snorkel head direction
Submitted: Thursday, Oct 03, 2002 at 00:00
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Andrew
After reading a thread on the overlander site regarding
snorkel head direction, comments were made about the different levels of fuel consumption relating to the direction of
snorkel. It was said that at low speeds forwards is best, however at highway speeds they reckon that reversing the head is better???? It sure confused me as i was always under the impression the more air that was avalable the better, i.e the ram air effect. The bit that stumped me was when they said that too much air confuses the air flow meter and pumps in to much fuel, resulting in rich black exhausts. Does anyone have any ideas?? Andrew....
Reply By: Grant - Friday, Oct 04, 2002 at 00:00
Friday, Oct 04, 2002 at 00:00
Bit harsh Troy, I believe David was being critical of the idea rather than any persons. I can quite clearly see your point re donaldsons etc, the air intake on both my vehicles is behind the grill and breathes pretty
well (for all I can tell), I was under the impression that while a
snorkel allows reduces the likelihood of water in the intake it also force feeds air (somewhat) but yeah I guess you're correct in that it also attracts a lot of unwanted into your filter as
well. Have you experienced reduced economy at higher speeds with yours reversed?
Grant
AnswerID:
7156
Follow Up By: Troy - Friday, Oct 04, 2002 at 00:00
Friday, Oct 04, 2002 at 00:00
Hi Grant,
ummm - yeah - looks by the reactions to my last post - it did come across a little aggressively - so apologies for that.
Economy not effected adversely for me with
snorkel reversed.
will lay off the angry pills too....
FollowupID:
3268
Reply By: Welshmun - Tuesday, Oct 08, 2002 at 00:00
Tuesday, Oct 08, 2002 at 00:00
I can't resist joining in with this one :)
Lots of discussion in this thread about ways of preventing dust &
debris entering the intake by pointing the
snorkel head every which way, but I'd be pretty sure if there's
debris around the intake it wouldn't matter too much which way it was pointing - in it would go.
Even at moderate revs there's quite a suction from the motor.
Isn't a major point of a
snorkel that (apart from letting you run under water -
well diesels anyway) it takes air from 2 metres off the ground which just has to be cleaner .. .
Doug (newbie)
PS just got back from Fraser and found bird feathers in
mine -
It was probably a magpie doing a swoop from behind . . .
Joking aside, of course the
snorkel head has to point forward !
AnswerID:
7263
Reply By: IAMGQ - Saturday, Oct 12, 2002 at 00:00
Saturday, Oct 12, 2002 at 00:00
Face forward, get everything inside the
snorkel e.g insect.......no doubt it increase the air flow (assume clean air filter) it MAY improve eng combustion. (that's why most of trucks use
snorkel face fowward)
Face backward/sideway, can prevent object,
debris get into
snorkel directly (e.g. insects). It may not get as much air flow into the intake port but I doubt if it really lower the performance. Since even travelling 100km, there are still plenty of air can get into the engine even it face backward. Simple experiment but may be dangerous, When driving 100km/h, open window, extend your head (ask your mate to do it ! ) outside the window and face backward, is it really that hard to breath ? I don't think so. Same principle, It may create a slighly higher vaccum area but the eng still can get enough air for max performance.
Ask you self :
(1) Would you prefer to get more air(face foward) including most of
debris in air directly to get extra air which may not improve performance but you need to clean filter more often ...............OR
(2) Would you prefer to get less air (face backward) which may not worsen performance but you may not need to clean air filter so often ?
For me, City/Hwy face forward like truck. Dusty environment e.g. in convoy or there is potential getting mud into the intake (easily when driving trough
mud hole), turn it backward.
THAT'S WHY THEY DESIGN TO ALLOW TO TURN IT FORWARD OR BACKWARD.
If still need to debate, I think we really need to have a "Wind Tunnel"
test for it.
EVERYBODY IS RIGHT !
AnswerID:
7340