RV 4 air intake old vs new

diamondjim · #1 10-02-2017, 12:00 PM

Can anyone tell me the pros and cons to the newer style snorkel opposed to the older flat style. I am looking at an older 4 and it has the flat style air intake. I was wondering if anything can be done or should be done with it. If so does anyone make a kit or can I just make a snorkel. Thanks
Jim

AX-O · #2 10-02-2017, 01:11 PM

Can you be a little more specific? Carb or fuel injection? Vertical or horizontal induction? What does the "newer style snorkel" look like?

What do you consider old? The early RV-4 did not have a specific design. Most were home made by the builder.

diamondjim · #3 10-02-2017, 02:19 PM

0320 built in 89 , has just a flat area where the intake is. Trying to figure what would be more advantageous. Sorry for the lack of info it's in an rv I am looking to purchase.
Jim

AX-O · #4 10-02-2017, 06:48 PM

Can you post a pic? Is the flat area on the cowling or the "airbox".

Nothing is too difficult to change. But it may require re-painting.

David Paule · #5 10-02-2017, 07:15 PM

Also, why do you want to change it? Is there some specific goal in mind?

Dave

diamondjim · #6 10-02-2017, 08:02 PM

Wanting to have the best set up, I figured there must have been a reason they changed the design. I don't have a good picture of the carb air intake. Will update when I do. Thanks

Saber25 · #7 10-02-2017, 08:34 PM

Here is the original -4 intake. Early kit 1150 completed in '89. Straight inlet, no filter, very efficient and used with updraft carb. Works good lasts a long time.

Cheers, Hans

YellerDaisy · #8 10-03-2017, 07:21 AM

Quote:

Originally Posted by diamondjim

Can anyone tell me the pros and cons to the newer style snorkel opposed to the older flat style.

Hi Jim, I think you are talking about the squarish inlet style like on a Cessna 140 (and others). I'm no expert but I think the difference is that the newer design offers a tiny bit more ram air effect, possibly better airflow behavior (into the engine), and possibly better filtering. I believe those are all insignificant to typical recreational flying. The most significant difference, IMO, is that the newer design looks better.

diamondjim · #9 10-03-2017, 07:43 AM

Wanting to have the best set up, I figured there must have been a reason they changed the design. I don't have a good picture of the carb air intake. Will update when I do. Thanks

diamondjim · #10 10-03-2017, 07:47 AM

Quote:

Originally Posted by YellerDaisy

Hi Jim, I think you are talking about the squarish inlet style like on a Cessna 140 (and others). I'm no expert but I think the difference is that the newer design offers a tiny bit more ram air effect, possibly better airflow behavior (into the engine), and possibly better filtering. I believe those are all insignificant to typical recreational flying. The most significant difference, IMO, is that the newer design looks better.

You are correct, it doesn't have the small snorkel like the pic above. It is the square 140ish style opening. I wondered if the snorkel would be more streamlined and flow better.