lower shrouds on corvair engine

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dick2256
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lower shrouds on corvair engine

Postby dick2256 » Fri Dec 30, 2016 7:57 am

I need someone older that used to run coevair engine on a airboat
did you run with the lower shrouds on?
I have never had them on my motor but the guys on the corvair forums say I should be
and think that is why my engine runs hot

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Deano
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Re: lower shrouds on corvair engine

Postby Deano » Fri Dec 30, 2016 8:50 am

Never ran a Corvair engine on an airboat, but after seeing the dramatic results attained on A/C engines by running proper shrouding, it seems hard to imagine that any air cooled engine would not benefit from using them.

I don't know that the way the originals were configured would be optimal for an airboat. There are a few examples around here of such shrouds that do work vey well in our application, and appear most often to be upper rather than lower.
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Deano
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Re: lower shrouds on corvair engine

Postby Deano » Fri Dec 30, 2016 9:11 am

From a quick search:

Image

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Image

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"The suppression of uncomfortable ideas may be common in religion and politics,
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dick2256
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Re: lower shrouds on corvair engine

Postby dick2256 » Fri Dec 30, 2016 10:07 am

baffles.jpg
Deano wrote:Never ran a Corvair engine on an airboat, but after seeing the dramatic results attained on A/C engines by running proper shrouding, it seems hard to imagine that any air cooled engine would not benefit from using them.

I don't know that the way the originals were configured would be optimal for an airboat. There are a few examples around here of such shrouds that do work vey well in our application, and appear most often to be upper rather than lower.
https://www.corvair.org/chapters/corvanatics/files/documents/manuals/shop64/6A-engine-64.pdf
have a look at the engine and see what you think I am referring to parts # 29 & 11

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Re: lower shrouds on corvair engine

Postby gruprgetr » Fri Dec 30, 2016 10:27 am

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IF YOU PISS SOMEONE OFF MEANS THEY HEARD YOU
AIRBOATS DONT SPREAD HYDRILLA

AIRBOATS DONT CAUSE ANIMOSITY- PEOPLE DO!!
PROTECT YOUR FUTURE WEAR A PFD AND VOTE!!
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Re: lower shrouds on corvair engine

Postby GMAC 76 » Fri Dec 30, 2016 11:08 am

I ran corvair engines for several years back in the 70's and we always ran with the fan and upper fan shroud and without the lower cooling baffles....it seemed to keep that center cyl cooler by moving the engine heat and exhaust manifold heat down and and away from the engine....there was always the argument with corvair engine car guys that claimed the lower baffles actually kept the exhaust heat away from the cyls but they were always referring to the engine when it was in the corvair....we also found that a high octane fuel and a slight retard in the timing helped with the heating problem but did not affect performance...

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Re: lower shrouds on corvair engine

Postby dick2256 » Fri Dec 30, 2016 1:04 pm

did you ever have a problem with the end play on the crankshaft
Mine seems to move more than it should but doesn't seem to hurt anything

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Re: lower shrouds on corvair engine

Postby GMAC 76 » Fri Dec 30, 2016 1:15 pm

dick2256 wrote:did you ever have a problem with the end play on the crankshaft
Mine seems to move more than it should but doesn't seem to hurt anything

to answer your question....no......really never had any problems with the corvair except keeping them center cyls cool

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Re: lower shrouds on corvair engine

Postby dick2256 » Fri Dec 30, 2016 3:33 pm

GMAC 76 wrote:
dick2256 wrote:did you ever have a problem with the end play on the crankshaft
Mine seems to move more than it should but doesn't seem to hurt anything

to answer your question....no......really never had any problems with the corvair except keeping them center cyls cool

when I built my first covair powered boat we ran it hard for over 5hrs giving people rides and I burnt the number 5 piston and after that I was more carful and never had that happen again
I am running with a tranny cooler out of a 92 buick for an oil cooler and I can run hard now and let it set a minute or two and it starts right up again.
Only reason I was asking about those shrouds was I thought after I had it tore down to put o rings in the return tubes I would check the shrouds out
My tubes are leaking pretty bad and I have some pan bolts that are stripped and going to heli-coil those and put in a new pan gasket and valve cover gaskets
Thanks you guys for the help but I am not going to put those lower shrouds in

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Re: lower shrouds on corvair engine

Postby Duece » Tue Jan 03, 2017 10:50 am

My old man and uncles ran corvair boats in the late 70's and early 80's and I'm not sure they ran any shrouds?! I also don't remember any cooling issues either. They had one on a 10x6 deck over and the other on an 11x7 gore. The one on the deck over had the 4 1 barrel carbs, but we could never get the back 2 carbs to open up fully. Those things would scoot, would love to see pics of those old corvair rigs. All our stuff was from Banks Maxwell at the time.

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dick2256
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Re: lower shrouds on corvair engine

Postby dick2256 » Thu Jan 05, 2017 7:58 am

corvair 012.JPG

mine was a bank & Maxwell but I added the top half of
the cage and wire for safety
I remove the cage with 4 bolts and it fits in the garage
still on the trailer

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Re: lower shrouds on corvair engine

Postby Duece » Thu Jan 05, 2017 8:59 am

dick2256 wrote:
corvair 012.JPG

mine was a bank & Maxwell but I added the top half of
the cage and wire for safety
I remove the cage with 4 bolts and it fits in the garage
still on the trailer

Is yours one of the Jon boat conversions? We put them on custom hulls w/pancake cages. They were good running little motors for what we were using them for which was to duck hunt the tidal marshes in the Big Bend area of FL.

Duece
"Welcome to the Dark Side..."
14'x7'6" Diamondback ZZ4 350/355hp 2.37:1 Stinger gearbox 80" 3 blade NGR series

dick2256
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Posts: 294
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Location: Carson Iowa

Re: lower shrouds on corvair engine

Postby dick2256 » Thu Jan 05, 2017 4:41 pm

Duece wrote:
dick2256 wrote:
corvair 012.JPG

mine was a bank & Maxwell but I added the top half of
the cage and wire for safety
I remove the cage with 4 bolts and it fits in the garage
still on the trailer

Is yours one of the Jon boat conversions? We put them on custom hulls w/pancake cages. They were good running little motors for what we were using them for which was to duck hunt the tidal marshes in the Big Bend area of FL.

Duece
yes I was running it on a 44"bottom width and it was nto easy to upset so I ripped the hull and made it 6'8"s on the bottom
and it was 14' long and I shortened it to 12'


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