russbost
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| posted on 19/7/18 at 09:53 AM |
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Cooling an "air" cooled engine - How smart are you?
Sounds simple - Yeah, trust me it's not - see the pic below
[img]
 
[/img]
This is our 6 cyl 3.3l aero engine in the plane I own a share of, it's a Jabiru, if that means anything to any of you.
You are looking at the engine from underneath, cyl's 1,3,5 are on the RHS as pictured, 2,4 & 6 on the left; fuel is supplied by a single
Bing carburettor fitted where the towel is currently blocking the entry - that plenum has a vertical "strut" on the entry designed to
split airflow equally left & right & has various vanes/fins within designed to get airflow to each cyl (yes, I know it''s a crap
design!)
We, along with other Jabiru owners have always had difficulty in getting consistent cooling equally to each side, the LHS (2,4,6) always tends to run
warmer than the RHS (by as much as 40 degrees). The engine does have an oil cooler, but that only really controls oil temp, has very little to do with
cyl head temps which are what we have to monitor The engine has air ducts/cowls which fit around the top of the heads & direct air around the
cooling fins - these have to be a little different side to side, because as you can see the cyl's are staggered
Reading the Jabiru forums everyone agrees that the engine is not just air cooled it is air/fuel cooled & having experimented with mixture, we
would certainly agree that running richer lowers both EGT's & CHT's (Exhaust gas temps & Cylinder head temps)
Now; we've done manometer checks within the cooling ducts at entry & exit & pressures are as near the same as we can tell with the
limited resources available, so there would not appear to be any significant difference in the airflow
Even with all the ducts & cowls removed if the engine is run up on the ground the LHS always warms up significantly faster than the RHS -
EGT's are very close to equal, cyl head temps miles different & airflow around all cyl's with the ducts is fairly random, just from
the propwash
There are suggestions on the Jabiru forums that one side runs richer than the other, our plug colours would deny this as would our EGT's so why
should one side run hotter than the other, I also fail to see how with only one atomiser putting vapourised fuel into ALL air drawn thro' the
carb how more fuel could end up consistently one side or t'other???
Is it feasible that as cyl's 2,4 6 are "fed" first from the single carb that they are actually getting MORE of the same mixture, a
bit like having twin carbs, but with one carb bigger than the other, but delivering equal air/fuel mix. This would probably keep EGT's very
similar, but would presumably give those 3 cyl's more power & more power = more heat, or is that idea just plain daft
We can overcome the basic high cyl head temps issue by running a richer mixture at WOT when the demands on engine & cooling are greatest, but that
still leaves us with a significant imbalance between the 2 sides, which means it's impossible to run both sides at the ideal running temps
Any ideas or input welcome it's got me tearing my (already grey!) hair out
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
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furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
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Schrodinger
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| posted on 19/7/18 at 10:29 AM |
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I'm not really into air cooled engines but IIRC they do need good oil flow as part of the cooling so could it be that the oil is not getting
to/from the hot bank as fast as it should?
Keith
Aviemore
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Dick
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| posted on 19/7/18 at 11:03 AM |
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Is it not possible to fit afr/ lambar sensors to the left and right side exhaust so you could check fuelling on the 2 banks. You would then have a
better idea if its cooling or management of fuel
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theconrodkid
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| posted on 19/7/18 at 11:20 AM |
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assuming all the parts are the same and just the location changes, how about the exhaust, a restriction there will cause it to run hot, have you been
onto the engine manafacturers ?
who cares who wins
pass the pork pies
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Mr Whippy
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| posted on 19/7/18 at 11:56 AM |
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Remembering that the prop wash is in a spiral one intake will have the cooling air entering the intake from the top and the other from the bottom,
although the flow may seem to be equal in pressure the flow direction sure isn't so poor ducting could be causing issues there or the assumption
that both sides should have identical ducting. Tufts of wool attached to the visible internal cowling should help identify turbulent air flow or
stagnant pockets. Even a spot infrared temperature gun should help identify overheating sections.
Also having an over-size intake can actually cause overheating if the exit is undersized. I was always told the exit should be about 3 times larger
than the intake to accommodate the expansion of the hot air. You don't show the engine baffle arraignment, I'm assuming its leak tight and
close fitting passing from the top to the bottom. The rear cylinders are always going to have a hard time unless fed by their own dedicated baffle. I
can't see in between the barrels but VW / Porsche fitted plates between the barrels to force air sideways rather than directly through the fins
to cool the underside. Not that that always worked as there was one cylinder that cooked and use to drop valves.
Nice engine but the fins look a bit chunky on the heads, would have liked them to be tapered thinner.
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907
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| posted on 19/7/18 at 12:11 PM |
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I did an exhaust for an H/O 8 cylinder version than was installed in a Spitfire lookalike, hence the 6 outlets per side at the top.
This engine is now running water cooled cylinder heads.
Paul G
 
Description
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russbost
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| posted on 19/7/18 at 12:20 PM |
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in answer to the first 3 Q's, there is nothing in the top end of the engine to allow any significant oil cooling, it's a pushrod engine
& only fairly limited flow to the rocker covers, no one has ever mentioned anything connected with oil cooling the engine other than airflow
thro' the oil cooler affecting the overall flow over the engine as a whole.
Fitting lambda sensors or anything to properly monitor air/fuel on each bank would be ideal, but unfortunately would require a "Mod" with
LAA engineering, we can only do stuff which would be regarded as temporary & test on the ground, anything fitted more permanently or to be used in
actual flight needs a Mod applied for & is a proper PITA!
We've had the exhaust to bits in the past, no restrictions other than the crap (typical aeronautical - think pre '50's - design!) -
the manufacturer are no help, they take the attitude that every plane is different & will be assembled differently & it's an Australian
manufacturer - which makes it all the more strange that they didn't design it with decent cooling in the first place - these are the 2nd
generation barrels & heads, the early ones had b*gger all fins on worth talking about - strangely they suffered with overheating problems
...............
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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russbost
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| posted on 19/7/18 at 12:35 PM |
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quote:
Originally posted by Mr Whippy
Remembering that the prop wash is in a spiral one intake will have the cooling air entering the intake from the top and the other from the bottom,
although the flow may seem to be equal in pressure the flow direction sure isn't so poor ducting could be causing issues there or the assumption
that both sides should have identical ducting. Tufts of wool attached to the visible internal cowling should help identify turbulent air flow or
stagnant pockets. Even a spot infrared temperature gun should help identify overheating sections.
Also having an over-size intake can actually cause overheating if the exit is undersized. I was always told the exit should be about 3 times larger
than the intake to accommodate the expansion of the hot air. You don't show the engine baffle arraignment, I'm assuming its leak tight and
close fitting passing from the top to the bottom. The rear cylinders are always going to have a hard time unless fed by their own dedicated baffle. I
can't see in between the barrels but VW / Porsche fitted plates between the barrels to force air sideways rather than directly through the fins
to cool the underside. Not that that always worked as there was one cylinder that cooked and use to drop valves.
Nice engine but the fins look a bit chunky on the heads, would have liked them to be tapered thinner.
Yup, aware of all the oddities of spiral airflow & you may well be right that that is where the problem lies, but, if that were the case I would
be surprised that it was still similarly unbalanced in cooling when run with all the ducts & cowls off.
It's not much fun working around the engine when running due to that big whizzy thing on the front  being a constant threat to the unwary -
you tend to make mistakes only once (so I'm told!) ..........., but the tufts of wool idea might work, we could then video from the front of the
ducts to avoid getting anywhere near. I do also have an infra red "gun", but TBH it doesn't appear to be a localised problem, other
than the fact it's local to the one bank!
The individual cylinders do have baffles in the ducting, which we have played around with in the past & got a much more even balance between
cylinders, but it doesn't help with the overall balance between the sides & they also have plates between the barrels such as you
describe.
It feels as though we need to take cooling from one side & transfer it to the other, there just isn't any easy way of doing that without
getting into the whole "Mod" scenario as described above. I feel sure if we can get it balanced on the ground it will be fine in the air
& if we could achieve that, however it was done, then would actually be worth the aggro of applying for the necessary mod to make a permanent
update
Your comment about the chunky fins is rather prophetic - guess what the phase 3 heads looked like ! Annoyingly, we can "upgrade" to the
later heads, but at the same time they changed the exhaust, upper & lower cowls & the ducts - I think we'd be looking at around £4k
& a load of work, which seems somewhat excessive for what appears on the surface such a simple issue ..................
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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russbost
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| posted on 19/7/18 at 12:38 PM |
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quote:
Originally posted by 907
I did an exhaust for an H/O 8 cylinder version than was installed in a Spitfire lookalike, hence the 6 outlets per side at the top.
This engine is now running water cooled cylinder heads.
Paul G
Description
That looks lovely! 
I believe there's an aftermarket water cooling option, but, aside from the cost & time fitting & needing to apply for a Mod to do so, it
adds weight & would move our CoG forward, which would not be a good thing & I don't particularly like adding water cooling to what
should be an air cooled engine!
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Simon
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| posted on 19/7/18 at 08:00 PM |
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Iirc (and this has nowt to do with aircooled but may help in a roundabout way), Suzuki found that the inner cylinders on the Hayabusa ran hotter than
the outer so run the inner cylinders slightly richer. No idea how true but may be a way to control temps (if you can do that sort of thing with your
engine)
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Angel Acevedo
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| posted on 20/7/18 at 01:45 AM |
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Hi Russbost,
Some questions...
Are the differences in temperature the same (or similar) at all power settings or airspeeds?
Have you changed CHT probe cables from side to side? To see if temperatures switch sides?
Is baffling tight to the cowling on both sides?
From some pics on the internet I see that the oil filter is on the left side of the engine, but I don´t think that will produce 40 deg difference.
Do you have pics of your engine bay?
Beware of what you wish.. for it may come true....
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Pigsy
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| posted on 20/7/18 at 06:35 AM |
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Re: Suzuki found that the inner cylinders on the Hayabusa ran hotter than the outer so run the inner cylinders slightly richer.
There are plenty of 3 cylinders Triumph motorcycle, 3 row injection throttle bodies available on ebay, or the like of ebay. If you placed one per bank
you would get individual cylinder mixture control. You can fit different sized injectors. Alternatively, fit an oil cooler per bank of cylinders, or
one that is much larger. Can you fit them to be sited remotely? VW air cooled flat 4, or Porsche flat 6 engine parts may be adaptable.
How about swapping it with a Porsche flat 6 engine? Get the simpler normally aspirated engine with the distributor etc.
I hope that this is of help.
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Angel Acevedo
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| posted on 20/7/18 at 06:37 AM |
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quote:
Originally posted by Pigsy
Re: Suzuki found that the inner cylinders on the Hayabusa ran hotter than the outer so run the inner cylinders slightly richer.
There are plenty of 3 cylinders Triumph motorcycle, 3 row injection throttle bodies available on ebay, or the like of ebay. If you placed one per bank
you would get individual cylinder mixture control. You can fit different sized injectors. Alternatively, fit an oil cooler per bank of cylinders, or
one that is much larger. Can you fit them to be sited remotely? VW air cooled flat 4, or Porsche flat 6 engine parts may be adaptable.
How about swapping it with a Porsche flat 6 engine? Get the simpler normally aspirated engine with the distributor etc.
I hope that this is of help.
Don´t think he can do that, it´s a plane, not a car...
Beware of what you wish.. for it may come true....
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jollygreengiant
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| posted on 20/7/18 at 06:52 AM |
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IF the engine rotation is clockwise from above, could it be poor splash lubrication from the crankshaft, or poor drainage down the RHS banks from the
push rod tubes.??? JMTP'sW.
Beware of the Goldfish in the tulip mines. The ONLY defence against them is smoking peanut butter sandwiches.
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Mr Whippy
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| posted on 20/7/18 at 11:12 AM |
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Mind too that the oil does have a large part to play in the cooling of the engine, though it doesn't explain the imbalance... I'm assuming
you have tried swapping round the temp sensors and wiring to check it's a reliable reading? that they are mounted to identical area's on
the engine? If you have access to the heads when running I would have taken average readings again with a infrared thermometer. Maybe borrowing a IR
camera could highlight problem areas on the engine??
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02GF74
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| posted on 20/7/18 at 04:25 PM |
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My guess is that it is the air flow from the prop. I assume you run the engine with prop fitted, can you ru. Without it?
If not, make a cylindrical cowl around the engine to control air flow. Will this be symmetrical around d the prop, then where do the cylinder heads
lie in the space, is one side going ebe better cooled.
Depending on which direction the prooeis spinning, can hot air from one bank be directed to the other so it has hotter air flow g onto it?
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russbost
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| posted on 20/7/18 at 04:55 PM |
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quote:
Originally posted by Simon
Iirc (and this has nowt to do with aircooled but may help in a roundabout way), Suzuki found that the inner cylinders on the Hayabusa ran hotter than
the outer so run the inner cylinders slightly richer. No idea how true but may be a way to control temps (if you can do that sort of thing with your
engine)
Unfortunately not, it has just the one carb delivering fuel to all 6 pots
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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russbost
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| posted on 20/7/18 at 05:38 PM |
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quote:
Originally posted by Angel Acevedo
Hi Russbost,
Some questions...
Are the differences in temperature the same (or similar) at all power settings or airspeeds?
Have you changed CHT probe cables from side to side? To see if temperatures switch sides?
Is baffling tight to the cowling on both sides?
From some pics on the internet I see that the oil filter is on the left side of the engine, but I don´t think that will produce 40 deg difference.
Do you have pics of your engine bay?
The difference in temps ranges from around 20 deg C across opposing cyls. ie, comparing 1 with 2, 3 with 4 etc, to around 40 deg at worst, they are
probably closest at climbout when we typically see around 200 on the LH bank & around 180 on the RH, they differ most when in straight, level
cruise when you may have 160 compared to 120 (the low side, ironically, is actually too cool!)
We did individual checks with both infra red & a single under plug additional lead as a check on existing, we're happy readings are accurate
to certainly within 5 degrees
Baffling/cowls are equally tight both sides, over the years various small gaps have been filled, doesn't seem to make a scrap of difference.
I've attached some pics below - you'll see the oil filter is completely outside all the ducting. We were doing a service on the engine
today &, as an experiment, completely taped over the inlet entry ports so the heads & barrels had only still air, we only ran briefly for
obvious reasons & stationary at relatively low RPM, but there was still a significant difference between the 2 sides with the LHS (as viewed from
cockpit) warming up substantially quicker by around 15 - 25 deg across comparative cyls
1st, the engine "naked"
[img]
[/img]
Here you can see the plenums/ducting
[img]
[/img]
Looking down inside the LHS plenum, this is the side that gets hotter
[img]
[/img]
Looking down the RHS plenum - due to no.1 cyl being further forward than no. 2 the air entry is very different
[img]
[/img]
Finally with upper & lower cowls fitted, & the front ducts completely taped over - I fail to see why one side should warm up b4 the other when
there's no air movement!
[img]
[/img]
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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russbost
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| posted on 20/7/18 at 05:41 PM |
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quote:
Originally posted by jollygreengiant
IF the engine rotation is clockwise from above, could it be poor splash lubrication from the crankshaft, or poor drainage down the RHS banks from the
push rod tubes.??? JMTP'sW.
Looking at the engine from the front rotation is anti - clock, which I would have thought would create MORE splash to lower bores/pistons on the side
that is the hotter, which again makes no sense at all ........... As said b4 from all the info we've gleaned oil cooling does not seem to
feature
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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russbost
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| posted on 20/7/18 at 05:55 PM |
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I think I've answered Mr Whippy's Q's with the info above, & one bit at the end of this one
02GF74 unfortunately can't run without the prop, but I think what we did by taping over the ducts is similar as it removes prop air almost
entirely from the equation
Re can hot air be transferred from one side to the other, not to any significant degree due to the plenums/ducting, & given the prop rotation, you
are getting air travelling in an upward spiral on the LH bank (the hot side) & a downward spiral on the cooler bank, it would seem logical that
having the air forced directly down onto the heads rather than up into the cowl & along (that's what the temporary baffle at the front of
the LH bank is for, with no baffle there no. 2 runs much hotter & no. 6 much cooler)
You're coming up with some interesting & sensible stuff guys, but, unfortunately we've already tried most of it, I was just hoping
someone might spot something obvious we'd missed - air cooled engines are not a strongpoint for me 
Possibly Mr Whippy's idea with bits of wool to detect laminar flow & an infra red camera (does anyone have one they' like to lend
me???  ) might just throw up something useful, but, problem is, if we have good laminar flow on the cool side & disruptive flow on the hot side,
what the hell do we do to straighten out that disrupted flow?
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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NOTE:This user is registered as a LocostBuilders trader and may offer commercial services to other users
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Angel Acevedo
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| posted on 20/7/18 at 05:56 PM |
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I think I may have the answer...
The soft baffling looks a tad too soft...
Inflight it may be collapsing back, therefore not enough cooling air being directed over the cylinders.
HTH and Solves your problem.
Angel Acevedo
Beware of what you wish.. for it may come true....
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Pigsy
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| posted on 20/7/18 at 06:07 PM |
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Re: Don´t think he can do that, it´s a plane, not a car...
I appreciate fully that this is an aeroplane and not a car. Are you not aware of how many light aircraft use VW beetle flat four, air cooled engines
(from their car range) where you can fit extra large oil coolers. By enrichening the fuel passing into the bores, if you keep the same engine, you
will reduce the running temperatures. It is perhaps too simple for some. Using two sets of Triumph fuel injection throttle bodies from their
Motorcycles, you will find that they will fit straight on to the induction pipes of your flat six air cooled engine. You will not need the Bing
carburettor at all. A small aftermarket fuel injection with its own ecu is available. You need to look for it. With this you will have a far greater
control over your fuel mixture.
The Porsche engine has been used many times, but then, hey, what do I know.
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Angel Acevedo
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| posted on 20/7/18 at 06:22 PM |
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quote:
Originally posted by Pigsy
Re: Don´t think he can do that, it´s a plane, not a car...
I appreciate fully that this is an aeroplane and not a car. Are you not aware of how many light aircraft use VW beetle flat four, air cooled engines
(from their car range) where you can fit extra large oil coolers. By enrichening the fuel passing into the bores, if you keep the same engine, you
will reduce the running temperatures. It is perhaps too simple for some. Using two sets of Triumph fuel injection throttle bodies from their
Motorcycles, you will find that they will fit straight on to the induction pipes of your flat six air cooled engine. You will not need the Bing
carburettor at all. A small aftermarket fuel injection with its own ecu is available. You need to look for it. With this you will have a far greater
control over your fuel mixture.
The Porsche engine has been used many times, but then, hey, what do I know.
Didn´t mean to be rude,
But for sure my reply was not clear:
Even though what you propose is feasible, it will require approval fron aviation authorities as already stated by Russbost.
Best regards
Angel Acevedo
Beware of what you wish.. for it may come true....
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russbost
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| posted on 20/7/18 at 06:48 PM |
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Pigsy, I'd not replied as felt Angel's answer covered it. But, yes, a different engine could be fitted, but with aero stuff this just
opens up a whole new bunch of nightmares. Firstly there is the weight & balance & CoG which it will certainly screw up - these things rarely
seem to accidentally work out better. Then there's the matter of mounting it, suitable exhaust etc & then you have a fuel injection system
designed to work typically between 0 & 3 or 4,000 feet on Mogas rather than at up to 10,000ft on avgas. If I was going for an engine swap then I
think a ZZR1400 would be choice, I think it might need a reduction box tho'!!!
As said we could chuck £4 or £5k at it with the later heads, plenums, cowls & exhaust & given that there's 5 of us sharing that's
not even that much money, certainly not in aviation terms, it just seems like using a sledge hammer to crack a relatively small nut ..........
Angel, a nice thought re the soft baffling, which allows the plenums to mate with the top cowl ducts, but we've had several different versions
in the past, none have made any difference, also, that wouldn't explain the issues on the ground with little or no airflow & still a huge
difference side to side, added to which when the cooling is at it's best, ie straight level cruise, is surely when the soft rubber would be most
likely to be disturbed, at around 125mph rather than ground speeds
I'll keep looking/trying stuff .............
I no longer run Furore Products or Furore Cars Ltd, but would still highly recommend them for Acewell dashes, projector headlights, dominator
headlights, indicators, mirrors etc, best prices in the UK! Take a look at http://www.furoreproducts.co.uk/ or find more parts on Ebay, user names
furoreltd & furoreproducts, discounts available for LCB users.
Don't forget Stainless Steel Braided brake hoses, made to your exact requirements in any of around 16 colours.
http://shop.ebay.co.uk/furoreproducts/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
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steve m
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| posted on 20/7/18 at 06:57 PM |
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Russ,
What is baffling me, is which bank is at fault, is it the hot one is too hot, and shouldn't be, or the cool one is to cold, and should be
hotter?
Does the engine have separate EGT gauges, as in one for each bank, and if it does, are you able to verify that both are reading the same temps ?can
they be swapped with wiring to the opposite sides, to allow a comparison ?
Is carb heat fitted? and if so is it working off one bank or both,
Are the cold air feed ducts the same size, and placed equally behind the propeller,
Hot air needs to exit the cowling equally from both sides, does the hot side have any obstructions in its air exit, like startermotor
battery, or any large obstruction, that would impede its exit
steve
Thats was probably spelt wrong, or had some grammer, that the "grammer police have to have a moan at
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