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RV-8 /IO-390 EXP Exhaust

Laird

Laird

Well Known Member
Hello all,

Looking to collect different options for a IO-390 EXP exhaust that fit in an RV8 and stock cowl.

If you have any info, please include vendor, P/N, configuration (4 pipe, crossover, 4:1, etc), cost, if you have it.

I'm assuming that if it fits the stock cowl inlet, it would work with some custom ram air inlet. (That might be a bad assumption).

I have a line on a exhaust builder in San Diego that custom built a 4:1 for about #3K. I haven't confirmed availability or lead time. I was going to wait to see what else is available before I mount my engine.

Anyone else? I'm about Van's support the same question, but I'm not expecting they'll have an answer.

Thanks,

Laird
 
I have a Vetterman crossover exhaust for an IO-360-M1B RV8 with 760 hours that I will be selling in a few weeks for reasonable $.

Sam
 
Pilot8 said:
I have a crossover exhaust for an IO-360-M1B RV8 with 760 hours that I will be selling in a few weeks for reasonable $.

Sam
Click to expand...
Thanks, but I'm not sure that will fit the IO-390 EXP, but if anybody knows for sure, speak up.

I think the IO-360 parallel valve (180hp) exhaust is different than the IO-360 angle valve exhaust
(200hp, which the 390 is based off of) are different.

Regards,

Laird
 
Laird said:
Thanks, but I'm not sure that will fit the IO-390 EXP, but if anybody knows for sure, speak up.

I think the IO-360 parallel valve (180hp) exhaust is different than the IO-360 angle valve exhaust
(200hp, which the 390 is based off of) are different.

Regards,

Laird
Click to expand...
Laird, you are correct, the IO-390 is an angle valve- checked the RV14 wrap-around view on vansaircraft. Sam
 
The cross-over exhaust for the RV-8 with the angle-valve IO-360 should fit fine. Someone please tell us if that is wrong.
 
Laird said:
Hello all,

Looking to collect different options for a IO-390 EXP exhaust that fit in an RV8 and stock cowl.

If you have any info, please include vendor, P/N, configuration (4 pipe, crossover, 4:1, etc), cost, if you have it.

I'm assuming that if it fits the stock cowl inlet, it would work with some custom ram air inlet. (That might be a bad assumption).

I have a line on a exhaust builder in San Diego that custom built a 4:1 for about #3K. I haven't confirmed availability or lead time. I was going to wait to see what else is available before I mount my engine.

Anyone else? I'm about Van's support the same question, but I'm not expecting they'll have an answer.

Thanks,

Laird
Click to expand...
Have you asked Vetterman exhaust? He probably can you give a precise answer.
 
Laird said:
Hello all,

Looking to collect different options for a IO-390 EXP exhaust that fit in an RV8 and stock cowl.

If you have any info, please include vendor, P/N, configuration (4 pipe, crossover, 4:1, etc), cost, if you have it.

I'm assuming that if it fits the stock cowl inlet, it would work with some custom ram air inlet. (That might be a bad assumption).

I have a line on a exhaust builder in San Diego that custom built a 4:1 for about #3K. I haven't confirmed availability or lead time. I was going to wait to see what else is available before I mount my engine.

Anyone else? I'm about Van's support the same question, but I'm not expecting they'll have an answer.

Thanks,

Laird
Click to expand...
Laird,

I worked with my friend who built the "Red-Tail" RV8 that we flew to AirVenture 2022 ("Outstanding Workmanship Award"). The 4-1 exhaust done in CA was probably his.
We thought that the setup from the IO360 would work but it did NOT! After some "Lowe's Aviation Department Engineering", we came up with appropriate adjustments to the dimensions to get it to fit.

It took an iteration or two to get things right. Contact me offline for further info from my friend. He does not post that much here.
 
Laird said:
Hello all,

Looking to collect different options for a IO-390 EXP exhaust that fit in an RV8 and stock cowl.

If you have any info, please include vendor, P/N, configuration (4 pipe, crossover, 4:1, etc), cost, if you have it.

I'm assuming that if it fits the stock cowl inlet, it would work with some custom ram air inlet. (That might be a bad assumption).

I have a line on a exhaust builder in San Diego that custom built a 4:1 for about #3K. I haven't confirmed availability or lead time. I was going to wait to see what else is available before I mount my engine.

Anyone else? I'm about Van's support the same question, but I'm not expecting they'll have an answer.

Thanks,

Laird
Click to expand...
I would give Vetterman a call and discuss it with them. I found them to be extremely helpful with my IO-375 in an RV-8. They actually guarantee that it will fit and it did. I wouldn't hesitate to go back.
 
Laird said:
Hello all,

Looking to collect different options for a IO-390 EXP exhaust that fit in an RV8 and stock cowl.
Click to expand...

Been flying this on an early kit 390 for a long time, still happy: https://awi-ami.com/4-1-exhaust

IIRC, the version of the 390 intended for the Gen2 RV-14, with a Lycoming big mouth intake manifold (see 390C, 390-119), uses different intake tubes, and may not work with an exhaust intended for the earlier 390.
 
scsmith said:
The IO-390 that the OP asked about is an angle-valve engine. The cross-over exhaust for the RV-8 for the angle-valve IO-360 should fit. No parallel-valve engines involved in this discussion.
Click to expand...
Per Van's:
Hi Laird,

We don't have an exhaust for the EXP in the RV-8.

Oh well.....I'll call Clint next.
Laird
 
jclark said:
Laird,

I worked with my friend who built the "Red-Tail" RV8 that we flew to AirVenture 2022 ("Outstanding Workmanship Award"). The 4-1 exhaust done in CA was probably his.
We thought that the setup from the IO360 would work but it did NOT! After some "Lowe's Aviation Department Engineering", we came up with appropriate adjustments to the dimensions to get it to fit.

It took an iteration or two to get things right. Contact me offline for further info from my friend. He does not post that much here.
Click to expand...

Hi James,
I did make contact with your friend, and he passed on the information from the custom builder in San Diego. That was the contact I mentioned in the original post.
Thanks for reminding me.
Laird
 
DanH said:
Been flying this on an early kit 390 for a long time, still happy: https://awi-ami.com/4-1-exhaust

IIRC, the version of the 390 intended for the Gen2 RV-14, with a Lycoming big mouth intake manifold (see 390C, 390-119), uses different intake tubes, and may not work with an exhaust intended for the earlier 390.
Click to expand...
Thanks Dan,
I looked at them earlier and figured it was for the "non-exp" version. I need to contact them to see if they have an updated version for the EXP. I'll report back soon.

Thanks,
Laird
PS Great job rounding up oil filters for accurate testing. If you need another round of fund raising, I'm in. I didn't see the post before you target funds were achieved. What a great community. Thanks for taking on the task.
 
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