Tired of rod knocks...

turbonicsperformance · 11-04-2011, 08:05 AM

ill try that.
the thing with the burnt spot was that it was just as loud then as it is now. it never gets louder it just makes the exact same sound the same volume but this time i have some flaking in my oil so i know its further gone.

anybody with experience hard mounting these know if it makes a difference? I've heard of people having issues with hard mounting certain engines because at a certain hertz they match the frequency the oil flows and it causes the oil surface tension to break... and miatas are known to chew rod bearings with aftermarket crank pulleys for the same reason. just a thought anyone running solid mounts?

the engine sits 2 degree tilted not enough to make any sort of difference. and the first time it was rod #3 ill know when i pull it apart if its the same rod.the first set of bearings were run for about 15 minutes and started making noise along with the head (there was a blocked passage in the head) i didn't pay attention to which bearing it was because I knew the head was the issue. everything mic'd good on the crank and i cleaned all the passages AGAIN got a new head cleaned it THOROUGHLY and put it all back together.

cre · 11-04-2011, 08:39 PM

Solid mounts are miserable; If you want something more rigid look at the pre89 mounts. Harmonics breaking the surface tension isn't an issue anyone I know of has ever gone through in one of these engines (definitely not at power levels like you're seeing); You're grasping at a straw that isn't there. It's not worth the stress on the frame as it's not going to fix anything.

You sure there wasn't still crap from that blockage in the head stuck in there and waiting like a timebomb? You did miss it the first time. Could have been debris got stuck in the oil cooler too; Did you flush it?

turbonicsperformance · 11-05-2011, 04:30 AM

Quote:

Originally Posted by cre

Solid mounts are miserable; If you want something more rigid look at the pre89 mounts. Harmonics breaking the surface tension isn't an issue anyone I know of has ever gone through in one of these engines (definitely not at power levels like you're seeing); You're grasping at a straw that isn't there. It's not worth the stress on the frame as it's not going to fix anything.

You sure there wasn't still crap from that blockage in the head stuck in there and waiting like a timebomb? You did miss it the first time. Could have been debris got stuck in the oil cooler too; Did you flush it?

the head was replaced with a different one and the engine was torn down 100% and all passages were cleaned and and bearings replaced.
the oil cooler and lines were replaced when the engine was torn down and head replaced (i just happened to get a new one at the same time).
and the mounts are solid not for rigidity but for the pure problem of clearance. the miata is a short car and the oil pan sits 1/8th inch off the steering rack and still doesn't clear the hood. I've gotten use to them and don't really notice the vibrations etc. any more. it just makes riding in any other car more comfortable lol it also has the stiffest springs available for the car along with coilovers setup for drift. i basically dd a race car. You gotta pay to roll in style (:

cre · 11-05-2011, 12:43 PM

I'd still want mounts with SOME dampening there; Even if I had to build a mould and cast it myself.

Yeah, they're tiny... smaller than my MR-2. Fun rides these cars.

Sonyps307 · 11-05-2011, 03:49 PM

R u running a cheap aftermarket solid crank pulley they also wipe out the bearing on a 7m. Can the stock oil gauge even read 6 psi.

cre · 11-05-2011, 11:36 PM

True about the pulley.... Your undampened clutch sends a nice shock down the line too; That's not going to do it by itself on a rebuilt engine, but your issues may be cumulative.

I just want to reemphasize, an undampened crank pulley and an unsprung clutch aren't going to keep killing a new engine, not unless something seriously out of balance. I agree that an oiling issue is most likely the primary culprit.

What oil are you running and how are you breaking the engine in? Are you running a stock flywheel and was it resurfaced?

turbonicsperformance · 11-06-2011, 10:16 PM

stock ge flywheel brand new 3k ago and stock pulley that appears straight but its possible its out of balance i guess. the clutch was installed after the first set of bearings went out so i doubt thats it. plus the clutch is actually not all that harsh at all it only chatters if i drive really slow from a stop. other than that it feels like the sprung full face i had before. im pretty much 100% sure i have a ge pump in my engine. When i have the engine out this time i'm gonna have the crank machined or replaced and clean all of the oil passages again. i'll also replace the stock cooler setup with a thermostat full flow system and another set of piston squirters just to cut out ALL possibilities.

the engine was broke in on 10w30 conventional oil and the oil was changed at 300 then 1000 then 1500 miles running 100% stock boost and tune.

11-04-2011, 08:05 AM	#1
turbonicsperformance 3" Exhaust Join Date: Apr 2010 Location: sarasota fl Posts: 194	ill try that. the thing with the burnt spot was that it was just as loud then as it is now. it never gets louder it just makes the exact same sound the same volume but this time i have some flaking in my oil so i know its further gone. anybody with experience hard mounting these know if it makes a difference? I've heard of people having issues with hard mounting certain engines because at a certain hertz they match the frequency the oil flows and it causes the oil surface tension to break... and miatas are known to chew rod bearings with aftermarket crank pulleys for the same reason. just a thought anyone running solid mounts? the engine sits 2 degree tilted not enough to make any sort of difference. and the first time it was rod #3 ill know when i pull it apart if its the same rod.the first set of bearings were run for about 15 minutes and started making noise along with the head (there was a blocked passage in the head) i didn't pay attention to which bearing it was because I knew the head was the issue. everything mic'd good on the crank and i cleaned all the passages AGAIN got a new head cleaned it THOROUGHLY and put it all back together. __________________ 92 miata 7mgte swap forged pistons,studded mhg, 3 inch dp with a glass pack,blowthrough MAF-T,550cc inj, act stage 2 clutch, fmic kit, greddy rs, full wire tuck, rx7 lsd rear with 4.10s. 15psi "ct26-A"??(waiting on dyno #s) if anyone knows whats up with my turbo let me know it has a larger comp wheel nicer machining and 6 dual fins rather than 5? its confusing and keep finding too much contradicting info. would LLLLLOOOOOOOOVVVVVVVEEEEE a compressor map Last edited by turbonicsperformance; 11-04-2011 at 08:12 AM.

11-04-2011, 08:39 PM	#2
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	Solid mounts are miserable; If you want something more rigid look at the pre89 mounts. Harmonics breaking the surface tension isn't an issue anyone I know of has ever gone through in one of these engines (definitely not at power levels like you're seeing); You're grasping at a straw that isn't there. It's not worth the stress on the frame as it's not going to fix anything. You sure there wasn't still crap from that blockage in the head stuck in there and waiting like a timebomb? You did miss it the first time. Could have been debris got stuck in the oil cooler too; Did you flush it? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

11-05-2011, 12:43 PM	#4
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	I'd still want mounts with SOME dampening there; Even if I had to build a mould and cast it myself. Yeah, they're tiny... smaller than my MR-2. Fun rides these cars. __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar --->

11-05-2011, 11:36 PM	#6
cre Toyota Racing Development Join Date: Apr 2007 Posts: 5,038	True about the pulley.... Your undampened clutch sends a nice shock down the line too; That's not going to do it by itself on a rebuilt engine, but your issues may be cumulative. I just want to reemphasize, an undampened crank pulley and an unsprung clutch aren't going to keep killing a new engine, not unless something seriously out of balance. I agree that an oiling issue is most likely the primary culprit. What oil are you running and how are you breaking the engine in? Are you running a stock flywheel and was it resurfaced? __________________ If something breaks or you need to contact a member of the administration please post HERE. Unless it's a private or administration matter please post it on the forum. It benefits no one else if car related questions aren't posted for future users and takes away from the time I'm able to spend helping on the rest of the forum. If you're so inclined I'm always more than happy to accept tips via PayPal. Tip Jar ---> Last edited by cre; 11-05-2011 at 11:55 PM.

11-06-2011, 10:16 PM	#7
turbonicsperformance 3" Exhaust Join Date: Apr 2010 Location: sarasota fl Posts: 194	stock ge flywheel brand new 3k ago and stock pulley that appears straight but its possible its out of balance i guess. the clutch was installed after the first set of bearings went out so i doubt thats it. plus the clutch is actually not all that harsh at all it only chatters if i drive really slow from a stop. other than that it feels like the sprung full face i had before. im pretty much 100% sure i have a ge pump in my engine. When i have the engine out this time i'm gonna have the crank machined or replaced and clean all of the oil passages again. i'll also replace the stock cooler setup with a thermostat full flow system and another set of piston squirters just to cut out ALL possibilities. the engine was broke in on 10w30 conventional oil and the oil was changed at 300 then 1000 then 1500 miles running 100% stock boost and tune. __________________ 92 miata 7mgte swap forged pistons,studded mhg, 3 inch dp with a glass pack,blowthrough MAF-T,550cc inj, act stage 2 clutch, fmic kit, greddy rs, full wire tuck, rx7 lsd rear with 4.10s. 15psi "ct26-A"??(waiting on dyno #s) if anyone knows whats up with my turbo let me know it has a larger comp wheel nicer machining and 6 dual fins rather than 5? its confusing and keep finding too much contradicting info. would LLLLLOOOOOOOOVVVVVVVEEEEE a compressor map

11-05-2011, 03:49 PM	#5
Sonyps307 Lexus & 550's Join Date: May 2010 Location: Baltimore Posts: 526	R u running a cheap aftermarket solid crank pulley they also wipe out the bearing on a 7m. Can the stock oil gauge even read 6 psi.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Tired Engine	WhosYourSupra	Non-Generation Specific Questions	2	03-06-2007 06:34 PM