So I started up my car for the first time after the winter. And Im hearing a LOUD rattle (KNOCK, KNOCK, KNOCK....) when the revs are coming down... I suspect it can be rod knock. I switched the car off after I distinguished the noise to prevent any further damage to the crank... I do plan on pulling the oil pan to check.

Now my questions are.

- If the crank isnt scratched too bad, can I just replace the bearings of that rod and be done with it (assuming only one set of rod bearings spun)

- It is a type R motor and if I do have to swap out cranks... Can I use an LS crank? I believe the LS crank will lower my compression ratio?

Lastly, what are good Bearings? Clevites? ACL?

 

you have to replace the crank if the bearing is spun it doesn't matter how scratched it is because if you just replace the bearing those scratches on the crank is going shred the new bearing and u going to end up with a spun bearing again

 

Can you post a video of the noise? Just for all of us to hear to confirm or deny the conclusion you have come to?

Yes you can just replace a rod bearing, but it will burn up again in pretty short order.

I would not disgrace an itr motor by putting an ls crank in it. The ls crank is and 89mm stroke while the itr crank is 87.2mm so you will increase your stroke and your compression ratio. Just look for a good used itr crank. You may also need to replace the rod itself depending on damage.

ACl bearings are meh, clevites are trash for honda motors. I wouldnt use anything other than OEM honda bearings. There is a code on the bottom of the block between the oil pan and the block that tells you what OEM bearings to buy. Makes everything pretty simple if your just doing an oem rebuild.

 

good info^ post a video, you might have a spun bearing if it sound the way your saying.

 

You can also just use a gsr crank but good luck finding one . I had a hard time finding a crank. You can also get your old one micro polished . Just make sure to get it heat treated. Also if you go that route the machine shop should be able to tell you the clearance.

 

If it was me again, and this is if you def have a bad block, i would forget about rebuilding the block! and buy a new block for $2,500.
A. because even if you have it rebuilt by the best shop its never gonna run as efficient as a new block! it will burn oil eventually cause you just cant beet the work honda does when they assemble the motor new themselves.
B. because you spend around $1,200-2,000 on a new rebuilt block with new oil and water pump. not to mention you have to find a good crank! good luck.
C. you dont have tpo wait long or worry about how well the motor was rebuilt.

Iv had many motors built and they all went to crap eventually cause of a poor rebuild, they burn oil or spin bearings, I invested just a lil bit more and baught a new ITR block for $2,500. comes completly assembled and ready to run with oil and water pump and oil pan assembled.

you can sell the block as is for a few hundred bucks and ad it to what you would pay to rebuild the spun block along with the other parts you will have to buy like the crank and water and oil pump and just put it all together and get a new ITR block like i did. search ebay. Mine has 60k miles boosted and still running strong!

 

^^^Are you serious? People rebuild blocks ALL THE TIME, and they run fantastic, and just as good as a factory prepped block. Just because you have your blocks built by **** builders apparently, doesn't mean people can't assemble a block to run correctly.

OP, check the head as well. Could be a bent valve. I got a loud knock in my old B16...thought it was rod knock. Turned out to be a bent valve.

 

Having a hard time uploading to photobucket. It keeps stopping halfway :S If it was a bent valve, it would be a constant noise (hear it all the time while the engine is running). Bent valves usually click or tick. This is a noticeable "Knock Knock" sound, and it happens when the revs are coming down.

Its a built turbo motor running 9:1 CR so Im going to rebuild it and I dont mind bumping the compression a bit and I have a nice LS crank just sitting here, lol. We'll see if there's any damages to the type r crank first.

 

Nevermind the smoke. Grease on Downpipe

http://www.youtube.com/watch?v=6OiMS-y1HAc

 

Can you get the noise to stay constant at a certain rpm? If you can, get it there then pull and replace the plug wires one by one. If the noise stops and starts again when you pull and replace a plug wire then you have a bad rod bearing on that cylinder. Pulling the plug wire takes the load off of the rod and stops the knock.

Also, pull the oil filter and see if there are bronze colored shavings in it. If there are, then you definitly have a bad rod bearing.

 

 

doesn't really need to keep the noise consistent. just need to see if it goes away.
and yes, what we like to do is pull the filter and slice it open with the air chisel to look through the pleats.
that is, if you still suspect it after power balancing

 

Ahhh gotcha.

 

man that sucks. do you know why it spun a bearing?

 

I'm sure people rebuild motors and they run Fantastic as you say! but how long will it last? not saying a rebuilt motor will run bad but compared to a brand new honda b18c5 engine im sorry it just aint gonna run or last as good! and iv ad many motors rebuilt by reputable builders but for a oem rebuild i would rather just get a new block for $2,500! and this is a new block not REBUILT!

 

Or you can save a grand and rebuild a block with all new parts that will run just as long as OEM from the factory...."it just ain't gonna run or last as good"?

Do you understand how many rebuilt B-series motors are out there that have YEARS of use on them? Do you understand how many rebuilt motors are out there that run BETTER than a stock b-series from the factory?