Main and rod bearings

[03spoolindmax]

What are you guys running for main and rod bearings?

Engine will be around 850-900 with a compound setup.

I've been looking at the clevite h series bearings.

I know they have standard size and .001" over. Any benefits to running it slightly looser or should I stick do stand size?

 

[paint94979]

For that much power how about hx bearings?

 

[03spoolindmax]

For that much power how about hx bearings?

Never heard of them. I figured most guys were running h series. That's why I asked before I bought them so I could figure out what to use.

 

[03spoolindmax]

I just looked it up. Are you referring to the hx bearings as the .001" over bearings like I had mentioned in my first post?

What's the benefit of building it slightly looser

 

[Evan@InglewoodTrans]

Hx are extra clearance bearings.

 

[paint94979]

Race motors are generally built looser.

 

[03spoolindmax]

Hx are extra clearance bearings.

Got it :thumb:

But that still doesn't answer why they are being used. What's the reason for the extra clearance? Will a modded oil pump be need to help with oil pressure due to more clearance between the bearings and possible oil pressure drop?

 

[DaveB]

Hx are extra clearance bearings.

Is that what you're going to use when we put mine together? :hug::woott:

 

[03spoolindmax]

Is that what you're going to use when we put mine together? :hug::woott:

Finally decided to build your motor

 

[Evan@InglewoodTrans]

Is that what you're going to use when we put mine together? :hug::woott:

Depends on my pricing

 

[Hot COCOAL]

Any more info on which bearings are suggested for higher performance goals???

It's been suggested to me that for 1000whp goals to use the Hx bearings and to also use a heavier weight oil, like 20-50 to yield higher oil pressures to squeeze more oil into the added clearances.

Any thought on this thought process, what are you guys that "are" using the Hx series or similar, extra clearance bearings using for oil? And at what point in performance is it suggested to use an extra clearance bearing, 800-1000whp, 1200 and higher or maybe far less, like anything over 700???

And then what are the recommended oil change intervals for an engine built this way? It was mentioned to me that the oil would actually sheer and break down faster running the 20-50 due to the added pressure running said oil would create.

And final question(s); what would this do to the ability of the engine for towing/hauling, general work and daily driving? Would building an engine like this limit the trucks ability at all? And what about climate/temperature the rigs subjected to? For a truck that sees primarily cold weather and very cold weather would using extra clearance bearings and using a heavier oil be a less than desirable build?

Please discuss
Thanks

And as always, FLAME SUIT ON, so feel fee to let me have the fire storm
:hug:

 

[Dave c]

Any of the bearings listed will work, main thing is proper clearance and oil.

 

[Fahlin Racing]

What is the stock clearance spec anyhow?

 

[motoking_1990]

Subscribed

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[motoking_1990]

That's the question what is the proper clearance for aftermarket builds?

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[meshanic]

Sub'd for info

 

[PureHybrid]

You should probably tear into the engine, see what needs to be done, and check dimensions to get a preliminary clearance. You may not need an oversize bearing to gain clearance in some cases, just depends on how it all cleans up at the machine shop. I'm not positive on factory clearance, but .001 over stock might be too much in some cases, it'll probably still work. Start pushing .004 total and you might lose some pressure.

 

[meshanic]

We did a full build on an LMM using HX bearings but we had the machine shop spec everything. The line bore with the billet caps was done with my machinist having the bearings in hand to make sure it was right. We reused the Carrillo rods after they were checked. That engine broke the crank so we'll get to see the internals again real soon. I could never tell that the oil pressure was lower than any other engine running the same oil. We'll be going back with the same bearings so come summer time we'll know how the oil pressure holds up at 100 plus degree temps.

 

[Fahlin Racing]

Remember journals should always be checked for out-of-round and taper before any rebuild stock or modified. More accurate or high quality machine work will give you the option of using tighter clearances. Just because the crank may be machine perfect doesn't mean you can neglect the main bores of the block, they move too.