[Che]

What sort of plastic is the stock air filter housing made out of? I want to go visit a plastic welder for a neat fill in of the original side hole and unused vacuum connection points... seeing the original intake system is only half there, i'm gonna mod it to better suit me.

I never thought of it, but a recent post suggested you know what type of plastic you're dealing with first.


Also, what's the K&N air filter part description for a 1990 Sierra with stock intake? Usually cheaper to buy online, so if I know what i'm looking for I can try find a bargain

[watermouse]

Most plastic parts in cars have the type of plastic, molded in letters, on them to aid in recycling. Usually preceeded by the letters SAE.

The air box in my Jimny has PP for polypropylene

The radiator head has PA66 a grade of high temp polyamide
The rubber airbox inlet is EPDM, ethylene propylene diene monomer
etc

Plastics are awesome...Find a code and google it.

[Che]

Can find the filter code for a US Samurai, but not sure if their intake setups are the same as ours... different stock carby after all.

[eldo]

che_guitarra wrote:

Can find the filter code for a US Samurai, but not sure if their intake setups are the same as ours... different stock carby after all.

a little bit of parts interpreting goes along way, look for a samurai listing of a common brand that is available in australia, then see if its the same listing thats in the aus version. if it is one would assume that the samurai one fits, also look at US based engine bay pics

[Che]

All I can see on the airbox is:

(X) JA51 (X), and

00 20 30

Maybe recycling codes were introduced after 1990?

[Gwagensteve]

K&N filters are rubbish. They are a waste of money and do not filter as well as the stock filter. This isn't opinion, it's scientifically proven.

I've also seen visible dust inside the intake of a car running a well sized and well serviced K&N filter.

In any case, in relation to the plastic welding - we're not building show cars (are we?) I would save my money to spend on things that add capability and/or performance. Maybe that's just me though.

Steve.

[ball]

Gwagensteve wrote:

K&N filters are rubbish. They are a waste of money and do not filter as well as the stock filter. This isn't opinion, it's scientifically proven.

I've also seen visible dust inside the intake of a car running a well sized and well serviced K&N filter.

In any case, in relation to the plastic welding - we're not building show cars (are we?) I would save my money to spend on things that add capability and/or performance. Maybe that's just me though.

Steve.

The K & N filters for cars must be different to the ones I use on my speedway karts.

19000 rpm sitting 3 inches from the dirt unprotected and I DON'T have dirt in my engines.

The people that have filtration problems with them don't service them correctly. It only take 1 time for an idiot to dry them with compressed air and they are stuffed. Most people are also to stingy to by genuine K & N oil and cleaner. That makes a big difference.

I don't need scientific proof to know what works and what doesn't. Half a lap in a kart with an ineffective filter and the engine is basically worn out enough that they barely run.

There is nothing else I will use anymore.

[Gwagensteve]

No, they're not different, but what you require from a filter isn't what a car driver needs from a filter.

I'm going to guess that your motors don't last more than a season or so- how many hours of running? 10? 20? 100?

The motors are so highly stressed that they wear out/break/blow up at fairly short and well calculated intervals.

Sure - if you use a filter that's inadequate, your motor will fail very, very quickly, However, your motor is ingesting particles that are large enough that they would also destroy a road car engine very quickly.

The difference is that so long as your filter doesn't wear the engine out before it was due for a rebuild anyway, your fine and your filter is great.

My guess is that if your Kart filter was chosen from the Donaldson catalogue for a "high dust" environment, it might be larger than the Kart you are driving, but it would be a total waste as your engine would wear out before there was any possibility the dust passing the filter could wear it out.

Oiled gauze and foam filters do not filter as well as stock paper.

Most of the interesting tech is here: http://carl.outerlimits4x4.com/ftopic74825.php

isuzurover is a filtration engineer.

A road car requires a much more efficient filter (at filtering, not passing air) than a race engine filter.

Steve.

[royce]

did you read the part where the thing runs IN DIRT?

funny that you also point to a thread about race engine failing because of the filters yet here you are saying you would never know its a race engine, are you american?

[Gwagensteve]

Sorry Royce - I can't understand that post at all.

Steve.

[atari4x4]

i would grab another stock air filter housing & shave plastic off that & plastic weld it in.

[eldo]

Just silastic up the un used holes. Cost about ten bucks and is reversable should you ever want to. K&N filters are fine for use in road conditions, just dont expect them to do real well in the dust for extended periods, they do clog up fast due to their ability to filter quite well and the tacky oil.

[ball]

Gwagensteve wrote:

No, they're not different, but what you require from a filter isn't what a car driver needs from a filter.

I'm going to guess that your motors don't last more than a season or so- how many hours of running? 10? 20? 100?

The motors are so highly stressed that they wear out/break/blow up at fairly short and well calculated intervals.

Sure - if you use a filter that's inadequate, your motor will fail very, very quickly, However, your motor is ingesting particles that are large enough that they would also destroy a road car engine very quickly.

The difference is that so long as your filter doesn't wear the engine out before it was due for a rebuild anyway, your fine and your filter is great.

My guess is that if your Kart filter was chosen from the Donaldson catalogue for a "high dust" environment, it might be larger than the Kart you are driving, but it would be a total waste as your engine would wear out before there was any possibility the dust passing the filter could wear it out.

Oiled gauze and foam filters do not filter as well as stock paper.

Most of the interesting tech is here: http://carl.outerlimits4x4.com/ftopic74825.php

isuzurover is a filtration engineer.

A road car requires a much more efficient filter (at filtering, not passing air) than a race engine filter.

Steve.

Engine time isn't measured in hours it may be only 15 - 20mins of run time before a piston is replaced.

If you get any dirt in the inlet tract then piston life at that rpm is measured in seconds.

Dirt can be felt just by running a finger in the blowback through the filter adaptor, it feels like very fine grinding paste and the aluminium parts inside turn black

I don't get your logic that a road car requires better filtration than a race engine.

I am aiming for maximum engine life just like anyone would want from a road engine. Clean air gives me the best chance at that.

My engines don't require rebuilds because of dirty air.

[Che]

Dust isn't an issue for me - the only non-road driving I do is on the beaches and hinterland tracks around SEQ and northern NSW. I've used K&N's in the past, they worked for me without issue, so i'll use them again on the Sierra.

Wanna do the plastic welding thing... checked out repair vids on youtube and it looks dead easy. If it costs more than $50 to fix the hole, i'll buy the tools to fix it myself (costs $100 for a basic welder), then I can fix the dash holes and mod other bits and pieces myself down the track. If I stuff up there's still plenty of air-boxes around to replace with.

Just gotta know what it's made of to buy the right plastic filler rods (or to get a plastic welder to fix), otherwise I like your idea Atari4x4.