Jaguar_5's 87 Turbo Build

[Jaguar_5]

This is the first one i've built lol, i've read and read and read some more, i thought i had every last detail down, but of course that is not the case! I'm determined to get this done, and get it done right! I'm taking your advice as serious as cancer IJ

 

[IJ.]

Jag: It's just a case of as soon as you change the slightest spec from the Toyota standard it all becomes custom fit and as said this applies to any motor.

Even if you weren't machining the crank you'd still have to micc it up before ordering bearings from Toyota to compensate for wear as we're talking tenths of thousanths of inches difference here!

 

[Jaguar_5]

Finally i have some numbers!
My main caps, torqued to 80 ft/lbs w/ arp studs, have a reading of 2.5218" x 7, and my crank is 2.3620" x 7

 

[Jaguar_5]

Ok, so after some more confusion, i think i figured out what bearing size to order, anyone care to check my work? I'm not 100% sure if i'm doing this right.

So 2.5218" - 2.3620" = 0.1598"
Toyota says Mark 5 bearings are 0.0788" - 0.0789"

0.1598" - (0.0788 x 2 or .0789 x 2) = .0020 - .0022"

Which appears to put my just out of standard spec, while the next step up appears to be (even though theres a typo there - http://cygnusx1.net/supra/library/TSRM/em/EM_73.html ) 0.0836" - 0.084"

Which either means i'm going to have to regrind my crank, or my math is all wrong... Did my machinist screw me here?

 

[IJ.]

Jag: Your Math is correct but why did your machinist grind the crank without having bearings in hand to check first?

Are the 5's the thickest shells Toyota do?

 

[Jaguar_5]

I'm not sure IJ, the truth is i assumed he'd do what should've been done, as i did have to order ARP hardware for the balancing before he started anything, and i had him take his time. He builds mostly 350's, but does lots of racing engines and says he's built 7M's before. The machine work does look fantastic, but here comes problems with clearances :icon_evil

I don't think he grinded the crank, all he did according to the receipt, involving this, is check & polish crank, and align hone the block.

According to that link i posted above, my crank is in spec for Mark 2 sizes, while my journals are .0003" larger than U/S .25. It also looks like the 5's are the thickest, until the U/S .25, which would require me to regrind the crank since theres a huge gap between the 2 thicknesses

Edit: I just realized the bearings that were in this engine before are ACL's 1165 / 16JA95 are the markings. I mic'd them at .085 - .0851. Maybe i'll be able to find some ACL's or Clevites that are already the correct size?

 

[IJ.]

Personally I'd go for the .25 U/S as this is only 0.010" and is still within Toyota's hardening so crank life won't be affected.

I's buy the bearings and the ARP hardware have the machinst that's doing the work torque the Mains in place and measure it then Grind the crank to the correct clearence.

You could possibly juggle Shells and arrive at good clearences but that's just a little dodgy if you're going to pound on this motor!

Normal wear and then being polished could have removed more than you think so getting an off the shelf bearing to fit isn't too likely.

 

[Jaguar_5]

What really throws me way off.. is that the bearings that were in there before won't fit anymore according to that math... it's 0.0102" (total, so 0.0051 each side) too thick
If i have to pay to regrind the crank now, i'm going to be very sore :icon_evil

 

[IJ.]

Jag: This is why it's important to do a mock assembly and triple check any math with real world results as a few tenths here and there can add up!

 

[Jaguar_5]

If by that you mean assemble w/ plastigauge, torque, and check before you assemble it for the street, i wouldn't think of skipping that step, i just don't want to have to go through the hassle of returning bearings or regrinding again!

Edit: I spoke with my machinist, he said to order one shell of the .0789's, and one of the .084's, then torque the caps down and he'd be happy to measure it for me with a bore gauge. He said i can't really figure it out with math because of the crush value of torquing it down...

 

[IJ.]

Jag: The <edit> Part is what I meant by a mock assembly!

As your machinst said it's just about impossible to do it on paper within acceptable tolerances!

The juggling bearings is what I described earlier that while it can work it's not "the way" when building a performance motor.

 

[Jaguar_5]

It all makes perfect sense now, i just wish i would've know this earlier... now it's a little late, i don't see my machinist re-grinding the crank for free, so juggling bearings might be my only option...

I sent in the order to elmhurst toyota for the 2 bearings, and a bunch of other random parts... so soon i'll know!

 

[IJ.]

Hope it all works out Jag!

 

[Jaguar_5]

So i spoke with Curt @ elmhurst toyota this morning, you can only get the bearings as a full set, he said although it would be a strange request i can return the bearings if for some reason they don't fit. I don't have measurements for the rod journals, So i dissasembled, placed 2 bearings with tabs facing out, sticking about a quarter inch out the side of the rod, torqued it up, and measured the outside of the bearings. Using this approximate number, the thickness of my crank for the rods, and the thickness of the old rod bearings, i came up with the same of about -0.0112 clearance... so i guess since my machinist told me standard sizes, I just ordered the .25 over for both rods & mains since that's what appears to have been there before. So either it will all work out perfectly by some miracle, or re-grind here i come.

LET THIS BE A LESSON TO ALL YOU NEWBIES BUILDING A 7M!!!

Learn from my mistakes, make sure your machinist understands these precise clearances, and knows to have parts in hand before removing any material off of anything!!!

 

[Jaguar_5]

So my first toyota order is shipping monday (freeze plugs, rod bearings, main bearings, oil pump driveshaft bearings) And now i'm working on more of the list!

I'm trying to figure out what the huge banjo bolt is on the back of the head, i cant find anything that looks right according to the EPC, i think this is it, but it doesnt quite look right...

http://cygnusx1.net/supra/library/EPC/MKIII_NATO/291410/1603_2.html

part # 16281B & 16281D

Is that it?

 

[IJ.]

16268H, C and 2 x G

 

[Jaguar_5]

Ooooh, right off to the side, although your typo threw me off for awhile!

For future reference, it's 16268 =P

 

[IJ.]

DOH!

 

[Jaguar_5]

Yay, new parts!! Got my rod bearings, main bearings, freeze plugs, oil pump bearings...

I have a feeling they're going to be too thick, one of the mains bearings measured 0.0901". I'm almost positive i'm going to have to have the crank re-ground... grrr. I won't jump to conclusions yet. Gotta buy a torque wrench, and mock everything up! It's gonna be a bitch torquing the rod's 3 times to eliminate stretch... does everyone use a rod vice? Or is there some other trick...

On a positive note, after this is taken care of, it's ORDER FRENZY!! Finally making some large strides here, with my immediate budget increasing, and my time decreasing, i'm hoping on having her running in 1-2 mo's. A little over-zealous for a first time build with a blank block at this point? I hope not

 

[Jaguar_5]

Well, things have been VERY hectic lately, i'm currently moving and trying to get the Supra running as soon as possible!

So my clearances appear to be ok, my machinist measured .0017-.0019, so a little on the loose side, but still ok clearances, my machinist told me to just go right along with it, so thats the plan. I ordered a BUNCH of parts to start putting everything back together, including a cometic MHG, headstuds, $800 of toyota parts, DDP and Cooleze 3" catback

Things are falling into place, and pictures will be up soon!