Jumping off the Diesel Bandwagon - UPDATED

transamz9 wrote:
I can't believe I'm going to say this out loud but here goes....

The gas engines today in the HD trucks are capable of putting as much torque to the rear wheels while pulling the hills as the diesels are through gearing. The main difference is the RPM's at which they do it.

If one is going to tow a few times a year but mostly use their truck as a DD then the gas motors are more than capable to tow the biggest of RV's. They are just going to have to run in their power range (upper RPM range) to do it. Some people can live with that and there's nothing wrong with it. I believe that it shortens the gas motors life buy doing this towing a lot.

You are not out of line by saying "this". It is quite true and it can actually be carried further in "out of the box" thinking.

It is apparently proven (EcoBoost) that gas can successfully approach the torque of a diesel engine at similar low rpms, if gas has the turbo advantage that the diesel has. We can also be reminded that an unturbo'd diesel is a dog. Power and comparable rpm range are all about boost... and not so much fuel types.

I think the power delivery of both type engines can be very similar if they have similar displacement. The fuel is not the limiting factor, but the amount of oxygen that can be crammed into the cylinder is, which is why displacement-or-boost is everything. There is no substitite for cubic inches, even if they have to be crammed in.

Similar amounts of burned oxygen produce similar amounts of heat expansion, although diesel may do it with less weight of fuel added. In the end, similar heat expansion equates to similar torque and torque range. IMO, it never was the type fuel that determined torque. The type of fuel just means one can carry more miles in a tank by choosing the one with the higher calorific value.

Note that most diesels must have oil squirters bathing the bottom of the pistons to survive the high heat of serious turbo-charging. The reasoning is that pistons can normally only conduct heat pathwise through their contact with the water-cooled cylinder walls, and combustion temperature is occasionally higher than the melting point of aluminum. The relative distant centers of pistons therefore can become very hot, as they have no immediate cool pathway to dump excess accumulated heat. The bottom squirters therefore serve this cooling function by oil-cooling the piston centers. That is their sole job. And, yes, it is an advantage to any engine running at sustained heavy load, blown or not.

What may become relevant in relation to ib516's 6.4L gas truck is this. The Ford 3.5L EcoBoost V-6 has the same squirters (as the Ram 6.4L) which is the main reason why the EB can live in high boost conditions. But since the new 6.4L Ram engine also has these squirters, it means the 6.4 could easily be factory boosted down the road to deliver gas power ratings between the 5.9 and 6.7 diesels. At that time the 6.4 could match the torque of its diesel brethren at a similar rpm range (or perhaps even run at a higher rpm than diesel for still more exorbant HP). And, I picture ib516 could perhaps easily add a mild OEM type turbo topside if he wished. I say mild because the original gas pistons may need more beef for full boost, the weight of which might also unfortunately limit the extra gas rpm I mentioned above. I do realise that ib516 has no present need for more power, but just sayin'.

Note Ford also added squirters to their V-8, 5.0L gas engine, although nothing has been released about Fords intent to turbo it... yet. It is intensely interesting that the various squirter designs are in production though.

Why? When done properly, a turbo'd engine is more fuel efficient than a naturally aspirated counterpart. The new EPA standard is looming.

Wes
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