Acl Race Bearings

[Mik]

On ACL's application guide, they reccoemnd the following bearings:

RB25 mains: 6B296OH

RB25 Big ends:7M2424H

RB26 mains: 6B296OHX

RB26 big ends: 7M2424HX

Does anyone know what the difference is?

[Suspense]

I think 1 is TRI-metal... i got trimetal on my car... goes good

[proengines]

The HX bearings run an extra .001" clearance over the H series.

[pnblight]

hi Greg,

what you think of the ACL bearings in comparison to std nissan and nismo. As i was about to order a full set of nismo bearing.

pete

[proengines]

The ACL's are a good bearing, the race series bearings have a hardened steel backing which keeps them well located in the housings even when they have had some heat. They are fairly soft which is a good thing if there is anything floating around in the oil as it can embed in the bearing. They are not hard on the crank either, not really an issue with an RB as the crank is pretty hard to start with.

I still prefer King bearings, the material is better, only one layer of bearing material about .015" thick on a super hard backing, the alecular material has a melting point almost 3 times higher than the babit on a regular trimetal bearing so there is less chance of delamination even under extreme loads and heat.

Nissan bearings are made by NDC and are a trimetal bearing, I have seen these delaminate when they cop some detonation. I haven't used Nismo bearings, I'm still pretty sure that they are a trimetal bearing, one benefit I suppose is you can buy them graded to adjust clearances but then if the bearing housings are not on size they should be remachined anyway. I haven't had problems getting spot on clearances with the king bearings, all the bearings in a set are guaranteed to be within .0001" tolerance so there is no chance of tolerances stacking up and changing clearances. The other benefit of Kings is the price, they're cheap as dirt compared to Nismo bearings as they are a standard replacement bearing.

[Mik]

The HX bearings run an extra .001" clearance over the H series.

<{POST_SNAPBACK}>

Yeah..thanks for that. I guess ACL reccomend the extra clearance for the 26 because they typically make a bit more power than the RB25.

When they say 1 thou extra clearance, any idea what the clearance will come out at with a brand new crank?

Cheers.

[pnblight]

The ACL's are a good bearing, the race series bearings have a hardened steel backing which keeps them well located in the housings even when they have had some heat. They are fairly soft which is a good thing if there is anything floating around in the oil as it can embed in the bearing. They are not hard on the crank either, not really an issue with an RB as the crank is pretty hard to start with.

I still prefer King bearings, the material is better, only one layer of bearing material about .015" thick on a super hard backing, the alecular material has a melting point almost 3 times higher than the babit on a regular trimetal bearing so there is less chance of delamination even under extreme loads and heat.

Nissan bearings are made by NDC and are a trimetal bearing, I have seen these delaminate when they cop some detonation. I haven't used Nismo bearings, I'm still pretty sure that they are a trimetal bearing, one benefit I suppose is you can buy them graded to adjust clearances but then if the bearing housings are not on size they should be remachined anyway. I haven't had problems getting spot on clearances with the king bearings, all the bearings in a set are guaranteed to be within .0001" tolerance so there is no chance of tolerances stacking up and changing clearances. The other benefit of Kings is the price, they're cheap as dirt compared to Nismo bearings as they are a standard replacement bearing.

<{POST_SNAPBACK}>

ok cool ,

so who sells King Bearings and what kind of cost we looking at for a set of bigs and mains.

on another matter the nissan specs clearances are pretty damn good

ie there factory spec 0-3 for main tunnel and main journals is only

+/- 0.0005" for the 4 spec sizes or a mass producted engine thats pretty impressive and no wounder people dont have many problems with tolerances even with out using the 6 grades of nissan bearing.

pete

[proengines]

Pete,

$80 for mains, $80 for conrod brgs. I just have to make sure they are back in stock, a shipment should have arrived by now. These are RB30 mains, I just drill the extra feed holes.

[blk180]

hi all i have have kings bearings in my 26 but i was wounderig when i had my engine rebuildt it had the crank grub screwed what was the deal with doing that thanks

[proengines]

It has had the alloy plugs that seal off the oil galleries in the crank removed and been tapped to take screw in grub screws to seal the galleries. You need to remove the old plugs when you rebuild the engine to clean the crank properly.

It's a good thing, whoever did your engine did it properly, it doesn't affect anything else.

[blk180]

OK thanks yes fingers crossed they did a good job

[the_tonkau]

Warning!!! ACL PRODUCT WARNING. Were supplied new race series forged ACL pistons, rings and bearings for an rb30/25 hybrid. Engine built buy a reputable engine builder and run in by ex Perkins engineering mechanic/tuner. Rattled from new and pulled down at 2000Klms to discover massive wear on the drive side of the bore. Piston to bore clearances measured at 7 tho and within spec. ACL denied refund/replacement and rolled out these excuses in this order. 1. Detonation (cleared after hardness test) 2. Foreign substance in bore (brand new engine run in on dyno with standard air box and new filter) Cleared after excuse number three. 3. Over boosting causing rings to break down and cause abrasion on bore. (Stat decs signed by engine tuners engine stating run in boost set to max of 14psi). ACL now tell me that there FORGED race series pistons are only rated for 10PSI. This engine has a comp of 8.2:1. Standard engine runs 9:1 with cast factory pistons at around 9psi...do the math. Currently taking legal action. Any questions regarding this "race designed product" PLEASE contact me @ [email protected] .This is not a rant, but an opportunity for other people to learn from experience.

[Duncan]

That is very interesting. Do you have written confirmation from ACL that their pistons are unsuitable for most turbo applications? seems amazing doesn't it?

[NXTIME]

Unbelievable!

[pnblight]

Warning!!! ACL PRODUCT WARNING. Were supplied new race series forged ACL pistons, rings and bearings for an rb30/25 hybrid. Engine built buy a reputable engine builder and run in by ex Perkins engineering mechanic/tuner. Rattled from new and pulled down at 2000Klms to discover massive wear on the drive side of the bore. Piston to bore clearances measured at 7 tho and within spec. ACL denied refund/replacement and rolled out these excuses in this order. 1. Detonation (cleared after hardness test) 2. Foreign substance in bore (brand new engine run in on dyno with standard air box and new filter) Cleared after excuse number three. 3. Over boosting causing rings to break down and cause abrasion on bore. (Stat decs signed by engine tuners engine stating run in boost set to max of 14psi). ACL now tell me that there FORGED race series pistons are only rated for 10PSI. This engine has a comp of 8.2:1. Standard engine runs 9:1 with cast factory pistons at around 9psi...do the math. Currently taking legal action. Any questions regarding this "race designed product" PLEASE contact me @ [email protected] .This is not a rant, but an opportunity for other people to learn from experience.

<{POST_SNAPBACK}>

7 thou clearance thats f**king hugh what is there recomend clearance on install out of interest

[boostedvk]

hi there i am in the middle of building a rb30/26 and wanting to use acl race series bearings but they are on back order i have the option of using th hx bearing which give 001" extra oil clearance are there any pro and cons to using these or should i wait for the standard one which will be weeks

[zebra]

ACL are in Liquidation, so stocks are pretty much Zero on things, the extra clearance will help if you want to rev it fairly hard or want to run big power, (if its a 26/30 than I assume you want a fair whack of grunt)

[gobiz]

In liquidation! No wonder i havent got my order. Anyone got any clue on whats the latest status with them?

[old mate]

my acl forged pistons that are 20thou over for my rb25 say 4thou clearance max. any bigger and you bound to get some slap right?

[gobiz]

Apparently Ill be getting my acl rb30 bearings delivered this week. :)