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Discussion Starter · #1 ·
Hi everyone I'm new to the forum but not to minis. I've got 4 minis from ones to a cooper s.
I'm going to rebuild my cooper s engine as it's spun a big end because it had oil starvation from timing guides breaking up and blocking the pick up pipe.
My question to you all is, what mains would you use? I've seen some cheap ones and some mid range that are made by a company called ET, has anyone used these mains and are they any good?
Also, what about the big ends? What do you all recommend I use for these?
Ok what about the flywheel, do I go single mass or stick to duel mass?
My other problem is, when I opened the engine I found that one of my con rods is a different colour to the other 3. Has anyone got any ideas on why this is? What colour is the std cooper s rods?
Oh and by the way, yes I am using another crank as mine is toast.

Thanks for your reply.
Tony.
 

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you could be rebuilding a can of pain, as when bearings get spun and are spun for a while all the metal ends up all over in the insides of motor thats first concern ie rebuild and in oil ways somewhere there is a lump of metal and carbon that releases it self down the road killing another set of bearings, so strip down to engine block and cleaning is a must, ie engine builder have special cleaning machines, also the crankshaft its by far the best way when have crankshaft reground get engine builders to surplie the new bearings as they will need to grin journals to match them as such, i only ever order new bearing on standard sizes and use uk based machine shops who advertise on line or ebay as they seem to care enough to get things right more than a chinese seller would.
would also think about a second motor and refresh it , ie re rind and bearing and oil pump and timing chain and lap valves and do stem seals and all other seals, at least you know for sure its going to be fine,, when they spin a journal always have that thought was it due to internal crack somewhere or carbon dirt build up somewhere you cant see,, i know i have seen this happen to many times over the years
 

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Discussion Starter · #3 ·
Hi and thank you for your reply. I will make sure the engine is cleaned. I will be plastigauging the journals to make sure all is ok. I've got another good crank which hasn't had any problems so that should be good. The hole engine is already stripped and will everything will be cleaned. I have also changed the oil pump, stripped and cleaned the con rods piston that I'm going to use. New rings will be fitted. The head will be sent for a skim if needed and a good clean.
If I have missed anything please let me know.
 

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would deffo do valve oil stems seals and reseat the valves lap them in, would also do chain while in there, you will need to lightly hone the bores helps bed rings in, on gen 2 r56 prince engines i use course scotch brite pads glued on to the hone tool stones as the bores are low friction tech and deep scratches will hurt them, the scotch brite just gives it enough to clean and leave very slight scratches, i.ve been doing that for years and not had any issue with blow past after, also change oil and filter after 500 miles max make sure get any bits out etc, also check filter when change it for metal parts in it, i also when first start up form rebuild run on idle get warm let it it cool and do it it few times before putting loads on it like driving it etc, ie rather find a leak or a issue when its sat there in front of you where out on a run it could cause big issues say, you can buy special engine builders paste wurth using also crank engine over with coil pack off until oil gets around the motor just avoids risk of picking up a bearing surface when dry
 

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Discussion Starter · #5 ·
Yep I have a full chain kit to go in as that was the main cause of all the problems. Who ever had it before me m7st have just drove it when the chain had started to rattle and drove like an idiot till it just stopped. Crazy.
I will also be fitting all new seals and gaskets. Fitting with lube and break in oil.
Thanks again for your input. I will keep in mind the hone advice. I have a hone tool that is fairly new but the bores are really good so think a scotch bright may do what I need.

Cheers.
 

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Discussion Starter · #6 ·
Ok so I've been collecting parts for a couple of weeks and now have all the bearings hepolite rings oil pump timing chain kit new RMS and front oil seal. Also clutch and new solid mass f/wheel.
The hole engine is stripped and the block and head are going for professional clean and the surfaces will be checked and skimmed if needed. Head will be skimmed regardless. Valves are going to be lapped in and bores will be honed.
Once I start to rebuild I will post some pictures. I've posted a picture of the head before it's trip to the engineers.
 

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Discussion Starter · #7 ·
Ok so picked the block and head up from the engineers and they look sweet.
I'm going to start putting it back together now slowly. I do need to find the torque setting for the piston oil injectors if anyone knows it.
I have painted the block but that's it, nothing else to be painted.
 

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looks nice job, dont forget when all back together before first start without spark plugs in better way crank engine over untill got oil coming up to the head and camshaft etc
 
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Discussion Starter · #10 ·
looks nice job, dont forget when all back together before first start without spark plugs in better way crank engine over untill got oil coming up to the head and camshaft etc
Oh yes oil pressure is a good thing. I will be spinning it over till light hoes out.
I've built with plenty of build up oil, wow it's sticky but very important for the first turn over.
Only thing I've had trouble with is the oil injectors as number 4 was just touching the piston skirt so had to undo again and move as to clear the piston skirt.
Turning the big end cap bolts a further 90 degree was so scary hahahaha but all is good.
Can't wait to get it done but have always said I will take my time.
Only thing I would like to ask people is, duel mass or solid conversion?
 

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trouble is the car was designed to have dmf so all was designed around this cushion within the drive train, most single mass flywheels tend to vibrate unless lathe produced and balanced,, C&G MOTORSPORTS do the best flywheels but dont know of they do one for the mini, safe option dmf it should last 70-120k in a petrol car,
 

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Discussion Starter · #12 ·
trouble is the car was designed to have dmf so all was designed around this cushion within the drive train, most single mass flywheels tend to vibrate unless lathe produced and balanced,, C&G MOTORSPORTS do the best flywheels but dont know of they do one for the mini, safe option dmf it should last 70-120k in a petrol car,
Ok i will call at c& g as they are not far from my work.
I was thinking about getting it lightened and balanced before fitting anyway just to try help it spin up faster.
 

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i have done this to a few cars there is a sweet spot where you lose momentum in high gears on hills ie you end up with a engine that just wants to scream with not much torque as such flywheel is a rotary storage item, to light terrible of main roads good on a flat track,
 

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Discussion Starter · #14 ·
I will keep this in mind.
The company I use for all the work builds race cars for a few friends so will see what they have to say too.
Would you say it's best to just balance it and leave the weight? I'm not building a race engine but an engine that will work very well on the road.
 

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i've not done one on cooper s before but have on other stuff finding a balance between how fast it picks up to how easy can drive down the road without for ever changing down the and up the gearbox
 

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i got a cooper s r53 works in at present with oil in the water have stripped it down and found the normal head bolts to be not very tight etc and evidence of rad weld etc and running with no aniti freeze in it as well so some rust, so will coat the internal on the block with rust cure that should sort the rust out, this car has 100k on it and all bores have no wear ridge and all 4 seal ie fluid test leave seafoam on the bores to soak in, the camshaft was very pitted and worn so told the guy gave him a option of factory camshaft or a stage two road came link below anyway he's having the fast road cam, also found the super charger had new rollers in it ie think has been recon unit not long ago, fitting new camchain as well when all done will be put on rolling road and see what we can get out of it, the camshaft seller says the idle stays normal but the 4000 rev onward become more
 

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Discussion Starter · #18 ·
I will be interested to see what power you get with just a cam.
Oil in the water could be because the head wasn't bolted down right if the bolts are not tight. I found I had to do mine twice to make sure they were all 40nm after the first stage then I was safe to go the further 90deg. I then turned up the torque wrench to about 80ftlb and made sure the wrench clicked on them all and felt the same.
If the engine has had no antifreeze in for a while, then that is crazy as it can cause all sorts of problems. I would want to take the sump off to check the crank but it depends how far the customer wants to go with it.
Do you think the engine will be ok once you put it back together?
 

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fairly sure its one of those has he knows it a repair and if i find other stuff then it gets done, the car ran really nice thats the mad thing idle was ok and pulled like a train, the oil issue was only slightly ie got a 5 mm or oil residue on head tank i've also got a new oil cooler on the way no water in the oil did not even biol in anyway just slight oil in the water, once i got all fitted back together it will be stuck on rolling road and run up see what it making, what colour are your injectors
 

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Discussion Starter · #20 ·
My injectors are standard grey.
I'm going to get it running first before I change anything else.
I've got a spare block and crank now so may just build a monster motor and see if I can get it over 400bhp haha
 
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