Author Topic: Help me pick an engine tranny from scratch  (Read 4058 times)

September 14, 2005, 02:11:12 am

SnapDemon

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Help me pick an engine tranny from scratch
« on: September 14, 2005, 02:11:12 am »
I have an opportunity to purchase a diesel registered rabbit that is a 78 or 79 (I can't remember) for $700 the body and interior are in tip top shape but the engine and tranny are GONE. I was wondering what would be the the best combination for this car and what would the approximate cost be for the complete setup. I believe it had a 1.6 in it and all wiring and fuel lines etc are supposed to be there. No local yards have ANY rabbit parts so everything would be from internet classifieds, online retailers, or ebay.

I am most concerened about and in the following order:

1-Reliability
2-Cost
3-Performance and MPG are tied.

I have some mechanical skills. I have rebuilt small engines and had the heads off of my 68 beetle. I would like to do the work myself if it is not going to make me crazy. I would like to have the car up and running ASAP but have other means of transportation so it is not essential.

Is this project going to end up being a money pit or is it a pretty straight forward operation.

Thanks in advance and any advice or opinions will be considered and appreciated.

Marcus

Reply #1September 14, 2005, 07:41:20 am

zyewdall

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Help me pick an engine tranny from scratch
« Reply #1 on: September 14, 2005, 07:41:20 am »
Seems like a pretty easy project to me.  I'm sticking a diesel in a 1990 gas GTI, which doesn't look that bad, and it's got to be harder than just replacing a missing diesel engine.

I recently bought a completely rebuilt 1.6NA from an 1988 jetta for $1400 on ebay.  If you rebuilt it yourself, it would probably be much cheaper -- I'm sure some people on this list have a core sitting around.  I'll let other speak to how much work it is to rebuild one.

For the transmission, my donor car had the close ratio transmission, which with the diesel would give good drivability around town, but can't go over 60 or so on the highway.  The highway gas mileage would also suffer because of the higher RPM.  So I'm planning on getting an old wide ratio transmission instead.  The nice thing about VW's is that so many parts are interchangeable over the years.  The 5 speed trannies are supposed to be alot better than the 4 speeds (because you can stay in the proper power band of the diesel engine better, and lower the highway rpms for better mileage).
'84 Mitsubishi 4x4 2.3L turbo biodiesel pickup
'91 VW Rabbit GTI with 1.6 biodiesel transplant
'81 Toyota longbed 2wd 2.2NA biodiesel pickup (for sale)
'89 Subaru 4x4 touring wagon
 '82 subaru 4x4 TDI wagon -- project on hold
1976 Ford Sasquatch pickup

Reply #2September 14, 2005, 08:17:18 am

veeman

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Help me pick an engine tranny from scratch
« Reply #2 on: September 14, 2005, 08:17:18 am »
Marcus... Do you have a budget for the project? Are you planning on commuting / daily driving this one?

If it were my car and I wanted to go for all out economy, I'd probably look around for a used normally-aspirated 1.6 motor in good condition and go for that.     If you can hear/see it run or vouch for the amount of miles it has on it, then you should be set for a good long time.

If you're going to rebuild, plan on some expense since it appears that diesels cost a bit more to rebuild than gas motors, especially if you need new pistons.  

You'll also want to find a good machine shop that knows diesel heads and is equipped to bore 4-cyl VW blocks if that's necessary.

A nice 1.6TD would also be good in your rabbit and wouldn't really take all that much to swap in.  There are minor wiring issues along with the fact that the exhaust setup is different.  The TD will definitely have more power, but on the downside, they can be more costly to find / rebuild since there are additional elements such as the turbocharger to deal with.  

Where I'm from (Ohio), there are hardly any of the "old" diesels let along TD's, so an NA might be your best bet.

As far as transmission options, there are websites around that can give you the trans ratio's of all the units VW produced.  From that, you can get an idea of what code transmission you'll need to look for.  

I also have a spreadsheet a friend of mine made that will allow you to calculate road speed and eng rpm in certain gears.  Let me know and I can send that on to you...

The earlier diesels had four speed transmissions, so you could probably find one of those, however, I found them to make the engine seem to be working pretty hard at highway speed...

I have an FF trans (5spd)  in my caddy TD right now and the ratio's appear to be pretty good for highway cruising.  I don't think I'd want anything shorter, especially in the top two gears.     Remember that if you're going from 4-speed to 5-speed in that car, you'll have to change some of the shift linkage components.  It's not that hard and a donor junkyard car should have what you need.

That all said, you could also have someone here "make" you a transmission with the gears that you want (within reason).  You could make a real "highway cruiser".

Mechanically, installing an engine and transmission is not that hard to do, but if you get stuck, there are plenty here that can help out.  I might suggest that you locate /borrow an engine hoist which really helps out a lot when doing that sort of thing.
81 Caddy TD
98 Audi A4 Quattro V6 TDI
83 VW GTI FSP
86 4ktq

Reply #3September 14, 2005, 03:31:14 pm

chrissev

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Re: Help me pick an engine tranny from scratch
« Reply #3 on: September 14, 2005, 03:31:14 pm »
The answer to your question:

Engine:  1.6TD
Transmission 020 AGS five speed

You cannot find a better combination of performance, fuel economy and reliability.  In order to bolt this setup into a German built rabbit you will need to do some modifications to the engine and transmission mounts.  Also the shift linkage and speedometer cable will have to be changed.  The AGS transmission uses 90mm flanges so it bolts right onto the CVs in your car.  It is best to get the alternator bracket and injection pump with the 1.6 engine as they are different from the ones on the 1.5 that came with that car.  If the rabbit was a diesel the cooling system will be adequate.  If it was a gas rabbit you might have to upgrade to a bigger radiator.  That's it I think.  All I can remember anyway.
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #4September 14, 2005, 03:43:13 pm

janb

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Re: Help me pick an engine tranny from scratch
« Reply #4 on: September 14, 2005, 03:43:13 pm »
Quote from: "chrissev"
The answer to your question:

Engine:  1.6TD
Transmission 020 AGS five speed


agreed !

but... if you are on a budget, you might need to go with an NA, the AGS is still good choice.  or the ACH,
I like ASF / ACN's in Flat-lander cars

FF's came with .71 and .75 5ths, I prefer .71, but... my economy is better with my .75's (for some crazy reason)

a 9a with a .75 5th is really fun in the mountains (close ratio, but tall 5th)

good sites
http://www.vwdieselparts.com/
http://autos.groups.yahoo.com/group/Audi-VW-Diesels/messages/
http://www.scirocco.org/gears/
http://www.4crawler.com/Diesel/VW_020_transmission.shtml

and here, of course...
 :wink:
The Stealth Rabbit
VW-d's are forever

Reply #5September 14, 2005, 07:26:12 pm

chrissev

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Help me pick an engine tranny from scratch
« Reply #5 on: September 14, 2005, 07:26:12 pm »
Re:

Quote
That all said, you could also have someone here "make" you a transmission with the gears that you want (within reason).  You could make a real "highway cruiser".


this can result in very unworkable (but also quite funny) gear combinations.  For example a guy I used to talk to online decided to swap a 0.71 fourth gear from a 3+E into his 77 Scirocco 4spd to make it better for highway driving.  He wanted to keep the car stock as a classic but at the same time make it into a useable daily driver.  It seemed like a great idea.  The GC tranny in it had a 1.29 third and a 0.97 fourth.  When he swapped in the 0.71 fourth and got rid of the 0.97, his gear ratios went as follows:  3.45, 1.94, 1.29, 0.71.  Third gear was good to about 68km/hr at redline, and then shifting into fourth got him about 900 rpm with the 0.71.  So it was a very funny car to drive.  And it took a long time to accelerate to highway speed (but cruised great once it got there).  What he really needed was a giant sling shot to get him past the hole between 68km/hr where third was used up and 80 km/hr when fourth became useful.  So weird.  But a learning experience I guess.
88 Jetta TD....sold for $1000, bought an 06 Cobalt, clearing out the diesel jetta stuff now

Reply #6September 14, 2005, 07:48:44 pm

watsongs

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Help me pick an engine tranny from scratch
« Reply #6 on: September 14, 2005, 07:48:44 pm »
Does anyone have any thoughts on a good 5-speed for a 1.5?  I understand there's something different about the mate-up of the 1.5 vs 1.6 block.

Thanks -

Greg
Greg Watson
'79 Rabbit, 1.5 liters of fun...
If they can get you to ask the wrong questions, they don't have to worry about the answers...

Reply #7September 14, 2005, 08:08:48 pm

fspGTD

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Help me pick an engine tranny from scratch
« Reply #7 on: September 14, 2005, 08:08:48 pm »
Chris: The guy with the scirocco's story doesn't add up.  He should have been able to easily get past 68km/h in 3rd gear.  (According to my calculation assuming stock tire circumference, he would have only been turning 3100rpm in 3rd at that speed.)  And he should have been able to easily shift into 4th gear leaving RPMs well above 900rpm.  (He would have been traveling 35km/h to turn 900rpm in 4th.)

I have a 4K with a .71 fifth and it's not as bad you as might think.  Shifting from 4th to 5th is like shifting a "gear and a half".
Jake Russell
'81 VW Rabbit GTD Autocrosser 1.6lTD, SCCA FSP Class
Dieselicious Turbocharger Upgrade/Rebuild Kits

Reply #8September 14, 2005, 11:46:19 pm

fatmobile

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« Reply #8 on: September 14, 2005, 11:46:19 pm »
Where in Iowa are you at? Don't forget euroblitz.org (our local VW club)when shopping for used VW parts in Iowa.
 I found a 7A. It has the .71 5th.
 If you can find a trany with the same kind of reverse switch conection, it will save you a little wiring. Not sure if that's the FF or FN ... or FO in your case. I'd have to go out and see which one has the 2 prong switch.
Tornado red, '91 Golf 4 door, with M-TDI 12mm pump, south bend clutch, VNT-15 turbo, 02A trany
MK4s: 2000 TDI jetta, 2003 TDI wagon, 2000 golf 2.0 gasser.
'84 Rabbit with 1.7TD KY block pistons bored to 80mm, VNT-15
'84 GTI with stock 1.6TD starion intercooler.

Reply #9September 15, 2005, 05:27:13 am

veeman

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Help me pick an engine tranny from scratch
« Reply #9 on: September 15, 2005, 05:27:13 am »
>>this can result in very unworkable (but also quite funny) gear combinations.

You're correct in that some combinations would be pretty awkward, however, with a little bit of calculations and the right choices, I think a good set of ratios can be found.  

When I was looking at swapping my TD, one poster here offered to build me a box based on a close ratio gearset.  The plan was to have close 1-3 gears for zipping around town and then have 4th and 5th longer for highway cruising.  I never got to try out that combo, but it looked good on paper...

That all said, is making a custom box easier / better than going with a stock five speed diesel trans?  Not sure... but it is an option.

>>I have a 4K with a .71 fifth and it's not as bad you as might think. Shifting from 4th to 5th is like shifting a "gear and a half".

In another car, I have a rabbit with a 2H transmission that came with a .91 fifth transmission.  A friend helped me swap to a .75 fifth and I agree with Jake... It does indeed drop off, but it's not show-stopping.  It really does make the car more livable on the highway.

The old transmission would drive me nuts at 65-70mph.  The 4k was only slightly better with a stock .89 fifth...
81 Caddy TD
98 Audi A4 Quattro V6 TDI
83 VW GTI FSP
86 4ktq