I am interested in an Evo 4 which has an engine that has had some block parts replaced after crankwalk started to come into play. Apparently the crank has been replaced by an Evo 6 crank and rods and pistons by parts from an Evo 9. I can't find wether this is a good solution or not so I hope someone can shine a light onto this. Is this a good solution? Does this solve the crankwalk problem for good?

 

Nobody?

 

I don't know any with a usable block after a crank-walk. Sorry. Everyone I saw soon failed afterward.

 

Thanks for your answer. The block was completely overhauld, not just those parts were replaced. What's really weird is that I called the company that did it and they told me that you cannot put evo 6 crank and evo 9 rods/pistons in an evo 4 engine. So before I call them again I'd like to know what is and is not possible.

 

^ rubbish, all the cranks will work from 1-9 so will the pistons and rods, the problem is the e1-4 uses center bearings with trust washers and 5-9 uses thrust washers at the end. The block and main girdle is different.

 

Ok, that complies with what the seller told me. I don't understand why forwarded mails from the overhauler contained the information about the evo 6 crank etc while on the phone he told me it's not possible...

But if I understand correctly then the problem is not solved and can only be solved by replacing the block where the bearings are located on another position?

 

i have rebuilt some 20 crankwalked blocks with no subsequent failures. I believe strongly the evo 4 has a "internet only" crankwalk problem. when the truth is all 4g63 blocks with a "soft" 7 bolt crankshaft have a chance of developing crankwalk. my advice would be based on how many miles are on the rebuild. if its not rebuilt correctly the crankwalk will return very quickly. like in less than 5000 miles. all crankwalk blocks from mitsu have at least 50k miles before wear starts. most are well over 100,000 miles. but many rebuilders will put a new bearing on an old crank and cause a crankwalk condition.

 

Jerry
So crankwalk in 4G63 is mainly caused by soft crank?
Can you kindly educate us a bit.
So we can monitor and understand: I guess pressing on the crank pulley to find if it moves back and forth and measuring the total "walk" is one way to check for it.
But what is the root cause? Crank? If so is cleaning the block, using different crank, and shimming for correct clearance/freeplay the solution?

Thank you

 

The engine was rebuilt around 12.000 miles/20.000 km's ago. So you're saying I am running a very low risk here providing the rebuild was done the right way?

 

yes very low risk. I would go for it.

 

I just heard that the new bearings involved are from ACL which makes it even more interesting. So I think I will take a look at this car, getting very interesting now.

 

it's not an "Internet only" issue where I am from we have JDM and EDM, the center bearing on the evo 1-4 has an integrated thrust which is very weak and thin, problem is when you use heavy clamping pressure plates it pull/pushes the crank and prematurely wears the thrust causing crankwalk.

 

the early 7b 4g63 blocks have same thrust setup. I assure you I have seen FAR more 4g63 blocks than exists on your whole island. I have been using the heaviest act 2600 plates for 15 years now. never had crankwalk