after arp rod bolts install less than .002 clearance.

[pj91gsx]

Is it fine that I have less than .002 clearance after install arp rod bolts? Everywhere else the clearance is between .002 and .003 because of the polish job. The rod clearances are clearly .015, I think that is the measure about .002.

 

[turboglenn]

Your crank must be machined after an ARP bolt install, this goes for the crank journals and rod journals.

Do NOT run the car or even assemble the motor until you've had it machined or you're not going to have a motor that runs very well and if it doen the tight tolerances are going to cause some failures almost right away!

 

[absolute_DSM]

Your crank must be machined after an ARP bolt install, this goes for the crank journals and rod journals.

Do NOT run the car or even assemble the motor until you've had it machined or you're not going to have a motor that runs very well and if it doen the tight tolerances are going to cause some failures almost right away!

Id like to know the specifics in this "too tight" of clearance after ARPs. I hear both sides saying it will be ok and some saying things need to be machined.

I dont hear much of guys boring the crank mains or or the rods, or turning the crank to get a clearance for ARPs. Maybe its just an unspoken "duh" thing I missed...

 

[turboglenn]

Id like to know the specifics in this "too tight" of clearance after ARPs. I hear both sides saying it will be ok and some saying things need to be machined.

I dont hear much of guys boring the crank mains or or the rods, or turning the crank to get a clearance for ARPs. Maybe its just an unspoken "duh" thing I missed...

I don't know too much on the specifics, but my machinist said that if you don't do it you wil eat bearings and possibly eat up the journals because there's not enough room/clearance for a good enough film of oil , that's how my last motor died (it's the oil film that actually acts as the bearing), the bearing surfaces shouldn't touch the journals when the motor has oil pressure... call a machine shop and ask them the details i just tried calling mine and he must be millling or something because he didn't answer. . The reason my last motor came out of the car is because the half ass machine shop i took it to machined the journals, but not enough.. i ate main bearings every 500 miles until i pulled the motor, took it to my new machinist and he said there wasn't enough clearnace machined out after the ARP main install.

 

[absolute_DSM]

Ugh, not good....

I understand completely, I just didnt think the ARPs would cause that much of a clearance issue.

I could have sworn it didnt cause many people issues. Post 7 http://www.dsmtuners.com/forums/newbie-forum/273286-arp-mains-not-so-tight.html

 

[Burnett03]

I've never heard of having the crank machined to run arp main's, so i call BS on your post turboglenn. I have however heard you need to have your mains line-honed when running arp mains.

 

[absolute_DSM]

I've never heard of having the crank machined to run arp main's, so i call BS on your post turboglenn. I have however heard you need to have your mains line-honed when running arp mains.

So you cant really call BS, line honing the mains is doing the same thing as turning the crank. Its removing material to allow for more clearance.

 

[turboglenn]

So you cant really call BS, line honing the mains is doing the same thing as turning the crank. Its removing material to allow for more clearance.

Exactly.. The line honing does take out enough material to open the clearnaces up while making sure they are perfectly inline with each other. I dont' care if you call BS or not.. You can put your moor together without haivng them clearanced, but i won't. I dont' post on things if i haven't had experreince with them. Like i stated earlier, call your local machine shop and ask. Even if they odn't know "mitsubishi motors" it's the same concept on every motor, right down to your classic chevy 350.. There's a reason i have a fully built 6 bolt in the basement waiting to go to the machinist to be re-clearanced and assembled. the only thing stopping me is i have a Eagle H-beam rod that i'm having checked before i put them in (it broke a piston at the wrist pin and ate teh bushing up pretty bad on the small end) Plus i am wanting to go up on CR to about 8.8:1 or 9:1 when it's put back together. I'm not so happy with the 8:1 units off boost performance after having driven a few 9:1 static CR motors in other DSM's

 

[absolute_DSM]

So this all applies to the ARP rod bolts to then? Or does Eagle make sure they are round with the ARPs installed?
Reason Im wondering...
This is not looking like a good day for my car. Im about 2 weeks from starting the 2.3 and I had the block line honed with the stock bolts for one stupid mistake, then assembled it all (rotated just fine, no issues) and threw it all in the car. Now Im looking at moving 3 months in reverse just to get this right. There may be one big part out ad coming.

 

[turboglenn]

Just called my machinist again and he said that 80% opf the time you have to re-size the journals if you want the motor to perform decently and last more than a hundred miles. He said that it's not so much the bearing clearnce (said that's only machined if nessesary) but that the ARP's will deform the cap just slightly to where the bolt holes have to be machined in order to line up correctly because of the higher clamping force of the ARP bolts.

So there it is from the horse mouth

call him if you don't believe me , his name is Jeremy
402) 331-5037

 

[absolute_DSM]

I definately believe you Glenn, no arguement there. Thanks for the info and calling your machinist.

Although, I think Im about to cry.

 

[h8r]

FYI... It's called Align Honing or Boring not LINE.

 

[turboglenn]

So this all applies to the ARP rod bolts to then? Or does Eagle make sure they are round with the ARPs installed?
Reason Im wondering...
This is not looking like a good day for my car. Im about 2 weeks from starting the 2.3 and I had the block line honed with the stock bolts for one stupid mistake, then assembled it all (rotated just fine, no issues) and threw it all in the car. Now Im looking at moving 3 months in reverse just to get this right. There may be one big part out ad coming.

Yes, the eagles are correct right out of the box. I have the older H-beams and they are as close to a perfect circle as you can get ( but we all know there's no such thing as a perfect circle)

h8r, thanks for the correction...

Absolute dsm...why are you about to cry? Did you not size something? As long as the machine shop assembled the motor you should be fine. A lot of people try and save a few hundred by assembling them selves, but i prefer to pay the machinist to do it, that way if something's off, it's his responsibility. But if you're putting it together and something is off, then you end up paying for the little extras and so forth, so you might as well just have them do it and pick it up as a short block!

 

[absolute_DSM]

FYI... It's called Align Honing or Boring not LINE.

Very true, I knew that... Im just pretty angry to type. Eh, beer time.

Yes, the eagles are correct right out of the box. I have the older H-beams and they are as close to a perfect circle as you can get ( but we all know there's no such thing as a perfect circle)

Good, so I may have a simple solution. He align honed my block with stock bolts. Ill just pick up a new set, pull the ARPs and throw those in. Makes me a hell of a lot less pissed to go through the work of pulling everything again. Hopefully the 2.3 assembly wont cause any extra force that would cause OEM mains to fail...

 

[turboglenn]

Very true, I knew that... Im just pretty angry to type. Eh, beer time.



Good, so I may have a simple solution. He align honed my block with stock bolts. Ill just pick up a new set, pull the ARPs and throw those in. Makes me a hell of a lot less pissed to go through the work of pulling everything again. Hopefully the 2.3 assembly wont cause any extra force that would cause OEM mains to fail...

Hmmmm... you might want to call him and see why he did that (unless you didn't have the ARP's at the time) I'm not sure that the ARP's would work, but since it has been align honed, you could always ask him. I'm only directly knowledgable in smaller machining (don't have the large equipment needed for motor work except for small displacement motors.. I have a 14x20 lathe and a mill that has a 10x10 table on it..both are more hobby type machines but very accurate) So i leave all the motor work to the guys who do it for a living, so if i make a mistake in something i say, it's only because i have mis-understood the machinist or have got things confused over the years (havne't had a motor in a shop for about 5 years) I'm sending the afore mentioned motor back to the machine shop as soon as i get that one rod done and buy some better slugs

 

[absolute_DSM]

Yes, the reason he did that was because I didnt have the ARPs available at the time. I didnt think anything of it. I figured they all provided the same torquing strength, the ARPs just had more tensile strength. Basically, wouldnt distort the bore! Oh well, at least I caught this.

 

[JamiesTSI]

To the original poster what are you using to measure the clearance? If you are using plasta gauge keep in mind there is a + or - .005". Or are you using micrometers? I personally like .003" rod clearance. You could have the machince shop re-do the large end or try another set of bearings. You do not have to machince the crank to use ARP rod bolts.

 

[pj91gsx]

JamesTSI, I did use plastigauge. The clearance was dead on with the clearance below .002. for the rods. I also install main studs but did NOT get the caps align honed. I will throw the stock bolts back in anyway. I had the crank polished and the guy that did it polishes the crap out of it. The clearances measured between .002 and .003. So, a little more clearance than stock. Which means that my rod journals should be the same way.

 

[pj91gsx]

when I measure the clearances, the rod caps were a little hard to get off so I tapped on the rod bolts with a hammer which may have made the plasti-gauge smudge more than usual. And on my last rebuild I used stock bolts and the machine shop lightly polished the crank shaft and the clearance was probably the same, because it did read a little more than .002, I think the plasti-gauge does measure more rather than less. Im going to measure the clearances one more time and see what I get and I will make sure I don't smudge the plasti-gauge by tapping the rod bolts. Has anyone else had this issue?

 

[RipperXX]

Damn, I didn't know that either.

 

[92awddsm]

Rods need to be resized when apr bolts are installed. It not so much a clearance issue, but the big end egg shapes with replacement rod bolts. The crank is fine with a polish if it is still in spec.

 

[pj91gsx]

yes, the rod journals were resize and the turned out perfect. and yes the journals are in spec. Im just wondering now that it had to be the way that i took the caps off. they were a little tough so I hit the rod bolts lightly with a hammer, which i realize probably made the rod cap slightly tap the journal smudging the plastigauge.

 

[92awddsm]

yes, the rod journals were resize and the turned out perfect. and yes the journals are in spec. Im just wondering now that it had to be the way that i took the caps off. they were a little tough so I hit the rod bolts lightly with a hammer, which i realize probably made the rod cap slightly tap the journal smudging the plastigauge.

You really should check clearances for the rods with a micrometer. Plastigage usually doesnt work because the rod tends to slide or twist while torquing giving you a false reading. If it was a main, the plastigage would work properly.

 

[pj91gsx]

ok. I will do that tomorrow. thanks for the help.

 

[absolute_DSM]

The crank is fine with a polish if it is still in spec.

... when installing ARPs you mean?