Rod and Main Bearings.... A must?
11-08-2012, 05:14 PM
#1
Rod and Main Bearings.... A must?
OK guys, I've raped the search button as well as google so now I will ask and hope to unearth some questions I have for all of you HR builds who can shed some light for me. There's not alot of info on the HRs and specifically the HR rod and main bearings.
Currently conservative 525-550whp.
Just to give you an idea my current internals are:
-GTM HR rod set w/ ARP2000 rod bolts
-GTM/Wiseco Extreme Duty Lightweight Pistons
-Top Ceramic Coating
-Skirt Graphite Coating
-9.0:1 Compression Ratio
-APR 2000 11MM Head Studs
-APR Main Stud Kit
-Just FYI, I will also be running a 34 row oil cooler for cooling.
My question is for any of you with 500-600whp builds, are the rod bearings, main bearings or both necessary to safely run this power rating for the HRs?
Are the OEM HR bearings good for this power? Any experiences?
Any help would be great on this guys, I've got a couple calls and waiting on a quote from GTM. I've tried to get some answers on the bearing clearances from them but I can't seem to get a straight answer. Hope someone can help me out with this.
Currently conservative 525-550whp.
Just to give you an idea my current internals are:
-GTM HR rod set w/ ARP2000 rod bolts
-GTM/Wiseco Extreme Duty Lightweight Pistons
-Top Ceramic Coating
-Skirt Graphite Coating
-9.0:1 Compression Ratio
-APR 2000 11MM Head Studs
-APR Main Stud Kit
-Just FYI, I will also be running a 34 row oil cooler for cooling.
My question is for any of you with 500-600whp builds, are the rod bearings, main bearings or both necessary to safely run this power rating for the HRs?
Are the OEM HR bearings good for this power? Any experiences?
Any help would be great on this guys, I've got a couple calls and waiting on a quote from GTM. I've tried to get some answers on the bearing clearances from them but I can't seem to get a straight answer. Hope someone can help me out with this.
Last edited by Nismo350z#0310; 11-13-2012 at 09:52 AM.
11-09-2012, 05:13 AM
#2
Any help would be great, guys. I'm seriously contemplating just scraping the whole build plan and going FI low boost on stock. I've read so many horror stories and people unsatisfied with our VQ builds. A lot of "I wish I just went FI and stock block." I'm not sure $10k more is worth 100 more hp.
11-10-2012, 01:00 PM
#4
the OEM stuff now is very good, no reason for a properly built shortblock to need anythins other than OEM bearings. Maybe when you are talking in excess of 1000hp and sheer force will deform the bearings, you could consider a switch to a different design, but for your goals stock is more than enough.
11-10-2012, 02:09 PM
#5
horrible advice and the reason so many spin bearings in this platform, too many people who have never built a engine giving advice or listening to what nissan puts out for a STOCK engine. you will never deform a bearing even at 1000 hp its all about coatings, friction, and clearances.
OP while the stock bearings MAY work they are going to be on the very edge of there limit, not because of the pounding they will be taking but because of the clearances. even with the oil cooler there is going to be significant extra heat generated in the engine before it ever gets to the cooler, this will result in more expansion of metals and tighter clearances. stock clearances are horrible for performance and are designed for thin oils which dont protect at high power levels, they are made for emissions purposes. stock bearings put you under .020 bearing clearance unless you shave some off the journals with polishing. to put that in comparision our bearing journals are about the size of a big block chevy, which at those power levels run aout .032 clearance MINIMUM most around .035 to .040. our jounals are BIGGER then a small block chevy which can run .035 all day with 0 issues, bigger journal means you need a bigger clearance(there is more material so it expands more.) get a set of the acl hx bearings(additional oil clearance) and you should be around .032-.038 clearance and run rotella 15w40 or a similar oil to to stand up to the abuse of additional power as well as being thicker so it stays in the larger clearance.
if you browsed the FI forum you would see that its been discussed several times, de, rev up, or hr its dosnt matter the rules on things like this are universal to all engines, try running that power level at a stock clearance and your flipping a coin every time you floor it to make that power.
OP while the stock bearings MAY work they are going to be on the very edge of there limit, not because of the pounding they will be taking but because of the clearances. even with the oil cooler there is going to be significant extra heat generated in the engine before it ever gets to the cooler, this will result in more expansion of metals and tighter clearances. stock clearances are horrible for performance and are designed for thin oils which dont protect at high power levels, they are made for emissions purposes. stock bearings put you under .020 bearing clearance unless you shave some off the journals with polishing. to put that in comparision our bearing journals are about the size of a big block chevy, which at those power levels run aout .032 clearance MINIMUM most around .035 to .040. our jounals are BIGGER then a small block chevy which can run .035 all day with 0 issues, bigger journal means you need a bigger clearance(there is more material so it expands more.) get a set of the acl hx bearings(additional oil clearance) and you should be around .032-.038 clearance and run rotella 15w40 or a similar oil to to stand up to the abuse of additional power as well as being thicker so it stays in the larger clearance.
if you browsed the FI forum you would see that its been discussed several times, de, rev up, or hr its dosnt matter the rules on things like this are universal to all engines, try running that power level at a stock clearance and your flipping a coin every time you floor it to make that power.
the OEM stuff now is very good, no reason for a properly built shortblock to need anythins other than OEM bearings. Maybe when you are talking in excess of 1000hp and sheer force will deform the bearings, you could consider a switch to a different design, but for your goals stock is more than enough.
Last edited by jerryd87; 11-10-2012 at 02:11 PM.
11-10-2012, 02:34 PM
#6
horrible advice and the reason so many spin bearings in this platform, too many people who have never built a engine giving advice or listening to what nissan puts out for a STOCK engine. you will never deform a bearing even at 1000 hp its all about coatings, friction, and clearances.
OP while the stock bearings MAY work they are going to be on the very edge of there limit, not because of the pounding they will be taking but because of the clearances. even with the oil cooler there is going to be significant extra heat generated in the engine before it ever gets to the cooler, this will result in more expansion of metals and tighter clearances. stock clearances are horrible for performance and are designed for thin oils which dont protect at high power levels, they are made for emissions purposes. stock bearings put you under .020 bearing clearance unless you shave some off the journals with polishing. to put that in comparision our bearing journals are about the size of a big block chevy, which at those power levels run aout .032 clearance MINIMUM most around .035 to .040. our jounals are BIGGER then a small block chevy which can run .035 all day with 0 issues, bigger journal means you need a bigger clearance(there is more material so it expands more.) get a set of the acl hx bearings(additional oil clearance) and you should be around .032-.038 clearance and run rotella 15w40 or a similar oil to to stand up to the abuse of additional power as well as being thicker so it stays in the larger clearance.
if you browsed the FI forum you would see that its been discussed several times, de, rev up, or hr its dosnt matter the rules on things like this are universal to all engines, try running that power level at a stock clearance and your flipping a coin every time you floor it to make that power.
OP while the stock bearings MAY work they are going to be on the very edge of there limit, not because of the pounding they will be taking but because of the clearances. even with the oil cooler there is going to be significant extra heat generated in the engine before it ever gets to the cooler, this will result in more expansion of metals and tighter clearances. stock clearances are horrible for performance and are designed for thin oils which dont protect at high power levels, they are made for emissions purposes. stock bearings put you under .020 bearing clearance unless you shave some off the journals with polishing. to put that in comparision our bearing journals are about the size of a big block chevy, which at those power levels run aout .032 clearance MINIMUM most around .035 to .040. our jounals are BIGGER then a small block chevy which can run .035 all day with 0 issues, bigger journal means you need a bigger clearance(there is more material so it expands more.) get a set of the acl hx bearings(additional oil clearance) and you should be around .032-.038 clearance and run rotella 15w40 or a similar oil to to stand up to the abuse of additional power as well as being thicker so it stays in the larger clearance.
if you browsed the FI forum you would see that its been discussed several times, de, rev up, or hr its dosnt matter the rules on things like this are universal to all engines, try running that power level at a stock clearance and your flipping a coin every time you floor it to make that power.
As far as your reference to a SBC (which I happen to be in the middle of a build on one at the moment), a straight forward comparison is not possible, a full aluminum engine has different thermal changes than an all-iron engine. Granted it's not a lot at ~250 degrees, but when you are talking half-thousandths (.0005), it matters.
11-10-2012, 02:58 PM
#7
my bad on forgetting a 0 in there that is right 35 thousandths is what i wanted to say im working on a final atm and typed quickly and dint really proof read before posting.
your right a aluminum engine does have different thermal changes so how about we go to the ls1 which has even larger journals and still runs those clearances despite being aluminum? the block itself might be aluminum but the actual journal isnt so its going to have very similar properties i believe its iron but i dint really check, and again the journals are nearly the size of a big block chevy(ill have to look it up but iirc only about 15 thousands smaller in diameter) which will run anywhere from 40 thousands to 65 thousands on oils ranging from 15w40 to 25w50.
considering a ~730 whp small block chevy often times will run even higher then 35 thous, sometimes as much as 42 thous(i say 730 because thats the same power per bearing as a 550 whp vq35) then i will continue with my statement that you need that clearance which means you MUST go to acl. theres no way to get those clearances on stock bearings without spending more on machining then the cost of the bearings to have the journals polished a crapload to remove the needed material. thats just stupid to do since if you do have a problem down the road theres no way to fix it because you wont be able to find a bearing for it. going acl hx you can get what you need then if theres a problem and the journals need machined down the road(assuming its bearing surface and not the journal bore the bearing sits in.) you can use stock size bearings to get the proper clearance again.
whole point is thicker oil is needed to stand up to the abuse and keep oil in the bearing, and looser clearances are needed to avoid the journals from trying to lock up and catch when operating temp.
your right a aluminum engine does have different thermal changes so how about we go to the ls1 which has even larger journals and still runs those clearances despite being aluminum? the block itself might be aluminum but the actual journal isnt so its going to have very similar properties i believe its iron but i dint really check, and again the journals are nearly the size of a big block chevy(ill have to look it up but iirc only about 15 thousands smaller in diameter) which will run anywhere from 40 thousands to 65 thousands on oils ranging from 15w40 to 25w50.
considering a ~730 whp small block chevy often times will run even higher then 35 thous, sometimes as much as 42 thous(i say 730 because thats the same power per bearing as a 550 whp vq35) then i will continue with my statement that you need that clearance which means you MUST go to acl. theres no way to get those clearances on stock bearings without spending more on machining then the cost of the bearings to have the journals polished a crapload to remove the needed material. thats just stupid to do since if you do have a problem down the road theres no way to fix it because you wont be able to find a bearing for it. going acl hx you can get what you need then if theres a problem and the journals need machined down the road(assuming its bearing surface and not the journal bore the bearing sits in.) you can use stock size bearings to get the proper clearance again.
whole point is thicker oil is needed to stand up to the abuse and keep oil in the bearing, and looser clearances are needed to avoid the journals from trying to lock up and catch when operating temp.
Speaking to the reliability of the bearings, my advice is proper. Notice I used the phrase "properly built"? I am assuming someone checking and setting proper clearances. You may not have the right idea when it comes to that, as you managed to post the wrong measurment in every single example you used. Clearances in bearings are in the thousandths (.004) not hundredths (.035) as you stated multiple times. Run your bearings a .040 and see how much oil pressure you can manage...
As far as your reference to a SBC (which I happen to be in the middle of a build on one at the moment), a straight forward comparison is not possible, a full aluminum engine has different thermal changes than an all-iron engine. Granted it's not a lot at ~250 degrees, but when you are talking half-thousandths (.0005), it matters.
As far as your reference to a SBC (which I happen to be in the middle of a build on one at the moment), a straight forward comparison is not possible, a full aluminum engine has different thermal changes than an all-iron engine. Granted it's not a lot at ~250 degrees, but when you are talking half-thousandths (.0005), it matters.
Last edited by jerryd87; 11-10-2012 at 03:01 PM.
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11-11-2012, 04:18 PM
#9
Yeah, thanks for the input guys, I've talked with GTM and my local shop and decided on going with a High performance GTM bearings on the fact the engines going to be open anyways and might as well spend another $300 and make sure I've got the safe pieces.
Edit: I was going on the GTM high performance bearings that are basically OEM rod and main bearings with protective coatings for the additional heat and friction. Am I seeing that this will not suffice for 585 whp?
Edit: The only ACL bearings I could find were for the DE. Will this fit an HR? Also only clearances I see offered or standard, .25 and .50. I'm not sure which one would be best and if standard would suffice I'd just want to go with the high performance GTM option. Any input on these questions, guys?
Edit: I was going on the GTM high performance bearings that are basically OEM rod and main bearings with protective coatings for the additional heat and friction. Am I seeing that this will not suffice for 585 whp?
Edit: The only ACL bearings I could find were for the DE. Will this fit an HR? Also only clearances I see offered or standard, .25 and .50. I'm not sure which one would be best and if standard would suffice I'd just want to go with the high performance GTM option. Any input on these questions, guys?
Last edited by Nismo350z#0310; 11-11-2012 at 05:04 PM.
12-07-2012, 09:41 PM
#11
I've got the GTM stage 2 kit with oil cooler, various parts ordered. Hopefully get it installed in January. How's your build though? Any pros or cons so far?
12-07-2012, 09:50 PM
#12
I've scrapped this build and decided on a conservative stock block FI seeing I had an HR and much less expensive. Just too many factors on an engine build that pushed me in a different direction.
I've got the GTM stage 2 kit with oil cooler, various parts ordered. Hopefully get it installed in January. How's your build though? Any pros or cons so far?
I've got the GTM stage 2 kit with oil cooler, various parts ordered. Hopefully get it installed in January. How's your build though? Any pros or cons so far?
do you have a daily driver / beater as a backup and go ahead start looking for a backup motor on ebay, craigslist and forum to keep on stand by. FI is a wicked journey....buckle up
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