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Various unrealistic OHV engines balance observations


#21

Execuse me Killrob :grinning:

What are these if they are not performance cars .

I believe that DOHC and OHV belong to totally different school both are very capable very reliable and delivering power on there own way both are powering millions of cars among all world , the bottom line , if I m convened by one kind of technology this isn’t mean that the others are totally wrong every person is correct from his point of view :slight_smile:


#22

No, they’re totally performance cars, but they acheave it via a fair bit more engineering effort, and displacement than would likely be used in an equivalent DOHC engine. And in the case of the Venom, it’s done by large displacement AND lots of boost.

The point is, if you’re designing a clean slate performance engine, and don’t have engine bay constraints, tight cost constraints or a bunch of familiarity already in your company for OHV, then DOHC is likely the best bet. Not that you can’t make OHV engines that make a ton of power.

I can not think of any reason where, if you ignore the other factors that you’d choose OHV to get MORE performance.


#23

Yes, that is my argument here exactly.


#24

I’m a OHV fan, but, to be honest, there a lot of variables from weight, aerodynamics, tires, gearing, suspension, boost amongs others to only say that a car is faster only cause of its valvetrain…

That remained me of one of the worst posts ever in this forum where some guy said a car with delayed timing should be immediatly faster than others just cause an advance timing interferes with the movement of pistons… :confused:


#25

I suggest that we need to ask the second biggest automobile company in the world to stop the most succeed automobile engine in history , because there are people that cant understand why they keep produce it until know :grinning:

Also I believe that we close this topic because it turn faraway from the game discussion :slight_smile:


#26

They make up for it’s shortcomings with lots of capacity, lots of fancy engineering, and having had 70 years of experience engineering high performance OHV engines. Which is exactly what we’re saying will be how it works in the game :stuck_out_tongue:


#27

I got both engines fairly close to spec, I had a little trouble with where the torque peaked and the torque peak.

For the Coyote replica I didn’t need to use any tech sliders, but for the LT86 I had to go +15 across the board ending up with a much more expensive engine.


#28

Yeah, that, in theory, if we’ve balanced it right, should mean that the OHV engine needs to be built by a company that has been building OHV engines for decades and is now really good at it. Or will cost a lot of engineering.

But that depends how well the campaign balance for familiarity works out I guess?

Because OHV is viable way before DOHC is affordable, if you make OHV engines from the beginning of the game, and just never change over to DOHC, you should be able to get a whole load of familiarty with them by the 2000s… hopefully.


#29

I think the OHV does need re-balanced to the point where for the same size of package with the same tech they might be equalish maybe not completely equal but definetly not to where material costs alone are 5 times greater and production units are 8 times greater assuming the engineering time is compensated for by the familiarity.

Note: I did go back through both engines to remove any special lower end parts that would inflate the price before posting this, which was after my previous post.

I agree that for the displacement a DOHC is superior for performance, 2 out of 3 engines I have are DOHC and the third is OHV partly because a DOHC of any decent displacement wouldn’t fit.


#30

If you would have OHV and DOHC similar in performance where’s the point of choosing?..


#31

When physical size isn’t an issue, or when you have a displacement limit.

edit: it might be taking it too far, but right now its too far in favor of DOHC


#32

Considering both DOHC and OHV would be fairly close in terms of power/torque and price/production units, OHV would be still lighter an you could squish more displacement in the engine bay, so why would you chose DOHC in first place if OHV would be clearly superior? That’s what I meant…

Then, there is no way OHV can compete in thee same level as DOHC without extra engeneering (tech pool and engineers experts in OHV and familiarity as will be in the campaign mode). For starters, you need to consider the rods which need to be really srong and lightweight because of mass inercia, then there is the area of the valves, 4 smaller valves cover a larger area than 2 bigger valves, then there is the design of the heads and the airflow (if I remember correctly, by design itself isn’t as optimized as with DOHC design) which again requires extra engineering to overcome.

GM keeps using OHV because it has used them for decades, they have engineers, experience and they have refined them over the years, the same as Subaru with Boxers and porsche with rear engine design :slight_smile: doesn’t make much sense for those companies to drop entirely all their experience…

EDIT: Besides the current LS engines and the ones in modern muscle cars (which aren’t that many anyways) there aren’t that many performance modern OHV engines right? Maybe we’re talking about the exception and no the rule :stuck_out_tongue:


#33

I don’t know if this is something we can fix beyond the fact that it’ll make much more sense in the campaign where familiarty and techpool come into play for companies that have specialized in OHV stuff etc.

And if OHV was the best option for small physical size and good performance, then I’d expect loads of compact cars to use it, but in reality it’s basically only LS engines and a few Dodge V8s using OHV anymore.

They fundamentally ARE the product of companies with loads and loads of experience with that design of engine, who have taken an otherwise not that great fundamental design and put a lot of effort into getting it to perform well.

Even then, the best factory LS engines are making 90nm/ltr and 53kw/ltr vs 111nm/ltr & 75kw/ltr for a 5.2 DOHC Modular V8.

That doesn’t mean the LS is bad, it’s small, lightweight and makes a ton of power, but if you’re looking for performance vs displacement (rather than performance vs weight, physical size or cost) I don’t see any arguments for OHV being anything like as good.


#34

Beyond what you pointed out I know there is the GTA Spano with a turbocharged viper V10 which is OHV and also the Devel Sixteens concept engine was an OHV engine built by an engine builder who specializes in drag racing engines.


#35

I see all people talking about OHV evulotion among the time ignoring the same scenario for DOHC, I believe that we should apply the same engineering tech balance for both engine, It seems that there are people who can not accept the revolution of these OHVengines in the past 25 years


#36

My random 2cents:

I think the devs have done a great job with OHV ingame as far as production/stats/emissions/etc goes, the only grip I have is in rpms.

I think by late 60s early 70s there should be a little more rpm range available to ohv, but without adding additional power (IE: Taking the same calcs and simply stretching them over slightly more rpms).

I know the basis for this is in the American engines, but, even with a +8 on heads (to simulate the great experience American manufacturers had), in that era for similarly sized engines (4.6 to 5.0L), The automation equivalents could barely reach into the 5000 rpms.

Fast-forward to the mid 1980s, and with a 5.0L ohv V8 it still takes +8 or more to get it into 5000 rpms still.

It seems like after the late 50s early 60s, the Automation ohv engines don’t get any more rpms for the rest of the years. That is what bugs me.

This is just my 2 cents though, take it as you will. This topic has been beaten to death in the past, and I’m not going to defend myself in this thread, as we’re all just beating a dead cow. Same arguments as always… Same fights as always…

TL;DR - OHV needs a slight rpm stretch in later years, but we’ve all just beating a dead cow right now.


#37

I can see having tech in the head being offset by the familiarity, but I had to go +15 in the fuel system as well.

http://www.gmperformancemotor.com/parts/19301326.html?gclid=Cj0KCQjwx8fOBRD7ARIsAPVq-NkPuU_cVaZutbTYi_iWPZoXTsFo7vP5R1JZdKHFK_jTk77VL1qE_I8aAm3tEALw_wcB

The 6.2L LS is about $400 more for almost as much power as the 5.0 Coyote from the factory engineering costs, and Ford getting familiar with DOHC is catching up with them.


#38

The difference in head/valve train design of DOHC over the last 25 years has been fairly static, with not much more possible now than was with late 80s tech and we reflect that, in that DOHC engines don’t get a great deal better with time/techpool.

Meanwhile GM has been pushing OHV stuff much harder than was ever possible before, and overcoming a fair bit of it’s performance disadvantage.

Your posts seem to be turning into “I like cars with OHV engines so you should make them better” rather than compared to worrying about good game balance and mostly realistic simulation of what real companies are building.

Other than that, yes, there are a few issues with OHV stuff sometimes not revving quite as hard as it should in some types of engine design. That’s probably not solvable until hopefully we do a complete engine designer revamp one day and have more detailed head/valvetrain options.

For now we’ll be doing the best we can to get things well balanced with the engine designer as it is now. OHV may not be entirely perfect, but it should be close enough to work well and be a valid choice.

I don’t think we have anything more to add on this topic. We’ll do our best.


#39

Dude, what revolution you’re talking about? I gave you solid and easy verifiable reasons on why OHV can’t compete, as well as the devs an again, we’re talking about a few engines that remain existing, builded by experts on the matter, which again, translates to tech pool, familiarity and how the engineers system (would) work in the game.

Literally you’re just saying “there are a couple of powerful OHV engines so all of those should be the same”.

There is no incentive to work on OHV engines from the car manufacturers in real life. When DOHC started to became a common thing in the 80’s there were lots of companies workingon them, which translates to a lot of research and eventually by the 90s they gave us some amazing technologies such as VVL and VVT. Right now, there is no incentive for majors companies to work on OHV (except for American racing, like Nascar and dragsters). It’s like what is happening now with electric cars, there is a huge incentive for companies to come up with amazing electric cars, so there is a lot of research and investigation, lots of money invested.


#40

Dear Sillyworld

The fansy engineered 430 HP LS3 engine will cost you almost 8000$ brand new.

How much you need to pay to get 430 HP DOHC V8 engine.

I believe the cost is the major none accurate issue in the game for know,