Air filter!!!!!!!!!!!!!!

Jul 05, 2004 20 Replies

Good evening, hope there is the answer out there for my problem??? I have an engine without any air filters. How do I work out the size of filters to fit to the engine so as not to restrict the air flow, or suck the filters in to the cylinders!!!!!!!! Are filters sized as to Cubic Feet per Minute?? ( CFM ) If they are how do I work out the maximum CFM for the engine


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The bigger the better !

What kind of power is the engine making ?

Nope. K&N sell theirs rated by bhp - although they don't seem to have the ratings on their site anymore !!

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Slap a nice big pancake filter on and don't worry too much about the CFM.

What have you got at the moment? Any ducting or tubing, just a carb pointing up?

But how big because if the filter is not big enough it will restrict the flow ? so how do I know how big a one to fit ( by the way there is two inlets so I need 2 filters each able to handle about 14 Litres.

well it should be 650 BHP as it is but if I get blowers and new carbs it will probably be much more out of 27 Litres !!!!!!!!!

But if they cant flow the air surley it will effect the performance of the engine?????

Rich

Ah ha close, a Meteor, land based Merlin, de tuned to 650 HP and no super charger but 2 huge Zenith 56 up draught carbs !!!!!!!!! :))))))

but what about my questions !!!!!

In which case, you're gonna need a pair of house-sized filter cones :D

I'd get in touch with K&N directly, and see what they say.

Yes - that's why you buy the appropriately sized filter ! If your car is making 200bhp, then you buy a filter rated to 250bhp etc. It's gonna be a bit different on a 27l engine though - it will flow hurricane's worth of air :)

You're looking at a pair of HGV air filters then. Something akin to those for a Scania 550. The lorry ones are tubular in shape.

Ah yes all very interesting thanks very much all. Did not think of trying K and N will give them a go :)))))))))

Rich

What do the racing trucks use?

Yes have thought of that but would like to know actually how big a filter it does need then I can choose from there

Rich

Question.

Where did the 27 litre engine come from?

Fell out the front of a lorry.

Rolls Royce Meteor (from further up the thread).

Related to the Rolls Royce Merlin I think (as used in Hawker Hurricane and Spitfires - ask your grandad.)

Were they used in trucks? If so it would be some truck!

Ended up in later incarnations with superchargers and badboy power figures - nicey nice!

Not big power from 27 litres by today's standards perhaps.

Anyway, I think I'm glad we didn't lose.

Douglas

Have you tried the bods who supply gear for boats? Might have something about the right size. OTOH, get some rough figures for Volumetric Efficiency (won't be very high on that engine compared to something modern), work out CFM and get a filter to fit. I'd expect K&N or Rolls would help you if you emailed them.

I cant remember where it came from, but I have had it about 15 years and only started it a couple of times !!!!! :)))))) Joys of getting houses getting married having kids etc, Toys have to wait. It is a Rover Meteor Mk III as fitted to the Cromwell Tanks in the second World War, also many other versions were used in tanks up until they went over to Diesel. It is almost the same as a Merlin out of the Spit, they were turning out about 2500 HP with super chargers, but it is de-tuned to 650HP and has 2 twin carb Zenith 56 updraught carbs producing 1250 Lb's foot of torque at

1500 RPM !!!!!!!!!!!!!! Like you say not much HP from 27,000 cc but lot and lot of fun to start up on a Sunday morning in the back garden :)) If you have enough fuel I ran it some time ago at a fast idle for about half an hour and use 5 Galls of petrol :(((((

Rich

By the way, have you seen the Rover SD1 with a Meteor fitted?

Do what !!!!!!!!!!!!!!!!!!!!!!!!!!!

got any pics I would love to see that :)))))))))))

Rich

June's Practical Performance Car magazine (got a V8 MGB on the front). Looks as if the engine's stuck through the bulkhead into the passenger compartment to me :D. I'd scan it but I don't have a scanner. I'll see if I can use someone else's. And hope none of the PPC writers are reading this and waiting for me with a crack squad of copyright lawyers ;).

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