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Do cars need valve adjustments?

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i have been on thumpertalk for about 3 years now and 1 topic i have read soooo much about, and annoys me, is the issue of valve adjustments. everyone keeps banging on about it and how often u should check them. we'll some people like to ride but cant adjust valves.

my self for example i dont think i have enough skill or know how to adjust valves.

anyway, what i want to ask is why dont sports cars have to have their valves adjusted so often? im talking about production sports cars.

i dont know how high most bikes spin up to and how high most sports car spin up too but they r close im guessing.

so y is that the case? the only thing i can think of is that it only has one piston doing all the work?

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Most sports cars (and regular cars for that matter) have hydraulic lifters. These pump up with engine oil and effectively remove all valve lash and therefore are inherently self adjusting. If a car has a failing lifter, you will hear a little clatter on startup and once the engine heats up, the lifter will finally pupm up and the clatter will go away. When the clatter never goes away, it needs a new lifter. Google "Hydraulic Valve Lifter"

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In a bike parts are lighter, rev faster especially smaller 250f, valve adjustment will depends on model(brand) also.

If you check Husqvarna they do not need much adjustment other than a initial one after 5 hrs(if needed, mine did not at all like many) and after will start to need some after couples of 100 hrs, a member on this forum and husky cafe forum, Rayray run a 250f Husky with past 700 hrs and 0 major maintenance.

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i have been on thumpertalk for about 3 years now and 1 topic i have read soooo much about, and annoys me, is the issue of valve adjustments. everyone keeps banging on about it and how often u should check them. we'll some people like to ride but cant adjust valves.

my self for example i dont think i have enough skill or know how to adjust valves.

anyway, what i want to ask is why dont sports cars have to have their valves adjusted so often? im talking about production sports cars.

i dont know how high most bikes spin up to and how high most sports car spin up too but they r close im guessing.

so y is that the case? the only thing i can think of is that it only has one piston doing all the work?

Automobiles use so much more technology than bikes, thus, little to no adjustments.

And you should be ashamed of yourself, you don't know how to do valve jobs on a dirt bike at 17? Dang I'm 17 and know how to tear down every part...

Come over to my house, I'll show ya.

"If ya can't fix it, don't ride it." :busted:

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Google valve adjustments for whatever ride you have. You'll find some great info. Before I bought my crf250 I knew nothing of dirt bike motors...the 04 Honda CRF250r will turn you into an expert haha.

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Most sports cars (and regular cars for that matter) have hydraulic lifters. These pump up with engine oil and effectively remove all valve lash and therefore are inherently self adjusting. If a car has a failing lifter, you will hear a little clatter on startup and once the engine heats up, the lifter will finally pupm up and the clatter will go away. When the clatter never goes away, it needs a new lifter. Google "Hydraulic Valve Lifter"

This. Unless you have a solid lifter/cam set up , you have no need to worry about adjusting anything.. As William said, you hear a constant chattering at operating temp coming from the top end of your car , most likely a lifter

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i think the distance will hurt Adem , you in UTAH and Adem in :busted:

come to my house Adem , and bring beer .

:busted: Yeah no beer here! :bonk:

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Most sports cars (and regular cars for that matter) have hydraulic lifters. These pump up with engine oil and effectively remove all valve lash and therefore are inherently self adjusting. If a car has a failing lifter, you will hear a little clatter on startup and once the engine heats up, the lifter will finally pupm up and the clatter will go away. When the clatter never goes away, it needs a new lifter. Google "Hydraulic Valve Lifter"
This. Unless you have a solid lifter/cam set up , you have no need to worry about adjusting anything.. As William said, you hear a constant chattering at operating temp coming from the top end of your car , most likely a lifter

This is your answer.

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Several reasons:

(1) as described above, most car engines use hydraulic lifters, therefore no adjustment required.

(2) your dirtbike engine, especially an MX bike, revs far higher than any production car engine. 250f revs to about 13000rpm, 450f to about 11500. Most sports cars peak out between 7000 and 8000 rpm.

(3) race dirtbike engines are in a far higher state of tune than most production car engines. 450cc making 55hp/42kw = 93kw/litre. Very few turbo production car engines are in that range, let alone naturally aspirated engines...

Porsche 911 Turbo - 96kw/litre

Lambo Gallardo V10 - 82kw/litre

Ferrari 458 - 94kw/litre

Holden 6.2l V8 (Chev LS3) - 52kw/litre

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Several reasons:

(1) as described above, most car engines use hydraulic lifters, therefore no adjustment required.

(2) your dirtbike engine, especially an MX bike, revs far higher than any production car engine. 250f revs to about 13000rpm, 450f to about 11500. Most sports cars peak out between 7000 and 8000 rpm.

(3) race dirtbike engines are in a far higher state of tune than most production car engines. 450cc making 55hp/42kw = 93kw/litre. Very few turbo production car engines are in that range, let alone naturally aspirated engines...

Porsche 911 Turbo - 96kw/litre

Lambo Gallardo V10 - 82kw/litre

Ferrari 458 - 94kw/litre

Holden 6.2l V8 (Chev LS3) - 52kw/litre

To add to this, when you have the equivalent in cars ie; highly tuned street cars you run into the same problems.

Compare a Subaru Imprezza to the highly tuned version, the STI. You'll find that the maintenance intervals on the STI are much shorter.

And I can't say for certain but I'm guessing Gallardos, Murcielagos, Ferraris have shorter maintenance intervals than your average grocery getter.

The only exception to the rule seems to be japanese I-4 sport bike engines. You can run those things on paint thinner and mud and they just don't quit.

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Maint. intervals have nothing to (well almost nothing) to do with lifter type. Is more of a factor of valve/seat material and the environment. Most valves go out of adjustment due to dirt wearing off the hard coating. Dirt is not common for a Pprsche/Ferraria or Lambo. Even a Rally car does not see the same level of gritty dirt a bike does. Add to that the skill level of most owners and you have valves that wear quickly. Regular clearence checks will tell you when this has begun and gives yo a chance to service the valves (meaning replace) before a catastrophic failure occurs.

Hydraulic lifters have zero clearence when running and therefore are quieter. Being the valves rarely wear (beacuse of a very clean environment) they are very suitable. There are slight performance gains when not using hydraulic lifters but for 99.99% of the owners, this gain is mere bragging rights and they'd never notice it.

Most engine life is directly proportional to the abuse it suffers. My 08 Wr250F Yamaha has never been apart. Checked and everything is on the money. I take good care of it.

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There are quite a few cars and trucks out there that do require valve lash to be check and adjusted. Vehicles that do have adjustable rocker arms do require the lash to be checked and adjusted, if needed, usually every 30,000 miles. Those types of vehicles are not high performance machines and don't spin high RPMs either.

Get to know your machine.

Learn how to work on it.

Ask lots of questions and never stop being curious

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Maint. intervals have nothing to (well almost nothing) to do with lifter type. Is more of a factor of valve/seat material and the environment. Most valves go out of adjustment due to dirt wearing off the hard coating. Dirt is not common for a Pprsche/Ferraria or Lambo. Even a Rally car does not see the same level of gritty dirt a bike does. Add to that the skill level of most owners and you have valves that wear quickly. Regular clearence checks will tell you when this has begun and gives yo a chance to service the valves (meaning replace) before a catastrophic failure occurs.

Hydraulic lifters have zero clearence when running and therefore are quieter. Being the valves rarely wear (beacuse of a very clean environment) they are very suitable. There are slight performance gains when not using hydraulic lifters but for 99.99% of the owners, this gain is mere bragging rights and they'd never notice it.

Most engine life is directly proportional to the abuse it suffers. My 08 Wr250F Yamaha has never been apart. Checked and everything is on the money. I take good care of it.

To add to this in a high performance engine such as in a dirt bike your going to need stronger valve springs to avoid "Valve float" which in turn, put's more pressure on the seats and valve faces when closed. Creating more wear and shortening your maintenance intervals.

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Yes automobiles need valve adjusments! Some jap cars still use solid lifters an may need adjusted in the engines life span. Generally not until high mileage. Oddly enough the most common is 2.0L and 2.4L honda engines. I do about 1 a month. Normally around 200K miles though. These are far from performance engines as you originally refered too.

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as stated above, most car engines have hydraulic lifters.

one engine that does not is the old Isuzu 4ze1/4zd1. valve adjustments are required ever 15k although it is not a high performance engine by any stretch of the imagination.

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Lots of cars and light trucks need valve lash adjustment. Even many that come equiped with hydraulic valves.

In fact, many Japanese vehicle adjust valve lash with shims, just like our bikes. I can think of several off the top of my head. Toyota 4(2.4l & 2.7 l) 6(3.0 l & 3.4 l) and 8 (4.7 l) cylinder engines have selective shim valve lash adjustment.

It is obvious that many of the people commenting in this thread are talking out their a$$.

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Cars dont come with Ti valves. Also I have 80 plus hours on my 450 and have yet to check the valves or even pull the valve cover off. It starts first kick so why bother?? I think most people that have valve adjustment problems do not mantain their air filter very well.

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from the top of my head i can think of a few cars that need valve adjustments. the honda D series motor ( prelude, CRV) has adjustable valve lash. bmws from the late 80s also require valve lash adjustment. the 5.9L and the 6.7L Cummins Turbo Diesel engines found in dodge ram trucks also require valve adjustments.

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