# International Harvester V8 gas engines **URL:** \ **Category:** Factual Questions\ **Created:** [June 18, 2018, 1:53pm UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318 "2018-06-18T13:53:32Z")\ **Posts on this page:** 7\ **Page:** 1
**Author:** ![Enola\_Straight](https://avatars.discourse-cdn.com/v4/letter/e/dec6dc/32.png) [@Enola\_Straight](https://boards.straightdope.com/u/Enola_Straight)\ **Post date:** [June 18, 2018, 1:53pm UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/1 "2018-06-18T13:53:32Z")
I’m talking about the 304, 345, and 392. These motors were stout torque monsters rivaling diesels of the era, durable, dependable…and absolutely thirsty gas guzzlers. Was this because it had a big cam profile? The strange valve layout? (looks like an inverse hemi) [![](https://scoutparts.com/products/photos/18716a_237815.jpg) ](https://scoutparts.com/products/photos/18716a_237815.jpg) Would retrofitting a modern EFI meter fuel more precicely for improved mileage? [![](http://www.binderplanet.com/photopost/Data/699/266EFI15.JPG) ](http://www.binderplanet.com/photopost/Data/699/266EFI15.JPG) ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 18, 2018, 4:00pm UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/2 "2018-06-18T16:00:11Z")
it’s just a canted-valve design, similar to the Ford 351C/M/400 and 429/460. they weren’t “torque monsters” in any real sense; they (like most other low-revving truck engines) just made fairly low hp numbers for the engine’s displacement. > [@](#): > > Was this because it had a big cam profile? quite the opposite; these kinds of engines have “small” cams with lower lift and shorter duration. the lower valve lift contributes to better low-rpm mixing and turbulence, improving throttle response and low-rpm drivability. the trade-off is that they run out of breath by about 4,000 rpm. the reputation for being fuel thirsty likely has a ton to do with the vehicles they were tasked with pushing around. big, heavy, non-aerodynamic trucks. fuel injection would help a bit, but not much if the engine still has to power a vehicle which is harder to push down the road. ---
**Author:** ![Melbourne](https://avatars.discourse-cdn.com/v4/letter/m/b5e925/32.png) [@Melbourne](https://boards.straightdope.com/u/Melbourne)\ **Post date:** [June 18, 2018, 10:15pm UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/3 "2018-06-18T22:15:23Z")
Heavy for the amount of power it generates (which is why they were so tough compared to a modern car engines), and probably linked to a gearbox which requires a large power range. ---
**Author:** ![Weisshund](https://avatars.discourse-cdn.com/v4/letter/w/ba8739/32.png) [@Weisshund](https://boards.straightdope.com/u/Weisshund)\ **Post date:** [June 19, 2018, 2:23am UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/4 "2018-06-19T02:23:38Z")
Torque monster can be made in the gearing instead. An old 35hp Fordson tractor can make enough rear wheel torque to pull a new shiny diesel pickup truck with a lot more engine into nice little pieces. All in the gears ---
**Author:** ![rat\_avatar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/rat_avatar/32/255_2.png) [@rat\_avatar](https://boards.straightdope.com/u/rat_avatar)\ **Post date:** [June 19, 2018, 6:32am UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/5 "2018-06-19T06:32:27Z")
The bore and stroke is larger and longer, the compression is low. Longer strokes= high torque at lower rpms and comparatively low efficiency (in an automobile). Approximate V-392 specs using more “_modern_” net measures: Brake H.P. (Net): 191 @ 3600 RPM Torque (Net): 307 Ft. Lbs. @ 2400 They weren’t “torque monsters” as state above, they were just rated at a higher duty cycle with a longer stroke than other brands at the time. Almost any LS will better HP, torque and longevity than these old motors. We swapped a Detroit Diesel 6V53 into farm truck back in the day, and it was an incredible improvement. But a LS would be far better bet these days. The bummer about the good old days, is that they weren’t. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [June 19, 2018, 1:24pm UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/6 "2018-06-19T13:24:25Z")
> [@rat\_avatar](#): > > We swapped a Detroit Diesel 6V53 into farm truck back in the day, and it was an incredible improvement. . how long did it take for your ears to stop ringing? ---
**Author:** ![aruvqan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/aruvqan/32/2891_2.png) [@aruvqan](https://boards.straightdope.com/u/aruvqan)\ **Post date:** [June 19, 2018, 1:53pm UTC](https://boards.straightdope.com/t/international-harvester-v8-gas-engines/816318/7 "2018-06-19T13:53:59Z")
Hm, 345 in a 79 Scout 2 got 20 mpg, which was pretty common mpg at the time, and a good dependable truck.