EGR Cleaning at Hybrid Pit

If they bore the cylinders, then they are too thin. Someone menchioned Toyota doesn't
recomment boring because the walls are too thin. Do they put in new sleeves?

Do they use a thicker head gasketto make up for the lost material of the head, and block?
Which would increase the compression.
And bring the piston and valve closer to each other.

Does the head gasket have a second sheet of aluminum in it to make up for the cut material
to keep the correct compression?

 

Your are very persistent so I will answer some of your questions indirectly….

One of our test Vehicles we bored the max out 1.0 mm - no issues with performance had to send gasket over to get machined to match cylinder size with slight head adjustment

FelPro is a much superior product due to the coating and lip size per cylinder (Toyota revised the head gasket coating in later years)

We check every head and block for warpage - as with compression it all depends on how much you take off which affects the compression ratio

Much of what you mentioned is for crazy HP engines such as Muscle cars and Turbo engines. Unfortunately we are dealing with a 1.8 liter Hybrid motor

We would love to do all of that but there is no market for that and would screw up the 40 million ECU’s in our car


Pic for reference - that works




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My apologies to the OP for going off topic, this Gen 2 ABS install that I and doing now is giving me time to reflect my life choices JK

 

Simple questions to answer. At least you answered some of them.
But I do understand......
But not the photos???

 

Quantum solenoid track
Hotter spark plugs
Bored out Throttle Body

All works together in harmony….. just the many things we R&D at HP

 

Does that improve fuel mileage?

 

So 1.0 mm is the max according to whom? If i remember right, Toyota doesn't even say it's ok to hone.

Where do oversize pistons/rings come from?

 

So what your implying is that the engine is not rebuildable, since most quality rebuilds include these machining operations.


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It is rebuildable and should be most of the time instead of a hg job. Rebuilds don't require boring or honing 95% of the time. On these engines new rings or pistons and rings is the rebuild purpose along with a rebuilt head and careful inspection and cleaning. If the bore is scored you get another used engine. Simple.

My read of HP's comment is boring is sometimes used to maximize power for special needs or requests.

 

I would not replace pistons and rings without at least a hone. It's supposedly necessary for proper break in of the piston rings.


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Agreed!

 

Chapman has entered the CHAT!

Off Topic-

What do you do for a living?
Are you a hands on Mechanic?
Your Knowledge, I gather, is quite extensive so do you work for Toyota?

I have a feeling that you are Professor John Kelly using ChapmanF as a screen name

 

Just a guy who reads what Toyota writes about their cars.

I do like Professor John Kelly's videos. Does he have one that describes oversize boring a 2ZR-FXE?

 

Still think that is you, but I understand you want to keep your identity secret and I understand that

‘Reads’ so you are not a hands on mechanic?

Curious


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From our experience this is starting to be a common issue with some fuel injectors that we are testing out.

Could it be that the EGR ports from the intake manifold be the cause of this issue?

This picture is the extreme case where we were getting a misfire from cylinder one. Rather then tell the customer that he had head gasket issues we like to diagnose 1st so we can take the right steps to problem solve.

 

It's the internet, so even if I gave you a whole biography, you'd be no better advised to believe it than I would be to believe anybody else's. On the internet, nobody knows you're a dog. Or knows you're not.

If you're curious what skills or experience a PriusChat member brings to the table, don't look for posts where the member shoots off at the mouth about it. If the member has a long enough track record of posts, those qualities will be there to see (or not).

 

What's happening in the pic? You've take the fuel rail and injectors off, placed them over graduate cylinders in same order as on the car, and cylinder one injector is delivering significantly less gas when your run the fuel pump?

 

It looks like a smaller difference that was seen for injector #2 in astrolink's set back in 2013, but, yeah:



The problem with astrolink's #2 can be seen consistently in both pulsed and both static flow tests. And astrolink's car was running like cr‌ @‌ p before the restoration. The car has a limited ability to adjust for flow variations between injectors, because there's only one A/F sensor. (Somebody recently posted that late models really do have some ability to time the A/F sensor signals with the camshaft and know which cylinder's getting what!)

 

We were getting a misfire code on cylinder 1. It was a bit tricky to diagnose because we switched over the coil packs, ran a Camera inside the cylinder and checked spark plugs.

Code kept popping up for cylinder 1 - so we went that route and pulled the fuel injectors for a test.

 

Doing our best to keep the Shop stocked up with Toyota Parts for the Prius / CT200h







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