1zz strip and rebuild

[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

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.

I thought it was the scraper rings that were changed. The compression rings stayed the same right? 


Still, I guess it'll be minor.

[Carolyn]

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.

I thought it was the scraper rings that were changed. The compression rings stayed the same right?


Still, I guess it'll be minor.

It was in the metallurgy. The earliest ones lost their resilience over time.

[thetyrant]

Cleaned up the pistons today ready to send off for modification and found some interesting exhaust valve witness marks on number 4 piston, picture below of this and number 1 for reference, they were not visible until i cleaned the carbon off and dont look recent but its a harsh enviroment so hard to tell for sure so bit of a mystery, will be checking valves for marks as well.

Piston 4 top with the marks...
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Piston 1 top without the marks!
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[thetyrant]

Just found a pic of piston4 before i removed and cleaned it see below, you can actually see the marks but i didnt spot them until cleaned.....weird!

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[shnazzle]

Wow. Rough past indeed.

[Carolyn]

Don't spend any more on that engine until I've had a good look at them.

Would you, please, you go a petrol-tight test on the valves?

[thetyrant]

Don't spend any more on that engine until I've had a good look at them.

Would you, please, you go a petrol-tight test on the valves?

Will do, inspected and cleaned up valves tonight and no sign of any piston contact from what I can see. Will get plugs in and see if they are petrol tight later or tomorrow.

[thetyrant]

Ok while my food was cooking nipped back into garage and did the petrol test on the head  , seems we have some slight leakage on inlets but exhaust seem dry, cylinder 2 is worst see below for details, its not bad really for 105k if its never been touched, i guess i should be re-lapping these inlets?.

Filled with petrol @ 18:38
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Status after 5mins @ 18:43
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Status after 26mins @ 19:04
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[Carolyn]

Ok while my food was cooking nipped back into garage and did the petrol test on the head  , seems we have some slight leakage on inlets but exhaust seem dry, cylinder 2 is worst see below for details, its not bad really for 105k if its never been touched, i guess i should be re-lapping these inlets?.

Filled with petrol @ 18:38
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Status after 5mins @ 18:43
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Status after 26mins @ 19:04
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I'd lap the lot.

[thetyrant]

Yes i think will get all valves out for inspection, clean up and lapping in.

I must say ive found a few surprises on this engine now its open, not only the 1 piston with marks as above but  also spotted a what looked like silicone sealant in water chamber on head last night, see below for what i pulled out!  there is mention on service history of water pump weeping and found lots of black silicone sealing it when i removed!  guessing its been off/replaced to sort that in past with too much silicone used or old stuff not cleaned out but gone inside!, see below.

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Another one was when i pulled crank angle sensor out there was a large piece of metal debris and also a few small ones stuck to it!...see below

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Amazing what you find once you start pulling apart what you think is a good engine other than smoking issue.

[shnazzle]

That's almost identical to one of the pieces of metal I pulled out of the 2zz when I had it.
Fingers crossed the crank is in a good state 

Also highlights the level of care "professional" shops sometimes take. 
That's why it's so damn hard to find an outfit you can trust. 

Bit of a slog for you but if you were looking to have work done properly, AK Automotive near Gateshead do all of this. 
They charge a flat fee of 1000 for a drive-in/drive-out engine swap excluding parts and machining. 

They have a dedicated engine build room. How many garages have you seen with this? I've seen a mechanic rebuild a BMW engine about 10ft from an open garage door at a local dealership on a windy day.
Doesn't mean it's crap work perse, but chances are slim that no foreign matter made it in right?

[Carolyn]

The water pump should not have sealant on it at all. Just the O ring.

The water pump cavity (sealed by the timing cover), does need good sealant, properly applied.  Not silicone, however.  Dirko Elhring grey is the stuff.

I'm only adding all this stuff to your thread in an effort to assist others, as this will be a very useful thread.

Great work!

[thetyrant]

Indeed there are some proper cowboys/corner cutters out there and after many years finding this out trying different places i now do as much as i can myself, then i can be sure its done right or if not its only me to blame

I know the guys at AK and they seem a decent bunch but would rather do it myself, any proper garage will have an engine build room and if they dont walk away if wanting engine work done, although just having the room doesnt always mean they know what they are doing and ive seen some dusty manky engine rooms as well!, many places just rely on oil pickup strainer and filter to catch any crap that gets in but that is of course not the attitude to be taking especially if your charging a customer for the work!

Crank looks perfect at least on the conrod big ends so dont expect mains to look any different, im not pulling the crank out to check though and happy enough looking at big ends and cam journals that nothing has got in the pressurised oil side.

So summary so far.

Engine stripped and ready to hone the bores
Pistons shipped off today for inspection/modification.
Valves to remove and inspect/lap in for better seal.

Cam chain to inspect/measure
Cam chain guides etc inspected and no noticable wear.

TPR ring set ordered
VICTOR REINZ Top End gasket set with Head bolts ordered.

Water pump still to order and probably a few other bits yet!

[Carolyn]

I'd be tempted to add skimming the head to that list.

[thetyrant]

I'd be tempted to add skimming the head to that list.

It is in my mind to do it but im going to give it a good inspection with straight edge etc first, ive nobody local i would trust to skim it either which doesnt help or i would just drop it in.

[thetyrant]

Spoken to only local machine shop i trust today and he is going to tickle/skim head for me   will get valves and things sorted this weekend and drop it down to him next week

[m1tch]

Worth noting that 1ZZ2335488 is the engine number you want or newer - its the first engine with the revised pistons.

[thetyrant]

Worth noting that 1ZZ2335488 is the engine number you want or newer - its the first engine with the revised pistons.

Is that the 1st revison like mine ?  or the 2nd revison with the extra/larger holes ?

[Carolyn]

The last revision is so rare in an MR2 that it is non-existent for all practical purposes.

I, and others who have had a few of these apart, can attest to the fact that the revision that WAS done, had little or no effect.  The oil holes still were too small and too few.

The biggest factor in gumming up is regular oil changes, preferably at least annually and at a lot less than 10,000 miles.

[m1tch]

I am fixing my engine with these lol

[thetyrant]

The last revision is so rare in an MR2 that it is non-existent for all practical purposes.

I, and others who have had a few of these apart, can attest to the fact that the revision that WAS done, had little or no effect.  The oil holes still were too small and too few.

The biggest factor in gumming up is regular oil changes, preferably at least annually and at a lot less than 10,000 miles.

Agreed these longer service intervals i think are killing a lot of engines these days, that said service history on this car on paper at least is excellent and one of reasons i bought it, i will double check but from memory at least once a year at Toyota dealer with less than 10k between stamps in book iirc, makes you wonder if oil was always done and of what quality, i have the service sheets of what was done to back up stamps in book so might see if oils was  done each time.

Lack of thrashing i think is another factor as lots of these cars just potter about so less pressure in the cylinders to help keep things flowing as they should

[thetyrant]

I am fixing my engine with these lol

Show off What are the oil ring holes like on those ?

[thetyrant]

Been looking back through the history folder that came with this car, its not been short on servicing or at least going into toyota for its stamp!  there are service sheets for most of visits which have oil and filter on so probably lack of a good regular thrashing thats caused it to clog up!

Service history
Date  -  Mileage
28-3-06 @ 6487
26-3-07 @ 12114
13-6-08 @ 17411
13-7-09 @ 20600
6-4-10  @ 29518
4-4-11  @ 41473
13-3-12 @ 52316
5-6-13  @ 65811
8-5-14  @ 77773
30-4-15 @ 85291
25-4-16 @ 93241
23-6-17 @ 96310
27-10-18 @ 96736

[thetyrant]

OK little more progress as below.

Pistons modified and heading back to me next week
New Piston ring kit arrived
Gasket kit due anyday

Honing tool finally located (my brother had borrowed it for his vespa and i had forgotten)

This weekends jobs are get valves out of head to inspect/lap back in, clean and hone the bores and maybe tidy up a few other bits as well, also need to get a water pump ordered but will maybe just pop down local factors for that.

[thetyrant]

Todays progress was a good clean on outside of the head then valves stripped out, decoked and lapped back in, some didnt need much to get a nice visible band and others needed a bit more work but not bad all in all.

Few pics below.

Valve before lapping.
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Valve after lapping
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Valve seats before and after,  left side lapped in and right side still to do.
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