Date: Sat, 2 Jan 2010 04:26:25 -0500
Reply-To: frankgrun@AOL.COM
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Frank Grunthaner <frankgrun@AOL.COM>
Subject: Re: Conversion? JETTA ENGINE??
In-Reply-To: <c4e7c5f90912311916x179cb1e3y58acce20c13ede82@mail.gmail.com>
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I've recently become aware of this thread and though I add a few comments to Neil's quoted below.
First, I would like to emphasize for the newbies who have not been subjected to my lengthy posts on several of these subjects in the past that there is absolutely no mounting angle dependence on the vibration levels experienced in I4 Vanagon conversions. That is the vibronic polar moment of the mount angle has no impact on the vibration spectrum generated by the motor or on its transmission or resonances coupled to the body. 0˚, 10˚, 15˚, 22˚, 40˚ or 55˚ the vibrations generated by the motor will be exactly the same. The vibrations and resonances you experience in the installation are a function of the motor and transmission mounts, as well as the exhaust system mounting and in some cases the intake ducting. I've looked at all of these contributors and mapped them carefully for the VW and Audi 1.8 and 2.0L engines. Hydraulic motor mounts, appropriately sized will eliminate vibration over all rpm ranges if the exhaust system is properly isolated. The hanging mass of the exhaust is particularly prone to mid rpm resonances. With moderate attention to detail, the use of exhaust components from the Golf/Jetta or Audi group eliminates these issues. As you may note in the citations Niel made, I chose the SAAB hydraulic mounts because the internal valving was originally chosen for an engine with very similar vibronic spectra to that of the VAG I4 engines. Other systems including the hydraulic Audi 5000 series mounts and the Mercedes units will probably work as well. The '82 carrier bars work just fine, and I never tested the '83 units so YMMV!
Second, on the issue of conversion engines, there have always been two extremes to my way of thinking. High dollar and low dollar solutions. Changing out the engine in a vehicle and then demanding high reliability from that converted vehicle is a risky business at best. After all, the Vanagon or Westfalia are not readily adapted to the raceway or the showcar circuit. Typically, these are working vehicles and often they carry precious cargo such as family to areas in which specialized and competent service is not readily available. Of these extremes, the high dollar solution is one that is supported by a kit manufacturer. Here you will invest from $7,500 to $10,000 between the kit cost, the motor purchase and your mechanic's installation fee. This describes the Small Car, Bostig and TIICO groups as well as several independents. Each of these engine solutions have had a number of component difficulties. Add to this mix the experienced DIY and inexperienced DIY owners and one can see a number of significant problems. In general, the the number of custom (low volume) solution components is small. There are no cost resources to support serious component quality control and statistically there must be a failure rate inversely proportional to the number of replicates made. It is difficult to see how the kit manufacturer can afford to support the product to the level needed by the small group of purchasers. Therefore there must be a significant number of disappointed and frustrated users. The various forums are full of instance and discussion relating this point. If the kit vendor is just a subcontractor with inadequate primary engineering resources, the TIICO situation develops. The Subaru, Zetec and VAG engines solutions offered for conversion are all well engineered systems as installed in the original vehicle. I believe that in the hands of a careful and competent DIY owner, any of these units can be made to work successfully. The situation is more precarious in the case of the local non-specialist mechanic doing a contract install. It's hard to see where an adequate fee can be charged to cover time and inevitable problem resolution.
In the low dollar case, I believe there are several potential solutions, but none cheaper and more robust than the VAG I4 solution based on Diesel Vanagon components. First, it must be acknowledged that VW built approximately 850,000 T3 (includes T25 and Vanagon) vehicles equipped with I4 diesel engines from 1981 through 1990. Significant factory engineering and production resources were devoted to design, development and implementation of the package. More than 25 million I4 engines in the various fuel injected 1.8 and 2.0L families through the ABA have been delivered by VW in the similar timeframe. One must conclude that there is a major resource of factory engineered 55˚ mount I4 components available than can bolt up a series of gasoline and diesel VAG blocks. In general, those engines, their electrical and control systems are readily supported by VW and independent mechanics worldwide. To be sure, bolting up a Jetta/Golf/Fox/Audi 80 engine to the Vanagon transaxle will require some ingenuity. Exhaust systems have to be fabricated, air cleaner systems modded, oil pickups modded or swapped and some harness wiring changes need to be made. However those changes pale to insignificance compared to the changes needed to accommodate the Subaru or Zetec engines if you are on a modest cost kick (need to value your time at the $1.00 per hour rate here).
As many of you know, I have long concluded that the Digifant fuel injection system is quite robust and the 8V RV engine with dual port GLi exhaust is an excellent match to the DZ transmission. The engine will rev all day at 6500 rpm driving the Vanagon with air and power steering at a over-the-land velocity that should be reserved for the young and foolish. The engine will return reasonable fuel economy in the 65-75 mph range with plenty of reserve to push the brick up serious inclines or to provide the passing moxie to flash past the laboring trucker. With the diesel gearing, the engine will be moderately stressed in around town and freeway acceleration duties. Of course one can buy into the standard list wisdom of regearing to drop cruising revs. This will shorten the life of the engine, gain virtually no economy advantage and seriously grannize the Vanagon performance and usability. Low mileage RV engines complete with ECU can be had for $300. Add the cost of the diesel parts if you aren't beginning with a DV, throw in a tune-up, hydraulic engine mounts, another $100 for mount and exhaust fabrication, replace the clutch and bolt-on a straight-through muffler and you can be on the road for less than a grand. The engine will spin to 200,000 miles. If the sound of a good engine enjoying its work doesn't appeal, add some sound proofing or better tires and speed-up. The wind noise inherent in the van will drown out the engine noise. The above comments about transmission choice really only apply to 4 and 5 spd manuals and any manual can be used.
If you want a better and torquier engine, go to the 2.0L 3A engine from the Audi 80. The engine is more robust, has oil squirters and better intake manifold engineering. Use the Audi CIS-E or convert to the VW digifant system. I have shared the engineering drawings for a fuel rail and modified injector seals. The engine height is the same as the RV and DV engines and the block is slightly thicker.
If you are still greedy for performance, add the supercharger kit as Niel noted. Go low pressure or follow my Audi 3A turbocharged engine route with the SAAB control system. All on Alistair's site. Turbocharging to 5 psi will light up these engines and move more fuel to help you fantasize that you are running a Subaru H6. If you pressurize, always add an intercooler. They are cheap on eBay and seriously reduce the heat load on the engine.
Of course, with more cash, the informed DIYer can readily tackle the Subaru conversions. Not familiar with their longevity. I have never been impressed with the engines in their native habitat and my son has decomposed several of the 2.5's and 2.5 turbos. VW dealer service will be less enthusiastic and I have seen several independents in the LA area turn away Subaru conversions belonging to friends. But of course you will want to do this for the adventure.
The best conversions, in my view, involve the TDi engine. The 1Z/AHU engine is a tough system and can return excellent results. Its well suited to the Vanagon bulk, but poorly matched to the available transmissions. It is my opinion that the manual transmissions are almost too weak for the robust TDi. This is both in terms of rev matching to the engine RPM character but mostly in terms of its inability to handle serious torque. The Vanagon manual, from the factory is probably good for 150 foot pounds of torque continuous and 200 peak pulse. I'm using a DK with larger tires and the rev range is acceptable. The 1Z with a PD150 intake, RocketChip tuning, 520 injectors and a clocked VNT turbo in a nice package and I'm completing a number of mods and updates including a water to air intercooler and water injection system for EGT control. Unfortunately, the TDi engine is pricey and the additional component engineering requirements add more cost.
Sorry for the length, got carried away again. Happy new year and more satisfying wrenching,
Frank Grunthaner
-----Original Message-----
From: neil n <musomuso@GMAIL.COM>
To: vanagon@GERRY.VANAGON.COM
Sent: Thu, Dec 31, 2009 7:16 pm
Subject: Re: Conversion? JETTA ENGINE??
On Thu, Dec 31, 2009 at 10:03 AM, Mark Dearing <VWBrain@aol.com> wrote:
> hey Guys I just did this conversion using a 92 jetta motor into my 1985
> westy, I used the vannie diesel bellhousing, mounts, oil pan , oil pick up
> , flywheel etc. I kept the vannie control system complete works great,
> runs good , fair gas mileage. fits under the engine cover looks factory.
> later mark dearing salem import service salem va
>
This speaks highly of choosing the DIY path IMO.
As for Tiico, I have read that the actual mount angle has little if
anything to do with engine vibrations transferring to the body.
Basically you need hydro mounts, stable mount brackets and stable
carriers. I bet there's lot's re: Tiico vibrations on the Tiico Yahoo
user group.
Frank Grunthaner posts have great info. And Alistair Bell has lots of
great info/pics in his website. (including some from Frank himself).
i.e. this:
http://www.members.shaw.ca/albell/mounts_TiiCO.html
or this from Frank:
http://www.members.shaw.ca/albell/mounts_FG.html
Scanning some of that now reconfirms what little I know about
isolating engine vibrations.
Of note, do the later model NA Vanagons NOT have the forward mount
points for the DV carriers? If they don't, I would assume that if the
DV carrier is mounted at those points, and the metal is too thin, the
vibrations might be amplified and/or that area might get weakened.
I have a 2.0L ABA stock mounted at 15 degrees (much more upright).
There are no vibrations at idle, and it's fairly quiet while cruising
at speed. The only vibrations I *hear* (I don't really feel much....
maybe I'm just used to it) are under acceleration at mid RPM's. (sorry
no tach.... yet!) But. NOwhere near the vibrations I've read of with
some Tiicos. Like some have written that there side mirrors would
shake!
I'm using Fox motor mounts and brackets one of which has been modified
to clear the oil filter/cooler/lower rad hose. In spite of that, this
bracket seems to be faring well. (no cracks) I have mounted the home
made carrier to the frame with 3 fasteners per end. This is the same
thick part of the frame that the original engine carrier was mounted
to.
Pic of unfinished work, but shows where carrier mounts
http://lh3.ggpht.com/_01e3MpPuKwI/Sz1mXQVke6I/AAAAAAAACOI/Fw5TMbj7_pQ/s640/mount2.jpg
Neil.
--
Neil Nicholson '81 VanaJetta 2.0 "Jaco"
http://tubaneil.googlepages.com/
http://groups.google.com/group/vanagons-with-vw-inline-4-cylinder-gas-engines
