Bottom end bearings help!!!!

Ok guys

I am confused.....which main&conrod bearings I should buy?

What's the difference between H and Hx? Between coated or non coated?
Please help!

The X give slightly more clearance over the H in standard size, you need do your measurements & get the shell thicknesses for H & X and select ones that give clearance desired for your build spec.

plastigauge them to check clearances

What the f##k is plastigauge??? Just when I think I'm learning stuff summert else crops up

does as it says on the tin lol

gives you an accurate measurement between crank journals and bigend bearings so you have precise clearances.
all Nissan bearings are graded to crank size but acl do more of a multi fit size bearing but its not the best if you want to do the job properly youll need to plastigauge the crank to get correct journal to bearing clearance

Its a really simple idea but really precise ....all it is is a bit of plastic wich you put in the journal and clamp it back down then use the gauge to see what size bearings you need ...

Plastiguage is more for final checking of clearance in bearing. When doing a grind on a crank I supply suitable undersize bearings & machine shop can grind & polish to suit bearings to what ever oil clearance I specify by measuring with bore gauges & micrometers. during build testing plastiguage is used as simple way of checking clearance &  adjustments such as moving shells around to even out oil clearances to required tolerance range.

Ok Mr.B....

I will sent the block and crank to a machinist to have them checked....but I have checked myself the original bearing and they are like new...that's why I am thinking that there's no problem.

Can you supply the needed bearings?

Cheers,

B

Always good to have journals checked. If fine which sounds like is & no grind needed you should find the standard ACL H bearings will work & oil clearance will be in specified limits. Nissan bearings do allow for more oil clearance selection when dealing with standard unground crank. You will have markings on engine/crank related to current nissan bearings.
Most builds will be fine using ACL H, some people will go for Hx on standard crank if find oil clearance tight on standard H or desire fraction more clearance for a hot & hard running track build for example.

yep as above it depends on power your planning on running and rpm limit if raised and whether its going to be mainly a track or road based vehicle which will determine clearance.

don't forget you also need to get the crank checked for ovality as its no good if you have clearance on one part of journal and its tighter on adjacent side as this is where the bearing will pick up.

if you have a look on youtube or something like that no doubt there will be info on plastigage and how to do it, its not hard just a bit time consuming but you should check clearances especially if its a big power build

Aha Bob....will do that....my machinist actually!)

Bob check PM