11 replies to this topic

[minilee94]

Starting to build my engine now a 1380 I have a few questions about crank bearings etc its a brand new crank I have not reground been nitrided and x drilled

Main bearing size I take it I need measure the main journals and them but the right size am I right or wrong

And thrust washers to what one will I need or does this all come down to what the end float is

I'm trying to read the haynes but its useless is shows you very crap pic of end float checking with no measurments etc so can some one help please

And

[Frisco]

For mains and big ends you need to mic or plastigauge the crank journals. Thrust washers are sized by measuring the end float. Basically everything is sized by measuring the parts not the old bearings.

The haynes does list tolerances for all these so aim for the minimum figures

Edited by Frisco, 28 August 2013 - 07:50 AM.

[minilee94]

Okay thanks just to add I don't have any original bearings so I do I need to buy all standard thrusts and cap bearings then go from there then measure up then if needed to go fatter /bigger size then do that

[Frisco]

If the crank is brand new the journals will be standard size. Undersize bearings are only needed after a regrind 

[minilee94]

Okay thank you so will I just need std size bearings and thrust and yeah its brand new bought from mini speed spose I need to get std size then check endfloat anyway don't I med just tryed to sell me a bearing kit for £80 but that's a waste if I need thicker / bigger bearings or thrust washers

[Cooperman]

Measure the journal diameters first to confirm that they are standard and as original. Take nothing for granted.
If the journals are standard buy a complete set of main and big-end bearings and a standard thrust bearing set.
Do a trial build (sometimes known as a 'dummy build') to check that the crankshaft rotates freely and can be turned by a thumb and finger. Just use 20w50 oil for this build as you will be stripping down again. When doing the trial build you also fit the pistons with the rings removed to check how far from the block deck level the piston tops come so that the block can be skimmed to bring the pistons level with the block deck. The piston ring gaps can also be measured/checked whilst off the pistons (be careful not to snap a ring when removing/re-fitting).
When trial built, measure the crankshaft end float using a DTI with a magnetic base. If the float is more than 0.004", get one pair of thrust bearings at +0.003" oversize. If float is 0.007" get two pairs of +0.003" thrust bearings.
The key to engine building is to measure and measure using the right measuring equipment.
For accurate cam timing check you'll need a DTI and a crankshaft protractor.

Edited by Cooperman, 28 August 2013 - 09:17 AM.

[The Principal]

(Assuming this is an A+ Block) As Frisco says, a new crank will require standard shells (00'), there are varying quality of shells available good shells are available from ACL or better quality but more expensive are the Mahle versions - http://www.minispare...px|Back to shop

 

 

Thrust washers are pretty cheap you'll need to measure the end float to be precise -

[minilee94]

Okay thank you so will I just need std size bearings and thrust and yeah its brand new bought from mini speed spose I need to get std size then check endfloat anyway don't I med just tryed to sell me a bearing kit for £80 but that's a waste if I need thicker / bigger bearings or thrust washers

[The Principal]

MED sell ACL and Mahle (Vanderval) bearings which are excellent quality but they charge a lot of money for them, you can obtain those elsewhere for much less. I would ring up minisport and confirm the spec of the crank is 'Standard' shell size then ask them if they sell ACL shells

 

If your in Bromley pop along to Gosnay's they have shells for everything, - http://www.gosnays.c...log/search.html they are really friendly and very helpful

[KernowCooper]

At 1380 pay attention to the firing ring on the headgasket and check its not going to make contact with your pistons

[minilee94]

I have done the piston ring gaps today there all okay . And kenrow yes I saw that today I have a bk450 head gasket and the metal around the bore on the gasket looks like it will hit. And for the crank surely as said its a brand new crank I won't need oversized bearings and have already checked with minispeed were it was from a few years ago and they said it is brand new . And pete (cooperman) I have already fitted all the rings up my pistons I spoke to med and they said it should be okay just to buy a standard set and that's it should be about 5 thou as stated before I think .

[minilee94]

Measured and spoke to med and they said its a new crank not a regrind