The two stroke blower just ‘moves’ the air at atmospheric pressure from outside the engine to inside the bore in a similar way as the descending piston does on a 4 stroke inlet stroke.To aid the scavenging created by the expanded exhaust gases leaving the cylinder which also help drag in the inlet charge behind them.
A supercharger/turbocharger compressor pressurises the charge.
If it was supercharged why would they bother with all the expense and trouble of turbocharging it ?.
Oh wait you didn’t know that turbocharging even existed or would work in this case.
I didn’t ( want to ) qualify as an engineer because I wanted and preferred to be a driver.But in this case a driver who was expected to know the difference between a Naturally Aspirated two stroke Detroit v a Turbocharged one.
I guess the news of the around 10 year production run of Bedford TM and types ranging from 6v71N to 6 and 8v92T never had time to reach Australia.
I haven’t so far even seen any questions as to wether I drove a Detroit powered truck.
From memory I actually drove all of those types listed.
Now awaits you telling me that no one put a 16v71 N in a truck and even Bedford never put a turbocharged Detroit in a TM, because like you they thought it was fitted with a supercharger and didn’t need turbocharging and like Franglais a turbocharger would just make it slower if they did.
Failed indeed.
We never got a TM here, Isuzu products, being far superior, superseded them in the GM stable.
As for the Detroits, 53, 71 and 82 there would have been thousands more here than over there.
Drove as opposed to a short movement. Which one did you have regularly on linehaul or local pick-up and delivery?
Why would I? Unlike you I’m fully prepared to admit, I don’t know everything. No one ever fitted a 16V71 to a truck in this country, although more than a few 12V71s were fitted.
I’d like to see a link to a 16V71 fitted to a road going truck, the steer axle(s) weight would have been interesting.
Don’t assume everyone thinks like you, unlike you, most of us readily admit that we are not the consummate expert on everything.
I’ve already told you I know nothing about TMs.
I’ve also explained to you about the confusion in terminology about blower/supercharger. Are you now going to deny that a Bently Blower was supercharged?
Where have I said I didn’t think Detroit two stroke didn’t need turbocharging? Look back to some of my earliest posts on this forum, where I have refered to Detroit N, T, TA and TTA.
You probably think TTA means twin turbo aftercooled, I’ll let you into a secret, TTA is GM’s version of Cummins Formula or tailored torque. But then again you’ll no doubt say you knew that.
I used to drive a twin turbo 8V92TA from Cairns to Brisbane and return every week, I know it had two turbos because I saw them, it also had a decent turn of speed too.
Interestingly, that truck had a 15speed RTO 15 in it. If only I’d been on this forum then, you could have taught me how to drive it and which gears to split.
Yes indeed, finally we’re on the same page.
Radio silence from the sapient one, he doesn’t like being challenged.
It’s called ‘N’ because it’s 'N’aturally aspirated.
Why don’t you just admit that you got it wrong!
This is not exclusively ‘Detroit parlance’, as Cummins also described its non-turbo 14-litre NTC 250 engine as ‘naturally aspirated’ as opposed to turbo-charged. I suspect this is an American generic term for pre-turbo / non-turbo engines. Just nit-picking, but that’s what we do on here innit!
Our lingo too.
I think the NH 220 was also NA.
1 Like
dozens of comedians out of work and a truck driver has to try to be funny. 
In this case, unlike you, a truck driver who knows the difference between a naturally aspirated two stroke v a forced induction one.
A non turbo charged engine is by definition naturally aspirated, unless it’s supercharged In which case Cummins called it NHS.
A Detroit two stroke blower isn’t forced ( above atmospheric pressure ) induction.
A turbocharged Detroit two stroke is.
Tell us more about the Cummins NHS ?.Like Detroit Cummins knew the difference between forced induction ( above atmospheric pressure ) and naturally aspirated and supercharged v turbocharged.
Maybe you and Frangers can tell us the supposed boost pressure of a Detroit two stroke blower.
Or more more like not because it doesn’t boost the charge above atmospheric pressure it just helps to move it to where it’s required.Like the inlet stroke of a naturally aspirated 4 stroke engine does and the scavenging effect of a two stroke’s exhaust.
Yes, I already know that. I was suggesting that Detroit didn’t own the ‘parlance’ on it.
You tell us, you introduced it into the conversation.
In order to make gases flow there needs to be a pressure difference. Fluids move from areas of high pressure to low pressure. Basic enough.
After the expansion of the fuel/air the burnt gases flow through the exhaust because there is more pressure in the cylinder than in the atmosphere.
If the inlet side of a 2T diesel is not above atmospheric pressure those would flow equally through both the exhaust and through the inlet side.
No matter what it is called the inlet side is above atmospheric pressure. If there was no “blower” IE no form of supercharger a 2T of this type would not function at all.
I accept it is only a small pressure difference, but with no pressure difference it is not gonna work at all.
The supercharger does not need to make a pressure greater than the burnt hot gases in the cylinder, but it does need to be above atmospheric to push the spent gases out of the cylinder into the exhaust (purging the cylinder of exhaust gas) and replenish with fresh air.
Open to correction.
My earlier doubts about turbocharger fitment was because of the need to have as easy a passage as possible for the exhaust gases.
Exactly, if it didn’t/couldn’t move the gasses, it wouldn’t be there. The pressure it contributes to the compression is insignificant, but enough to move the exhaust gas.
Don’t waste your time trying to educate a cabbage who wants to argue semantics and delude himself that he has more knowledge than everyone else, combined.
I’m still waiting, months later, for him to tell me which gears are split in a 15speed RR.
Going off topic, I was going over a training module last weekend which touched on synoptic charts and I was confused to how come winds blow along isobars, not across them.
This video shows the formula to calculate the coriolis effect, but don’t imagine I can understand it, it’s half greek to me.
Curiously expressed as CF =
Going “off track” was achieved a long time ago here!