Questions tagged [valve]
Refers to engine intake or exhaust valves.
142
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Can I use hard tools to remove hardened carbon buildup on valves?
I used a brass brush by hand to clean the carbon off the aluminium head of my BMW R80GS 1991. The valves however are very stubborn, a brass dremel head won't do it either. I started using a soft steel ...
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Stuck valve, loss of pressure. Risky or only poor performance?
I have a 1998 Toyota Tacoma 2.7L 4cyl with 202,000. The engine has been running rough and will occasionally sputter and die when I let off the gas pedal. I had it diagnosed and they think it's a ...
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"Valve like" noise after modifying camshaft ninja 300
A friend and I bought a modified camshaft for his ninja 300/EX 300.
After installing and checking/adjusting valve clearance everything seemed ok.
After a few laps on our local track the bike started ...
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What are the characteristics and uses for desmodromic valves?
In an answer to another questions @Ceshion introduced a fascinating kind of valve train that I have never heard of, desmodromic valves, as introduced by Ducatti.
That answer is here:
What are the ...
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What are the various kinds of tappets / lifters and the advantages / disadvantages of each
A previous question about tappets found here:
What are Tappets?
covers the basics of tappets. If we go the next step, here are my questions:
What are the various kinds of tappets / lifters?
What ...
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Pneumatic Valve Spring Operation in Formula 1
In the 2006 Formula 1 World Championship the rules allowed for pneumatic valvesprings.
These engines were required to have a 90° V8 engine with 2.4 liters of displacement, 4-valve-per cylinder layout ...
- 33k
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Roller rockers to a stock valve train
78 Nova but the engine is from a different car; casting # V0707CMH. I have a 350 with 305 heads. Stock valves, pushrods, cam, and lifters. The nuts on my stock rocker arms are in need of replacement; ...
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Do straight/short pipes burn out valves?
I have heard that straight/short/custom pipes can burn out valves on an engine. However, with a 4-cylinder Ford Model A engine, I have been told this is not the case because it has such low ...
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Camshaft problem not sure what needs replacing
I'm Looking for a part name and info on what could have caused the problem.
So I have an 03 peugoet 206 1.4 HDI and I lost a cylinder after going though them by disconnecting each injector and can ...
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Formula 1 valve trains
There was a statement in a post regarding Formula 1 valve trains being pneumatic or magnetic. Are there valve trains driven magnetically or pneumatically that are on the market? When did they start ...
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What is valve float and how does it impact engines?
The Wikipedia entry is hard to grok:
Valve float is an adverse condition which can occur at high engine speeds when the poppet valves in an internal combustion engine valvetrain do not properly ...
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Why did Ducati decide to use the desmodromic valve train rather than a more tradition valve train?
Ducati's use a unique method to open and close their valves. It's called the desmodromic valve train.
The desmodromic valve system does not use springs to close the valve, it uses the cam and has a ...
- 33k
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Valve Adjustment - 1975 Harley Davidson Ironhead
On Harley Davidson Ironhead motor (1975 XLCH), how do I adjust the valves?
I seem to remember a mechanism in the bottom end but....I can't recall.
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Hyundai Santa Fe - Engine Oil Pressure Valve
Does anyone know where a 2007 Hyundai Santa Fe CRDI Engine Oil Pressure Valve is?
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74 Corvette with slight pop in exhaust
I've got a (new to me) 1974 Corvette with the 5.7 / GM 350 . Dual exhaust.
Driver's side exhaust sounds perfect. Passenger's side exhaust has a subtle pop/rattle to it and does not pass the "dollar ...
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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?
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1994 Honda Accord EX (F22B1) - Valves still making a ticking noise
I have a 94 Honda accord Ex (F22B1). When I bought it a few days ago the previous owner mentioned a few of the issues that he could remember. Since I've only ever owned Honda's and have worked on them ...
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Lapping Valves - Using Water as Test Medium
I've lapped my valves and want to check if they are sealing properly. Everywhere that I've read talks about using stuff like, acetone, gasoline, paint thinner... to fill the exhaust/intake ports and ...
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SAAB 9-5 wagon throws P1549 Code (Boost control valve)
I called an ASE-certified mechanic. He charged some $60 for the visit and $60 diagnosis and really he didn't quite spot on anything. Left me where I was - work-wise , diagnosis-wise and knowledge-...
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Can a valve suddenly break in half? Versys 650 destroyed engine
This week-end, I had to disassemble an engine from a Kawasaki versys 650 (early). The bike lost power while making ugly metal sounds. It never started again. RIP.
Context: 108.000km, mostly highway ...
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Can you change HP by adjusting valves?
This may be a crazy question but can you increase your HP if you adjust your valves (by changing your lifters or whatever other mechanism is used for shimming) to decrease the gap between the riding ...
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Symptoms of valve adjustment necessity
I have recently had to rearrange my valve lifters in order to tune to an optimal clearance between cams and lifters, which on my Tacoma is 0.15-0.25 mm for the intake and 0.29-0.39 mm for the exhaust ...
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When should I perform a valve head adjustment?
My 2012 Yamaha R6 has about 12000 miles on it. During that times I've had a couple rough accidents and I think the combination of those two factors it may be a good idea to check my valve clearance ...
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Do valve cover gaskets need to be replaced every time you reopen the valve cover?
About two weeks ago, I replaced my cork/rubber valve cover gaskets on my 84 2.8L V6 Ranger since the old ones were leaking pretty badly. I forgot to adjust the valves when I did the gaskets, and now I'...
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Gauging valve lashes with shuffled set of lifters
When I took my cylinder heads apart, I wasn't aware of the need to keep track of the order of valve lifters so I didn't. I did, however, separate the left from right side of the engine (V6 Tacoma). ...
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Do valves rotate over time?
As I was doing my valve servicing, one question came to mind: As valves undergo millions of cycles of reciprocating motion, do they actually rotate or is their position relative to the seal fixed? Or ...
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Burn marks near SOME exhaust valves inside heads
As you can see in the picture, there are burn marks around SOME of my exhaust valve tops and not others (2 out of the 3 cylinders in the picture):
What could be the reason for them? Could it be ...
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Why is this motorcycle burning oil, and how can I get it to stop?
I have a newbie question for you.
I'm considering buying a 2004 Yamaha TTR600RE- a single-cylinder, air-cooled dirt-focused dual-sport bike. It's perfectly set up for adventure touring, which is what ...
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Residue lapping compound in valve shafts
I have read that valve lapping compound, as it is abrasive, should by no means get into valve guides as it will impede the reciprocal motion or damage the valve. Should I worry about small amount ...
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Are valve guides normally reusable?
A valve assembly diagram from my Tacoma FSM designates valve guides as non-reusable.
I was wondering if that is just a CYA or really the case.
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Effects of leaky exhaust valves
While rebuilding my valves, I noticed that 4 out of 6 exhaust valves on one side of the V6 engine were leaking after lapping and I had to relap them. I determined that by doing a water test. I am ...
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Reliability of water test for valve seal
I took my valves out, cleaned and lapped them and put them back together. I also put new valve stem seals. At least on one side of my V6 Tacoma.
I performed several water tests to check the seal of ...
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Valve reassembly
After cleaning my valves and the ports, I am about ready to put them back in together. I have two simple questions:
Should I clean the inside of valve guides with a pipe cleaner, that looks like a ...
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1
answer
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Valve lapping and lubrication
I have recently taken all my valves out and cleaned them with a wire brush as well as the shafts in the cylinder heads. I am now getting ready to put them back in and have several questions:
What ...
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2
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Lapping valves with a drill
I think lapping valves using one of those suction cup sticks is hard and there must be better ways.
So here is what I was thinking. I was thinking to get a really thin (medical or engine) hose that ...
- 6,633
2
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1
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What does valve lapping compound actually do?
As I understand, valve lapping is done to ensure a seal between the valve and its seal ring at the end of the shaft. I am just curious how valve lapping compound facilitates that? Does it make a ...
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Should I care about valve order or are they interchangeable?
So I've just learned how to take valves down and I'm pretty fascinated by the whole mechanism. I got a C-clamp compressor and took two valves out just to try. Went smooth.
A question: is it important ...
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Why are intake valves dirtier than exhaust?
I took my engine apart and one of the things I noticed, on both cylinder heads of my Tacoma V6, is that the intake valves (picture right) are significantly darker (or dirtier) than the exhaust ones (...
- 6,633
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Should I lap my valves if I have easy access?
Now that I have my cylinder heads out of my V6 Tacoma, I am considering taking the valves out to inspect them in case they are bent or whatever and grind them. There is no symptoms of valves ...
- 6,633
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What exactly is a "burnt valve" and what causes it?
I've come across this term a couple of times in the context of diagnosing engine-related issues, but don't know what it refers to. Here is an example from an automotive forum I frequent:
I gotta ...
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What are the causes of fluctuating intake manifold vacuum
I have a 2005 Honda CBR600 F4i which suffers from occasional hesitation at low rpm when accelerating. I also get occasional fault codes from the ECU indicating a vacuum leak.
Today I connected a ...
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XJ600 1994 Seca 2
I am wondering if anyone can shed light on an issue we are having with this particular bike. Basically, the bike starts fine cold and warms up and drives perfectly for about 15 minutes ( responsive to ...
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