Engine Sim Software

[bob58o]

If anybody wants me to throw some numbers at the software I have, I will do that for them.

Here you go KF. This is what the machine spat out.

32mm/28.5mm Head
12.14 CR
220 dur
280 lift
106 ICL
111 LSA

97cfm carb

 

[itsid]

uhm.. that y scale (3,6,9,2,5,8,1,4,7)... I'd need an explanation for that.
yes I assume it's some tenth 3,6,9,12,15.. or 23,26,29,32,35... or whatever
Also:. I assume you list artificials there not metrics (giggle)
so how about at least adding some way of telling what it actually is...

just saying

'sid

PS what is it? performance trends' engine analyzer.. me curious

 

[c-gar]

What numbers do you need for input?

 

[KartFab]

looks like a screenshot, 3 hp to 27 hp and just cropped the left off too far. I was wanting to see what the potential was with a big valve head that they have special castings for that overcome a lot of what the clone engines suffer from with flow. Not available to the public yet, but a select few engine builders have been tinkering with them.

 

[ezcome-ezgo]

Bob, you have excessively cropped.

 

[itsid]

Wow Grant 27 is a mouthfull...
I hope it's no predator case, otherwise you'll need a ton of support structures added
(If I can rely on 4cycles general expertise on high power gx200/animal mods...
animals fail at such power for the msot part and GXs are likely to blow gaskets
IDK what that'd do to a chinese copy cast)

I mean that's quite a punch (especially at such rpms, no?)
And casts being designed for half the rpm and a fourth the power...

What I mean to say: please stay safe!
If this thing comes jumping at you, you'll open the book of pain on page 13

'sid

PS But that's indeed a nice idea..
seeing what a software sim spits out and comparing that to a small engine dyno's result..
such info could come in handy...

OOC: what does the simulator say for bone stock engines (just to get a baseline)?

 

[bob58o]

Yep the y axis was HP and LB-Ft. 3.0 to 27.0. Sorry for the crop.
Yes Performance Trends Engine Analyzer.

I ran that same engine with a 27mm/24mm head. This time I used 35% flow efficiency for both the intake and exhaust. Like I mentioned to Grant, the numbers get pretty big when that input increases.

These numbers look more reasonable.
16HP at 6000 RPM.

 

[bob58o]

And here I ran the 32mm / 28.5mm Head again.
Instead of the 47.8% flow efficiency that the software calculated using actual flow data from that head, I again just used 35%.
21.3 HP at 6750 RPM.

 

[bob58o]

Here is an 8.5 CR, 27/25mm Hemi Head with CL1 camshaft, stock carb, and 18" x .990" ID straight pipe exhaust. I assume the cfm for the stock carb doesn't include the stock airbox. So I guess this would be as close as I can get to stage 1 upgrades with CL1 camshaft.

11.7 HP at 5000 RPM

 

[bob58o]

This engine came preloaded in the software database.
Briggs 5HP Race Engine.

 

[bob58o]

And just for fun. This is another preloaded engine in the database.
Blown Top Alcohol Drag Race Engine.

 

[bob58o]

What numbers do you need for input?

Bore?
Stroke?
Rod Length?
Head Type?
Flat Head, Wedge, or Hemi
Compression Ratio?

Valve Size?
Port Dimensions?
Carb cfm rating?

Exhaust Length and Diameter?

Camshaft Intake lobe duration and lift?
Intake lobe center line?
Exhaust lobe duration and lift?
Lobe separation Angle?
Rocker Arm Ratio?

There's more too, but I should be able to work with that.

 

[bob58o]

Grant, here is the 27mm / 24mm head with 39% flow efficiency.
About as close as I can get to match your real data.

But remember I cannot input ignition timing. It optimizes it at every RPM, so I would expect the peak torque to be higher (and sooner) on the simulation.

real dyno data fresh off the press with no muffler is as follows:

peak torque ~ 14.5 ft/lbs at 5000 rpm
peak hp ~ 17.3 hp at ~7000 rpm

 

[65ShelbyClone]

Does EA provide the optimized spark advance numbers?

 

[c-gar]

Bore?
Stroke?
Rod Length?
Head Type?
Flat Head, Wedge, or Hemi
Compression Ratio?

Valve Size?
Port Dimensions?
Carb cfm rating?

Exhaust Length and Diameter?

Camshaft Intake lobe duration and lift?
Intake lobe center line?
Exhaust lobe duration and lift?
Lobe separation Angle?
Rocker Arm Ratio?

stock, stock, stock, stock, stock, stock, stock, stock,
exhaust = https://www.bmikarts.com/Exhaust-Header-Pipe-for-Super-Stock-Clone-Class_p_37.html with RLV muffler
stock, stock, stock, stock, and stock.
obviously nothing special from the starting Lifan 168F.... but that makes me think a cam and rod will be my next distraction after getting the torque converter (TC) worked out. Am I at the top of the TAV30 capability at stage 1 or 2 mods? Or stated another way, if I increase power any more do I need to go to the next TC?

 

[bob58o]

Does EA provide the optimized spark advance numbers?

If you look near the bottom of the of the chart....

 

[65ShelbyClone]

If you look near the bottom of the of the chart....

Do'h. I'll admit I was readin' the words more than lookin' at pictures.

stock, stock, stock, stock, stock, stock, stock, stock,
exhaust = https://www.bmikarts.com/Exhaust-Header-Pipe-for-Super-Stock-Clone-Class_p_37.html with RLV muffler
stock, stock, stock, stock, and stock.

What is "stock?"

 

[bob58o]

stock, stock, stock, stock, stock, stock, stock, stock,
exhaust = https://www.bmikarts.com/Exhaust-Header-Pipe-for-Super-Stock-Clone-Class_p_37.html with RLV muffler
stock, stock, stock, stock, and stock.
obviously nothing special from the starting Lifan 168F.... but that makes me think a cam and rod will be my next distraction after getting the torque converter (TC) worked out. Am I at the top of the TAV30 capability at stage 1 or 2 mods? Or stated another way, if I increase power any more do I need to go to the next TC?

I run the $50 ebay TC on this Hemi engine, but I use the 7" driven pulley and set the driver unit to engage at 4k RPM.

Cam 250 degrees duration, 0.285" lift, 102 intake center line, 111 LSA
24mm slide carb,
11:1 Compression ratio,
28.5mm intake valve, 25mm exhaust valve

 

[bob58o]

stock, stock, stock, stock, stock, stock, stock, stock,
exhaust = https://www.bmikarts.com/Exhaust-Header-Pipe-for-Super-Stock-Clone-Class_p_37.html with RLV muffler
stock, stock, stock, stock, and stock.
obviously nothing special from the starting Lifan 168F.... but that makes me think a cam and rod will be my next distraction after getting the torque converter (TC) worked out. Am I at the top of the TAV30 capability at stage 1 or 2 mods? Or stated another way, if I increase power any more do I need to go to the next TC?

The closest I can do for a stock engine is going to be the CL1 stage 1 build I showed already. I have cfm data for a stock carb, but probably not with the stock airbox. Plus it is hard for me guestimate the flow efficiency % for the stock exhaust. Plus mufflers are tricky without actual flow data. It gives me an option to add a muffler, but my options are car mufflers. I can change the valve size and show if a 25mm/24mm Gen 1 non-hemi makes much of a difference, but I still have to guess what number to use for the flow efficiency % and that number is pretty significant. A small change of a few percent makes a pretty big difference. The software also has an option to use actual flow bench data to calculate that number for you.

 

[itsid]

Sorry.. am I reading that you loose as much HP to friction @8600 rpms as you generate @3500 rpm or thereabouts ??

so essentially half the engine power is trying to destroy the engine at some higher level modification...
sounds plausible, but isn't exactly something I'd though about that way before tbh.

I'm fairly certain that includes compressive resistance in the cylinder;
but it might also include the compressive/decompressive resistance in intake manifold and exhaust *shrugs*
Would you mind to run the identical engine (well fictive twin engine) with an insane exhaust diameter and carb flow?
just to see what percentage is actually engine internals trying to break and what's neglibile air compression outside of the engine.
So that we might get an idea about durability of such mods?

'sid