2013 1.5 L Entry Level Engine

Heya there guys,

I’m a newbie and this is my first engine post here. I created a 1.5 L engine with balanced fuel consumption, production cost, power, and reliability in mind. This engine is going to be fitted to entry level compact sedan or a hatchback (passenger car). Fuel octane limit is 91 because the market is developing countries with limited access to high octane fuel and preference to cheap fuel.

Do you think the MBTF, Economy, and Man Hours needed are fine?

Constructive comments are highly appreciated :smiley:


Not bad :slight_smile:

Economy is good, MTBF is good, cost is good.
Peak torque is probably a little too high up in the RPM range, but man-hours is definitely much too high.

[quote=“machalel”]Not bad :slight_smile:

Economy is good, MTBF is good, cost is good.
Peak torque is probably a little too high up in the RPM range, but man-hours is definitely much too high.[/quote]

Thanks for the comment! I noticed that man hours needed is too high, I’ve been increasing quality on fuel system, reducing it affects the fuel consumption too high :frowning: Any tips on reducing man-hours?

Also I can’t figure out how to produce torque at lower RPM range without affecting total power and torque too drastic.

If you want to decrease man hours you have a few options…

First of all you could possibly change your head and block material to cast iron (sacrificing emissions and weight)
You could change your head and valves to a “Overhead cam” or SOHC configuration
And finally… feel free to play around with the quality slider!

Hope this helpz :smiley:

the only thing that i don’t like is the power curve, this one looks like a diesel one

[quote=“09webbad”]If you want to decrease man hours you have a few options…

First of all you could possibly change your head and block material to cast iron (sacrificing emissions and weight)
You could change your head and valves to a “Overhead cam” or SOHC configuration
And finally… feel free to play around with the quality slider!

Hope this helpz :smiley:[/quote]

Thanks! I changed materials to cast iron and using SOHC. Now I get 45.2 man-hours. Is it still too high?


Is it because of the torque curve? My intention is to make an engine with long stroke and high torque because it creates high illusion of power which is preferred at the target market.

Your man-hours looks decent to me… anything bellow 43 or 42 man-hours are good :smiley:

I’d probably go with a cast (not log) manifold to get somewhat better eco (resonance at lower RPM than tubular) and to lower the VVL bump a bit in comparison… that will save you some more manhours too!

This looks like a rev-happy engine, all the way to 6300 rpm.
And then the fun suddenly stops because of the revlimiter.
In reality it’s not a good idea to regulate the max. power using the limiter.
Otherwise it looks fine.


Second revision of the engine. It uses different cam profile and short cast header and some other fine tunings hence reduced man-hours, produces higher horsepower (similar to the initial DOHC design) and able to attain its peak torque 1000 RPM lower than the initial and first revision. RPM limiter is increased slightly to 6500 as going any higher won’t produce more horsepower and only will reduce MBTF.

However MBTF and economy is slightly worse.

Feel free to comment :slight_smile:

Looking good! Does a 3-valve setup limit the breathing too much? Have you considered it?


Thanks! I didn’t get good result with 3 valve setup. The reduction of torque, horsepower, and economy isn’t worth the cost reduction IMO.

Yeah, I’d agree on that, the SOHC-4 variant seems the best so far :slight_smile:

I couldn’t agree more. Generally I prefer using more valves if the man-hour, cost, and engine size restriction isn’t too strict.

Now I wonder if there’s a way to get the same horsepower at lower RPM.

A Challenger appears! (If I may)


95% of the power, 93% of the torq, 10% less weight, 10% less cost and less then half! the build time. Shame about the econ though, I can never figure that one out :confused:

Edit to add, I can switch to SOHC-4 and still come in a bit lower in weight and cost for i think 107hp and 139 nm torq, but econ is still only 18.5% :confused: are you running VVL/VVT? messing with quality sliders?

[quote=“mtm84”]A Challenger appears! (If I may)

starter engine.jpg

95% of the power, 93% of the torq, 10% less weight, 10% less cost and less then half! the build time. Shame about the econ though, I can never figure that one out :confused:

Edit to add, I can switch to SOHC-4 and still come in a bit lower in weight and cost for i think 107hp and 139 nm torq, but econ is still only 18.5% :confused: are you running VVL/VVT? messing with quality sliders?[/quote]

Hint: The economy comes with a price and more man hours :smiley:

I think I managed to make mine slightly better


Less man-hours, less noise, more economy, more power, more peak torque and at a lower RPM. However it came with little cost of emission, smoothness, MBTF, and extra $3 to material cost.

So, here is my challenger.
Not the most powerful of the pack, not the lightest of the pack, not the most reliable of the pack, not the most economical of the pack, not even the cheapest of the pack, but definitely the most balanced one.
I do not think the economy increase related to VVL it worth the costs, ivan.
1.5l 16 Zawor. SOHCRev0.lua (42.2 KB)

[quote=“Kubboz”]So, here is my challenger.
Not the most powerful of the pack, not the lightest of the pack, not the most reliable of the pack, not the most economical of the pack, not even the cheapest of the pack, but definitely the most balanced one.
I do not think the economy increase related to VVL it worth the costs, ivan.[/quote]

Interesting. Here’s my take without VVL.


The problem is I don’t really know how economy measurement in engine designer (g/kwh) compares to actual mileage (liter/100 km) thus making me blind on cost vs economy.

What do the economy percentage means anyway?

Economy percentage is the engine’s efficiency, and is not easily convertable into l/100km without informations about the car. In other words, you’d need to put the engine into car to know that.

Yes I am aware of that. But anyway, how much efficiency is considered as good? Chasing numbers without knowing about it is pretty useless :blush: