Firewall Forward Items

[JDA_BTR]

The firewall forward kit from Vans is for an IO360 and I'm installing an IO390. So I'd like some advice to start accumulating the items I need to get the job done from the Rv8-IO390 builders. I'm also using the showplanes cowl.

I suppose I could start with the 360 list from vans and start deleting/adding/replacing. Was going to use the RV14 baffling
and snorkel and modify snorkel to fit.
Off the top of my head I would like advice on:

Prop governor
Cable lengths for prop/mixture/throttle
Special adapters 390 needs for cables to route
Alternator (will also search threads for light/best not airframe specific)
Oil cooler location and mounting
15" spinner and spinner plate for the Hartzell prop
Engine mounts (I assume same as what the 14A calls out)


Thanks!
-dudley

 

[Carl Froehlich]

Some thoughts:
- Ask about using the RV-14 snorkel and FM-200 FM that they have for the IO-390 EXP119 engine. This snorkel flows better.
- A very nice Hartzell 15” polished aluminum spinner can be special ordered from Van’s. Be prepared for sticker shock.
- Jimmy at James Cowl makes a fiberglass 15” spinner, backplate and forward support. I’ve seen these and they are nice.
- Get the same oil cooler Van’s sells for the RV-14 IO-390-EXP 119 engine. It is the AirFlow Systems 2006X: https://www.aircraftspruce.com/catalog/eppages/xseriesOilCooler.php
- I prefer the PCU-5000X prop governor - but builders choice.
- Mount the cooler on the firewall. Here is how I mounted the AirFlow 2004X cooler for my 180hp IO-360 (RV-8).

If not already done, I suggest you do some W&B calculations for this setup (including the prop weigh shift forward as you will be adding a prop extension). You will most likely need to at least mount a big battery aft to compensate.

Carl

 

[JDA_BTR]

The 2006X cooler is now about $300 more than the 2006A. The A weighs 2.9 lbs; how much does the 2006X weigh?

 

[koupster]

how much does the 2006X weigh?

Can't answer that, but the 2006X has about 37% more cooling capacity according to AirFlow Systems.

 

[JDA_BTR]

How many builders have hung a 390 on an RV8? I know Dan has not sure who else. I wonder if the stock RV14 exhaust fits? And I’m particularly unsure about cable lengths and hose lengths. I have my 14 and it’s excellent plans to go by so I can use that as a template of what is needed. The 14 was so easy it was all laid out perfectly. But it’s a little trial and error on the exhaust, cables and hoses.

 

[DanH]

Some thoughts:
- Ask about using the RV-14 snorkel and FM-200 FM that they have for the IO-390 EXP119 engine. This snorkel flows better.

Depends on which 390. If equipped with a standard Lycoming horizontal intake sump, I'd just use an FM150, which didn't exist back when I built mine. If equipped with the intake manifold separate from the oil sump (C, D, and 119), go with an FM200. That manifold has a larger bore at the flange.

- Get the same oil cooler Van’s sells for the RV-14 IO-390-EXP 119 engine. It is the AirFlow Systems 2006X

Yes indeed. I think it's the minimum.

- Mount the cooler on the firewall.

Yes, and shape the diffuser.

If not already done, I suggest you do some W&B calculations for this setup (including the prop weigh shift forward as you will be adding a prop extension). You will most likely need to at least mount a big battery aft to compensate.

This is a big deal. With a metal Hartzell up front, no shaft extension, and a PC925 in the back, I still run out of trim on final, solo with flaps. And stick force vs G is quite high when solo. With a shaft extension, big spinner, etc, you'll be need some sort of light prop for sure. It's true of any angle valve in an -8, with the 390 being the worst.

 

[JDA_BTR]

Thanks Dan. What lengths of throttle and mixture and prop cables did you order for your setup? What exhaust did you use? Where did you mount the oil cooler and what length of the various hoses did you get? I’m hoping to not figure it out from scratch!

 

[DanH]

Thanks Dan. What lengths of throttle and mixture and prop cables did you order for your setup? What exhaust did you use? Where did you mount the oil cooler and what length of the various hoses did you get? I’m hoping to not figure it out from scratch!

Not sure any of my cables use standard routing. Length? No idea. Same for hose lengths. I've slept approximately 5110 times since then

Exhaust is a 4-into-1 from Aerospace Welding: https://awi-ami.com/

Oil cooler below. Hangs on a plate, right side of engine mount, ducted to a low pressure area in the cowl exit bell. You won't need the exit duct if you don't shrink the cowl exit.

I would rather work from scratch and get better fits.
.

 

[JDA_BTR]

Thanks for the pictures that's very helpful. Do you think a standard exhaust would fit and clear the lower firewall properly?

 

[DanH]

Thanks for the pictures that's very helpful. Do you think a standard exhaust would fit and clear the lower firewall properly?

You have not told us which 390 model.

Anything which works with an IO-360 angle valve will fit the 390A, manifold integral with the sump.

I don't know what exhaust will work the C/D/119 version, separate big mouth manifold, different intake tubes.
.

 

[JDA_BTR]

I’m getting the earlier 390 not the EXP and was planning to get the same exhaust that works with it in the RV14. What I’m not sure of is if it hangs okay on the rv8 airframe without trouble.

 

[Mark33]

I’m getting the earlier 390 not the EXP and was planning to get the same exhaust that works with it in the RV14. What I’m not sure of is if it hangs okay on the rv8 airframe without trouble.

You might want reach out to Clint (Vettermans exhaust) and get some advice from him.

 

[8MikeXray]

RV8 IO-390 Exhaust

Vetterman Trombone Exhaust
IO-390 with Superior Cold Air Induction

https://share.icloud.com/photos/01fkbsNuAjwjaZOXzSetg28jg

 

[Mark33]

Vetterman Trombone Exhaust
IO-390 with Superior Cold Air Induction

https://share.icloud.com/photos/01fkbsNuAjwjaZOXzSetg28jg

Very nice! I’m also doing the Superior Cold air induction along with Clint’s trombone exhaust on my 14 build. Where did you get that throttle/mixture cable bracket that’s bolted to the intake?

 

[Vfr1200]

7A

I’m getting the earlier 390 not the EXP and was planning to get the same exhaust that works with it in the RV14. What I’m not sure of is if it hangs okay on the rv8 airframe without trouble.

I’m kind of in same situation but a 7A ,So this is what ive learned to this point .

Second the idea of calling Clint, I’m currently mapping out my firewall for a IO-390 exp ,on a 7A ,ive got the exhaust installed. i went with the 14 baffle kit and the outlet for the oil cooler is a 5” everything on the market is 4” , I spoke with airflow sys they are currently working on 5” air duct . Like Dan was saying calculate CG’s , I received same advice and just sold my 59 pound prop for a composite 38 pounds prop i will be ordering .

Back to the oil cooler mount , I ordered every available mount on the market trial fit them all , I’m going with the 90* mount on the firewall . If you pm me your cell number i can send pictures .

Also installed the efii sys 32 so i will be doing dual alternators and dual earthx batteries on the firewall . Earthx battery box’s are over 1 pound each .

Throttle cable length i will have to go with a 51” I believe but they do make extensions if needed .

Will add to this as i go … good luck

 

[8MikeXray]

Throttle mixture bracket

Showplanes makes the throttle mixture bracket. I had it ceramic coated, that’s why it’s gunmetal grey cerakote.

I also used showplanes governor bracket.

https://share.icloud.com/photos/0dfvi6ckY-jk1ky2lF1y9ypuQ

https://www.showplanes.com/index.ph...=TMC-04S&sid=wvqt917sl9717j6av347g45g9g084x0f

 

[Mark33]

Showplanes makes the throttle mixture bracket. I had it ceramic coated, that’s why it’s gunmetal grey cerakote.

I also used showplanes governor bracket.

https://share.icloud.com/photos/0dfvi6ckY-jk1ky2lF1y9ypuQ

https://www.showplanes.com/index.ph...=TMC-04S&sid=wvqt917sl9717j6av347g45g9g084x0f

That’s the information I needed….thanks! Oh, one more question, is there any particular reason you went with the Superior cold air rather than the Lycoming cold air unit?….and do you think it added to your performance?

 

[DanH]

Vetterman Trombone Exhaust
IO-390 with Superior Cold Air Induction

It's a pretty system, and solves a few fit issues. That said, it makes no sense as a high performance exhaust.

The design goal is low back pressure with correct timing of the pressure waves echoing up and down the pipe. The desired result is a strong negative pressure arriving at the exhaust port during the early part of the valve overlap period, boosting initial intake tract velocity, and promoting flow across the combustion chamber.

Firing order is 1-3-2-4. Firing interval is every 180 degrees of crank rotation. Connecting 1 and 3 on the same pipe means 3 is venting high pressure into the header precisely when the desired result is low pressure at #1.

I've attached a pressure plot from an old CAFE report. I've edited it so it only shows the exhaust and intake pressures for one cylinder. Note how the exhaust pressure plot goes strongly negative about the time the intake valve comes off its seat. Since both valves are partially open, the intake pressure is also pulled negative, well before the piston has started down the bore on the intake stroke.

Now fire up your imagination. Place another another exhaust plot (#3) 180 degrees to the right. The #3 peak exhaust pressure will sit right on #1's overlap period. #1's exhaust pressure will have gone low, so it won't restrict #3's high pressure pulse. That aspect is fine...but that same high pressure kills #1's intake scavenge.

Same on the other side. #4's high pressure exhaust pulse kills overlap flow for #2.

Happy to be wrong. Show me. I think the Vans/Lycoming team went with a crossover on the -119 (below) for a good reason, even if it did force a new cowl.
.

 

[8MikeXray]

RV8 firewall forward

A few years back, I received a call from Superior telling me not to fly my XP400 due to detonation issues causing crankshaft fractures. They informed me that they will be buying the engine back from me and I was welcome to any external parts and accessories for 1/2 price. After I spoke with them I immediately called Lycoming to order a Thunderbolt IO-390.

Lycoming’s price on the cold air induction sump option was somewhere in the neighborhood of 7K. Superior’s cold air induction sump was 3K, and after 1/2 off that, it cost me $1500. That’s how I ended up with my setup. I did not run the XP-400 and have no data for comparison.

Also, with the FM-200 in the RV8 I had to build a custom snorkel. This was all done before Lycoming started producing the IO-390-119 for the RV14. Essentially my engine is the same as the -119.

 

[Mark33]

…….

It's a pretty system, and solves a few fit issues. That said, it makes no sense as a high performance exhaust.

……

Thanks Dan! I’m actually a fan of the 4 into 1. In the old hot-rod days we put headers on everything, and all of the cars, other than top fuel dragsters and funny cars, had 4 into 1 headers. I’m actually surprised Vans didn’t stay with the original 4 into 1 but just with a little bit different design…..maybe one that exited out of the bottom cowl without needing that tunnel.

 

[8MikeXray]

More on the Trombone

From Vettermans website………

There have been many requests for a muffler system on RV's that use the horizontal induction engines. Some of the requests were for noise reduction and some were for more cabin heat. When I was working full time I really didn't have the time to design a new system, dyno and flight test it. So when I decided to retire and turn things over to Clint, my first order of business was to capitilize on all the knowledge and experience gained and come up with a new concept exhaust system. My goal was a system that would produce as much or more power as the standard crossover system and fit on a number of engine/airframe combinations. I discussed the concept with Clint and he being the energetic and talented young fellow that he is, went to work on it. When I looked at the prototype that Clint designed on the M1B, I knew it just might work. We also installed the system on the standard vertical sump and superior sump fixtures and it fit them also. We sent the system down to G3I in Denver and Thomas dyno tested it. The test numbers came out well, so we knew the pipe lengths were right where they needed to be. Next step was to test fly it on my RV-7A. I now have the tests complete and am very satisfied with the test results listed below

Tests were done at 8000 ft. Density Altitude
2450 rpm 22.2 in. mp TAS 193.5 mph EGT #1 1312 #2 1336 #3 1322 #4 1316
2500 rpm 22.0 in mp TAS 196 mph EGT #1 1312 #2 1325 #3 1327 #4 1309
2550 rpm 22.0 in. mp TAS 198 mph EGT #1 1328 #2 1329 #3 1327 #4 1320

The data listed above concurs with other tests conducted using the same aircraft, ie. my RV-7A. Note the close egt spread at 2550rpm, which is where this system likes to be run. This should be a good setup for all the fixed pitch props running out there.

The trombone system will fit on the following aircraft: RV-6-6A RV7-7A and RV-8, we are not sure of the 8A at this time. The system will fit on these engines 0-320/0-360 vertical updraft, IO-360/375 Superior cold air sump, and Lyc. IO-360 M1B.

 

[Mark33]

A few years back, I received a call from Superior telling me not to fly my XP400 due to detonation issues causing crankshaft fractures. They informed me that they will be buying the engine back from me and I was welcome to any external parts and accessories for 1/2 price. After I spoke with them I immediately called Lycoming to order a Thunderbolt IO-390.

Lycoming’s price on the cold air induction sump option was somewhere in the neighborhood of 7K. Superior’s cold air induction sump was 3K, and after 1/2 off that, it cost me $1500. That’s how I ended up with my setup. I did not run the XP-400 and have no data for comparison.

Also, with the FM-200 in the RV8 I had to build a custom snorkel. This was all done before Lycoming started producing the IO-390-119 for the RV14. Essentially my engine is the same as the -119.

Like yours, my 390 is a little bit of a “homemade” version of the -119. I decided on the Super cold air for the same reason as you….that Lycoming unit is insanely expensive.

I also went with the accessory case that has the vacuum pump pad which will allow me to run a backup alternator. I also had my engine built with the lower 8.9:1 pistons/compression ratio. I know I’m giving up a little bit of power in doing so, but I’m planing on running car gas the majority of the time. Running car gas along with the advancing timing of the electronic ignition, I wanted to try and stay away from detonation as much as possible, so the lower compression should help. I am hoping though that the cold air induction along with the electronic ignition and electronic fuel injection will help me pick some of that lost power back up.

Also, as previously mentioned, I too will be using Clint’s trombone exhaust. Like Dan illustrated in his explanation, the pulse pressures that a crossover exhaust provides is very likely a more efficient system from the performance side of things, but from the installation and maintenance side, it looks like the trombone style may be the way to go.

 

[DanH]

From Vettermans website………

All four choices are there.

4-into-1
RPM 2500 MP 21.9
TAS 206 MPH

Crossover
RPM 2500 MP 21.3
TAS 204 MPH

Four individual pipes
2500 RPM MP 22.4
TAS 206 MPH

Trombone
2500 rpm MP 22.0
TAS 196 mph

 

[N82VM]

Why the drop in speed?

Why the huge drop in speed for the trombone?

 

[JDA_BTR]

Does anyone know if the io-390 exhaust pipes sold by Vans will fit in an RV8 airframe without modification?

 

[qtrmiledan]

PM sent

Hi Dudley, PM sent

 

[8MikeXray]

RV14 IO-390 Exhaust in RV8

I was working on a friends RV14 today and took a picture of the exhaust system.

The tail pipes are too wide to fit in an RV8 cowl tunnel area.

https://share.icloud.com/photos/0eakNBJR6PbfaYrJlydzq90Bg

 

[DanH]

I was working on a friends RV14 today and took a picture of the exhaust system. The tail pipes are too wide to fit in an RV8 cowl tunnel area.

A crossover with widely spaced outlets would be good on an -8A, if the builder reshaped the lower cowl to remove the entire stock exit. The end goal would be a lot like the latest -14 setup; fixed dual outlets with pipes, a flat section in the center near flush with the belly, and a closed ramp with an aux exit door. There is speed to be found there.

The downside to a crossover is, well, the crossovers, beaming lots of radiant heat to the throttle body and sump. Obviously not a deal killer, but it's not a good thing either.

For a tailwheel -8, the 4-into-1 avoids the throttle assembly and most of the sump, and it works well with the stock exit and ramp. It also allows subsequent reduction of exit area.
.

 

[8MikeXray]

4 into 1 for RV8

Dan,

Is there a 4 into 1 exhaust system for the RV8 available that clears the Superior cold air sump and fits the stock cowl exit area?

Thanks

Mike

 

[DanH]

Call AWI and ask. Mine was circa 2008, and I sent it back for some tweaks after a test fit...no problem.

Dan,

Is there a 4 into 1 exhaust system for the RV8 available that clears the Superior cold air sump and fits the stock cowl exit area?

 

[JDA_BTR]

I talked with Clint at Vetterman today and he says the exhaust for the RV8 with a 200HP 360 is the same as for the 210HP 390 (not the EXP though). It is a crossover and will work fine. He supplies the mounting gaskets, hardware, heat muff, etc with it.