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Tuning for Torque?

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DeltaForce

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Post Tue Mar 01, 2016 8:27 pm

Tuning for Torque?

I want to make some heavy duty engines like the large gasoline engines used to power GMC and Ford trucks in the 1950s and 1960s. I can't seem to match the performance of some of the historical engines of the same displacement as my engines, even with undersquare engines (the historical ones were oversquare). Does anyone have any advice for optimizing engines to produce maximum torque? Are basic pushrod engines always the best configuration for low end torque?
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strop

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Post Tue Mar 01, 2016 9:22 pm

Re: Tuning for Torque?

Basic pushrods will produce most of their torque at the low end because they're limited by their high friction and inherent fragility. They're nowhere near as good for specific output as OHC type setups. Their main advantage is that they're compact and light, meaning you can cram bigger displacements in the same engine bay, which will give you more absolute torque.
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07CobaltGirl

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Post Tue Mar 01, 2016 10:48 pm

Re: Tuning for Torque?

Define what you think "maximum torque" means. I have no issues with OHV engines, undersquare, square, or oversquare, producing mountains of torque equal to the engines of the 50s and 60s. These engines are all similar settings. The only adjustments made between variants is compression and timing. Exhaust size is tuned to the horsepower, but are all identical within the family and are all dual exhaust setups. Cams are consistent across all families at a mild 45 and fuel mixtures are comparable ranging from 13.7-13.5. The 1969 engines all use single 4bbl carbs and the 1951 engines all use twin-2bbl carbs. All quality sliders are at zero for all components. The only drastic change is RPM between the 1969 and 1951 engines, as the older years cannot rev anywhere near 4500 without major quality points, but this is also fairly realistic for the years. (I have a couple remakes which simply cannot do what their actual counterparts could do in terms of RPM **cough** 302 **cough**) Are you having difficulty reaching these numbers? They are pretty spot on for OHV V8 engines of the day for torque and also not terribly far off on hp.

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findRED19

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Post Fri Mar 04, 2016 6:49 pm

Re: Tuning for Torque?

I have also attempted certain Ford Small Blocks that cannot come near irl rpms, and on top of that, I also needed lots of q sliders to get anywhere close. This makes the engine unrealistically expensive to produce while still falling short of the real one's specs.
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07CobaltGirl

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Post Fri Mar 04, 2016 7:42 pm

Re: Tuning for Torque?

Which one? Most engines can get pretty close with a lot of tuning. Some engines are just impossible without quality sliders. A few engines are impossible even with gratuitous quality sliders.
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strop

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Post Sat Mar 05, 2016 5:50 pm

Re: Tuning for Torque?

Some of the more advanced pushrod engines do need quite a lot of tech on the valvetrain and/or fuel injection systems to get close to spec.
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GODMANEX

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Post Fri Mar 11, 2016 11:31 am

Re: Tuning for Torque?

:P :P TIR ENGINE Low End
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07CobaltGirl

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Post Fri Mar 11, 2016 5:16 pm

Re: Tuning for Torque?

^^^^Not OHV engine, N/A engine, nor 50s/60s engine. Turbo torque is easy to get. OHC is easy too. This thread was about OHV engines in the earlier years before turbos are available.


strop wrote:Some of the more advanced pushrod engines do need quite a lot of tech on the valvetrain and/or fuel injection systems to get close to spec.


That is why I emphasized none of the engines I was listing used any quality sliders. Still, they have quite good torque/hp numbers for 50s/60s engines.
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GODMANEX

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Post Sat Mar 12, 2016 9:33 am

Re: Tuning for Torque?

Happy ? :D
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Deskjetser

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Post Sat Mar 12, 2016 9:59 am

Re: Tuning for Torque?

GODMANEX wrote:Happy ? :D


Thats still not a pushrod engine :lol:
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07CobaltGirl

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Post Sat Mar 12, 2016 2:08 pm

Re: Tuning for Torque?

Deskjetser wrote:
GODMANEX wrote:Happy ? :D


Thats still not a pushrod engine :lol:


Got you on that one. :P
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findRED19

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Post Tue Mar 15, 2016 4:36 pm

Re: Tuning for Torque?

Here's an example of an engine I was trying to replicate. It's the Ford Big Six truck motor from 1965. It's 300ci inline 6 (inherently easier torque due to factors surrounding the I6 arrangement) But I don't remember how close it was to the real thing.


Image

One tip, a slightly restrictive exhaust (see photo, the exhaust indicator is very slightly yellowed) along with a cam around 20 to 34 should get you a good, early torque peak. And don't be afraid to drop compression so you can mess around with the ignition timing, as this can also change the torque and hp peaks by a lot.

Concerning ignition timing, I've found values around 55 to 64 can throw the torque peak around anywhere from one hundred to a couple hundred rpm.


CobaltGirl: On a related side note I was trying to replicate the Ford Windsor block v8's in the early 60s. Try getting a 289ci small block with a 4" bore to get a peak hp of 270 ish @6000rpm... There might be a way to fake the system, with just modeling the 289, but I was trying to model more of the family as an automation family with a max of 305ci. (the 351 windsor can be considered a new family due to the change in deck height)

(Side note: is there a size code I can put in the img tag to get the image to display at say 70% of it's full width. I don't want to cut down the pics original size, I would rather just display it scaled down.)
American Eagle Automotive (AEA) - ID 1948072
Redhawk Performance Group (RPG) - ID 1955073
The performance division of AEA. (same thread as AEA)

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