Pushrod or OHC

[90ft]

If cost is an issue why are then all engines of smaller cars, where costs are much more critical due to the lower margins, being fitted with S-or DOHC engines?

The majority of small cars are NOT in the US. Japan and europe where - what do you know - the price of petrol is double that in the US.
Cars are also insured and taxed based on engine capacity so manufacturers have to get max performance from their 1.6 four bangers.
How do you get max performance out of a small engine. OHC

It is only the US that can afford capacity.
And hopefully that will change.
Not as long as Bush is around granted. But it's about time the US manufacturers were forced by the government to reduce weight and increase the economy of their vehicles.
Becasue they aren't going to do it of their own backs.


The Harley running like shit reference was an example of a company sticking to tradition - which someone else clarified. The patented design and sound of the engine and the way it fires. I can't help it if you like these buckets, that's personal preferance.

[fpv_gtho]

i would go pushrods myself personally. the LS1/2/6/7 only need to rev to 6500rpm to get their max power, as opposed to 7-8000rpm. the LS7 generates 500hp/373kw at 6200rpm and 644nm at 4800rpm, while the M5 V10 needs 8000rpm for the same power level. whats gunna last longer when pushed, i'll put my money on the LS7.
also, pushrod motors can rev hard, ie V8 supercars have 5litre pushrods motors, getting 630+hp at 7500rpm

The V8 Supercars are a good example of a situation where whilst OHV works, DOHC would bring some good advantages. The engines being limited to 7500rpm and at tracks like Bathurst and Sandown, they spend alot of time near that so a DOHC valvetrain will not only last longer, but could provide superior breathing capabilities in a 4valve/DOHC setup to the 2valve/OHV setup. The engines afterall only last about 1000-1200km and whats to say with a well designed DOHC setup they could go 2000km?

[Slicks]

[QUOTE=crisis]

How do Harleys "run like shit"? They "rattle" because of the lobey cams they have, and long stroke for nice torque and a beautiful exhaust not. Its not about tradition, its about what people want, they want that "rattle."
QUOTE]
You may want to rethink that last line.

How so? Muscle cars tradition was big cubes, carburetors, OHV, and solid rear ends. That all has changed because of what people want. Now there running smaller displaced engines (no BBs) fuel injection, some have OHC, and IRS.

[CdocZ]

How so? Muscle cars tradition was big cubes, carburetors, OHV, and solid rear ends. That all has changed because of what people want. Now there running smaller displaced engines (no BBs) fuel injection, some have OHC, and IRS.

viper, and i believe the c6 is like that too (gotta love tradition)

[crisis]

How so? Muscle cars tradition was big cubes, carburetors, OHV, and solid rear ends. That all has changed because of what people want. Now there running smaller displaced engines (no BBs) fuel injection, some have OHC, and IRS.

Nah, you said its not tradition, its what people want. That kind of is the tradition. No one would still make a bike like a Harley unless it was for tradition.

[targa]

Nah, you said its not tradition, its what people want. That kind of is the tradition. No one would still make a bike like a Harley unless it was for tradition.

harleys kick ass no matter how they run(unless its not at all)

[Hunter]

Just wondering which one you prefered, discuss the pros and cons of each.

Old cars were always running on carbs and solid rear wheel drive but now they are changing because of what people want and cars are now mostly front wheel drive which i think is crap.

[jcp123]

Actually the Harleys have such a lopey idel because they use a single-pin crank. Using a dual-pin crank, like the Jap bikes do, would make it as smooth as anything you've ever ridden. But the Harley guys would murder any engineer who dispensed with the single pin crank (V-Rod notwithstanding). That lopey idle IS Harley-Davidson.

Anyway, I'm an OHV guy. For the kind of driving I do, OHV can produce the kind of low-end torque I prefer, with less complexity, less weight, easier maintenance, and lower cost. Case closed.

[Matra et Alpine]

Anyway, I'm an OHV guy...... with less complexity, less weight, easier maintenance, and lower cost. Case closed.

go pull the camshaft out of an in-block cam OHV engine and then do the same on an OHV
The weight issue is unproven when comparing LIKE with LIKE. Agreed when it's OHCs on a V or DOHCs. But single cam it's LESS weight ( no pushrods or followers ( heavy steel ) for slightly more head casting ( alloy ). See the Ford Pinto engine as prime example.
Maintenance - try to replace a cam follower in a OHV engine compared with OHC when all other factors remain the same !!
Sorry jcp, but the issues of complexity and ease of maintenance are MORE down to 1970s V8 engine versus 2000s OHC in many cases. Take an OHV engine and it is as complex as an OHC for the same emissions.

The BIG differnecs is in an OHV engien you dont' get to see the cam drive belts and tensioners and the followers, buckets and rods. Because on an OHC you SEE all those things it's easy to imagine it's more complex

[Slicks]

go pull the camshaft out of an in-block cam OHV engine and then do the same on an OHV
The weight issue is unproven when comparing LIKE with LIKE. Agreed when it's OHCs on a V or DOHCs. But single cam it's LESS weight ( no pushrods or followers ( heavy steel ) for slightly more head casting ( alloy ). See the Ford Pinto engine as prime example.
Maintenance - try to replace a cam follower in a OHV engine compared with OHC when all other factors remain the same !!
Sorry jcp, but the issues of complexity and ease of maintenance are MORE down to 1970s V8 engine versus 2000s OHC in many cases. Take an OHV engine and it is as complex as an OHC for the same emissions.

The BIG differnecs is in an OHV engien you dont' get to see the cam drive belts and tensioners and the followers, buckets and rods. Because on an OHC you SEE all those things it's easy to imagine it's more complex

The weight issure has been proven, OHC(especially DOHC) is heavier than OHV. Think about it, you have 1-3 more cams, the chain to drive those cams, and extra material in the heads to fin those cams. Pushrods(the acutal pushrods, not the engine) and rockers dont weight enough to make a substantial difference in weight when comparing the engines. Thats a good reason why the all aluminum DOHC northstar weighs more than the all aluminum LS1 (and is bigger too).


Remember this picture? Same displcement, about same block size...


Take the V configuration, with OHC you have 2 camshafts intstead of one, that alone is already more complex, then make it DOHC, you have 2 more cams now...
Sure, its not that much more complex but it still is more complex.

[Matra et Alpine]

[QUOTE=Slicks]The weight issure has been proven, OHC(especially DOHC) is heavier than OHV. Think about it, you have 1-3 more cams,[/QQUOTE]
FFS, will you guys get out of your tiny minds and READ WHAT IS WRITTEN.
I had already said if it was caopmring with all other things equal.

****ING RETARDS !!!!!!!!!!

the chain to drive those cams, and extra material in the heads to fin those cams. Pushrods(the acutal pushrods, not the engine) and rockers dont weight enough to make a substantial difference in weight when comparing the engines. Thats a good reason why the all aluminum DOHC northstar weighs more than the all aluminum LS1 (and is bigger too).

And if you'd actually bothered to read what was written it was NOT to comapre singel cam with 4 cams.

So the extra bits. PLEASE go back to where we went through this before. THERE ARE MORE COMPONENTS in OHV drivetrain that are movign up and down - that's the BAD kind of mocement in an engine.

If you think otherwise, then list all the components IN ORDER and their materials for each engien - lets take single OHV and single OHC so we're comparing liek with like as was suggested. Beacuse if it goes the multiple cams route then CLAERLY there's a weight advantage dickhead That's like sayign an I4 is lighter than a V16 because it has less piston - you dont' ****ing say bozzo

Remember this picture? Same displcement, about same block size...

Take the V configuration, with OHC you have 2 camshafts intstead of one, that alone is already more complex, then make it DOHC, you have 2 more cams now...
Sure, its not that much more complex but it still is more complex.

We'd covered the like for like - getting bored with numpties now

So go over how it is more complex with a single cam ?
it's actually less complex with single OHC in a V8 if you jsut go by component count. I think you dont' know very much about OHC engines. Try stripping each down. As said already - and I see it was ****ing ignored by the illiterate AGAIN - you take an in-block cam out of an engine and do the same with an OHC. It's a FRACTION of the work and rebuild necessary on the later. IF you had ever actually worked on an engine you'd know that.

****ING RETARDS ON UCP ARE GETTING ON MY ****ING GOAT AND I WANT TO SLAP THEM.

( sorry, my GWB-moment has passed )

[Slicks]

FFS, will you guys get out of your tiny minds and READ WHAT IS WRITTEN.
I had already said if it was caopmring with all other things equal.

****ING RETARDS !!!!!!!!!!

And if you'd actually bothered to read what was written it was NOT to comapre singel cam with 4 cams.

A little over reacting are we?
Pushrod engines are for V configuration ONLY, so to compare them to an OHC engine, it too must be a V config. And that means it MUST have ATLEAST 2 cams. But of course you want to compare an I engine that has a single cam, to a V engine with a single cam, always twisting things around to make your opinion sound "right."

So the extra bits. PLEASE go back to where we went through this before. THERE ARE MORE COMPONENTS in OHV drivetrain that are movign up and down - that's the BAD kind of mocement in an engine.

Wow, the pushrods and rockers are moving, big deal. Stop trying to go around this, its about weight and size, not moving parts.

If you think otherwise, then list all the components IN ORDER and their materials for each engien - lets take single OHV and single OHC so we're comparing liek with like as was suggested. Beacuse if it goes the multiple cams route then CLAERLY there's a weight advantage dickhead That's like sayign an I4 is lighter than a V16 because it has less piston - you dont' ****ing say bozzo

Again similar design "dickhead" were not going to compare an I engine to a V engine. 2 cams of the same size and material are going to be double the weight of one cam, its simple logic. The OHC design has the chain, gears to drive it, atleast 2 cams(remember same setup here), and a larger head design to fit those cams in. The OHV has pushrods, one cam, and rockers and a single gear to turn the cam.

We'd covered the like for like - getting bored with numpties now

So go over how it is more complex with a single cam ?
it's actually less complex with single OHC in a V8 if you jsut go by component count. I think you dont' know very much about OHC engines. Try stripping each down. As said already - and I see it was ****ing ignored by the illiterate AGAIN - you take an in-block cam out of an engine and do the same with an OHC. It's a FRACTION of the work and rebuild necessary on the later. IF you had ever actually worked on an engine you'd know that.

****ING RETARDS ON UCP ARE GETTING ON MY ****ING GOAT AND I WANT TO SLAP THEM.

Already did the component count, it seems that OHC has more, unless you want to actually do something for once, and do the count.
Strip them down? Sure let me get right on that one, got an OHV and OHC engine that I cna just tear appart? Lets try to stay realistic here.

Working with the cams alone doesnt mean that OHC is "less complex", because of where the cam is located, its easier to get to from inside the hood of a car, big deal. A tire with a rim is less complex than a tire with a hubcap. The tire with the rim has only the rim(and screws), the tire with the hubcap has the hubcap, actual wheel, and means of attaching the hubcap, whether it be bolting on or just poping it on. A hubcap is easier to replace then a tire rim, does that make the hubcap design "less complex" than an actual rim? No, stop trying to defend OHC so blindly, its a good engine design, but it seems you enjoy only listing the benifits, and the downsides to OHV... typical...
BTW, explain to me then, why the LS1 (aluminum block and heads) is lighter, and smaller than the Northstar (al. block and heads). Both have the same materials on the cams, crank, connecting rods, intake, and headers. So why is it that the "better" more "simple" design with the same materials is heavier and bigger?

[johnnynumfiv]

Pushrod engines are for V configuration ONLY

strange, my inline 4 has pushrods.....

[henk4]

strange, my inline 4 has pushrods.....

but that is one of those strange European engines.

[johnnynumfiv]

but that is one of those strange European engines.

What about Slant 6's? what type are those

edit:
looks like a push rod,