How to Stop valve float

[Nexxus]

This is an issue I run into constantly with no indication on how to troubleshoot it anyone have any ideas how I can try and deal with this issue?

[Killrob]

A few are:
More valves per cylinder, higher cam profile (stiffens springs), higher tope end quality.
A certain amount of valvefloat is not too bad, check if there are big chunks of reliability coming back when lowering the rev limiter, once you get to like 0.3 or less per 100 RPM you're all good.

[Nexxus]

Originally posted by Killrob:

A few are:
More valves per cylinder, higher cam profile (stiffens springs), higher tope end quality.
A certain amount of valvefloat is not too bad, check if there are big chunks of reliability coming back when lowering the rev limiter, once you get to like 0.3 or less per 100 RPM you're all good.

I see there is actually a few things in tool tips now giving you an idea how to fix it, none the less thanks

soemthing else im trying to do and struggling is getting some high rpm cars...im trying to make a 2L 4age like engine, but my peak power hand is very low like...6000ish, is there anyway to force that peak power at a higher RPM? I have tried to reliable do this since I 1st got the game and cant figure out how.

I wanna say I THINK that it has to do with bore vs stroke but I cant find any relation :(

[Daffyflyer]

Higher cam profile is the single thing that will make the most difference to top end power, although you need to make sure the fuel system/exhaust isn't holding it back too. You can use the multicoloured flow diagram thing on the testing screen to work out what is holding you back.


Short stroke is important for stopping the bottom end exploding, and large bore allows for more valve area and thus better flow and more power. You'll want the shortest stroke and largest bore possible if you want lots of revs.

[Yushio]

Do I have to go to University to understand any of what you said at some sort of level of depth...?

Originally posted by Daffyflyer:

Higher cam profile is the single thing that will make the most difference to top end power, although you need to make sure the fuel system/exhaust isn't holding it back too. You can use the multicoloured flow diagram thing on the testing screen to work out what is holding you back.


Short stroke is important for stopping the bottom end exploding, and large bore allows for more valve area and thus better flow and more power. You'll want the shortest stroke and largest bore possible if you want lots of revs.

[CPT. Doc]

Going with a wider bore gives you bigger valves, bigger valves weigh more and as a result is more prone to valve float.

Would be cool if you could go into more detail about cam specs....

Was trying to build a NASCAR engine not possible in this game.

[Daffyflyer]

Originally posted by CPT. Doc:

Going with a wider bore gives you bigger valves, bigger valves weigh more and as a result is more prone to valve float.

Ahh good point that. Usually a good plan is lots of cylinders, lots of valves, relatively large bore compared to the stroke, and very very short stroke. In other words the same way F1 engines are designed.

[Nexxus]

Originally posted by CesarTheDude:

Do I have to go to University to understand any of what you said at some sort of level of depth...?

Its not hard to understand at all frankly.

[Nexxus]

Originally posted by Daffyflyer:

Higher cam profile is the single thing that will make the most difference to top end power, although you need to make sure the fuel system/exhaust isn't holding it back too. You can use the multicoloured flow diagram thing on the testing screen to work out what is holding you back.


Short stroke is important for stopping the bottom end exploding, and large bore allows for more valve area and thus better flow and more power. You'll want the shortest stroke and largest bore possible if you want lots of revs.

Okay so before I spend a ton of time trying it, is making something like an f20c doable on here?
aka a not extremey expencive car/engine that will be able to dependably push itself to near enough 9 grand?

[Red_Arrow]

Should be, I don't make replicas but I have done a few free revving VVT-VVL engines without too much going bang!

[Nexxus]

Originally posted by Red_Arrow:

Should be, I don't make replicas but I have done a few free revving VVT-VVL engines without too much going bang!

I was toying with one and got it to about 9200, but the peak power was at like 86 so eh lol...

[aardvark]

Originally posted by Nexxus:

Okay so before I spend a ton of time trying it, is making something like an f20c doable on here?
aka a not extremey expencive car/engine that will be able to dependably push itself to near enough 9 grand?

Here is one I quickly threw together, same bore and stroke and compression as the original JDM spec F20C.
Of course it makes a fair bit more power than the real one, but then again the real one didn't require titanium parts I imagine. :P
But the real one would have had considerable engineering put into it and is a farcry from a budget vehicle.

In game it would have been much easier to accomplish with a shorter stroke and could be done using low end internals with light weight forged cylinders. Still kept the cost down pretty well despite it though.

http://steamcommunity.com/sharedfiles/filedetails/?id=529016296

http://steamcommunity.com/sharedfiles/filedetails/?id=529016378

[CPT. Doc]

Originally posted by Daffyflyer:

Originally posted by CPT. Doc:

Going with a wider bore gives you bigger valves, bigger valves weigh more and as a result is more prone to valve float.

Ahh good point that. Usually a good plan is lots of cylinders, lots of valves, relatively large bore compared to the stroke, and very very short stroke. In other words the same way F1 engines are designed.

If you used the bore and stroke of a 90s Formula one V-10 engine you will get valve float and the game doesn't allow you to rev to 17,000-18,000rpms. So this isn't going to be possible......

In practical applications what is done in the real world depends on what your goal is, if you are making a race engine that is only going to be used in the 5,000-10,000rpm range then you can sacrifice bottom end. They will go with stiffer valve springs in order to reduce valve float, also they will go with lighter valves (you can accomplish this by going with more smaller valves however a lighter material or design is generally done). You can always go with stiffer valve springs however if you need any type of durability this may come at the cost of excessive cam wear (not good if you want the engine to last at least 150,000 miles).

More smaller valves will give you lighter valves while maintaining or increasing flow rates, however just looking at Formula one engines is going to be highly flawed (lots of things done there that isn't done on street motors).

A higher cylinder count will give you more displacement at a given bore/stroke (would like to be able to make some V-10s and V-12 engines). If you are trying to make a 4.0+ liter 10,000rpm engine there are a multitude of ways to go about producing it and not just one (or you can make a rotary engine). I like to try and recreate engines in real life in the game, love early 240/280Zs and have fun remaking those engines then trying to upgrade it to make a ton of power.

[[CAMSO] Caswal]

The other thing to bare in mind is the Technology year vs Quality. You can think of the quality slider as being akin to this engine's Top End is +5 Years ahead of the average Engine technology of the time. The F20C was quite advanced for the time.

[Durolith]

been able to produce 273hp @ 8600 with 149tq @ 7500 with tje F20C core stroke