Engine Rebuild Question

[Lunch_Box]

I have my G4CS block in as we speek at the machine shop and it turns out 2 of my mains on my crank are out of spec. Is it safe to take the crank down 0.10 or even to 0.30 if I have to?

 

[sweet97]

I would address such a critical question with someone like Slow boy or Buschr or whoever you do most of your business with. I have read here guys will not even go .010" due to the removal of the original hardening of the journals though mains may not be as critical as the rods. Still ask the experts. Mark

 

[gixrman]

0.10 is ok, anything after that I would get a new crank if you plan on making any power.

 

[project_tsi]

yeah its not worth the risk of running a cranck .30 under. especially when a good one can be found for a couple hundred.

 

[Lunch_Box]

yeah its not worth the risk of running a cranck .30 under. especially when a good one can be found for a couple hundred.

Where can you find a good one for a couple hundred?

 

[Lunch_Box]

0.10 is ok, anything after that I would get a new crank if you plan on making any power.

Well I do plan on making some power,this is going to be a ross/pauter engine and I will be running an FP 3575. So you are saying that 0.10 is ok but anything else I should look into a new crank?

 

[boostedinaz]

Our cranks are heat treated. When you machine then at all it will go past the heat treatment. You can have them retreated but I would just go witha new one at that point. If this is a performance rebuild I would get a new crank. If you just need a driver then go .010.

 

[Lunch_Box]

Our cranks are heat treated. When you machine then at all it will go past the heat treatment. You can have them retreated but I would just go witha new one at that point. If this is a performance rebuild I would get a new crank. If you just need a driver then go .010.

Well this is going to be my daily driver but at the same time I want to make some nice numbers. Where would be a good place to get a new crank?

 

[sweet97]

Just so some don't get embarrased it's .010" an .030". 0.10 is 1/10th of an inch, tough to find bearings for that much!! Peace

 

[rdrkt]

Our cranks are heat treated. When you machine then at all it will go past the heat treatment. You can have them retreated but I would just go witha new one at that point. If this is a performance rebuild I would get a new crank. If you just need a driver then go .010.

Agreed. This is going to be a more common problem as these blocks get scarce. You have to weigh your options. If you cut your crank proper assembly is going to be VERY important. You have to make sure you have someone competent doing the assembly and machine work. As for replacing the crank vs getting it machined you have to weight your costs. The only way that I know to get a good crank is to get an entire block. So how hard will it be to find another one vs getting it properly machined?

 

[RedGsxEclipse]

how much to get your block machined?

 

[boostedinaz]

this is going to be a ross/pauter engine and I will be running an FP 3575.

If this is what you plan on running then I would find a new crank.

You can check the vendors here and see what they have. I wouldnt just look at the website, but I would call them and see what they have or what they can get.

 

[NDgsx]

I've had problems with the wrong fillet radius on journals of turned cranks, to small and the crank is weakened, too large and you get to spend time shaving bearings (which I would definetly prefer).
Nitriding is not the most consitent surface hardening procedure as far as depth is concerned, it should be re done after turning and before polishing IMO if you do turn the crank.
Personally I'd look for another crank.

 

[Lunch_Box]

The only way that I know to get a good crank is to get an entire block. So how hard will it be to find another one vs getting it properly machined?

What do you mean by this? My winter car was the 89 sonata that the engine came out of. The car ran good all winter with no problems then about a month ago I took the engine out to take in the get built.

 

[alexg1323]

turn the mains down 10 under and leave the rods std. That way it will remain balanced which they come balanced very well from the factory. Its the rod journals that receive the most abuse to i would be the most conservative with them. Or just get a good condition used crank out of some N/A 4g63, 4G67, G4CN or any of the other respective motors. I seen and sold good cranks for under a $100 ready to drop in.

 

[Defiant]

Our cranks are heat treated. When you machine then at all it will go past the heat treatment. You can have them retreated but I would just go witha new one at that point. If this is a performance rebuild I would get a new crank. If you just need a driver then go .010.

Well, nitrided, which is sort of the same thing.

 

[Lunch_Box]

So basically since I have plans to make some power with this engine I should not risk it and just get a new crank? People are saying that you can find a good crank for a coulpe of hundred bucks, where are you looking? I am in need of a G4CS 2.4L crank, out of a 89-91 Sonata.

 

[gixrman]

Replacment crank
http://www.rpmrons.com/eagle,cranks.html

 

[Lunch_Box]

Replacment crank
http://www.rpmrons.com/eagle,cranks.html

Those are top line cranks in that link, not a mistubishi product. Also I am looking for a 6 bolt 2.4L crank, not a 2.0L.

 

[swordfish]

Our cranks are heat treated. When you machine then at all it will go past the heat treatment. You can have them retreated but I would just go witha new one at that point. If this is a performance rebuild I would get a new crank. If you just need a driver then go .010.

I agree 100%

jeff