just took the big end shells out of the car today, had a bit of chew but got there in the end. having inspected the shells the number six set have worn a bit, showing the copper. the crank is still nice and shiny so i,m gonna order a new set for her.

 

my question is...are there different size bearings in these motors??

 

the reason i ask is when i have remove the shells i noticed that if you try and pair up different sets they look different diameters....

 

any info?

 

where is best place to order them and how much you reckon.

 

cheers :)

get in touch with mike (mr f) MJP, from the traders section, he can supply you with all the bits and will tell you how to work out what parts/size you need.

Did you notice all the numbers and letters stamped on the bottom of the block and on the end of the crank shaft????????

can of worms LOL

paul is right.dont over complicate things with grades.get a good machine shop to polish or grind the crank which ever is needed and they will tell you.and get them to supply the shells.any good make such as payen sell them as std or +10 etc.

get in touch with mike (mr f) MJP, from the traders section, he can supply you with all the bits and will tell you how to work out what parts/size you need.

Did you notice all the numbers and letters stamped on the bottom of the block and on the end of the crank shaft????????

 

 

been in touch with him tonight and he told me where to find the numbers for all the sizes.

paul is right.dont over complicate things with grades.get a good machine shop to polish or grind the crank which ever is needed and they will tell you.and get them to supply the shells.any good make such as payen sell them as std or +10 etc.

 

the reason for doing the shells was due to a very slight rattle on the bottom end, i think i caught it real early.after removal of all the shells i found the only one to have any wear was the number six set(back pot) the wear was very minimal with only the white metal worn exposing the copper colour, after close inspection of the crank there dosnt seem to be any need for any regrind or polish. as the engine is still in the car i am gonna try and stick a set of new shells in and see what happens.

The shells are colour coaded on the edges. If you have not mixed them up and can see the colour you can replace like for like. Also the as new grade sizes are stamped on the number 5 counter weight of the crankshaft and each rod bigend. You have to add the two marked grades to get the rquired shell size. This is not the best way to do it but unless you have accurate measuring equipment and skills its all you can do yourself.

The shells are colour coaded on the edges. If you have not mixed them up and can see the colour you can replace like for like. Also the as new grade sizes are stamped on the number 5 counter weight of the crankshaft and each rod bigend. You have to add the two marked grades to get the rquired shell size. This is not the best way to do it but unless you have accurate measuring equipment and skills its all you can do yourself.

 

you wont see the colour codes on the bearing after 15years, but as said you can add the number on the counterweight and correspond it with the rod which is stamped on the cap.

 

example crank+rod=

crank 121301

rod 111011

use 232312

never had this much chew with a set of shells before, so if i get this wrong i,m ****ed??

I know on other nissan big end shells they have S stamped on them for standard if they havent its had a crank grid and you need to get the crank mic,d up.It maynot be the same for the zed engine i know it works this way on the ca18det and sr20det engines.

never had this much chew with a set of shells before, so if i get this wrong i,m ****ed??

 

Just out of interest did you buy your car from Ryan ???

Nissan donot do oversize shells for the z32 any more. If the crank needs grinding you have to use aftermarket shells. The four grade sizes available from Nissan are all covered by a few thou and allow them to run close tolerances by using selective assembly. The standard crank and shells are so good that a propperly maintained engine with 150,000 miles will usually still be within tolerance on the crank pins and one of the four grade size shells will make it almost as good as new.

Nissan donot do oversize shells for the z32 any more. If the crank needs grinding you have to use aftermarket shells. The four grade sizes available from Nissan are all covered by a few thou and allow them to run close tolerances by using selective assembly. The standard crank and shells are so good that a propperly maintained engine with 150,000 miles will usually still be within tolerance on the crank pins and one of the four grade size shells will make it almost as good as new.

 

Ive just bought AC Ultralite shells (Austrailian i think) for mine they are a little more expensive than OEM but they are actual gray metal race bearings.

the reason for doing the shells was due to a very slight rattle on the bottom end, i think i caught it real early.after removal of all the shells i found the only one to have any wear was the number six set(back pot) the wear was very minimal with only the white metal worn exposing the copper colour, after close inspection of the crank there dosnt seem to be any need for any regrind or polish. as the engine is still in the car i am gonna try and stick a set of new shells in and see what happens.

You will waste your money just banging a set of shells in. If the shell on number six was showing copper, which is much harder than the white metal bearing lining, the crank will be worn. The knocking will certainly be less but because of the increased clearance on that journal, the oil pressure will be lower and thus it will start knocking again in quite a short time, especially if its a turbo model.

the shells have the std mark so gonna go with a set of standards

You will waste your money just banging a set of shells in. If the shell on number six was showing copper, which is much harder than the white metal bearing lining, the crank will be worn. The knocking will certainly be less but because of the increased clearance on that journal, the oil pressure will be lower and thus it will start knocking again in quite a short time, especially if its a turbo model.

 

well i reckon its worth a try for 45 quid and a few hours work. and as ive already stated i have had a real close look at the crank and she seems fine, the copper may be slightly tougher than the white metal but is no where near as tough as the crank mate. and as for the increased clearance i think i would notice if the crank had been ground away to the point where i would notice a knocking on new shells...

:xxx:

well i reckon its worth a try for 45 quid and a few hours work. and as ive already stated i have had a real close look at the crank and she seems fine, the copper may be slightly tougher than the white metal but is no where near as tough as the crank mate. and as for the increased clearance i think i would notice if the crank had been ground away to the point where i would notice a knocking on new shells...

:xxx:

i dont think he was being harsh towards you, like you say its worth a try, but just because everything looks ok, dont mean it is, ie.. the reason they failed in the first place, was it short on oil? mileage? oil starvation? iv seen a lot of replacement bearings go within 1mile let alone 100miles, but fingers crossed it may cure it for good, in which case fairplay. :D

i dont think he was being harsh towards you, like you say its worth a try, but just because everything looks ok, dont mean it is, ie.. the reason they failed in the first place, was it short on oil? mileage? oil starvation? iv seen a lot of replacement bearings go within 1mile let alone 100miles, but fingers crossed it may cure it for good, in which case fairplay. :D[/quote

 

:nelson: well i,ll give it a go and let u all know if i **** it completely....fingers crossed :D

i dont think he was being harsh towards you, like you say its worth a try, but just because everything looks ok, dont mean it is, ie.. the reason they failed in the first place, was it short on oil? mileage? oil starvation? iv seen a lot of replacement bearings go within 1mile let alone 100miles, but fingers crossed it may cure it for good, in which case fairplay. :D[/quote

 

:nelson: well i,ll give it a go and let u all know if i **** it completely....fingers crossed :D

im sure it will be fine :)

If the wear is due to high mileage then the mains will be worn as well. Before you do mega miles in order to save the crank I would plan a full strip down. There would also be some benefit from fitting new piston rings at the same time.

i dont think he was being harsh towards you, like you say its worth a try, but just because everything looks ok, dont mean it is, ie.. the reason they failed in the first place, was it short on oil? mileage? oil starvation? iv seen a lot of replacement bearings go within 1mile let alone 100miles, but fingers crossed it may cure it for good, in which case fairplay. :D

Thanks Greg. I was speaking from 48 years engineering experience and personal experience from doing just that. Changing some shells and leaving the crank as is and that in engines without turbos. It never lasted long. I was involved in motor sport in the 60's and 70's and you would try anything to keep going. And also, anyone that can look at a crank and spot the difference between .0002" (Ok) and .0010" wear (shite), is damn clever I say. I always use a micrometer myself.

Thanks Greg. I was speaking from 48 years engineering experience and personal experience from doing just that. Changing some shells and leaving the crank as is and that in engines without turbos. It never lasted long. I was involved in motor sport in the 60's and 70's and you would try anything to keep going. And also, anyone that can look at a crank and spot the difference between .0002" (Ok) and .0010" wear (shite), is damn clever I say. I always use a micrometer myself.

 

:bow: :bow:

:nelson: :nelson:

 

well dont i feel a royal prick. sorry mate, just had a bit of a bad day wen i read your response. i,m heavy goods qualified and worked on heavy diesel engines for a good few years then onto petrol. well i will give it a go and let u all know how it goes.

the reason i reckon it will work is the noise would only come on when the engine was at runnin temp,even then the oil press was ok. so hopefully indicating minimal wear.

 

thanks for all the comments

If I can add my ten pence worth. I had alook at mine, all OK. But the end float thrust bearings, as located on a main bearing shell, needed replacing. Nothing bad, just slightly worn.

 

Have a look at your mains before you rebuild it. Mine has been going for 18 months or so now, no problems. And remember that technology has moved on since the 60's and 70's. In those days things didnt last anywhere near as long as they do now. :-)

:D many thanks to greg for helping me with the grades.... :D

you might want to check your oil pump when i took mine off it was ****ed the steel gears wear the ally casing, oil pressure is fine until tick over and normal running temp, then gauge drops to nothing.