is only if you have a scoop.

I agree.

The ramp remains flat. Do not bend it. It will make sense once you begin fitting everything up.
There is a possibility that you will have to do some "surgery" on the fiberglass snorkle to fit it exactly the way you want. I had to cut and fiberglass mine in a couple of places. It wasn't a big deal and in the end it turned out great.

jeffmoreau said:

The ramp remains flat. Do not bend it. It will make sense once you begin fitting everything up.
There is a possibility that you will have to do some "surgery" on the fiberglass snorkle to fit it exactly the way you want. I had to cut and fiberglass mine in a couple of places. It wasn't a big deal and in the end it turned out great.

Click to expand...

So do I just lightly bend up the outside edge of the ramp to match the front of the cowling opening, then measure down 3/8" to trim the snorkel?

what a nice and shiny engine?I am envious One either needs some shade just to work on that engine.

Anyway, as others have rightly suggested, don't bend it. Good chances are that you will need to trim some of that inlet back so your filter will fit in there. If you put your filter or the snorkel, you will find that the cowl inlet is too close and not enough gap for the engine movement. Once you put the snorkel (hopefully won't require much surgery) it will be more clear as what needs to be trimmed and how much.

I am finishing up the left inlet ramp and the horizontal induction filter/airbox right now. Contrary to the previously posted advice, I bent the inlet ramp and everything turned out fine. The baffle to cowl fit is great and the filter simply conforms to the shape of the baffle.

One thing I would advise: don't trim the left inlet ramp very much at all until you see how the airbox and filter are going to fit. The filter is like 90% of the size of the whole baffle, so it's pretty easy to run out of room either laterally or longitudinally.

Some further documentation here:

http://www.rv7blog.com/2011/01/02/baffles-air-duct-filter/
http://www.rv7blog.com/2011/01/16/air-filter-brackets/
http://www.rv7blog.com/2011/01/23/air-filter-retaining-ring/

good luck,
mcb

+1

mburch said:

I am finishing up the left inlet ramp and the horizontal induction filter/airbox right now. Contrary to the previously posted advice, I bent the inlet ramp and everything turned out fine. The baffle to cowl fit is great and the filter simply conforms to the shape of the baffle.

One thing I would advise: don't trim the left inlet ramp very much at all until you see how the airbox and filter are going to fit. The filter is like 90% of the size of the whole baffle, so it's pretty easy to run out of room either laterally or longitudinally.

Some further documentation here:

http://www.rv7blog.com/2011/01/02/baffles-air-duct-filter/
http://www.rv7blog.com/2011/01/16/air-filter-brackets/
http://www.rv7blog.com/2011/01/23/air-filter-retaining-ring/

good luck,
mcb

Click to expand...

I'm with Matt on this one. The instructions for fitting the ramp and snorkel are not very clear (at least for the angle valve engine). I fit my snorkel first as the instructions suggest and then the ramp to the cowl, but at that point I could not bend the outer part of the ramp up to meet the inlet as suggested, so had to re-fit the snorkel to ramp after bending the ramp up to meet the inlet.

For those who say not to bend the ramp up to meet the cowl, how do you prevent all of the high pressure air from just spilling forward into the large gap between the ramp and cowl inlet, into the lower cowl?

I think you will find that the filter is very flexible and the ramp need not be flat for a positive seal around the edge of the filter.

Baffle bend

Seems the bend worked fine for some and no bend for others! Not realizing the bend didn't apply to my (snorkel) set-up, I did the bend and later ended up flattening it out almost completely. I think it's going to work out fine once the snorkel is fitted. I hope. Bill

totally agree with matt.
look at fitting the filter/airbox first.

the filter is able to take a considerable amount of "twist" without a problem. so if the right edge has a different slant than the left edge, it's not really a problem.
also, consider trimming the cowl just a bit if everything is too tight otherwise.
you will still want to be able to mount/unmount the cowl and be able to pull the flexible gap bridge cloth/rubber on top of the air filter easily.

fitting the airbox to the engine intake while still fitting with the alternator mounts, cylinder head oil supply line and starter is the trickier part.
it has to fit both sideways and fore/aft to the baffling and to the intake at the same time. also, there's not much left of the baffling ramp in the end.
we had to mod our airbox quite a bit and then re-glass it.

rgds bernie

Just sharing my recent experience with the snorkel and left baffle arrangement. I was happy to see that my snorkel actually was a good fit with it sitting pretty close to dead center of the left inlet ramp. This is on an RV7A with IO375 and Superior cold forward facing intake setup.

For anyone getting close to this stage I recommend studying the baffle instructions and the snorkel/air filter instructions till you really know them well and can easily pick out the contradictions and left out information.

The instructions are particularly deceiving in these parts as they get very specific with some hand holding involved, like reminding you to deburr the parts etc. but they are seriously lacking in the important details. The drawings for the air filter arrangement are not good.

I agree that the best approach is to use the directions as a general guide for what the end product should look like but to generally put them aside and do your own thing, very carefully.

I approached this with my motto being do not rivet anything until you really have to. This has saved me from making some mistakes. SAme thing with drilling

I have gone back a forth a few times between installing the air filter and then reverting back to finishing off the rest of the baffles in order to make sure the final placement of the cowling is not going to move and spoil my fitting of the air ramps up front. I had to cut the bafffle height down in order to put the top cowl on to double check this.

One particular area that had me confused is the baffle instructions have you making the conical gusset for both the right and left sides. The air filter retainer seems to take the place of the conical gusset on the left side when installing the filter. I am considering combining a conical gusset and air filter retainer into one part. Curious if others have done this... Perhaps after cutting so much of the inlet opening away to make room for the filter, a conical gusset is not needed like it is on the right side?

Randall in Sedona
New firewall forward install.

The baffles have to be done to fit the cowl correctly, and then you fit the snorkel to the baffles.
The inlet ramp has to have the bend to match up to the cowl inlet properly.
If you unpackage the air filter you will see that you can twist it.
That flexibility will allow the filter to have a bend from the fwd inboard corner, to the aft outboard corner.
If the snorkel is trimmed to match the shape of the inlet ramp (with the appropriate gap for the filter thickness) it will hold the filter tight to the bottom of the bent ramp.

Both ways....

For what its worth, i first did mine with no bend, but it didnt end up fitting the cowling. Studied my predicament and the instructions more and added back the fibreglas i had cut off the top of the snorkel and then bent the front ramp. It fits really nice and the filter conforms to the bend as stated above. I think it states in the instructions that the end result is more important than the process. I think that was a warning, that i had ignored.
Keep at it - you will get it.

Don't bend the #2 ramp, just twist until leading edge fits the cowl opening. Build rest of structure to fit the twist. Makes for a really nice fit with no kinks to challenge the filter fit. The filter will easily conform to a smooth twist.

You can bend the #1 ramp just like the carb engines do.

Lots of opinions (it is experimental after all....)

The filters I have worked with have stiffeners in the edges and they will not let the filter easily bend in a curve along the edge, but they will let the filter bend / twist at the corners.
If you bend the inlet ramp as designed, the filter will locate in such a way that two of the corners will lay just about directly on the bend line and it will easily conform to the shape of the inlet ramp.
The prototype RV-8A and RV-7A at Van's both have them installed this way.

Left ramp cut too much for Snorkle

UnPossible said:

Hey - I am working on the ever-so-fun baffles and am running into some issues with figuring out when to stop working on the left front baffle and shift towards the horizontal induction snorkel installation.

What I am struggling with is do I bend up the left front ramp to match with the cowling before I fit the snorkel?

One of the first instructions for the snorkel is to measure down 3/8" from the left front ramp and draw a line that you trim the snorkel to. If I bend this ramp to match up with the cowel inlet, the cut on the snorkel will not be straight. I also am struggling a bit with seeing how the filter will lay flat on top of the bent ramp.... it may be the correct way to go, but wanted to check with those that have gone before me before I screw up yet another part.

Thanks,
Jason

Click to expand...

Is there a work around if I trimmed the outboard edge of the left ramp too much to encircle the snorkle entry? Jason your photo looks like you may have had a similar issue. I'd be interested in your solution. My snorkle fits fine on the right and in the rear. But I trimmed too much material off the left ramp such that there is none in the front nor on the out board (left) side. I do still have the fold under flap of the vertical baffle on the left side so it seems like that could be used to support the snorkle. But I don't want the installation too weak. So does anybody have a solution to accommodating thus situation? I could buy a new ramp and start over but perhaps there is way to use the outboard vertical baffle.

Thanks for photos and ideas.

Buy a new one

sglynn said:

Is there a work around if I trimmed the outboard edge of the left ramp too much to encircle the snorkle entry?

Click to expand...

I did exactly the same thing. I didn't see this thread unfortunately before I started on this part of the baffles. I thought I had read everything I could on baffles, but apparently not.

I bought a new inlet ramp after spending hours trying to make the other one work. It's really cheap and took about 5 mins to get it ready. Funny how the second time I do something it's sooo much faster than the first!

The biggest regret I have with my 7 is not making the gap larger between the baffle ramps and the edge of the cowl! I cant remember what the planes call for but it isn't enough! A simple piece of the rubber or silicone material cover this gap so another .25-.5 inch would have been no issue. It makes removing the bottom of the cowl a real pain when the ramp and the edge of the cowl is too close.

MikeyDale said:

The biggest regret I have with my 7 is not making the gap larger between the baffle ramps and the edge of the cowl!

Click to expand...

Thanks for the tip. I'm working on this right now. Could you carefully cut the intake of the lower cowl now to provide more space? It seems like the air filter limits that amount that you could cut off the intake ramp.

MikeyDale said:

The biggest regret I have with my 7 is not making the gap larger between the baffle ramps and the edge of the cowl! I cant remember what the planes call for but it isn't enough! A simple piece of the rubber or silicone material cover this gap so another .25-.5 inch would have been no issue. It makes removing the bottom of the cowl a real pain when the ramp and the edge of the cowl is too close.

Click to expand...

Mike
How would you enlarge the gap? Would you cut back more of the pink fiberglass cowl? The snorkle I'm installing now on my 7 fits where it fits and without modifying it, it is already way forward with hardly any gap between the forward edge of the filter and the fiberglass cowl. I cut away all the aluminum ramp in the front already, which was a mistake, but I'm thinking I don't need to try and replace it because there is not much gap here, like you are saying.

Easy to cut the cowl I guess. I could do that then fill the present screw holes and make some new screw holes. Now that my memory has been jogged, it does seem like the filter left no room to shorten the ramp. I hate to have to touch up the paint on the cowl but I may do it. You guys have a chance to avoid that now. Just try to leave all the gap you can by trimming the cowl.

moving snorkle inlet rearward

sglynn said:

Mike
How would you enlarge the gap? Would you cut back more of the pink fiberglass cowl? The snorkle I'm installing now on my 7 fits where it fits and without modifying it, it is already way forward with hardly any gap between the forward edge of the filter and the fiberglass cowl. I cut away all the aluminum ramp in the front already, which was a mistake, but I'm thinking I don't need to try and replace it because there is not much gap here, like you are saying.

Click to expand...

To move my inlet rearward, I block sanded the fuel injector mounting end of my snorkel at a slight angle which helped move the inlet rearward.


Then I back countersinked the bolt hole surfaces to make square with the holes by putting a sanding tool for my dremmel through the hole.


I still trimmed my pink cowl back some but this gave me some more room.

My snorkel was also further to the left so I had to put the outboard filter clamping flange outboard of the vertical part of the baffle.



hope this helps.