Date: Thu, 6 May 2004 02:11:02 EDT
Reply-To: FrankGRUN@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Frank Grunthaner <FrankGRUN@AOL.COM>
Subject: Re: Questions re. Audi 3A engine swap (after searching the
archives)
Content-Type: text/plain; charset="ISO-8859-1"
Sam, List,
Here are a few answers to some of Sam's questions. Posted to list for
diversion only!
>
>
> Request #1: Could you send me the details +/or drawings of the Audi 3A
> intake manifold mods, the fuel rail hold-downs, and the Moroso oil pickup
> mods you offered on the list? I'd like to start getting the parts together. My
> email is bungeegull@hotmail.com. Thanks!
>
>
## I'll pull up the drawings and send a copy as well as Alistair to post the
drawings on his site for more general access. But a few updating comments:
A. On the issue of the intake manifold. The changes I have made are few and
simple. Firstly, purchase four spare injector inserts for the 3A and cut them
off and bore the interior to my drawing. This adapts the air shrouded CIS
injectors to the standard Bosch Digifant/Porsche/SAAB/Volvo type. I then cut a new
Aluminum fuel rail to properly retain the injectors and feed them. Print
available. I then made a set of rail holders that tie the fuel rail to the manifold
in the original injector retainer position/holes. I also eliminated the VW
digifant fuel pressure regulator and threaded the fuel rail to add a variable
pressure unit (ebay) with gauge for tuning. This is more important for the turbo
application. I also got a 3/8 inch thick sheet of epoxy fiberglas composite
and fabricated a manifold thermal spacer for the Audi head. Jigsaw and a
manifold gasket. Worked fine. Had to go up to the next length of socket cap screws,
but really reduces the thermal soaking of the manifold. I also ported the
manifold and thermal spacer to the head and polished the accessible area of the
intake manifold. Finally for the intake manifold, I changed the throttle body to
the G60 manual transmission version. More for the turbo plumbing. I had
tested the Audi 5000 turbo throttle body but this is superior. I also added a water
injector sprayer in the previous cold start injector port on the intake
manifold.
B. Oil pump pickup and pan mods. I experimented with the Moroso and Milodon
units (along with Ford, GM and Chrysler types) and found that the original audi
pickup was best. However the angles are complicated. Rather than try to draw
up the result, I found jigging to be the best approach. I made a simple jig
with a 2 x 8 inch base, several pieces of Al angle (1 inch on a side) and a set
of C-clamps. I set up a bolt pattern to take the diesel vanagon pickup and
constructed a plate reference to the center of that diesel pickup face. I then
bolted the audi unit in place, cut off the pickup tube about halfway between
flange and inlet. I then rotated the tubing with a coupling sleeve until the Audi
gasoline oil pickup inlet was at the same place as my jig showed the diesel
unit to be. Then welded the unit up. Pictures available on request. Of course I
also added the windage tray.
But there is more. The windage tray helps stop the crankshaft generated
aeration, but doesn't seriously effect front to back (or side to side) sloshing.
The diesel pan is one of the worst I have ever encountered with its flat base.
So I mapped out the primary oil level in the pan (full, stationary and level
vanagon) and designed an oil slosh cover with trap door (best dragster
tradition) to keep the oil pickup tube covered with oil at all times. Made the cover
and baffle assembly out of 1/8 inch aluminum, bolted to interior baffles. I
sealed this to the windage tray for oil collection to the sump. Seems to have
seriously reduced maximum oil temperatures but this could also be due to
cavitation control.
To clear my turbo auxiliary scavenging oil pump (goes where the PS pump would
mount in this configuration) I also designed a new oil input system for the
diesel pan. I built an adapter flange to bolt on to the existing oil fill port
on the pan. (Drawings on request) This flange incorporated an oil level sensor
(I used the sensor from a Porsche 944 Turbo) and set the trigger point in the
pan at 1 quart low. On the side of the bracket there is a port for mounting
the oil fill tube from the Vanagon 1.9 engine. Comes up at the same point as
the diesel original. Clears all the belts and pulleys nicely. I use the european
turbo diesel dipstick (still available from VW parts) for level checking when
filling.
I've already described the turbo oil scavenging system and the auxiliary oil
sump.
>
> I've posted the below on the vanagon list, and am including it here in
> an attempt to escape your delete key. Also, I think you may be the only one
> who can answer the question about Saab engine management. Many thanks!
>
>
> Sam Payne (up in San
> Fran.)
>
>
>
> Posted as: 'Questions re. Audi 3A engine swap (after searching the
> archives)'
>
>
>
>
> Hi again to the list,
>
>
>
> I'm finally getting back home and back to my engine conversion after 8
> months out of the country. While away, I searched the archives for information
> on the swap and the deeper I got into it them the more impressed I was. The
> list is a great resource--I wouldn't know about or attempt a conversion
> without it! Many thanks to all of you.
>
>
>
> The Plan: My choices are based on Frank Grunthaner's excellent and
> informative posts on engine conversions and Alistair Bell's excellent web site (no
> blame to either if I screw the swap up, though). I own an '86 westfalia,
> 2WD, 4 speed manual transmission. I plan to install an 8 valve Audi 3A with
> used diesel mounts and diesel bellhousing and to modify the intake
> manifold injector ports so I can use the Digifant II management system or
> the LH-Jetronic Saab management system. I want to put in a windage tray, modify the oil
> pickup, and chip the ECU if possible. And then bolt it up to a diesel transmission
> of either ratio. And then smoke someone, anyone, off a red light in a fully
> loaded Westy. I'm doing the swap to increase reliability and performance, to
> learn, and to have fun. Hope to finish it this summer.
>
>
> ## some more comments: The Audi 8V head is far superior to any of the
digifant 8V heads. The injection port mods are minor. But the SAAB LH-Jetronic engine
management system is superior to the VW for the turbo application. The NA
unit still includes the hot wire air mass sensor. Much more flow. I would use the
injectors from the SAAB engine as well. Get them professionally cleaned. But
for NA the Digifant II set up will work also (always better that CIS). For the
turbo, I use Iridium plugs (Nippon Denso), Magnacore wires and Crane high
power ignition system with rpm based timing retard for knock control along with
the SAAB APC system (Turbo driven).
>
>
>
> Questions:
>
>
>
>
> **Fit: Frank G. wrote an intriguing post with 3A head measurements
> suggesting that the engine compartment might not need to be clearanced for the 3A
> engine as it has to be for the 1.8 vw engines, but he hadn't yet tried mounting
> his turbo-ed 3A. I searched Dennis Atkins' and Simon Reinhardt's posts too but
> neither mentioned it. Anyone try it?
>
> ## Still have the Audi on the engine stand. Still need a clear week. Stand
> by my measurements though.
>
> **Transmission: My mounting parts are from an '82 diesel, van is an '86
> Vanagon, manual. Scenario 1: If I bolt a 4 speed diesel tranny with the diesel
> bellhousing to the Audi 3A, will the mounting points on the carriers, frame
> and front tranny mount work out? How much of a PITA is it to modify the
> transmission linkage? Scenario 2: If I have to use the existing transmission for a
> while (the standard 2.1 WBX tranny) and bolt it to the 3A engine via the
> diesel bellhousing, will all the mounts work out?
>
> ## Can't answer in detail as I have not touched an '85 and later. But the
> CV flange to bell housing face for the DK, DZ and DX transmissions are all the
> same. Lots of diesels in the yards. I'd go to the DZ or DX diesel trans with
> linkage for a NA conversion. Powerband of the turbo matched the aircooled
> final drive better. The diesel carrier will place everything in the right
> place.
>
>
## Now I sure that the same nonsense will be offered to the effect that the
diesel trans will give higher revs per mile, and the standing wisdom will be
offered as to the inadvisability of same. As I have offered before (argued is
probably more fitting) its torque translated into thrust! Whole story. Want a
peppy vehicle (the Westfalia is 4500 pounds give or take a few grams), put the
maximum potential torque at the tire patch for any given velocity. This says 14
inch rims, the diesel tranny and an engine that can sing to a 6500 rpm
redline. The Audi 2 liter is a healthy torquer and will run 24/7 at 6250 rpm. Drove
from St. Marie Eglise to Prague with just gas stops. No carbon in those
cylinder holes when I finished. Oil at the same level. These engines were designed
for prolonged 5000+ rpm operation on the AutoBahn, AutoRoute, Autostrada.
Noise is a legit complaint, but with insulation and the factory air induction
inlet, an Ipod and a 2000 watt stereo ... no problem.
## The engine life argument. Hogwash. You pay for the power you use
(maintenance and fuel). As I have said all too often in this forum, the determination
of analytically comparative fuel economy is quite easy. I've given the source
material on Alistair's site. Start with a Westfalia loaded to the gross vehicle
weight (GVW). Place it on a level highway (or a 10, or a 20% grade, etc.etc)
. Starting conditions. For any established case, it will require a minimum
level of torque generated at the rear wheels (syncro doesn't go this fast) to
maintain that speed. This requirement includes drag, frictional losses and other
terms, but its a function strictly of the speed and work expended in altitude
changes for a given vehicle at constant mass. For the I4's, the 1.9 and 2.1 L
WBXers, the engine fuel efficiency curves are given at Alistair's site. The
subie info is also available for comparison. So go to the plot. Gives power
output per unit fuel consumed as a function of engine speed. Surprise! fuel
consumption is not a linear function of engine speed. It is a function of the
design efficiency of the hot air pump (engine) which is a function of rpm. The I4
at 20% higher revs is far more efficient than the WBX units at the lower rev
number. The fuel used to push the vanagon is far less for the I4 vs the WBX at
lower rpm. In fact the reduction in power needed to drive the Westy at a given
(4th) gear velocity will be less for the higher revving diesel trans than for
the lower revving ac trans for the same power output. In other words at the
designed rpm range, the power output per gram of fuel consumed is virtually
flat. Therefore 10% less power (because of geared torque multiplication) uses 10%
less fuel.
## But I'm sure this common wisdom will go on. Run a NA 1.6L diesel with an
AC trans to get the rpm down! Aargh. Ignorant engineers!
>
> **Input shaft length: I've read a lot about it but am still confused.
> I need to use the original shaft from the gas WBX transmission (I bought diesel
> parts, not the whole van). Tom Carrington has side-by side photos of the gas
> and diesel input shafts on his site, showing that the gas shaft is longer.
> Given that the diesel owners have been cutting 11-12.5 mm off their input shafts,
> how much should I cut off the longer gas shaft?
>
>
## The actual shaft dimensions are given in the ETKA. Cut to size.
>
>
>
> **Engine management: 2 scenarios: 1.) Dennis Atkins used Digifant II
> engine management from a RV Jetta to run his Audi 3A 2.0 engine without using a
> 1.8 digifant cylinder head. How is this possible given the displacement/design
> differences? If it is possible--and I want it to be--does that also mean
> I could add the 1.8 digifant performance chip to the ECU?
>
>
## Sure! The fuel mass maps are pretty crude and determined by the air flow
or air mass sensor (Or MAP in terms of a 3rd world implementation). The
ignition timing map is more engine specific. But any knock sensor based ignition will
run the advance up to the onset of detonation. The digifant performance chip
removes the engine rpm limit and has a little richer fuel map with finer steps
in the timing roll-off vs. rpm. Not a big change. Been there, done that. The
SAAB LH-Jetronic much better for high rpm range. Better tuned for
displacement.
>
> 2.) If I go with the LH-Jetronic system from a Saab 2 liter 16 valve
> non-turbo engine (which Frank G. likes) what modifications would need to be made?
> I assume the distributor regearing and swap Frank did, and his intake
> manifold machining for the injectors, but what else? Would it make the wiring
> harness modification more difficult? Which is the best Saab repair manual?
>
> ## SAAB Bentley is a repair manual in contrast with the Vanagon collection
> of printed microfiche sheets.
>
> **Power Steering: Most of the recorded conversions have been to diesel
> vanagons with manual steering, but my '86 has PS. Does anyone know whether
> there's space for the power steering pump in a 50 degree 3A audi conversion, and if
> so where to mount it?. The pictures I saw online of post-conversion engine
> bays looked pretty packed, but it's hard to tell....
>
>
> ## As I said above. Readily adapt A2 brackets if you use my oil fill adapter.
Good Luck,
Frank Grunthaner
>
>
> That's it for now. Apologies if I have missed some easy answers in the
> archives-- it ain't for lack of trying.
>
>
>
> Sam Payne (in San Fran.)
>
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