How to prevent a bearing knock

illest · Post by **illest** » Tue Mar 29, 2011 2:52 pm

Hi guys.

I've google'd this a few times but still looking for a solid answer. I installed a RB25 and with doing that everyone has something to say.

I've heard get a meth kit (R6000)
Get a knock block kit (R12000)

My gosh, then i might as well get another motor again.

Any advice?

aep886 · Post by **aep886** » Tue Mar 29, 2011 3:00 pm

i am also looking for the same answer...

Daniel · Post by **Daniel** » Tue Mar 29, 2011 3:07 pm

Get a dry sump kit

Lol sorry, just couldn't resist

I think good quality oil with regular oil changes is about the best you can do without spending the earth.

illest · Post by **illest** » Tue Mar 29, 2011 3:09 pm

aep886 wrote:i am also looking for the same answer...

I'm considering the meth kit but i will NEVER spend 6k for it, apparently the water/meth mixed kit goes for 2,5K but rumor has it (either that or this guy is trying to boef me) the water/meth mix leaks.

My brother is using a "knock" sensor in his scooby and it's 2k for one, but i don't understand how it works. When the light is green it's all good, but so what happens when the light turns orange? Do you pull over and switch the car off or do you let it idle?

Daniel · Post by **Daniel** » Tue Mar 29, 2011 3:14 pm

How does a WI kit prevent bearing knock anyway?

illest · Post by **illest** » Tue Mar 29, 2011 3:41 pm

Daniel wrote:How does a WI kit prevent bearing knock anyway?

I've been told that the octane in the fuel we use here is low and doesn't go good with the high performance cars with turbos etc.

The WI kit increases the level of octane which prevents detonation.

Check this page: http://www.misterfixit.com/deton.htm
It's really insightful

Daniel · Post by **Daniel** » Tue Mar 29, 2011 4:16 pm

Ya I know what det is thanx, I just misunderstood the point of this thread then.

When you ask how to prevent bearing knock then you would expect answers of fit X or X bearings, increase sump capacity, make sure all breathers are clean, regular oil changes with decent oil etc.

If you asked how to prevent detonation then I understand the point of WI and knock links.

Maybe I still don't understand whats going on here

djtreble · Post by **djtreble** » Tue Mar 29, 2011 4:27 pm

Eugene, I think you are confusing DET with bearing knock.

Bearing knock is the bearings letting go where the rods connect to the crank shaft which is a common failure in the CA. To help with this just maintain your engine properly with regular oil and filter changes. Also using good quality oil helps.

Detonation is premature ignition in the combustion chamber and this can be prevented with proper mapping, good fuel/fueling & timing.
Install a knock sensor that warns you when detonation is occuring. If it indicates detonation is occuring, drive the car gently (keep off boost) back to your mapper/tuner and get them to map it correctly.

aep886 · Post by **aep886** » Tue Mar 29, 2011 4:34 pm

^^ I like ~!@#$%^&*()_ how the hell can water/meth injection prevent bearing knock?...

illest · Post by **illest** » Tue Mar 29, 2011 5:09 pm

aep886 wrote:^^ I like ~!@#$%^&*()_ how the hell can water/meth injection prevent bearing knock?...

JY

I basically wanna prevent my motor f'ing up. Is detonation a common problem?

djtreble - you are the s**t.

So to conclude this. A WI Kit in NOT a must have? And good maintaince will do the trick?

Looks like a knock sensor is a better investment.

djtreble · Post by **djtreble** » Tue Mar 29, 2011 5:14 pm

I honestly have no experience with a water/meth injection kit and it is something I am actually going to look into but until then I obviously cant recommend it.

Bearing knock - Regular maintenance and good quality oil will help prevent this

Detonation - Get the car mapped and tuned correctly by an experience mapper who will guarantee against detonation based on the map. Get a knock sensor installed for a piece of mind and if it indicates knocking, drive carefully back to the mapper and get it sorted out.

illest · Post by **illest** » Tue Mar 29, 2011 5:19 pm

djtreble wrote:I honestly have no experience with a water/meth injection kit and it is something I am actually going to look into but until then I obviously cant recommend it.

Bearing knock - Regular maintenance and good quality oil will help prevent this

Detonation - Get the car mapped and tuned correctly by an experience mapper who will guarantee against detonation based on the map. Get a knock sensor installed for a piece of mind and if it indicates knocking, drive carefully back to the mapper and get it sorted out.

Mail me some prices of knock sensors if you have

djtreble · Post by **djtreble** » Tue Mar 29, 2011 5:25 pm

None of my suppliers actually have them but a trusted tuner in the UK supplies these:
http://www.h-dev.co.uk/product_info.php ... 12eddc70a4

Seem like a good price compared to the 12K you were speaking of!

300sx · Post by **300sx** » Tue Mar 29, 2011 6:19 pm

a water injection installation is a last line of defence type of solution against detonation, a engine should be running proper a/f ratio's to start with. obviously the rest goes without saying, proper maintenence, a properly built motor to start with (proper bearing clearances essential)

with normal boost and a well built engine with correct a/f ratio's you should never run into detonation, although the stock ecu's do have knock detection, so i guess even nissan thought it might happen sometimes.

with that said i myself run a aquamist install on my nissan, exactly for peace of mind.. just make sure whoever installs it knows their stuff..