Bosch In-Line vs VE-rotary

[asavage]

(Overview of Bosch Inline and a Bosch VE)

OK. As a first pass and departure point for debate, if you want to avoid the pneumatic governor's issues with regard to adding a turbo:

• Use the SD23/25 VE IP that was used in some (apparently non-US) road-going applications;
• Ditch the pneumatic governor's throttle body altogether;
• Bolt on your turbo and plumb it

In basic form, and according to the results that Galen got, you should notice a sizeable increase in performance, without regard to fuel increase during boost ("boost compensation").

After that batch of mods is proven out, then look for the boost compensation bits from, say, a Gen1 VW turbodiesel IP and convince an IP shop to glue the top half of that style IP to the bottom half of yours.

You can't use the raw VW IP, because (for one thing) it's calibrated for a higher-revving OHC diesel and you'd quickly ventilate the SD's block. Governors are good.

[TooManyIdeas]

Ok so I don't NEED the ve pump right away?
How does one go about ditching the TB?
Can the ve pump gov's be "tuned" or is that another can o worms?

[philip]

Ok so I don't NEED the ve pump right away?

Remember where the most air restriction is .... the valves.

How does one go about ditching the TB?

You don't ... with the stock Bosch inline. But with one exception... when you plumb a turbo between a TB and the intake manifold. Follow the throttle cable to the TB.

Can the ve pump gov's be "tuned" or is that another can o worms?

Go to a diesel shop and look at the sophisticated machine required to "tune" an injection pump.

[Knucklehead]

Ok so I don't NEED the ve pump right away?

Notwithstanding what has been said in other posts about there being no restriction at WOT, I would like to clarify that the pressure differential measurements I made WERE at WOT, but at low RPM. As the RPM climbed the differential diminished. The differential suggests a potential improvement in performance without the TB. That is as much as I can truly say until I can give some more numbers. Whether or not you should put a VE pump on a naturally aspirated SD22 is a guess only educated by the fact that Nissan went that route.

If you are planning to turbocharge, as you have said, I think you should do one step at a time. Either change the IP first or turbo first, but not both at the same time.

You don't [ditch the TB]... with the stock Bosch inline.

That is not entirely accurate. From what I can tell, all the pumps are practically identical. Even the cam is symmetrical front to back so that it can be reversed should the application call for a different direction of rotation (the lobe profile is not symmetrical). The big difference, and the point of concern for us, is the governor, which is a separate thing. It appears only on the road vehicles is the pneumatic governor used (correction?). So if when Phil says "stock Bosch inline" the governor is included, then he's right. You don't ditch the TB. Although when my "exception" is cited, the TB is only moved, not ditched, and the problem is not really solved.

The manual governor I have been dissecting is labeled for 650~1100 RPM. Despite the fact that the guy at the pump shop told me he thought it could be done (he had never done, nor seen it done before), and despite the similarities with the RLD-K type from the SD33T, the dissimilarities suggest to me that it will still take a bit of experimenting and modification to make a forklift or marine governor give the nice RPM range that we want. I would like to be wrong, but it looks like the only bolt ons will be the VE type or the RLD-K governor, which won't know whether it's hooked to a six or a four.

[philip]

You don't [ditch the TB]... with the stock Bosch inline.

That is not entirely accurate. From what I can tell, all the pumps are practically identical.

I have never seen a VE using a Throttle Body. Are you pulling me tonight?

It appears only on the road vehicles is the pneumatic governor used (correction?).

WE have seen forklifts with SD22 / Bosch IP.

Even the cam is symmetrical front to back so that it can be reversed should the application call for a different direction of rotation (the lobe profile is not symmetrical).

Which "cam" are you referring?

-snip- I would like to be wrong, but it looks like the only bolt ons will be the VE type or the RLD-K governor, which won't know whether it's hooked to a six or a four.

You lost me. The early notion was an idea but now .... $,$$$.

[TooManyIdeas]

If I understand Knucklehead right he's refering to the cam plate inside the injection pump. Each hump operate injector firing (IE 4 excentrics - 4 cylinder 6 for 6 ect.)

The more I look at the VW IP's the more I'm liking the idea of using them for the retrofit. Reason being, people are making performance parts to upgrade them. I like this because
A: Aftermarket makes put put Vroom Vroom
B: There's alot of sick and twisted individuals who are intimate with the internals of these pumps. So there is a larger pool of knowlege about how to keep these things putting out. So the mystery of at least the VW IP is replaced with a nicely put loose whore metaphor

eBay: VW Diesel Injector Injection Pump Camplate Upgrade

[asavage]

You will have the capability to flow more fuel with the new camplate.

OK. When would you need this? The stock IP is capable of overfuelling.

You should be generating more pressure with the new camplate as well.

Oh, Gawd, the misinformation that can be spread faster and farther now that we have the internet!

Q: What is the major determining factor for fuel injection pressure?
A: The spring preload in the injector.

Sure, if you push a high enough volume through a fixed orifice, the pressure will rise, but what do you think that would do to your spray "pattern"?

More is not always better. And if you doubt that higher injection pressure requires significantly more HP to achieve, think again. There is a trade-off, several actually.

[Knucklehead]

If I understand Knucklehead right he's refering to the cam plate inside the injection pump.

Sort of.


Phil, I was just saying that the "stock Bosch inline" is a distinctly separate thing from the governor. They are all the same.


The governors on the other hand are quite varied and application specific. Just a few:

WE have seen forklifts with SD22 / Bosch IP.

Yes, but have we seen forklifts with pneumatic governors? I think that governor is specific to road vehicles.

[philip]

WE have seen forklifts with SD22 / Bosch IP.

Yes, but have we seen forklifts with pneumatic governors? I think that governor is specific to road vehicles.

I need be pedantic just for you?

All diesels have a "governor." Our 720's with Bosch in-line IP have two governors.

Revise: WE have seen forklifts driven by SD22 / Bosch RBD-MZ. (incidentally, I recall reading about a forklift having SD22 with pneumatic starter and LPG! Interesting.).



The MZ is the pneumatic governor and the RBD is the the flywheel governor. Our trucks have both governors together.

The MZ alone is also used (according to the manual) but ... I have not seen one on some vehicle.

[exsimguy1]

Oh, Gawd, the misinformation that can be spread faster and farther now that we have the internet!

Q: What is the major determining factor for fuel injection pressure?
A: The spring preload in the injector.

"Pop" pressure is merely the pressure set at the injectors to correctly deal with the pressure developed from the IP pump. "Pop" pressure from an inline IP to a rotary (such as VE) are different for that reason.

[asavage]

"Pop" pressure is merely the pressure set at the injectors to correctly deal with the pressure developed from the IP pump.

So, If I remove the spring from an injector altogether, the pressure in the injector line is unaffected?

[exsimguy1]

C'mon Al,
I was merely stating you cannot set "pop" pressure higher than the ability of the IP. So it is not set merely by the preload at the injector. Also if the delivery valve seat leaks, you may not "Pop" at all, or at the right time.
Terry

[asavage]

Sure, if the IP isn't capable of moving volume, the pressure won't come up. I said that the Seller's claim about pressure rise due to more volume will push pressure up is bunk. You appeared to rebut my statement (by quoting me) by mentioning, "Pop pressure is merely . . . ". Does this clarify what I'm saying?

[asavage]

Also, IIRC there are different diameter plungers for the distributor head, which affect injection volume far more than the cam lift.

The whole premise that Seller is selling make me cringe. This stuff requires a delicate, knowledgeable approach. I don't like the idea of swapping parts willy-nilly to chase some mythical goal. That breaks things, when a little knowledge could reduce wastage.

[Knucklehead]

This stuff requires a delicate, knowledgeable approach. I don't like the idea of swapping parts willy-nilly to chase some mythical goal.

I couldn't agree more. Years ago I was blown away by the huge changes made in my Cummins by a few IP parts with differences that I could not even detect. That's why I have been going about this info gathering for so long; it's hard to get information and what I have gotten has not satisfied me. If anyone wants to experiment I'm interested in the result, but make no mistake, understanding of diesel injection pumps is a field in itself. A salesman is the last person I'd put any confidence in.