Rod and Crank bearing inspection; do I have to replace?

[draven]

as some of you have read my post I'm tearing down Procarnut's 96 DOHC. Several issues were encountered when he originally built the engine i.e. mistimed and shredded/jumped 2-3 belts and brok timing chain. Engine is on the stand and drained and am about to inspect the crank and rod bearings..

Assisted rebuilding an old Chevy s10 60deg v6 years ago but that was a complete teardown where a new factory crank was installed with oem bearings, clearances etc..

In this case, "if" the bearings look good (maybe even plastigauge them), crate engine only has about 10-15K miles, can I just reinstall the bearing and cap, torque to factory specs and move on?

thanks in advance...

[The Dark Side of Will]

I would definitely plasti-gauge.
Be sure to check the entire circumference of each rod journal for damage.

But yes, if it's damage free, bolt the cap back on (IN THE SAME ORIENTATION!), torque to spec and move on.

You have a moly-based assembly lube for the rod bolt threads?

[draven]

I would definitely plasti-gauge.
Be sure to check the entire circumference of each rod journal for damage.

But yes, if it's damage free, bolt the cap back on (IN THE SAME ORIENTATION!), torque to spec and move on.

You have a moly-based assembly lube for the rod bolt threads?

Should I also check for OOR on the main journals as well?

I have royal purple max-tuff synthetic assembly lubricant... any reason to use the moly over the synthetic assembly lube on the rod bolt threads? (or did I just make an ass out of myself?)

EDIT: Ok just did a little "interweb edumacation" on molybdenum grease for bolts... Is there a locally available equivalent to ARP Moly Assembly Lube? Permatex Anti Seize? All I've got in my garage is Sta-Lube Moly Grease.

EDIT EDIT: Found a local 4 wheel drive shop that carries ARP Fastener assembly lube less than 5 miles away... I can see no reason why this wouldn't work with stock rod and main bolts.

[draven]

Moly based assembly lube such as permatex or arp or 10w30 synthetic engine oil as the lq1 factory manual recommends?

[Series8217]

Call ARP about the bolt lube. They will usually give you revised torque specs for whatever lube you have on hand.


A note about OOR on the mains.... make sure to carefully torque everything to spec with the heads (or torque plates) installed to spec too. The block moves quite a bit. The main cap bolt torque is VERY high. I don't remember the numbers, but my machinist and I were somewhat surprised when we checked roundness of the mains with the caps torqued with and without the additional angle. It moves a LOT!

[draven]

Call ARP about the bolt lube. They will usually give you revised torque specs for whatever lube you have on hand.


A note about OOR on the mains.... make sure to carefully torque everything to spec with the heads (or torque plates) installed to spec too. The block moves quite a bit. The main cap bolt torque is VERY high. I don't remember the numbers, but my machinist and I were somewhat surprised when we checked roundness of the mains with the caps torqued with and without the additional angle. It moves a LOT!

Didn't get any ARP lube as the 4 wheel drive store "says" in stock on their website until you show up and they "order" it for you. oh well.. Not going to go with any ARP studs at this point either, don't want to have the rods or mains resized

The factory manual states to use new engine oil for the bolts, any issue with doing this vs a moly based assembly lube? Or am I making much ado about nothing..

[The Dark Side of Will]

If you have the threads and under the bolt heads (or nuts) lubed and you're using exact torque procedures, you're 99.9% there. Worrying about which lubricant you're using is splitting hairs.
If your build is about splitting hairs, that's fine... otherwise it's a waste of worry.

As Series said, make sure that EVERYTHING is torqued before you measure clearances or check the assembly's rotating torque.

The machine shop I had do my block said that they established a torque sequence for the engine mount brackets on the Enfantis Brothers' Supra engines and stopped them from wiping the #5 main every other weekend. Of course that was running a 300 HP engine at 1600 HP, but the principle is the same...

[Series8217]

The factory manual states to use new engine oil for the bolts, any issue with doing this vs a moly based assembly lube? Or am I making much ado about nothing..

Then use new engine oil for the bolts. The torque spec is based on engine oil, not moly lube.

[draven]

Is there a torque sequence for the main bearing caps on the LQ1? is it an inside out spiral or alternating cross pattern working from outside in? or is it something else? Can't find anything in the factory manual? Just torque specs?

[The Dark Side of Will]

No, there isn't a sequence, as they are all separate pieces of metal.

[draven]

If I pull the crank to inspect out of round, run out on the journals, etc.. can I leave the cylinders with rods still in the block ( with hose over the rod bolts to protect the cylinder walls and crank journals) ??

thanks

[The Dark Side of Will]

Yes.

Install pieces of hose as you said.
Just push them up to the tops of the bores and leave them there until ready to reinstall crank.

Pull a big trash back over the block while the engine is apart on the stand to prevent contamination.

[draven]

Ok, after another detour taking care of my moms 95 lincoln continental with a 4.6 32v alum v8, misfire attributed to a broken valve spring.. finally got back to the 3.4 dohc tear down..

this is what i've found so far..

Previous owner jumped so many timing belts it eventually broke the timing chain an apparently it also brok the timing tensioner:



Looks like two broken areas, the internal plastic retainer the bit of metal at the bottom of the tensioner... definately a replacement item if the timing chain snaps..

Carrying on I got the crank and rod journal bearing caps removed with hopes of measuring run out, taper, and bearing clearance. And this is what I found.

Looks like some debris has imbedded itself into the crank bearings. The bearings looked to have done there job by imbedding the "bits" into the bearing surface and only minimal wear on the crank journals.

as you can see the thrust bearing imbedded the greatest amount of debris, but all have some...












Couldn't pull the crank as the heads are still on and had no properly sized hoses to sleeve on the rod studs, but here are the crank journals:









And here are the rod cap bearings





The block only has about 13K to 15K miles on it.. I might attribute the slightly above average wear due to the oversized injectors getting fuel in the oil. However, where is the debris coming from? I dont' think it could be from the timing chain as after it breaks the oil pump immediately stops due to the intermediate shaft ceasing to spin. However, could it be from the intermediate shaft bearings disintegrating under the radial loads put on it by the mistimed engine, throwing 3 timing belts and one timing chain? I know they are less than stellar bearings and Series replaced them with king bearings..

Regardless I already planned on replacing the intermediate shaft bearings so we'll see if they are indeed the culprit of the debris

Given the mild wear on the crank journals is it worthy of a regrind and over sized bearings? I did take a dental pick and could find no scoring on the journals...

Or do I bite the bullet ARP the caps and rods, have it center bored and put in hyper pistons and prep it for an eventual turbo like Matt Hawkins?

Opinions welcome...

[Series8217]

It looks good and normal to me. Send some oil to Blackstone to see if copper and lead are present --- then you'll know if the debris was present in the most recent oil fill or was there the first time the motor ever started.

I would definitely inspect the IMS bearing. I think all the SBC bearings are wider, but the front bearing might already be wide on the 60degree.

You could replace your mains with the King bearing set to get better rod oiling. Definitely measure clearances very carefully... I heard some cranks came with a journal undersized from the factory. They probably reworked some parts to improve yield.

[draven]

It looks good and normal to me. Send some oil to Blackstone to see if copper and lead are present --- then you'll know if the debris was present in the most recent oil fill or was there the first time the motor ever started.

I would definitely inspect the IMS bearing. I think all the SBC bearings are wider, but the front bearing might already be wide on the 60degree.

You could replace your mains with the King bearing set to get better rod oiling. Definitely measure clearances very carefully... I heard some cranks came with a journal undersized from the factory. They probably reworked some parts to improve yield.

Series, thanks for the words of wisdom..

Could you let me know the part #'s you obtained from King Bearings for the IMS as well as the crank and rod bearings.

edit: found the king bearing part #'s for std sizes: MB4080SI and CR 605SI

unfortunately King does not make a cam bearing set for the IMS but found the following IMS bearing sets with ACL having the better general experiences on the interwebs:
ACL 4C6001S
Clevite SH-1780S
Dura-Bond CHG-22
Fed. Mogul 1828M or SEALED POWER Part # 1828M
EngineTech CC436 (could be any of the above)

Would there be any benefit/danger to having the IMS and crank journals repolished? ( or would this be a foregone conclusion upon replacing bearings )

[Series8217]

Would there be any benefit/danger to having the IMS and crank journals repolished? ( or would this be a foregone conclusion upon replacing bearings )

You should have the crank polished if you can. Just measure them first to make sure you're not on the small end of the spec. If you're at the middle or tight end of the diameter spec you'll be fine.

I'm pretty sure I used SBC cam bearings for the IMS. I think they were mentioned in the 60-degree V6 power manual.

[draven]

Would there be any benefit/danger to having the IMS and crank journals repolished? ( or would this be a foregone conclusion upon replacing bearings )

You should have the crank polished if you can. Just measure them first to make sure you're not on the small end of the spec. If you're at the middle or tight end of the diameter spec you'll be fine.

I'm pretty sure I used SBC cam bearings for the IMS. I think they were mentioned in the 60-degree V6 power manual.

From my research and from your postings on here and 60degv6 only the center two can be replaced with SBC bearings while the front and back are unique to either 60deg v6s or the DOHC itself.. how much wider are the SBC bearings over OEM LQ1?

[Series8217]

From my research and from your postings on here and 60degv6 only the center two can be replaced with SBC bearings while the front and back are unique to either 60deg v6s or the DOHC itself.. ?

That sounds right. Not sure about the dimensions. DOHC front bearing might be the same as the SBC.

[ericjon262]

Would there be any benefit/danger to having the IMS and crank journals repolished? ( or would this be a foregone conclusion upon replacing bearings )

You should have the crank polished if you can. Just measure them first to make sure you're not on the small end of the spec. If you're at the middle or tight end of the diameter spec you'll be fine.

I'm pretty sure I used SBC cam bearings for the IMS. I think they were mentioned in the 60-degree V6 power manual.

From my research and from your postings on here and 60degv6 only the center two can be replaced with SBC bearings while the front and back are unique to either 60deg v6s or the DOHC itself.. how much wider are the SBC bearings over OEM LQ1?

you can use the SBC bearings, you'll just have to buy two sets and mix/match them.

[The Dark Side of Will]

Given the mild wear on the crank journals is it worthy of a regrind and over sized bearings? I did take a dental pick and could find no scoring on the journals...

Do you have a better photo of the journal above? That's the only one that looks concerning, but that could just be the photo.
Other than the embedded debris, the main bearings look beautiful. If a dental pick won't catch on the journals, then you should be good, as long as your clearances spec out.
If you're going to pull the crank out, you probably want to hit any questionable areas with 2000 grit paper. Obviously clean it fastidiously prior to reassembly.

That score on the rod bearing is concerning too... how does the journal look? Also, the rod bearings are considerably more worn than the mains.