Toyota Select Fit Bearings

[Kai]

Okay...so...the daily driver is still pootling around perfectly fine except the constant bother of looking over at the oil pressure gauge and seeing 'low pressure' at hot idle. Now, it's within spec still, but not by much. I'm getting roughly 11.5psi per 1000rpm, according to my EXTERNAL Snap-On Gauge (MT37), upto about 36psi, when it won't go any higher - presumably because of the oil cooler circuit.

As it's due for a service, i had an idea of just taking the entire engine & trans out, separating the two, and doing EVERYTHING that needs to be done.

It's a bone stock 7M-GTE, no mods except a filter, and staying that way (it's just a DD).

As the engine is rod-knock free, would it be acceptable to measure the clearances of the rod & main bearings (plastigage), and then swapping them out (if needed) for the right size Toyota Select Fit Bearing, without the need to have the crank taken away and machined?

The reason is...the whole gasket set is expensive, but i have the bottom end gaskets & new seals from my headgasket job on the other supra. The HG hasn't blown, and was last done 40k ago with stock bolts torqued to 70lb/ft (according to the notes i have).

I'd rather not just drive it til it goes *boom* as that'll be more expensive in the long run. I'd like to think of this as 'preventative maintenance'...if it can be done, of course!

 

[IJ.]

Can't see a reason it won't work as long as the engine hasn't been machined after Toyota.

I'd carefully measure the crankpins as it'd be a good opportunity to close the clearences up if there's wear.

 

[Kai]

Thanks Ian

As for the crankpin measurement...erm...where am i looking, and is it detailed in the TSRM?

 

[IJ.]

It is, in the "chart" it will list an Xxx/Y table one side being the Pin size the other being the Tunnel size, as long as it's Toyota spec the Tunnels will not have changed but the pins may have so you measure the pins find the correct shell from the chart order and install and you're golden.

If the pin has wear and you just replace with the exact same size shell you're in effect building a worn engine.

 

[Kai]

Got it - EM-70, looking at the chart. So... just to get this all straight in my head:

1) Remove Engine & Trans, split, mount engine on stand.
2) Mount engine on stand - remove spark plugs, spin upside down
3) Crack off sump & remove oil pump
4) Remove Rod Cap by cracking off and removing the nuts, tap with plastic faced hammer to get the cap off.
5) Mic the crank pin diameter, if it corresponds with the number stamped on the crank all good (ie, #0), if it's become say...#1 or #2, treat it as such?
6) lay plastigauge across crank pin, re-install rod cap & torque down.
7) Crack off Rod Cap again, measure plastigauge clearance, if good, leave alone, if bad, note the number on the bearing, fit the correct size according to chart, taking into account the crank pin diameter & rod cap number.
8) Re-install Sump & oil pump, bolt trans back on, slot engine back into vehicle...the end?

The chart was initially confusing, but now makes perfect sense. If that procedure is correct for the Rod Bearings, could i then do the main bearings in the same manner, albeit with replacing the relevant seals, and will it matter having the pistons/rods still in the bores & the head still torqued down?

 

[IJ.]

4) I sleeve the Rod studs with fuel hose so they can't nick the crank but yep all looks good Kai!

 

[max-89supra(t)]

I would change the piston oil squirters if you haven't already done so, faulty oil squirters will cause bad oil pressure at idle.

 

[Kai]

*phew*!

I remember the rod stud/hose trick - should have mentioned it though

Have i missed anything else out on the bottom end, while i'm there? If the crank looks a little squiffy, but not scored badly - is there any way i can hand clean/polish it - or is that a machine shop only kinda deal? The only shop around here, is 50+ miles away, and used to stuff for Tractors or 1950's Citroens :/

 

[Kai]

I hadn't thought of that...although, i don't know if they're still available?

 

[max-89supra(t)]

I bought them from toyota about a year ago, they should still be selling them, if you search on sm you can find the part number, if I remember correctly they were about $8 usd each. They have check balls with springs in them which are only supposed to open at about 40psi oil pressure, over time the tiny springs get weak and start leaking all the time, causing the oil pressure to be bad at idle.

 

[IJ.]

*phew*!

I remember the rod stud/hose trick - should have mentioned it though

Have i missed anything else out on the bottom end, while i'm there? If the crank looks a little squiffy, but not scored badly - is there any way i can hand clean/polish it - or is that a machine shop only kinda deal? The only shop around here, is 50+ miles away, and used to stuff for Tractors or 1950's Citroens :/

WetNdry sandpaper cut into precise strips, Lube with CRC-5-56 then wrap the crank pin with the wetNdry then wrap that with a long boot lace a couple of time, grab each end of the lace and pull back and forwards, this will rotate the sandpaper and polish the pin.

 

[Kai]

...what grit are we talking, 1200/1500 or higher?

And is this the same stuff i'm after: http://www.amazon.co.uk/MULTI-OIL-400-ML-CRC-5-56/dp/B001G4SUVA ?

 

[IJ.]

Depends how badly it's marked, 1500>2000 to finish and yes that's the stuff but any light oil will do the trick it's just to help wash out the paper as it works.

 

[Kai]

Would 3-in-1 mineral oil do the trick? That stuff is plentiful over here, been using it when chasing threads on bolts, seems to work okay.

Oddly enough i went to youtube to see if anyone else had hand polished the crank in the method you described. I didnt find any that weren't on machine, but i get the idea. I also found a prime example of how *NOT* to do it

[video=youtube;pnXhJMA2eTg]http://www.youtube.com/watch?v=pnXhJMA2eTg&feature=related[/video]

 

[JStoked]

4) I sleeve the Rod studs with fuel hose so they can't nick the crank but yep all looks good Kai!

Not trying to mess up this thread. But this is great info!! :aigo:

 

[IJ.]

Would 3-in-1 mineral oil do the trick? That stuff is plentiful over here, been using it when chasing threads on bolts, seems to work okay.

Oddly enough i went to youtube to see if anyone else had hand polished the crank in the method you described. I didnt find any that weren't on machine, but i get the idea. I also found a prime example of how *NOT* to do it

Yeah 3in1 should be ok Kai!

 

[grimreaper]

try shimming the oil cooler relief valve 2mm. If pressure increases,there is your problem. Toyo still sells the springs. New spring and 1/2 hr vs. R/R enigne.. worth checking at least.

If you do pull it the oil squirters are still around. Picked up a set about 6 months ago for my build. Toyo will bend you over the table. Might be cheaper to get DM to ship overseas. Considering its a stock output motor, I'd plug them(personal choice).

Dont forget the thrust bearings and give the oil pump a good going over. Check that relief spring as well.

Your cam journals have a big hand in the idle oil pressure too. Lapping helps but a line bore is always the end all solution.

 

[Kai]

Well, they didn't install them for no reason, so i'd rather stick with the way things are, instead of bodging it.

I have a spare oil cooler spring, i'll do that when i do the oil filter housing later next week. LS400 filter going on + Oil Change.

 

[suprarich]

*phew*!

I remember the rod stud/hose trick - should have mentioned it though

Have i missed anything else out on the bottom end, while i'm there? If the crank looks a little squiffy, but not scored badly - is there any way i can hand clean/polish it - or is that a machine shop only kinda deal? The only shop around here, is 50+ miles away, and used to stuff for Tractors or 1950's Citroens :/

If your not confident of doing it by hand then do not polish the crank pins by hand Kai, "should be" done on a special machine. Any crank shop can do this and you could try to post the crank to them if it is too far to drive. Then they could measure all the crank pins for you as well in several points around the pin to check for roundness. Too bad you are so far away, I would do it for you for free.

 

[IJ.]

My "tip" was just to clean up an otherwise good crank that's been checked for roundness as with Lapping Blocks/Heads it's just a finish procedure NOT an alternative for proper machine work.