Questions tagged [piston]

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2
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0answers
127 views

Bent push rod, valve bent as well?

so i finally got around to opening up the head of my lawn mower and found out why it wasnt running. the intake push rod is bent. and the exhaust is straight. obviously my valves were way out of spec ...
2
votes
2answers
43 views

How to clean up carbon

I was wondering what the best way to clean up carbon off of the Pistons and valves is since I have to change 2 head gaskets I heard abrasive cloths and cleaners aren't so good for the piston heads, ...
0
votes
0answers
68 views

Does this piston look normal?

I noticed a slightly reddish color on my pistons. Is it normal? It's an '08 Mercedes-Benz E350, gasoline (petrol), with 35k miles. Here is a little color correction:
1
vote
3answers
618 views

Is it possible to repair a piston in an engine

Continuing from my previous question (here) one of the pistons have no combustion and so the car is only working with three pistons, and there is a sound like a piece of metal smacking against ...
1
vote
1answer
345 views

How are compression rings lubricated?

My question relates to the lubrication of cylinder walls and piston rings. It is my understanding that pistons in cars consists of 3 rings; two compression rings and the oil/scraper ring. As far as I'...
0
votes
1answer
61 views

Removing Cylinders from engine block

Trying to take apart my bmw n51 motor for fun and not trying to rebuild it becuase it toast. Took evetthing atchatchet to block off and finaly got the cylinder head off. The big end bearing is exposed ...
1
vote
2answers
353 views

Lancer 2004 Piston Slap Concern

So yesterday i figured out my car has a piston slap because it keeps ticking during a cold start and goes away after warming up. Car is a lancer 2004 and has 260k KMs. I changed the engine oil to 20w-...
0
votes
1answer
59 views

Compression test

I have a 2002 Toyota Corolla (1zz-fe engine with 236k miles on it) and did a compression test on a warm engine. My readings are: 150 - 150 - 140 - 175 I've read that the difference should not be ...
3
votes
2answers
462 views

piston damage impact

something got in and caused these scratches. can/will they cause blowby if reused? I figure if the placement of its .018 mil piston ring gaps matter, then the gaps from these scratch just may as well....
2
votes
1answer
353 views

Can the bottom of a piston be scratched and not damage the cylinder?

I went to a mechanic and he showed me this custom piston made out of molten car pistons (there was no other option in this case). My question is: Is the scratch from the side of the piston going to ...
2
votes
0answers
314 views

Modify (cut) piston skirts: does it also cuts its lifespan?

I'm temped, as a challenge to a problem that raised when getting ready to assemble my engine, to modify the pistons skirts since one of the pistons got a crack in the skirt, under the pin side. I see ...
4
votes
1answer
54 views

Pistons ordeal: more pistons problems; two issues in one question

So, still having problems rebuilding this old engine (Skoda Estelle 120, 70's, RWD, rear mounted engine). First of all: getting new parts is out of the question since I have no access to those. So I ...
2
votes
1answer
609 views

Piston deck clearance: is 1.4 mm under deck too much?

I'm installing a piston set in a Skoda Estelle 120 engine. I know this is not a definite way to measure piston to deck clearance, but it jumped to my mind to measure it with a vernier caliper using ...
5
votes
2answers
2k views

Rebuilding an engine: pistons installed, crank rotation “very” stiff

As I'm assembling my engine back (Skoda Estelle 120, 70s, RWD, rear mounted engine) I have the following issue: installed crankshaft, camshaft and distribution chain, torqued as manual recommends, it ...
9
votes
3answers
2k views

3 rings vs 4 rings pistons: which design is better?

The engine I'm rebuilding (Skoda Estelle/120, 70's, RWD, rear mounted engine) was manufactured with two different pistons, depending the fabrication years: one piston kind has 4 rings and a cut from ...
4
votes
1answer
2k views

Rebuilt engine started, but with strong clanking sounds

So this is another question about my Skoda Estelle engine rebuild project. Now it cranked and started, after a session of neither of those. To fix that problem I released the head bolts and retorqued ...
6
votes
1answer
953 views

Do my new oil rings have an excessive gap?

Today I measured the new piston rings I will use while rebuilding my old Skoda Estelle engine. Skoda Set They are new from the Skoda factory (or that's what the box says), but they were ...
5
votes
3answers
158 views

Extracting piston rod's “wire” C clips

So now that I'm getting ready (soon :) ) to fit new pistons in my old Skoda Estelle engine, I found that the piston rods have "wire" C clips. I mean, they look like a piece of wire, no "eyes" or tabs ...
3
votes
2answers
1k views

Rear brake piston hard to turn back in, uneven wear on pads

2010 Toyota Matrix, Manual, Base model 1.8 L Some context It was time to replace the rear brakes (noise, grinding). When I took everything apart, I found that the inner pads were extremely worn, at ...
3
votes
1answer
155 views

Is it really necessary to resurface cylinder and substitute piston?

I believe this is common in motorcycle maintenance, I have heard in some places that, once you get the piston outside the cylinder there is no way back, you need to resurface the cylinder and get a ...
10
votes
2answers
5k views

What's gonna happen if I disconnect 'single piston'

I saw similar topics but that did not explain my things... As we can see 4 stroke engine with 4 pistons Is there any chance (only for test) to 'switch-off' two pistons? For this example I'm talking ...
6
votes
2answers
3k views

Where does the piston stop after the ignition is turned off?

Compression stroke at TDC or Exhaust at TDC or somewhere else? Is this position fixed or does it depend on other conditions?
7
votes
2answers
619 views

Safe to buy new piston for your two wheeler engine

I own a Honda Stunner 125 CC motorcycle. I bought it in 2009. Since last year I have observed that it is emitting white smoke. Mechanic recommends that I purchase new pistons or after some time ...
2
votes
2answers
860 views

Should I remove the rings when cleaning a piston?

I want to clean my piston in a small ultrasonic cleaner (with distilled water). Do I need to remove the piston rings to do so, or can I leave them on and make sure it dries completely? If I replace ...
5
votes
2answers
968 views

Cleaning pistons and cylinders with oven cleaner

Can I use oven cleaner (composition: 5-15% aliphatic compounds, 2-aminoethanol, butane and propane...) to clean the carbon off the cylinders and pistons of my BMW R80GS 1991 Motorbike (without ...
5
votes
2answers
243 views

Pivoted curved-path piston engine

Years ago, I saw a documentary about engine efficiency where people were testing a pivoted, curved-path piston engine. The claim is that the standard piston engine, with straight up-and-down path, ...
2
votes
1answer
4k views

How much force is needed to push a piston down? [closed]

Combustion from fuel and air is used to push a piston down. When they combustion it creates a lot of force, my question is how much force is needed to push the piston all the way down when the vehicle ...
14
votes
4answers
7k views

Do pistons keep moving when the car stops?

When you are driving and stop at a light, do the pistons still move up and down due to combustion? If not how will the engine know when to combust the fuel to keep it moving?
10
votes
1answer
4k views

What exactly is a “knurled piston”?

Recently I came across the term "knurled piston" and I don't know what it means. What is a knurled piston? What is the difference between that and a normal piston? Why should you use a knurled piston ...
11
votes
1answer
3k views

Interference vs non-interference engines

What do people mean when they say that an engine has an interference design? How does it differ from a non-interference engine?
4
votes
1answer
759 views

Why is lugging hard on connecting rods?

I was researching the effects of lugging and came upon this thread, one of whose answers claims that lugging is really hard on the connecting rods. but without explaining why. Can you explain ...
7
votes
3answers
549 views

What is an inverted triangle piston skirt?

The recently launched Suzuki GSXR150 boasts an inverted triangle piston skirt. From what I have been told, it seems to be MotoGP technology which has been stripped down to suit a 150cc bike. Kindly ...
4
votes
2answers
2k views

Motorcycle 125cc question about PISTON condition and battery

Last year I bought a 125cc bike, Modenas brand, most likely unknown to you. It is a moped. http://www.modenas.com.my/v2motorcycle.asp?id=70 It can go as fast as 110 km/h enough for the city, ...