1G Questioning crankshaft specs......Need some advice

[SasaniFab]

As some of you know im building a new motor, when i was assembling my motor I mic'd the crank and got 1.77 on 1,2,3 but 4 the crank measured 1.72 , would this concern you? I am using standard king bearings. The guy i was building it with said that this is withing service limit. I am running wiseco pistons and manley turbo tuff rods. No blalance shafts either. I want to make sure before I finish assembling this motor as I still can correct a possible huge mistake. Any input would be great.

 

[GST with PSI]

No, it's not in spec. Yes, you should be concerned. The guy you are building it with is an idiot.

Crank spec for the rod journal is 1.7709" - 1.7717". According to your measurements, the #4 journal is undersized nearly .050". If you measurements are correct, your crank is trash.

You not coming to this conclusion on your own tells me you don't have a service manual. In that case, you've got no business assembling this motor own your own, and I'd strongly advise against taking any further advice from your friend.

 

[SasaniFab]

No, it's not in spec. Yes, you should be concerned. The guy you are building it with is an idiot.

Crank spec for the rod journal is 1.7709" - 1.7717". According to your measurements, the #4 journal is undersized nearly .050". If you measurements are correct, your crank is trash.

You not coming to this conclusion on your own tells me you don't have a service manual. In that case, you've got no business assembling this motor own your own, and I'd strongly advise against taking any further advice from your friend.

Well.... I have the service manual, I guess I didn't want to believe this person would try to f*** me over. Look like I'm swapping the crank out. This person has run 9s..... I paid him to assemble the lower end. I'm going to check back with him.

 

[GST with PSI]

Sorry, dude. Unless your measurement is off, your crank is junk. .050" isn't even remotely close to being in spec. Consult your manual, it will verify what I'm saying.

 

[SasaniFab]

Sorry, dude. Unless your measurement is off, your crank is junk. .050" isn't even remotely close to being in spec. Consult your manual, it will verify what I'm saying.

Yah, I'm sitting here at work realizing that this guy might out f***ed me out of 550 dollars..... guess I just didn't want to believe it. I can't believe he would actually say that it would be ok, luckily I can still fix the issue as I have 2 other cranks

It's all good, I'm gunna handle it. I have two spare cranks. You can't give up when sh** goes bad. I should of taking care of this myself from the getgo. To be continued

 

[gsxeclipse102]

I would re check your measurements. kind of strange to only have rod journal that mych more worn out then the others.

 

[SasaniFab]

Everything feels great minus number 4 rod.... a lot of movement. I'm guessing the guy I bought it from damaged the crank on number 4 and had it polished to mask the damage. Number 4 is notorious for oil starvation. It's my mistake, I have the tools and the capability, just no time. I normally don't let people touch my cAr for obvious reasons. This is a lesson I will take forward. I'm going to push forward and fix it.... no sense in crying about it...

 

[biglady112]

This is why trying to run virgin cranks is a problem. I machine every crank I get my hands on. i would never trust a used crankshaft. My crank guy is one of the best in the country. I have not had to measure a crankshaft for assembly in probably 10 years. Let alone use plastigauge. I take him confirmed and torqued bearing measurements and tell him the journal size I want for each motor's oil clearance I have decided on.

I guess I have been doing this long enough I know what to look for and who not to use. There were a lot of issues trying to find someone who was comfortable and confident in working with high horspeower, specialty inline four engines.

And just because someone has gone fast does not mean that have done quality and efficient work to get there. I won't name the person but, there is someone who is converting their car to auto, awd, 4g63 right now who has been fast but, all his engine bays including his current one look like someone in a third world country assembled it. And people are impressed by it because of what kind of car he is converting. Cobbled together might not even be the right word.

 

[SasaniFab]

This is why trying to run virgin cranks is a problem. I machine every crank I get my hands on. i would never trust a used crankshaft. My crank guy is one of the best in the country. I have not had to measure a crankshaft for assembly in probably 10 years. Let alone use plastigauge. I take him confirmed and torqued bearing measurements and tell him the journal size I want for each motor's oil clearance I have decided on.

I guess I have been doing this long enough I know what to look for and who not to use. There were a lot of issues trying to find someone who was comfortable and confident in working with high horspeower, specialty inline four engines.

And just because someone has gone fast does not mean that have done quality and efficient work to get there. I won't name the person but, there is someone who is converting their car to auto, awd, 4g63 right now who has been fast but, all his engine bays including his current one look like someone in a third world country assembled it. And people are impressed by it because of what kind of car he is converting. Cobbled together might not even be the right word.

What would you suggest I do? I was going to pull the crank out my good running motor and mic the crank and if it specs out, drop it in. Would you suggest I send the crank out for polishing?

The crank In my running motor is flawless..... looking anyway.

 

[GST with PSI]

What's it measure out at?

 

[SasaniFab]

What's it measure out at?

I'll let u guys know, I'm stuck at work until Tuesday, Im gunna mic it out post some results. Hopefully u guys can help me through this. Failure isn't always a bad thing.... now I'm being forced to do it my damn self.

 

[Vegas Smith]

Have you talked to this guy about it?

 

[SasaniFab]

Have you talked to this guy about it?

Yes, he says it should of been "ok" , but kinda backtracked.....the bottom line is I brought him the stuff and paid him to assemble it. So it's really my fault. He told me when I picked it up.....I'm guessing as a warning. That number four was loose. If he was completely trying to f*** me he never would of warned me, or even measured it for that matter.

 

[Vegas Smith]

So basically he took $550 to build an engine that he knew was bad. I think you're being too nice.

 

[gsxeclipse102]

Why did he finish building it knowing the crank was out of spec. Measuring the crank should of been the first thing he did. He should of stopped and asked you if you wanted to proceed with the loose rod bearing spec or get another crank. If your paying for an engine to be built it should be done the way you want. Not "close enough"

 

[SasaniFab]

Why did he finish building it knowing the crank was out of spec. Measuring the crank should of been the first thing he did. He should of stopped and asked you if you wanted to proceed with the loose rod bearing spec or get another crank. If your paying for an engine to be built it should be done the way you want. Not "close enough"

I am being nice, but he still has some stuff of mine.....got to be smart about it .

 

[biglady112]

Just because the journals may measure "in spec" does not mean they are good. There could be a a nasty taper to the journals, the crank could have had run out that a micrometer will not catch, it could have bad end play, it could have a crack you may not catch until it is too late.

Just dropping a crank in is the worst idea. And just polishing one does not fix any potential issues I listed above. Especially if the polish is done terrible. I did an engine for someone before that listened to the internet that insisted we use a virgin crank that had nothing more than a polish. He was upset that I did not plastigauge the motor(he was not even willing to buy any with his own money). He took it upon himself to find the cheapest machinists labor in town and i told him I was just going to assemble it and he would have to accept the consequences for not wanting to listen. Because even if things were wrong he was not willing to pay the money to have things redone. Mind you I was doing this for free for him. He used his own machinists and crank guy(who went out of business less than a year after his engine failed). That thing went together okay but was not the smoothest Turner on the engine stand. I just figured it was cold because we were doing it in a storage unit in the winter. Well needless to say the engine siezed in 14 miles on the test drive. The awesome polish job cost that guy his car he bought showroom new and had out almost 400,000 miles on. The rod journals had a bad taper polished into them. .001" on the outside of the journal and .003" in the middle. Obviously the .001" caused it to starve and it locked up the number one rod bearing. That guy ended up throwing in the towel and sold everything after one big failure. He has not and likely will not ever race at the salt flats again.

This is also the same dude who stayed in his car bucking and kicked for nearly two miles (VIDEO and datalog confirmed) at the salt flats during a run until a piston melted and the car shut itself off on his first pass with a new setup turned up for the first time.

If you enjoy heartache, go ahead and throw a crank in. If not, do it right and make sure it is right no questions asked.

 

[gsxeclipse102]

I am being nice, but he still has some stuff of mine.....got to be smart about it .

Lol i'd do the same

 

[SasaniFab]

Just because the journals may measure "in spec" does not mean they are good. There could be a a nasty taper to the journals, the crank could have had run out that a micrometer will not catch, it could have bad end play, it could have a crack you may not catch until it is too late.

Just dropping a crank in is the worst idea. And just polishing one does not fix any potential issues I listed above. Especially if the polish is done terrible. I did an engine for someone before that listened to the internet that insisted we use a virgin crank that had nothing more than a polish. He was upset that I did not plastigauge the motor(he was not even willing to buy any with his own money). He took it upon himself to find the cheapest machinists labor in town and i told him I was just going to assemble it and he would have to accept the consequences for not wanting to listen. Because even if things were wrong he was not willing to pay the money to have things redone. Mind you I was doing this for free for him. He used his own machinists and crank guy(who went out of business less than a year after his engine failed). That thing went together okay but was not the smoothest Turner on the engine stand. I just figured it was cold because we were doing it in a storage unit in the winter. Well needless to say the engine siezed in 14 miles on the test drive. The awesome polish job cost that guy his car he bought showroom new and had out almost 400,000 miles on. The rod journals had a bad taper polished into them. .001" on the outside of the journal and .003" in the middle. Obviously the .001" caused it to starve and it locked up the number one rod bearing. That guy ended up throwing in the towel and sold everything after one big failure. He has not and likely will not ever race at the salt flats again.

This is also the same dude who stayed in his car bucking and kicked for nearly two miles (VIDEO and datalog confirmed) at the salt flats during a run until a piston melted and the car shut itself off on his first pass with a new setup turned up for the first time.

If you enjoy heartache, go ahead and throw a crank in. If not, do it right and make sure it is right no questions asked.

So even pulling a crank out of known good running motor , that was in my car is dangerous because the crank could have taper but be in spec? My original plan was to take the crank out of my talon, the motor was in perfect shape 90k. My second plan would be to have to the crank sent out to jam to have them take a look. Either way the head is on with the Pistons in the bores. I can still get away with just swapping a crank yes?

 

[GST with PSI]

I literally wouldn't listen to a single word Biglady112 says.

Mic the crank, check for taper, out of round, etc. The mic will show all of the above if in the hands of a capable person, contrary to what biglady112 would have you believe. If the crank specs out, take it and get it fluxed and checked for cracks. If it needs a polish, get it polished. End play is checked after the crank is installed. Again, easy check with a dial indicator.

This isn't rocket science. People have been reusing virgin cranks since the beginning of time.

 

[Vegas Smith]

I am being nice, but he still has some stuff of mine.....got to be smart about it .

You don't have to threaten the guy's life but say: "Hey, this crank is bad per service manual. Considering you measured it, I just payed you $550 for nothing." Maybe the guy can make it up to you in some way if he is reasonable.

 

[SasaniFab]

You don't have to threaten the guy's life but say: "Hey, this crank is bad per service manual. Considering you measured it, I just payed you $550 for nothing." Maybe the guy can make it up to you in some way if he is reasonable.

Yah he's gunna be powdercoating my valve cover and a few things , I'm gunna square it out that way- hopefully

 

[SasaniFab]

No, it's not in spec. Yes, you should be concerned. The guy you are building it with is an idiot.

Crank spec for the rod journal is 1.7709" - 1.7717". According to your measurements, the #4 journal is undersized nearly .050". If you measurements are correct, your crank is trash.

You not coming to this conclusion on your own tells me you don't have a service manual. In that case, you've got no business assembling this motor own your own, and I'd strongly advise against taking any further advice from your friend.

Total junk

 

[SasaniFab]

All the journals were off

 

[GST with PSI]

Wow.

Look on the bright side, least you found it prior to the motor knocking.