CFM Rating
Submitted: Saturday, Nov 15, 2008 at 00:36
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63533
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Rob Mac
Does anyone know the CFM (Airflow) Rating / requirements for a Toyota 4.2TD 1HDFTE. I am looking at putting a Pre-cleaner on in place of my Air-ram and wanting to size it correctly. I have downloaded the spec's from Toyota and cannot find it, and working in parts I know this sort of info is usually not available through parts and service.
Thanks
Reply By: Richard Kovac - Saturday, Nov 15, 2008 at 00:49
Saturday, Nov 15, 2008 at 00:49
Rob Hi
A 4.2TD = 4.2 l/rev
max rpm = (you need to know) then convert to CFM, I think, its late and sorry I can't B stuffed trying to work it out.
Sorry
Richard
AnswerID:
335315
Follow Up By: Harrow - Saturday, Nov 15, 2008 at 09:42
Saturday, Nov 15, 2008 at 09:42
its a 4 stroke
2.1L/ Rev
FollowupID:
603036
Follow Up By: Richard Kovac - Saturday, Nov 15, 2008 at 21:44
Saturday, Nov 15, 2008 at 21:44
Harrow, Thanks didn't think of it that way.
Cheers
Richard
FollowupID:
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Follow Up By: Rob Mac - Saturday, Nov 15, 2008 at 23:07
Saturday, Nov 15, 2008 at 23:07
Hello Richard,
I think the most revs I would have done is about 3400 with red line 4000 , so I come up with 3400 x 4.2L= 14280 divide by 27( as per other follow up) = 529.
The Donaldson 3" outlet Precleaners are available with a 7" bowl (170CFM) and a 10.63" bowl (320CFM), so using these figures neither would be suitable.
The 10.63" ones might not sound big but when you look at it it is huge and would stick outside the line of the cab and would not last long on close tracks.
Years ago in
Darwin I used to sell the 7" ones to Toyota owners and they seemed ok.
I will keep working on the problem, most likely keep the air ram and check filter element more regularly on the Simpson and Tanami.
Thanks
FollowupID:
603166
Reply By: Mick15 - Saturday, Nov 15, 2008 at 10:30
Saturday, Nov 15, 2008 at 10:30
Well you'd have to consider volumetric efficiency(less flow), and then the turbo boost(more flow).
It'd be better to over estimate than under estimate, so...
If we assumed the engine had 100% volumetric efficiency each rev would suck 2.1 litres.
Then if the turbo was pushing 14.7psi (1atm) that would double your air requirement making it 4.2 litres per rev.
Boost probably isn't this high but better to over estimate - in case you decide to wind the boost up!
Therefore at 4500rpm (and peak volumetric efficiency would be closer to max torque, tapering right off as torque drops and revs rise) it would suck 18900 litre/minute, if 1 cubic foot is 27 litres, that would be 700cfm.
Thats a pretty high figure but thats assuming its got higher VE than what it would have, it'd probably be closer to 60% at max revs.
Also another thing to consider is that those donaldson pre cleaners that sit in place of the air ram supposedly don't work effectively at highway speed - something to do with air turbulence and the cyclone action - do a search and see what you find.
AnswerID:
335343
Follow Up By: Rob Mac - Saturday, Nov 15, 2008 at 22:42
Saturday, Nov 15, 2008 at 22:42
Hi Mick15,
It is a bit dizzying trying to work through those figures, but I will try and apply them to my engine, which at 4500 RPM would probably be trying to jump out of the engine bay. Red line is 4000 RPM.
Thanks
FollowupID:
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Reply By: Member No 1- Saturday, Nov 15, 2008 at 21:33
Saturday, Nov 15, 2008 at 21:33
litres per sec X 2.119 = CFM
AnswerID:
335427
Reply By: Mick15 - Sunday, Nov 16, 2008 at 10:36
Sunday, Nov 16, 2008 at 10:36
Site Link
Heres a link you may find useful
and heres a link to one for sale
Site Link
Up to you i guess like some of the other guys said, probably run the ram head at highway speeds and change to a pre cleaner for slow dusty stuff
heres some info on finer filter filter socks
Site Link
AnswerID:
335485