7M pistons taking out

[Bass_Man]

Hi guys :naughty:.
Do you can tell me is it possible to take out pistons from 7M block from bottom side ?

[Clip]

when i took mine out i used the TSRM procedure. I removed the oilpan and disconnected the conrods from the crank, then used a rubber coated hammer handle to press the pistons and conrods into my hand underneath (block is upside down).

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?S=EM&P=70

[FlipSupra8]

yea

[CyFi6]

If youre trying to remove them OUT the bottom, you cant.

[Rennat]

Hi guys :naughty:.
Do you can tell me is it possible to take out pistons from 7M block from bottom side ?



even if you could... why? you have to put the pistons in from the top when you reinstall them.

[sean210]

Thats good to know.
Quick question how are our engines balanced?

[Bass_Man]

even if you could... why? ..........

Because I hear one knocking noise from one piston bolt and I do not want to ruin my brand new ( on 4000 km ) MHG for one stupid bolt :3d_frown: .
For me is better if there is a way to replace piston bolt from bottom side .
Please if someone of you have spare block from 7m just check if there is way to remove piston from bottom side . And also will be better if someone can make one picture of bottom block side .

[Clip]

how would you get the ring compressor in to push the piston back into the cylinder?

[92TealSupra]

If youre trying to remove them OUT the bottom, you cant.

Correct, you cannot take them out the bottom. Some MHG are reuse bale. What Type do you have, I know HKS Stopper gaskets you can reuse. I have used a Hks 1.2mm HG before and had no issues.

Just do it the right way, you take the pistons out the top, you put them in the top.

Period.

[CyFi6]

First off what is a piston bolt? Second i have looked and tried and you cannot remove the piston out the bottom, the main journal webbings are in the way. Heres a shot of the bottom end for you.
http://img.photobucket.com/albums/v313/cyfi/supra%20engine/IMG_1032.jpg
http://img.photobucket.com/albums/v313/cyfi/supra%20engine/IMG_1097.jpg

[grimreaper]

one slip and a nick on the crank journal = full rebuild.

[Clip]

cheap fast good, pick two.

[Bass_Man]

First off what is a piston bolt?

Thank you for pictures :thumbup: this is actually what I need !
And piston bolt is bolt between piston and rod .
Something like this :
http://www.made-in-china.com/showroom/cnnina/product-detailGodxtNvrhAcW/China-Piston-Bolt.html

Head need to be removed and I know about MHG reusing but do I need to grind block and head one more time ?

[pogoism9]

thats a wrist pin, and no, you are NOT going to change that without taking the head off and taking the piston out of the bore on TOP of the engine.

As far as the head and block machining, I would certainly inspect them, you may need to rework them, but if they are still straight, i would imagine you would be fine.

[IwantMKIII]

how in the hell did that go bad???? How do you know for sure?

[Bass_Man]

how in the hell did that go bad???? How do you know for sure?

From my point of view there is a few reasons :
1. When I ( not I but when ) rebuild engine I do not change them and they are old and worn ( around 150 000 km ) together with rods,pistons, shafts, block, head and few other parts .
2. Very low pressure of oil ( 2 bar from 2000 to 6000rpm ) because of great "high volume low pressure" 7M oil system .
3. Also because not proper set advance ( I saw this to late ) .
I think all together this reasons are absolutely enough to hear knocking :icon_roll .
Around 4000km after rebuild I start to press little more on gas pedal and after 200km I start to hear this knocking .
How do I know for sure? I do not know for sure but from this typical noise and from little more diagnostic this need to be for 80%.

[IwantMKIII]

i'd suspect a bearing or an improperly installed bearing before ever suspecting that. (i don't think i'd ever suspect that piece going bad unless it had it had serious flaw)

[Bass_Man]

i'd suspect a bearing or an improperly installed bearing before ever suspecting that. (i don't think i'd ever suspect that piece going bad unless it had it had serious flaw)

Yes but noise is not from bottom side .
And when remove spark plug on cylinder 4 noise is gone . And noise is only when accelerating harshly and from 2000 rpm and above . And is not on every revolution . And all of these goes to wrist pin .
This with improperly installed bearings is not possible .

[p5150]

It may sound like its up top - its not. You are probably going to need to at least change/cut the crank

[Bass_Man]

It may sound like its up top - its not. You are probably going to need to at least change/cut the crank

Do you think if this noise is from bearing ( and I drive around 1000km ) noise will be on every 2-nd revolution only and will disappear when disconnect spark plug ? And also sometimes when car is cold and when I start engine in first 5-10 seconds hear this noise and after that ( oil pressure in cold start is around 3 bar depending on ambient temperature ) when car become hot you can hear this knocking only if you accelerate if gas pedal is not pressed does not meter of rpm-s engine is absolutely quiet .
And noise is like form head very short and sharp . Like from not proper adjusted valves .
I can bed for worn wrist pin :icon_razz .

[Poodles]

Wrist pin failure is extremely rare and when it does happen it usually toasts the block (back out and hit the cylinder wall).

MHG's are reusable (remove rivets, remove all viton coating from layers with solvent, spray with sealant on both sides of each layer and assemble on block, search for more info).

2 bar is about 29 PSI, which is high for 2K RPM, but low for 6K RPM... Honestly, it's probably a rod bearing...

[IwantMKIII]

^he will find out eventually...

[IJ.]

http://blogs.fayobserver.com/faytoz/files/2008/08/yoda.jpg

Yaaah pistons out hmmmm

[Poodles]

:rofl:

[CyFi6]

You will hear a "double knock" with a piston pin issue.

[Poodles]

Same thing you hear with a rod bearing ;)

Could be piston slap as well (doubt it)

[Bass_Man]

Yeahhh will see :icon_bigg . Usual rod knock can be checked very easy but with this "good" oil pan construction ( and not only !!! ) I need to remove engine from car (or to put down front suspension) in every case .

[p5150]

Do you think if this noise is from bearing ( and I drive around 1000km ) noise will be on every 2-nd revolution only and will disappear when disconnect spark plug ? And also sometimes when car is cold and when I start engine in first 5-10 seconds hear this noise and after that ( oil pressure in cold start is around 3 bar depending on ambient temperature ) when car become hot you can hear this knocking only if you accelerate if gas pedal is not pressed does not meter of rpm-s engine is absolutely quiet .
And noise is like form head very short and sharp . Like from not proper adjusted valves .
I can bed for worn wrist pin :icon_razz .

Rod knock knock knocking on heaven's door.

Pony up and plan on a rebuild.

[IwantMKIII]

i expect pictures of any carnage....

[Bass_Man]

Rod knock knock knocking on heaven's door.

Pony up and plan on a rebuild.

Engine is after rebuild ( around 5000km ) ! All internals except shafts , pistons and rods(also wrist pins) are brand new original Toyota OEM parts ( also new oil and water pump ! ) . Crank is measured ( from man in grind shop not from me ) and not grind because is OK . Also grind face of block and head, 1,2mm MHG ( some japan brand I just do not remember brand ) , ARP head studs and also new gaskets , O-rings , belts ,rollers and etc . New RPS segmented flywheel and Spec Stage 2+ clutch . Head is with adjusted valves and new o-rings ( or whatever they are called ). Total cost to this point only for parts ~ 5000$ and I can not get 5000km without problems .
For me there is a few main reasons for my problems :
-to much advance ( maybe 15 degrees more total 25 degrees base advance = detonations ) but when I saw was to late ...............
-to low pressure from my brand new Oil pump
-stupid Oil cooler system
-mechanics made from wood

I forgot to mention when I block valve for oil cooler circulation ( But this was after knocking comes .) I get around 1bar more pressure on hot oil. And now I have readings around 3 bar on original instrument after 3500 rpm . Compared to 1,8 - 2,2 with oil cooler and hot oil .

Up to date I look for garage for rent in or near to my hood because I do not have and I do not want to disassemble my car on the street . Also I do not wont already someone ( technician, mechanic , etc.... ) to touch my car. I want to disassemble this engine part by part to see where are burned my money .
Maybe now situation is little more clear ?

[IJ.]

You didn't plastigauge the bearings on assembly?

[Bass_Man]

You didn't plastigauge the bearings on assembly?
No ! I am not mechanic but how I see I will become .
I am not a man who was assemble this engine .
But usual in grind shops people have instruments who can measure shafts without plastigauge . Plastigauge is cheap way to measure PROs need to have instruments .
But this is how need to be what is is different conversation ..............

[IJ.]

I've been using the same shop for 30 years they're experts in cranks and bearings and I still to this day use plastigauge to check clearences before final assembly for my own peace of mind (I have a full set of mics and the skill to use them)

In all the time I've been playing 7M's I've never heard of a bad wrist pin, not saying it doesn't happen just that I haven't come across it.

[IwantMKIII]

^i've never heard of a bad wrist pin period

[IJ.]

It's rare on full floating pins like ours, used to happen a bit in the old days on pressed pin engines.

[Bass_Man]

Fist I need to say that man who measure and man who assembled engine are different people .
And what I think about measuring is usual when people measure crankshaft they mainly do not measure for size . They just check if there is circumference or ellipse and also curve . If there is a ellipse you need to grind to circumference with next size thick bearings . And this is where you need a tool for measuring . Because if you measure on only one place on shaft surface and this is apex of the ellipse you can get good gap readings . In other side with plastigauge very easy you can catch some mistakes like wrong bearing size and etc . ( correct me if I am wrong ) I am not saying you do not need plastigauge but if you have enough tools measuring with plastigauge will be more like safety procedure .
I checked in manual for 7M crank gap need to be between 0.03 mm and 0.05 mm with maximum 0.07 mm . If I do not have ellipse and crank surface is OK there is no way to be worn out with 0.04-0.05mm ( or more ) in good circumference .
And also I think how car was with old bearings worn for 150 000 km and they was completely worn out and at this time was no knocking and other problems with bearings . And now with same crank with no ellipse on crank necks and new bearings is strange for me to have problems with rod knocking .
But everything will go clear when engine will be disassembled .

[92TealSupra]

I like having the same person measure, and assemble my engines. The area for error is increased when you have many people work on the same thing. I am wondering why there would be two people building a motor anyhow.


$0.02

[Bass_Man]

I like having the same person measure, and assemble my engines. The area for error is increased when you have many people work on the same thing. I am wondering why there would be two people building a motor anyhow.


$0.02
Of course you are right !
They are not just two people . Here we do not have one place for all .We have specialized places for different procedures like :
1.grind
2.adjusting and fixing valves, valve guides , valve beds
3.welding
4.assembling
Usual man who assemble engine take care for all this procedures .