Main bearing clearances?!

[mk3-4-me]

Ok so I'm ready to put my built motor together... Nothin fancy just JEs, eagles and fully balanced.

So I got my .25 clevite bearings in yesterday and plastiguaged my mains.

Most of the readings were around the .0038 green marker on the plastiguage paper. Except for my the middle one that was around .0025. Now I accidentally spun the crank a bit while trying to take them off, so I know the reading wouldn't be to accurate.

But let's say the clearances are that big, is that not gunna work? I have the new oil pump shimmed for higher pressure.

I've searched for people with the same situation but didnt really find anything...

So let me know what you guys think.

Would just running thicker oil help? I plan on being up around 600 whp in the future if that has anythin to do with it...?

Thx!

---------- Post added at 11:37 AM ---------- Previous post was at 11:33 AM ----------

I also have ARP studs that I used 30wt oil and torqued to 105 ft lbs.

The middle main I torqued down the smoothest out of the rest, cause it's on a stand, when I torqued the rest it would mOve around, so maybe I didmt torque the rest down to well...? I'm gunna redo them today after work.

 

[Kai]

What measurement is this in, inches, millimetres, what? Be specific.

Read the TSRM - it TELLS YOU what the spec for the bearing clearances should be.

Judging from your question history, i wouldnt bank on you making more than stock horsepower. The likelyhood of you getting to 600rwhp is remote.

 

[mk3-4-me]

I know what the specs should be... I'm asking wat I should do, or idk just some insight. And it's in MM, sry I thought that woulda been obvious...

And I'll be up the in horsepower soon enough... Lol by nxt summer, I just wanna get it goin this summer..

---------- Post added at 12:57 PM ---------- Previous post was at 12:56 PM ----------

And ya from all my questions, I wouldn't expect me to get it runnin! Haha but I will! Thx for looking at all my question! Lol

 

[Devin LeBlanc]

So are the clearances within spec? Yes or no.. That means yes its okay or no its not okay.. And if you rotated the crank you should re measure it.

 

[hvyman]

Rods .021-.053
mains .030 - .048

 

[CyFi6]

You say it is OBVIOUS that you are measuring in MM. If you are measuring in MM your clearances are around 0.0001" which is much smaller than a piece of plastigauge can measure. I think the lack of replies has more to do with your lack of detail and extremely hard to read posts (lack of grammar and poor spelling). Not making fun of you or anything but I am just saying that if you can't take the time to be thorough and use proper grammar, the guys that actually know the answers to your questions are not going to take the time to respond.

 

[mk3-4-me]

Ya well I'm at work right now, replying when I can quickly... Lol so that's why. I'll way till I get home them and fill u guys in I guess...

Thx

 

[hvyman]

Rods .0008 -.0021 in
.021-.053mm
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=69

mains
.030-.048mm
.0012-.0019in
http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=72

Better to be in the middle of the spec or slightly tighter for a stock or lower hp car.

If you run larger clearances it usually for higher revving motor like 7500+ and you need to run the proper weight oil for that as well.

 

[mk3-4-me]

AH HA! i was measuring in MM and goin buy IN!! LOL ok so it looks like im good! thx hvyman that exactly what i needed.

thx evryone else for the input!

ill let you guys know the clearences after i remeasure it!

 

[mk3-4-me]

Remeasured.

Mains in MM:-

1- .038
2- .038
3- .038
4- .04 (not exactly sure, it's just a tad smaller than the .038 marker)
5- .038
6- .038
7- .038

I have yet to do all the rods, but the ones I did r within spec!

Thx again!

 

[mk3-4-me]

ok well all my rods r within spec, except for my number 6. Thats the one that spun a bearing. i checked it 3 times and it came out to anywhere from .076 to .051 being the smallest clearence. (it smooshed differently in some parts of it) what do you guys think i should do?

I looked on the TSRM and like HVYMAN stated the clearences are from .021 - .053 mm with maximum being .07. I dnt quit think the thinnist part of the plastiguage read .076 but its somewhere around there.

please let me know what you guys think!

thanks

 

[hvyman]

Personally I'd look for another crank or machine more oversized. But bigger oversized beatings are not the best option.

 

[mk3-4-me]

Ya that really sucks! Damn... I replastiguaged it, and it matched up to .076 and even a lil smaller than that in one place... The shimmed oil pump wouldn't help huh? Damn that really sucks!

 

[Devin LeBlanc]

no, it will knock. You need a new crank or need to get it turned for .50 undersized bearings.

 

[mk3-4-me]

Ok well I'm not goin .50 undersize... Lol I'm pretty sure that's a no go for the 7m's... I have another 6m that I guess I'll have to wait for it to be rebalanced... another week of summer that's gunna slip by!

 

[Devin LeBlanc]

make sure you check the clearances before you get it balanced

 

[CyFi6]

You need to measure the crank and the rod, it is not necessarily just the crank that is out of spec.

 

[Devin LeBlanc]

They should all be re sized. Brand new rods and crank OEM Eagle crank for our stroker ls2 we had to take 2 thousands off to get it in spec. And resize the rod.

 

[mk3-4-me]

Ya actually I just thought of that... The guy said it was all in round, and so he didn't do anythin to it... I went back this mornin cause I noticed the lil scratches from when the bearing must of spun, cause all my other rods still have the clean cross hatching marks... The number 6 like I said has just lines goin around.

He said he measured it and it's all within spec. So idk u think that's it? I'll take my rod into AMS here in Milwaukee if they're open 2morrow. They are mostly imports. So hopefully it's just that!

 

[Devin LeBlanc]

Have them measure a rod that didn't spin, I bet the spun one is out of clearance