LET Big End/Main Bearing Dimensions

[Nova_Tek]

Good day too all,

I've decided to go pretty much all out and get the LET rebuilt and freshened up; main/big end bearings, piston rings, headgasket, vavle seals, etc before it goes in.

As I don't know the history of the engine I'm just thinking of all the possibilities and one of then being if the engine has been rebuilt before and if it's had it's crank reground or not. So I need the measurments of standard bearings so when the current ones come out I can measure them up and know for sure if it's had any work done to it, thus knowing what size bearings to go for.

So... what exact size are they? (no guesses needs to be definite).

+rep for those that help :thumb:

[Southie]

Not sure if anything is in this but maybe worth you having it anyway >LINK (http://www.google.co.uk/url?sa=t&source=web&cd=1&ved=0CBsQFjAA&url=http%3A%2F%2Fwww.cavalierturbo.com%2Fdownloads %2Fworkshop_manual%2FC20LETWorkshopManual.pdf&rct=j&q=c20let%20manual%20PDF&ei=U03eTZbVKoyx8QPQlu2cCg&usg=AFQjCNEika6TedJVFfN-W0x8ZQW__iAxuQ&cad=rja)< ;)

[Nova_Tek]

Link won't open or download dude :(

[Southie]

Link won't open or download dude :( It will download mate, just give it time as it's 12mb :)
Original link is the top one here >LINK (http://www.google.co.uk/search?q=c20xe+haynes&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#sclient=psy&hl=en&client=firefox-a&hs=Xdv&rls=org.mozilla:en-US%3Aofficial&source=hp&q=c20let+manual+PDF&aq=f&aqi=&aql=&oq=&pbx=1&bav=on.2,or.r_gc.r_pw.&fp=30c8ac2b1f88265c&biw=980&bih=758)<

YHPM

[Nova_Tek]

Got your PM, think it's just Windows 7 being ghey! the iMac is sucking it off the interwebz lol

have some +rep for being helpful :)

[mowgli]

follow the linky on my sig. look in the ks engine stuff, then select the vauxhall stuff. its all you will need.

you end up with this (http://www.ms-motor-service.com/ximages/PDF_Kataloge/gl_vauxhall_web.pdf) 258kb of pdf.

[Nova_Tek]

I owe you some +rep Sir (must spread first :( )

[thedondy]

if you remove 1 of your old berrings they should be marked with something like std for standard size or +5/+10 or what ever if they have been changed to for a crank grind.

[Nova_Tek]

Thanks for the tip +rep

[thedondy]

no sweat
first rep:d

[Southie]

Glad to help Mr Tek ;)

[Plug]

i did mine the easy way lol

Rang steveboyslim with the numbers on mine haha

[mowgli]

i did mine the lazy way lol

Rang steveboyslim with the numbers on mine haha

it really isn't a special skill to read a parts book, then order them from the local supplier.

[Plug]

/\ yea i know mate as you say im just lazy

haha lol

[Nova_Tek]

I'll be checking the bits see if there are any markings on them otherwise will take a look Mowgli's catalogue and get it off there.

[mowgli]

i'd always recommend taking it to an engineer and get them to measure & check the crank. this engine is probably 20 years old now. if it needs a grind, they will match the shells to it. remember, there are early & late ones on a big block, but i can't remember if the let was ever made with the early, small ones

[philip]

usually .25 or .50 on the bearing or std, but if oversize then it will have a .25 or .50 on where as some standard bearings may not have STD stamped.

[Nova_Tek]

My mate is well clued up about the LET he totally stripped and rebuilt his own one. According to Mowgli's catalogue all LETs had the same bearing sizes. But I'll be measuring for extra security and will look out for markings.

[philip]

what way do you mean same size? i know they should be the same size, but you dont know if cranks been previously ground and if so they may have only ground the mains, big ends or if like my machinist he does both. so bearings could have .25 or .50 on the back of the bearings.

[Nova_Tek]

^ it's for that reason I wanna measure the size of the bearings. Now that I know what size they should be standard I'd be able to tell what has been reground and what's normal.

[Plug]

Well the main bearing i have here infront of me

markings on it are : GM 15 R 781 N

measures 19mm across the flat, couldnt tell you if thats a standard bearing thou

[Nova_Tek]

According to one of Mowgli's catalogues it stated it as 20.30mm across (bearing in mind (pardon the punn) they are a pressure fit) and 1.500mm thick. That's standard.

[Plug]

Arh saying that mine is a converted Xe so may be an early crank with the smaller bearings??

i defo measured 19mm across with a tape measure mind

[Nova_Tek]

They do reduce in size once fitted as they are slightly larger than the cavity they sit in according to this manufacturers catalogue.

[AlexW]

I do wish you the best, But its not going to be perfect since you aren't measuring it accurately, and you can't tell if the crank has worn or if its gone oval shape.

[philip]

they did 2 width bearings btw, but couldnt tell you why.

and plug...there standard bearings