Engine Re-build

[mickie 3]

hi, im stuck, i've been re-building my engine over quite a few months now, on and off and today desided to torque my main and big end bearings down and it wont move..

 

i measured the crank with a digital measuring gauge and its not far worn off being new, the main bearings are off a bottom end i got free, they're new, the lad was in the middle of doing what im doing now, but i took his bearings and put them with my engine and crank, his crank messured up the same as mine so thought they'd be fine.

 

and the big end bearings are new too, which are original sizes..

 

would plastiguage find my problem ? what guage do i need to buy and if i do use it how do i know whats good and bad, guage wise? its a 1.9 engine, first time i've re-build a bottom end before..

 

i re-build a 1.6 top end a year back tho, also im confused about when the bottom end caps are slack i can turn the bottom end fine, but if i turn the crank all the way round pistons dont hit valves, is this normal ?

 

i've done a search and there isnt that much info on plastiguage

 

thanks for any help

[DamirGTI 344]

Hi !

 

Regarding using plastigauge read this : http://www.guy-croft.com/phpBB3/viewtopic.php?f=3&t=950

and also other posts on Guy Croft's site , you'll find them very useful

 

Best luck !

Damir

[welshpug 1,666]

loosen each cap in turn and see if the engine will turn over, work along the engine until you find the culprit

[Miles 331 1 Cars]

Check that the main bearing cap's are on the right way around and also the big end caps as they cannot be swapped from one engine to another or even one rod to another

All the bearings will have a size written on the back of them too

[weejimmy 1]

mayby im not reading it right but were the bearings fited to the other car but not used?

if so they may have been over tourqued and miss shappen.

but if you work along the rods to find the culprit like welshpug said, it could be a bent rod. thats what hapend to me on my last mi and was how you describe with turning fine slack then not at all when bent rod was tight.

[mickie 3]

i've just had a look tonight, put them through there torque and degree settings and found 3 problems..

 

2 main bearing caps when torqued up stop the crank moving and one big end cap stops the crank when up to 70 degrees..

 

i remember when i first took the engine apart i just pulled them out in any old order and didnt keep track and it was a pain getting it to work when putting bearings and caps back as it just didnt work at all but im pretty sure now i have the main caps in the right order and the right way round, but im unsure about the big end caps, how can you tell they're in the right order or right way round ? and what can i do about 2 of my main bearings ?

 

also i remember tapping the middle main cap down and i think the bearing may have poped out and when i've fastened it down bent the bearing a little and the middle cap is one of the ones jamming the crank, guessing thats enough to jam a crank ?

 

if anyone wants pictures to help me out i'll stick them up.

thanks for the good advice up to now

Edited January 28, 2008 by mickie

[Miles 331 1 Cars]

If you can have a look in the haynes manual as this explains it all in detail, The main bearings are all numbered but the big ends are not

[mickie 3]

is the only way to put the big ends back in order, are to swap the caps around, till it works ? or use some plastiguage and see if i can find some slack spots in the bearings and tight spots ? they dont even give you a bearing running clearance for big ends, but thats another question, im guessing if you get standard size bearings and your crank is within tolerance i should be ok. the main thing i need to know is that its all in the right order then i guess its faulty bearings after that

 

what i've messed up on is taking my bottom end apart without reading up on it first..

 

but my main bearings aint numbered, if i stuck some pictures up could you see if they look in the right order ?

[ALEX 98 1 Cars]

I put mine together once, filled it with oil and used a spanner on the crank pulley to build the oil pressure up before starting it.

It only turned about 3/4 of the way before locking up.

Took me ages to find the problem. I'd dropped a nut down one of the bores!

You've not done something stupid like that have you?

[mickie 3]

haha no, miles answered what i was after and welshpug.. i've mixed main caps up with my engine and also with another engine, i should have looked into it before starting but just went for it, im learning from my mistakes..

 

at the time i thought it would be pretty hard to mix as you can only really mix 2 main caps up as the others only go in one place, as in the cap in the middle up to the cap at the end near the flywheel, you know where they go..

 

the main bearings jamming were the middle ones and the ones with the thrust bearings with them.

i swaped both of these with the spairs i have and torqued them upto 49nm and the cranks moving ok now, the big ends haven't been swaped with any other engine, just swaped with each other so i swaped them around a few more times and thats ok now too. so everythings torqued up and degreed up and i can move it now but im still unsure about them being right so i've bought some plastiguage and when that comes i'll check again.

 

it still doesn't give me a big end bearing running clearance for plastiguage in haynes which i think i may need now i've messed them all up. if your crank isnt that worn you can use standard bearing sizes, so no need to use plastiguage, so haynes says, fair enough but i've mixed all my caps up

 

at least i have main bearing clearances