geoffbeaumont Posted January 26, 2006 Share Posted January 26, 2006 As ram tops seems to be hard to come by I was looking at sticking an air precleaner on the end instead - found some that could be made to fit (these ones looked promising), but no prices. I vaguely recall someone on here saying precleaners on snorkels had been tried and didn't work out. Anyone know if that's right, and if so why they didn't? Seems like a great idea to me... Going by the crude engine capacity x rpm = flow rate calculation suggested by astro_al, I reckon the range of flow rates for a 3.5 V8 are in the region of 50-402CFM, for a 3.9/4.0 56-460CFM and even something silly like a 4.8 will top out at 550CFM (not that I'm every likely to stick one in my truck... ). That's based on an idle speed of 800rpm and max of 6500rpm. The specs for the precleaners linked above give the flow rates for the various models (they stock other ranges but these ones were reasonably compact and wouldn't look too silly ) - there are none that quote a flow rate range anything like that large, which suggests to me that if I fitted one that wouldn't restrict air flow at high revs it wouldn't actually be spinning off anything much at the engines normal operating revs. For instance, the smallest one that will cater for a flow rate over 400CFM (KC91) has a minimum flow rate of 388CFM. On a 3.5 that roughly equates to 3140rpm, so the cleaner would only be working if you boot it? I think I'm talking myself out of this idea, but I don't know how accurate my flow rates are. Does anyone have any personal experience to offer? I know these things work well on generators and the like, but they're running at more or less constant revs which makes things a whole lot easier... Quote Link to comment Share on other sites More sharing options...
white90 Posted January 26, 2006 Share Posted January 26, 2006 Southdown sell Ram tops seperatley £25 IIRC Quote Link to comment Share on other sites More sharing options...
BogMonster Posted January 26, 2006 Share Posted January 26, 2006 I know somebody that used to run one on a 300Tdi 130 and I think he reckoned he had never had to change the air filter element. Not sure if he has one on his current Td5 130 but I think so. I think the one he used was off a tractor of some sort? no idea what type though, I seem to think it was an oil-bath one but I might well have imagined that Quote Link to comment Share on other sites More sharing options...
isuzurover Posted January 26, 2006 Share Posted January 26, 2006 A "cyclonic pre-cleaner" to use the correct term, will remove between 30-70% of dust by mass (depending on flow rate and efficiency of the cyclone) before it gets to your filter. It will induce a small extra pressure drop on the intake (but not much). If you never drive in dusty conditions you may as well just fit an air ram. The smaller the pre-cleaner, the higher the flow velocity through it and therefore the higher the dust removal efficiency (but also higher pressure drop). The standard (Donaldson) one for most engines of 4L or so is made for a 3" snorkel tube, and should provide more than enough flow for a V8. Quote Link to comment Share on other sites More sharing options...
Michele Posted January 26, 2006 Share Posted January 26, 2006 I fitted a Donaldson pre-cleaner to my Safari 1 or 2 years ago (soon after I got the snorkel itself). Never went back to the original air-ram. Works grand. I leave the airflow science to Ben as it's not my job Quote Link to comment Share on other sites More sharing options...
BogMonster Posted January 27, 2006 Share Posted January 27, 2006 OK, I just caught up with the guy I know here who has one on a 130 The precleaner he uses on his current Td5, on a Safari snorkel, is off a JCB 3CX, just the right size for the Safari and only about 50% bigger than a normal mushroom snorkel top so it doesn't look like some alien spaceship just landed on your snorkel Judging by the amount of crud in it, it works quite well it spins the muck out into a collection bowl which you empty every so often Don't know how big an engine a 3CX has in it but I guess bigger than a Td5 probably so capacity shouldn't be a problem. Quote Link to comment Share on other sites More sharing options...
jules Posted January 27, 2006 Share Posted January 27, 2006 This may seem over kill but my Dakar rally freelander has three air filters. Due to the Sand issues in the Sahara. Main Engine TD4 filter ITG conected to a RR3 filter (ITG) where the battery would be then a snorkel over the screen to the rear of the truck and in the pick up bed is a nother RR3 air box to hold a paper air filter from a 4.4v8 to remove the very fine sand and general carp. yes cleaning between events is a pain. But it works very well. Before anyone says anything the whole system has been worked out by ITG so they would know more about air flow than I ever will. Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted January 27, 2006 Author Share Posted January 27, 2006 OK, I just caught up with the guy I know here who has one on a 130The precleaner he uses on his current Td5, on a Safari snorkel, is off a JCB 3CX, just the right size for the Safari and only about 50% bigger than a normal mushroom snorkel top so it doesn't look like some alien spaceship just landed on your snorkel Judging by the amount of crud in it, it works quite well it spins the muck out into a collection bowl which you empty every so often Don't know how big an engine a 3CX has in it but I guess bigger than a Td5 probably so capacity shouldn't be a problem. The newer ones don't even have a bowl - they eject the crud out the side. So pretty much zero maintenance JCB engine is probably bigger, but does it rev as high? Quote Link to comment Share on other sites More sharing options...
BogMonster Posted January 27, 2006 Share Posted January 27, 2006 Dunno about airflow Doesn't seem to slow him down though Quote Link to comment Share on other sites More sharing options...
JST Posted January 27, 2006 Share Posted January 27, 2006 if its specifically designed then it doesnt seem to be a problem. Such as Jules setup. I can only comment from my experience which is that the XD Waterproofed variants with the snorkel and large mushroom top (as opposed to the new Mantec style you see fitted to std XD nows) meant a drop in economy and top mph by about 10%. They worked though, evident of the dust trails out the ejection ports. Bear in mind this is 10% worse than std XD with the twin side air intakes bits on the wings. will try and find a pic. Quote Link to comment Share on other sites More sharing options...
JST Posted January 27, 2006 Share Posted January 27, 2006 Found a pic, excuse the other carp, we were busy at the time!!! That pre- cleaner Quote Link to comment Share on other sites More sharing options...
Paul Posted January 27, 2006 Share Posted January 27, 2006 You could always get something sent over from these guys: http://www.donaldsonfilters.com.au/product...1ID=1&intT2ID=1 Paul Quote Link to comment Share on other sites More sharing options...
western Posted January 27, 2006 Share Posted January 27, 2006 The precleaner he uses on his current Td5, on a Safari snorkel, is off a JCB 3CX,Don't know how big an engine a 3CX has in it but I guess bigger than a Td5 probably so capacity shouldn't be a problem. JCB spec sheet for a 3CX super sitemaster shows engine size as 4.4 litres just a bit bigger than a Td5 Quote Link to comment Share on other sites More sharing options...
BogMonster Posted January 27, 2006 Share Posted January 27, 2006 JCB spec sheet for a 3CX super sitemaster shows engine size as 4.4 litres just a bit bigger than a Td5 Probably only does about 2500rpm flat out though, if anything like a traaaaaaactor (our Case 685 which is about 4 litres does about 2200rpm IIRC), so the overall air consumption is probably similar to a 2.5 litre Land Rover diesel. It seems to work well anyway. Quote Link to comment Share on other sites More sharing options...
western Posted January 28, 2006 Share Posted January 28, 2006 Probably only does about 2500rpm flat out though, if anything like a traaaaaaactor (our Case 685 which is about 4 litres does about 2200rpm IIRC), so the overall air consumption is probably similar to a 2.5 litre Land Rover diesel. It seems to work well anyway. Just had another look at the 3cx supersitemaster spec sheet it quotes 92bhp, rated rpm 2200 with max torque 287lbft @1300rpm, a bit smaller hp wise but more grunt where it's neeeded. Quote Link to comment Share on other sites More sharing options...
Jon W Posted January 28, 2006 Share Posted January 28, 2006 Just found this on flea bay. http://cgi.ebay.co.uk/cyclone-snorkel-top-...bayphotohosting it quotes a few figures with it too. Not sure if this is of any help to you at all. Jon Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted January 30, 2006 Author Share Posted January 30, 2006 You could always get something sent over from these guys:http://www.donaldsonfilters.com.au/product...1ID=1&intT2ID=1 Found some dealers for them in this country. No prices, but worth investigating. Looks like they do standard snorkel rams too, if I decide not to go down the precleaner routes. Just found this on flea bay. http://cgi.ebay.co.uk/cyclone-snorkel-top-...bayphotohosting it quotes a few figures with it too. Not sure if this is of any help to you at all. Saw that last week - it helps in that I can get a better idea what that size of precleaner looks like in place, but not so sure about the flow rate. Just because someone supplies it doesn't mean it's up to the job... Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted January 30, 2006 Author Share Posted January 30, 2006 Found a pic, excuse the other carp, we were busy at the time!!! That pre- cleaner I was planning on fitting a snorkel, not a roof mounted chicken feeder... Quote Link to comment Share on other sites More sharing options...
isuzurover Posted January 30, 2006 Share Posted January 30, 2006 You could always get something sent over from these guys:http://www.donaldsonfilters.com.au/product...1ID=1&intT2ID=1 Paul Donaldson are international (Based in the US) - they are the largest automotive filter manufacturer in the world, and make very good products (and no I don't work for them). Quote Link to comment Share on other sites More sharing options...
Michele Posted January 30, 2006 Share Posted January 30, 2006 Me neither but I'm happy with it and found out a dealer is 20 mins far from me, so I recently got spares,good service and easy to find. Winter cold killed the plastic bowl... ...or,better,I did,slapping it to get the snow out... Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted January 30, 2006 Author Share Posted January 30, 2006 Me neither but I'm happy with it and found out a dealer is 20 mins far from me,so I recently got spares,good service and easy to find. Winter cold killed the plastic bowl... ...or,better,I did,slapping it to get the snow out... They do a self cleaning one now (ie. it chucks the muck out a side vent instead of collecting it in a bowl). If I go down the precleaner route I'll be getting that type 'cause I'm lazy and it needs less maintenance Quote Link to comment Share on other sites More sharing options...
Michele Posted January 30, 2006 Share Posted January 30, 2006 Yup,I had seen it at the time in the catalogue. Useful,but it was too high IIRC (a la Wolf above...well,ok,not so high but...) It's an option anyway. Good for African use & abuse. Quote Link to comment Share on other sites More sharing options...
geoffbeaumont Posted January 30, 2006 Author Share Posted January 30, 2006 Yup,I had seen it at the time in the catalogue.Useful,but it was too high IIRC (a la Wolf above...well,ok,not so high but...) I'll probably be making my own snorkel anyway, so I can adjust for that to some extent - just make the pipe a bit shorter It's an option anyway.Good for African use & abuse. Or Machynlleth in a dry spell...* *Yes, I do realise the folly of building a truck to cater for dry weather in Wales... Quote Link to comment Share on other sites More sharing options...
Michele Posted January 30, 2006 Share Posted January 30, 2006 the folly of building a truck to cater for dry weather in Wales... Nice idea of the shorter pipe! Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.