21 replies to this topic

[MINI 1]

ok , been having some troubles with mine 1380 just recently , knocking , tapping sound on tickover so decided to remove the engine and strip it down to see where the fault was. so removed the camshaft and looked at the bearings and lobs of the cam , and basicaily their **cked , the camshaft was a mini sport one , which i think must of been made from playdow lol , then took out the bearings from the crankshaft , the big ends look like there are going down but the mains looked fine.

oh the joys of mottoring !

the thing i carnt get my head around is why are the cam lobes so damaged? is it because its a cheap cam? the engine has been built correctly .

so what i plan to do is ring MED tomorrow morning get a new cam and see if i can get my crankshaft reground with new bearings and build it back up again , see if it cures it, wich i think it will looking at the state of them bearings. my other question is will the bores and rings be ok ?, the engine had only done about 20 miles and you can still see the honeing marks . rings look fine , slight marks on side of pistons but apart from that , they look fine. When i build it back up ill just make sure i put the same piston back into the same bore.
what cam would you recomend going for ? was thinking a piper cam?

thanks

ash

[mini_mission]

if you think your cam was a poor material, I wouldnt recommend getting it re ground, it may only happen again.

what are the poundage of your valve springs?

[Jupitus]

1.5 ratio rockers installed?

[Rosslin Racing]

you should measure the mains and big ends with a micro meter they may need nothing doing to them.
if you have any ridges or sratches that you can feel with your finger nail it will need looking at.
as for the cam if you had a high lift they will wear real quick so if you want it to last get a billet steel cam they are drilled to allow oil movement.
i use Minispeed and have NEVER had problems, dont forget to get followers as well not cheap schit.

Edited by Rosslin Racing, 15 February 2009 - 02:33 PM.

[MINI 1]

yes , i have MED 1.5 roller rockers and single strong valve springs but i think am going to change them to double valve springs.

when i built the engine i did check the tollerence of the crank and it was just on the limit and had tiny marks which i dident think was that bad , the crank hasent been regrinded before so i will just get it regrinded by med and buy bearings to suit.

hopefully the knock should go

[Sprocket]

Not being funny mate, but a wrecked cam and crank in 20 miles?!

Thats screams poor attention to cleanliness!

Did you fit new cam followers with a new cam? did you break the cam in on first startup, raising the revs to 2000rpm for 20 minuits? did you use assembly lube?

Also, pistons that have picked up after 20 miles says the same thing. Lack of cleanliness.

[Jordie]

Thats what i was going to say!

[MINI 1]

Right , yes we made sure everything was clean and tidy and did not rush . we did also used assemble lube and made sure everthing went together correctly , at the end of the day if them bearings were going to go it doesent matter who built it , they will go . the gernals on the crank shaft wernt briliant when we assembled the engine so i think thats why the bearings are looking slighty scored . as for the camshaft , we dident use brand new cam followers but the ones we used had only been used for 500 mile or so. its very easy for people to coment on how you build your engine when they get someone else to do theirs for them , my father is a engineer and has built a few engines in the past so he isent stupid and has the brains to no that you need a clean workspace.

ash

[mike.]

very easy for people to coment on how you build your engine when they get someone else to do theirs for them , my father is a engineer and has built a few engines in the past so he isent stupid and has the brains to no that you need a clean workspace.

ash

Steady on!

[Southy]

When you say that the Cam is knackered whys that?Is it cause all of the heat treatment on the lobes has worn off?If thats your reasons why then the kent 286 I pulled out of an engine the other week is knackered too.....

At the end of the day think of the speed at which the cam rotates, it only takes a lil while for the cam and followers to bed in, and dont forget its in perminant contact with the followers.

[MINI 1]

ye sorry , just abit worked up when people think you have just thrown it together.

my apoligise

[Rosslin Racing]

might also be that the spring rate was to high for the cam 1.5 rollers do put an extra bit of stress on the cam as well. who did the block for you? maybe the cam bearings are tight. I also wondered if the rods and pistons are balanced?

[Paul Wiginton]

ye sorry , just abit worked up when people think you have just thrown it together.

my apoligise

Understandable, but the only way for you to get the problems you say you have is to assemble it with dirt in there somewhere. Thoise used followers didnt help either

Paul

Edited by Paul Wiginton, 15 February 2009 - 06:22 PM.

[Jordie]

So if the crank wasnt brilliant.

Did it rotate with just a couple of fingers effort when placed in the engine with the main caps bolted/torqued up?

The crank should spin relatively freely with just the mains torqued up. if it ever got tight or hard to turn from there on, you would have needed a regrind or ofcourse, the bearings would get damaged relatively quickely.

I build my own engines, so I arent just passing comment if the above was aimed at me and sproket.

[Saxo-Fiesta-Mini]

gutted mate good work will see how this turns out hope it goes well