1zz strip and rebuild

[thetyrant]

Ok following on from my other thread about fitting a used engine which didnt work out   ive decided to pull my original 105k mile engine apart and assess it for possible rebuild as one of my options going forward.

Last night got the head off and so far it looks reasonable in there, i need to inspect/measure the timing chain and slippers etc to see if they are ok to reuse but i suspect so.

Bores look ok visually with no obvious wear and cross hatching still visible, will see if i can borrow a bore gauge to measure them for ovality and general size but dont see any obvious issues.

Next job is sump off and pistons out to see what state bigends are in and how bad the oil ring/holes etc look, im hoping nicely gummed up which explains the oil usage.

Parts that so far will definitely need replacing below....

Headgasket
Head Bolts
Intake Manifold to head seal
Crankshaft seal in timing case
Waterpump (signs of seepage on shaft)

Will be adding to this as i go, pistons not sure whether to just clean up/mod and refit or fit some of the 8 hole ones from Mag engine, will see what they look like once removed.

Oil pump not sure if worth changing this or not ?

Any tips welcome and few pics of progress so far below...

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Bore1
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Bore2
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Bore3
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Bore4
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[m1tch]

Get a service manual, there are specs of what to replace at what point, might have a few spare parts for you such as timing chains, oil pumps and various gaskets - have quite a lot spare in the garage!

Will be interesting to see what the pistons are like.

[jvanzyl]

From memory you can do a complete soft rebuild with around £300 of parts. New timing chain kit, water pump etc..  new pistons will obviously cost a fair bit.

[Carolyn]

Those bores definitely need honing.

You might as well put in a new thermostat while you've got it on the stand.

Pistons can generally be re-used, we enlarge the oil holes with a slight overlap on the bottom land and add a third one to each side.

[thetyrant]

Those bores definitely need honing.

You might as well put in a new thermostat while you've got it on the stand.

Pistons can generally be re-used, we enlarge the oil holes with a slight overlap on the bottom land and add a third one to each side.

Yes i will dig out my honing tool for the bores they are a bit smooth but generally in good order from what i can see.

New thermostat went in not long before i pulled motor so that is one less thing to buy!.

Im curious to see what pistons are like and tempted to reuse if they clean up and maybe send to you for your mods, that said these  8 hole Mag pistons are not a lot of money but they only listing .5 oversize at moment, ive asked if they have any in stock bore size.

What have you see oil pump wise on these? is it worth me removing to inspect/replace etc ?

[thetyrant]

Also tempted to throw some uprated rods in so i dont need to worry about stock ones if i boost it again, thing is i dont know if im going too do that so would be a bit of a waste for N/A motor, also if i do boost it i dont think i would go much over 220hp/trq so stock ones should be fine, however i can probably get a good discount on these ... https://www.part-box.com/4-br-028-02-bw-bridgeway-billet-4340-connecting-rods-h-beam-toyota-1zz-fe

I think if i was going to go down this route a complete strip and build would be best, i need to remind myself this is meant to be a low budget fun car....not a fire breathing monster....hmmm

[Carolyn]

I've got MAGs in my MR S. They are excellent quality.  We'd be happy to modify yours, though - we've done it on a few and they've all worked out fine.  A good long soak in diesel/kero makes it a lot easier to clean them up.

The oil pumps are pretty bullet proof.  I've never heard of a failure. (Now I've said that, doubtless someone will have a tale about a failure!)

You're right about the stock rods.

You can go mad on upgrades!! 

[thetyrant]

Haha yes its hard to draw the line sometime with mods   Good info on oil pump think i will leave it alone providing bearings look ok, certainly top end does so dont think we are lacking oil pressure.

Got sump off this morning before work so will have pistons/rods out tonight... if i can find my multipoint sockets for bigend caps!  used to have nothing else but they have nearly all been replaced with 6 sided now and typical i need them again lol

Interested to see what big ends are like, im thinking if no signs of wear

[m1tch]

Those bores definitely need honing.

You might as well put in a new thermostat while you've got it on the stand.

Pistons can generally be re-used, we enlarge the oil holes with a slight overlap on the bottom land and add a third one to each side.

Yes i will dig out my honing tool for the bores they are a bit smooth but generally in good order from what i can see.

New thermostat went in not long before i pulled motor so that is one less thing to buy!.

Im curious to see what pistons are like and tempted to reuse if they clean up and maybe send to you for your mods, that said these  8 hole Mag pistons are not a lot of money but they only listing .5 oversize at moment, ive asked if they have any in stock bore size.

What have you see oil pump wise on these? is it worth me removing to inspect/replace etc ?

I have a 79.5mm taper piston ring compressor if you need it

[shnazzle]

Those bores definitely need honing.

You might as well put in a new thermostat while you've got it on the stand.

Pistons can generally be re-used, we enlarge the oil holes with a slight overlap on the bottom land and add a third one to each side.

Yes i will dig out my honing tool for the bores they are a bit smooth but generally in good order from what i can see.

New thermostat went in not long before i pulled motor so that is one less thing to buy!.

Im curious to see what pistons are like and tempted to reuse if they clean up and maybe send to you for your mods, that said these  8 hole Mag pistons are not a lot of money but they only listing .5 oversize at moment, ive asked if they have any in stock bore size.

What have you see oil pump wise on these? is it worth me removing to inspect/replace etc ?

I have a 79.5mm taper piston ring compressor if you need it

I'll remember you have one as well when my time comes  

I've got the clamp type but don't like the look of it

[thetyrant]

Remember 79.5mm is only good if your overboring to suit , these taper compressors need to be bang on from what ive seen at work so you cant use the 79.5mm one on a stock 79mm bore despite being very close.

I pulled a couple of the pistons out at lunchtime and much to my dismay them and rings all look pretty decent considering the mileage, at least on initial visual inspection as all rings are not gummed up, free to rotate and move as they should, i havent removed the rings yet to check the oil holes yet though will do that later when i get rest out, is it typical for rings to seem ok but oil holes blocked still ?

Bearings and crank look nearly new so think i will run them all again, unless some have found that a bad move on these ? ive done it before on other engines and always worked ok even when torn down again for other issues in future.

Pic of pistons out of bore 1 below..

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[m1tch]

Those bores definitely need honing.

You might as well put in a new thermostat while you've got it on the stand.

Pistons can generally be re-used, we enlarge the oil holes with a slight overlap on the bottom land and add a third one to each side.

Yes i will dig out my honing tool for the bores they are a bit smooth but generally in good order from what i can see.

New thermostat went in not long before i pulled motor so that is one less thing to buy!.

Im curious to see what pistons are like and tempted to reuse if they clean up and maybe send to you for your mods, that said these  8 hole Mag pistons are not a lot of money but they only listing .5 oversize at moment, ive asked if they have any in stock bore size.

What have you see oil pump wise on these? is it worth me removing to inspect/replace etc ?

I have a 79.5mm taper piston ring compressor if you need it

I'll remember you have one as well when my time comes

I've got the clamp type but don't like the look of it

I had the clamp type but it worked out cheaper for me to buy a taper piston ring compressor than to snap or damage a ring putting them in the block!

[m1tch]

Remember 79.5mm is only good if your overboring to suit , these taper compressors need to be bang on from what ive seen at work so you cant use the 79.5mm one on a stock 79mm bore despite being very close.

I pulled a couple of the pistons out at lunchtime and much to my dismay them and rings all look pretty decent considering the mileage, at least on initial visual inspection as all rings are not gummed up, free to rotate and move as they should, i havent removed the rings yet to check the oil holes yet though will do that later when i get rest out, is it typical for rings to seem ok but oil holes blocked still ?

Bearings and crank look nearly new so think i will run them all again, unless some have found that a bad move on these ? ive done it before on other engines and always worked ok even when torn down again for other issues in future.

Pic of pistons out of bore 1 below..

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With regards to bearings, OEM makes are Taiho and Daido, they are very cheap for a full set so might be worth swapping them out whilst its apart.

[thetyrant]

With regards to bearings, OEM makes are Taiho and Daido, they are very cheap for a full set so might be worth swapping them out whilst its apart.

Noted thanks and I will see what the rest look like, its not so much about cost on this one for me but more about sizing as these are obviously well matched to the crank with oil film keeping them apart with no contact obvious so far, switching to new getting the sizing can be a bit of a fiddle in my experience but we will see.

[Carolyn]

The original bearings are sized to the rods, with four graded thicknesses of the 'standard' shells.  That's Toyota being OCD.  If they look ok and  clean, I'd use them again, as the graded ones are from Toyota and they ain't cheap.

You could put in a fresh set of 'standard' - one-size-fits all, shells and they'll be within tolerance for oil clearance.  Unless you have a rod with a 'four' stamped on it, which might be worth checking with plasti-gauge.

Early oil control rings weren't too great, so fresh rings and a good honing will make a big difference.

You're right, that  piston looks pretty good.

[m1tch]

With regards to bearings, OEM makes are Taiho and Daido, they are very cheap for a full set so might be worth swapping them out whilst its apart.

Noted thanks and I will see what the rest look like, its not so much about cost on this one for me but more about sizing as these are obviously well matched to the crank with oil film keeping them apart with no contact obvious so far, switching to new getting the sizing can be a bit of a fiddle in my experience but we will see.

I will check my stock of parts, might have a spare oil pump, head gasket, timing chain etc if needed.

[thetyrant]

The original bearings are sized to the rods, with four graded thicknesses of the 'standard' shells.  That's Toyota being OCD.  If they look ok and  clean, I'd use them again, as the graded ones are from Toyota and they ain't cheap.

You could put in a fresh set of 'standard' - one-size-fits all, shells and they'll be within tolerance for oil clearance.  Unless you have a rod with a 'four' stamped on it, which might be worth checking with plasti-gauge.

Early oil control rings weren't too great, so fresh rings and a good honing will make a big difference.

You're right, that  piston looks pretty good.

OK thanks for the info on bearing sounds like same as Mitsubishi with at least 4 sizes for stock size!  if all bearings are good as ive seen so far  will refit.

Ive pulled the rings off 1 piston this afternoon and its not terrible but not what i would call clean either!  2 oil holes i could see light through shining torch underside of piston, 2 on other side i couldnt but it was only oil really in there when prodded with a small drill and not badly gummed up but not ideal either, there is some crud in bottom of oil ring groove as you can see on pics below so not good.

Need to work out if i clean up/mod these pistons with new rings or go for the Mag engine 8hole design pistons and rings, tempted to go that way as not going to be a lot more than doing just rings and modding pistons etc by time ive shipped them about etc.

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[thetyrant]

I will check my stock of parts, might have a spare oil pump, head gasket, timing chain etc if needed.

Cool let me know thanks, certainly headgasket would be of interest

[Carolyn]

The original bearings are sized to the rods, with four graded thicknesses of the 'standard' shells.  That's Toyota being OCD.  If they look ok and  clean, I'd use them again, as the graded ones are from Toyota and they ain't cheap.

You could put in a fresh set of 'standard' - one-size-fits all, shells and they'll be within tolerance for oil clearance.  Unless you have a rod with a 'four' stamped on it, which might be worth checking with plasti-gauge.

Early oil control rings weren't too great, so fresh rings and a good honing will make a big difference.

You're right, that  piston looks pretty good.

OK thanks for the info on bearing sounds like same as Mitsubishi with at least 4 sizes for stock size!  if all bearings are good as ive seen so far  will refit.

Ive pulled the rings off 1 piston this afternoon and its not terrible but not what i would call clean either!  2 oil holes i could see light through shining torch underside of piston, 2 on other side i couldnt but it was only oil really in there when prodded with a small drill and not badly gummed up but not ideal either, there is some crud in bottom of oil ring groove as you can see on pics below so not good.

Need to work out if i clean up/mod these pistons with new rings or go for the Mag engine 8hole design pistons and rings, tempted to go that way as not going to be a lot more than doing just rings and modding pistons etc by time ive shipped them about etc.

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Those are the later 'revised' pistons.  The earlier ones had no overlap. What year is the car? Remember to add in for shipping and import duty....

[thetyrant]

Those are the later 'revised' pistons.  The earlier ones had no overlap. What year is the car? Remember to add in for shipping and import duty....

Ahh i did wonder when i saw the slight hole overlap on bottom of ring grooves, its on 05 plate so early 2005 car.

Based on this would say a good clean up then new rings and fire them back in ?

[Carolyn]

Those are the later 'revised' pistons.  The earlier ones had no overlap. What year is the car? Remember to add in for shipping and import duty....

Ahh i did wonder when i saw the slight hole overlap on bottom of ring grooves, its on 05 plate so early 2005 car.

Based on this would say a good clean up then new rings and fire them back in ?

If it were me (having the mill and a jig available) I'd still enlarge the existing holes and add two more.

If you have needle files available, you could well do it by hand. They don't have to be perfectly round, just free of burrs.  Hone the bores until the surfaces are uniform with a hood cross hatch and you'll be fine.

[thetyrant]

If it were me (having the mill and a jig available) I'd still enlarge the existing holes and add two more.

If you have needle files available, you could well do it by hand. They don't have to be perfectly round, just free of burrs.  Hone the bores until the surfaces are uniform with a hood cross hatch and you'll be fine.

Ok thanks i will have a think and maybe send you these down to mod as while i have a milling machine at work its always setup for something else!

Any recommendation on ring kits ?

[thetyrant]

Been doing some research on the various piston used on these 1zz motors over the years, this info i found on here but thought i would bring it into this thread for easy reference, if ive got any of this wrong let me know i will amend.

So 3 different pistons as below with difference in oil holes obvious thing, amount of holes is per face so x 2 for all holeson the piston, as in 2 hole pistons have 2 on each face so 4 in total on piston.

1999/12-2001/12 - PISTON - 1310122030 - Original - 2 small oil holes no overlap  -

2001/12-2002/08 - PISTON - 1310122031 - 1st Revison 2 holes (larger?) BUT overlap on bottom of ring groove
2002/08-2005/05 - PISTON - 1310122031 - as above

2005/05-2005/09 - PISTON - 1310122032 - 2nd Revison 4 holes (larger?) overlap on bottom of ring groove

This 2nd revison is very rare in an MR2 i believe as it was introduced very late in production.


Rings seems to be 2 types as below
1999/12-2001/11  RING SET, 1301122090  - Original

2001/11-2002/08  RING SET, - 1301122150  - Revised
2002/08-2005/09  RING SET, - 1301122150 - Same as above

Ive been looking for good clear pictures of new pistons but only found 1 of 2nd revised 1310122032 as below..

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And piston out of my 2005 - edit to confirm its 1st revision 1310122031

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[shnazzle]

Brilliant post Ian! 

I had an argument with someone on YouTube of all places about latest pistons in MR2s. He worked for a Toyota garage and was trying to a)educate me on the Toyota factory line process and b) convince me that there is no way the latest pistons won't be in all 1zz after they were made.

I gave up arguing with the idiot but as we all know, those rev1 and original pistons are the ones you're likely to see in any mr2 block.

As for the rings, it'd be good to get a pic of the differences between them. I've only seen descriptions of the differences

[thetyrant]

Brilliant post Ian!

I had an argument with someone on YouTube of all places about latest pistons in MR2s. He worked for a Toyota garage and was trying to a)educate me on the Toyota factory line process and b) convince me that there is no way the latest pistons won't be in all 1zz after they were made.

I gave up arguing with the idiot but as we all know, those rev1 and original pistons are the ones you're likely to see in any mr2 block.

As for the rings, it'd be good to get a pic of the differences between them. I've only seen descriptions of the differences

Thanks, i pulled the info from deep in another thread on here but it wasnt laid out as clear as i have done above, makes it more obvious which years etc, of course late registered cars could have early pistons as well, im sure Dick Sloan mentioned there was a list of engine numbers which dictated piston fitted but ive not found it yet.

Most people that work in dealerships have no clue as you found out, ive come across a mere handful in my many years who actually had decent knowledge of what they were selling, its brilliant when you done find such a place/person though.

I dont think there would be much to see on rings as difference is probably very small as believe they are all interchangeable, could just be the grade of metal or slight difference on edge profile etc, however would be interesting to find out for sure.