Ok so I got a used crank and have the original block codes for it.
now when I use that crank in my block do I use my block main crank bearing journal dia numbers and the new cranks main bearing bore inside dia number and match them on the bearing chart for the main bearings I need.

and on the connecting rod bearings use the new crank connecting rod journal dia numbers to get the bearings I need?

 

Personally, I'd get it reground and get new shells to match. If you have taken the time and effort to strip down the engine this far, it would be a shame to f**k it up by wiping the bearings and having to do it all over again. Used journals and new bearings don't always go together

 

According to Engine repair course code 168 page 6 of the engine overview it states that the crankshaft should not be reground. It states that it will damage the rolled fillets and weaken the ctankshaft.

I haven't replaced bearings on our engines but did it several on 1200cc Yamaha engine. Same principle. Take the code for the crank mains and match it up to the code on the block for the mains. Take the code for the rods from the crank and match it up to the code on the rods.

 

yea I dont want to regring.so I do pretty what I said or do I have that backwards

 

The replacement crank should have a code on the flex plate end. What is the code on the crank?
Next what is the code on the block?

 

I dont have the crank here yet.I have the codes from the block it came out of and the codes from my block

 

You need the crank. The code for the journal sizes is on the crank. You will need that code before you order bearings. Look at the example in the course code 168. The crank has letters on it. Take the letter from the crank then transfer to size shown on chart. Then take the code for the correspondong journal on the block code then transfer it to the size shown on chart.Then use the main bearing slection chart to determine what color bearings you need.

 

ill wait for the crank to come is but dont the codes on the block the crank came from also show the codes for the bearing size for the charts

 

No. The code on the block only shows the sizes of the journals on the block not the crank. You need the size of the crank journals and those sizes are only on the crank.
Do you have the bad crank out of your motor yet?

 

oh ok....no bad cranks not out yet.just disassembled the motor down to block.2 front pistons had down movement. Motor will be pulled tomorrow.

 

I haven't come across a crank yet that couldn't be reground, unless it was beyond size limits of course. You will probably find that the manual also says not to use used parts as well but you are ignoring that advice. Get it ground and get the matched shells, chances are it will only need a scim to the next size shell, and if they are supplying shells to that size ,then Jaguar must have been grinding their cranks to that size so there cant be any issue in doing what they did at the factory anyway??? Jaguar never advise grinding cranks just as they don't advise boring out engine blocks, they only advise to replace but tell that to the engine remanufacturers and they will laugh in your face

 

If the cranks are nitrided or use some other surface hardening process you will grind that away. I don't know if that is the reason but.....

bob

 

Nitriding does not stop you from grinding the crank, it can be redone if necessary but the journal will probably only need a 0.1mm taking off tops, more likely just a polish, the point is, who in their right mind would strip an engine and then swap out their crank from another engine without at least getting it checked first. It's a job that's a ballache the first time, doing it again 1000miles after....

 

I have done a little research after the discussion with phanc60844. The issue about having it reground is you will cut the fillets. The rods and mains are made to fit these fillets. If it is reground these fillets will need to be ground the same amout and not cut out. I'm not a machinist but this sounds like an expensive process to regrind with fillets.
What I read in the engine repair course code 168 is that the cranks in our engines are not harden and to carefully hanle the crank to prevent damage to bearing surfaces.

Probably phanc60844 and motorcarman have more experience with this subject than I have but I'm just posting what I have researched. But I agree with phanoc60844 that it would be a good idea to have it checked by a machine shop.

 

I did a little research also:
CRANKSHAFT GRINDING JAGUAR XJ6 XJ8 XJR XK8 3.2 3.4 4.0 4.2 V8 PETROL ALL YEARS

like I said, I haven't come across a crank that couldn't be reground, if it can be made, it can be reground. This seller wont grind beyond journal limits, others can reweld journals and grind, the point is, they have to be in a terrible state (cracking usually) for a repair to be not possible regardless of what the Jag manual says

 

Just to add, a little info on the process with regards the fillet:
The Regrinding Process
H T Howard perform this specialised machining operation on our Prince crankshaft regrinding machine.

The grinding wheel to be used is selected depending on the width of the journals to be machined and also paying special attention to the size any fillet radii present.Before the grinding process begins the wheel face is diamond dressed and the required radius set.
- See more at: Crankshaft Regrinding Services for cars and vans from HT Howard | HT Howard and Co | motor machining and engine restoration centre in Slough, Berkshire

 

Just to add, a little info on the process with regards the fillet:
The Regrinding Process
H T Howard perform this specialised machining operation on our Prince crankshaft regrinding machine.

The grinding wheel to be used is selected depending on the width of the journals to be machined and also paying special attention to the size any fillet radii present.Before the grinding process begins the wheel face is diamond dressed and the required radius set.

 

Ok.got the motor out.pulled the oil pan and the plate after that.oil pickup scree was clogged with plastic guide pieces and what im guessing pieces of the bearings.the first 3 rod bearings are no longer there.the connecting rod journals look fine(didnt mic them) and the crank journals dont look that bad either, again didnt mic them.is it possible that the crank just needs to be polished?

 

take it to the machinists and ask them, they are the experts and will select the correct shells at the same time so at least when you rebuild it you will know it will work.Having the journals polished is peanuts compared to having to do the job all over

 

The only maching shop I have here is napa and last time I had them gring a crank they knicked it.the company I got the crank from said they had the crank checked and it was within factory specs.I had them put a hold on the order cause if I can get this one ground down and shells to match itd be cheaper cause the crank is 330.00 shipped to my door.here for a ground crank they charged me 100.00 plus bearings.