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Mrs shavenYak's 1985 Mitsubishi L200


shavenYak

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I would use red still. But up to you Oscar.

My reasoning is red does 0.051 - 0.152. I doubt the problem will be too tight a tolerance as the engine is already worn, as you are allowed UP to 0.100 I would be measuring to make sure the clearance is no bigger than that..

PS Phil - red measures 0.051 - 0.152 and last time I checked my maths 0.100 is in between them numbers.. KTHXBAI :D

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but 0.1mm is the absolute limit, the Mitsubishi manual specifies that it SHOULD be between 0.02 and 0.05, which if MY maths serves me correctly is below what the red one can measure. This is assuming he is going to be using NEW bearings - I would highly doubt you would see anywhere close to 0.1mm when using new bearings. From memory when I put my motor together with new bearings and existing crank I was seeing clearances from 0.03 to 0.04mm

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I understand what you are saying - But with a worn crank and new bearings I highly doubt you are looking for tight clearances - you are looking for too loose a clearance which in my opinion is what the red would pick up better than the green. If the red squishes wider than 0.51 (the tightest red can measure) then it is a fairly safe bet to say the tolerances are sweet on a worn crank. If it was tighter than 0.51 and you wanted to be 100% safe then you should really check for tight clearances and this would then need green to measure it.

I think we both are going for the same result but one of is pessimistic and one is optomistic - I just can't figure who is which.. LOL

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If the red squishes wider than 0.051 (the tightest red can measure) then it is a fairly safe bet to say the tolerances are sweet on a worn crank. If it was tighter than 0.051 and you wanted to be 100% safe then you should really check for tight clearances and this would then need green to measure it.

corrected. I think. you had 0.51.

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haha fair enough. Just I found in my experience with that very same type of motor, fitting new bearings on a 'worn' crank resulted in tolerances far lesser than 0.05mm, with one being quite close to 0.025mm. I would say this is determined by the quality of the bearings used and the care of fitting them. Sometimes if something is trapped between the rod and the bearing, or the bearing just doesn't quite seat right then you can have really tight clearances and risk running a bearing again. It just pays to be double sure when checking bearing clearances rather than saying 'she'll be right'.

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Oh yeah Beave - oops my bad typo..

Sometimes if something is trapped between the rod and the bearing, or the bearing just doesn't quite seat right then you can have really tight clearances and risk running a bearing again. It just pays to be double sure when checking bearing clearances rather than saying 'she'll be right'.

You are right there Phil - I'm definitey being the optomist in this case... puhuhuhu

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ok, so pulled off the rest of the caps etc and pulled the crank out. Here's what I found:

DSCF1173Large.jpg

DSCF1177Large.jpg

all were ok except the middle one, took the crank in anyway and got it measured up. Will need a machine. $180+gst they reckon.

DSCF1178Large.jpg

Found a crank in Tauranga for $100 which is "mint" apparently and has been polished, but not machined. Might be a good option?

http://www.trademe.co.nz/motors/car-par ... 851656.htm

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if it measures up to standard spec then you wont need to get it machined. polishing a standard sized crank is all the machining you will need to do. I wouldn't machine a crank because you are removing the factory hardening.

Do you know what the crank looks like in the original engine (am guessing it's even worse?)

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if it measures up to standard spec then you wont need to get it machined. polishing a standard sized crank is all the machining you will need to do. I wouldn't machine a crank because you are removing the factory hardening.

Do you know what the crank looks like in the original engine (am guessing it's even worse?)

Nah the guys at the rebuilders reckoned it was out of spec

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was meaning that crank on trademe, or were you meaning that the engine builders checked your original engine's crank too?

Oh right gotcha - I just meant it was good that it was still standard size.

Nah the original engine's still skulking away under the hood in Hastings. Be interesting to see just what's happened to it. Cause there was knocking, but also a hideous screetching from it when running.

Raizer - good to know, I'll keep that as a backup for now. Will probably get this crank in tauranga.

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cause it's later model and FWD it runs the wider cam belt and has the distributor hanging over the gearbox, would be unideal for RWD. You can get around the wider belt issue by running DOHC crank and oil pump housing but you may as well just go DOHC especially as you would have to go fuel injection (the SOHC 16V doesn't come carb'd).

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Ok seen you found another crank in spam. I don’t know about you guys but putting a different crank in a old engine with STD size bearings makes me cringe. Not every crank is sized exactly the same from the factory, you could easily end up with very fucked up clearances. If any of the crank journals are out of round at all your plastigauge won’t tell you, I’ve seen plenty of engines that after a zillion heat cycles aren't round on the mains any more.

If it was me I would get the journals measured properly by a shop with a dial bore gauge and check for roundness. If its ok Give the crank the minimum grind possible and buy bearings to suit, this will give you known clearences to your specs. I have no qualm with grinding a crank and removing the factroy hardening, it is common practice and a minimal grind will be fine, you can get it nitrided if it was a extreme perfomance build

What are the big ends like? if they are as shit as the mains look they may need to be resized

I seriously only used plastigauge to double check machine work and to make sure my method of torqueing up the bolts is giving repeatable clearances. Its easy (especially with a cheap torque wrench) to tighten up the mains several times and get large variations in clearance each time .

Anyway I would only chuck a foreign crank, with no machine work into a engine I didn't give a shit about at all, or wasn't going to keep. Chances are high you will nip up a bearing again or have way out of spec clearances are high.

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Hmm what to dooooooooo?

Yeah just paid for the new crank, so don't really want to pay for a crank grind for it if it measures up ok, or do you think it would be better to abort abort abort and get my money back and spend it on machining the old crank instead? :?

Still new to this, so appreciate the input - trying to do a good job but not spend too much in the process.

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