T25 Engine Swap HELP...

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monsterVW1982
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T25 Engine Swap HELP...

Post by monsterVW1982 »

Hi all,

After a little bit of advise with selecting a new enginer, gearbox and a turbo for my van after the current engine give up the ghost on the way to Bus Types at the weekend just gone :(
The engine seams to have given up internally and can not be turned over by hand (gets so far and is solid)

The van is a T3/T25 transporter on a G plate (89/90)

Current installed engine & gearbox (not sure of codes tho)
1.7 Diesel (no turbo)
4 Speed Gearbox
Guessing this is the original engine and gearbox

Proposed Engine
1.9TD Diesel (AAZ) (believe from a M or N reg Passat Estate)
5 Speed Gearbox
Bigger Turbo from a Mk 2 Golf 1.6TD

Now for a few questions: -
I believe the proposed engine is a straight drop in for the current engine?
What is the required 5 speed gearbox that will drop straight in for the as a replacement matched to the proposed engine, van year and linkage
Will the bigger turbo drop straight on to the proposed engine?

Any help on selection, infomation on any issues, modifications etc... would be appreciated and if you need any other information from the current engine and van, let me know

Cheers in advance

Andy

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Re: T25 Engine Swap HELP...

Post by langb20 »

Andy,
Hello and welcome - have you looked in the WIKI yet? or the first post in this section on diesel engine upgrades?
good choice on upgrade option, you will need a few bits however...
the sump on the 1.7D (KY?) doesn't have a turbo oil return connection - you can get a JX (1.6TD) sump or a kit a brickwerks to tap your existing sump
exhaust manifold and turbo arrangement may not work - could foul the nearside engine mount or stud pattern may not be the same (check - there are 3 or 4 stud types i believe) some people use a JX exhaust manifold here too. not sure about upgraded turbo, my standard aaz one is fine.
exhaust fabrication might be required if you're swapping turbo's etc. ideally something 2" and straight through is what you want, can use a JX setup if needs be but your 1.7D will not cut it
If the 1.7D inlet manifold is anything like my old 1.6D then you will need a JX setup here too

gearbox - there are some codes for these, have a look in the WIKI
5 speed petrol box code AAP is the best ratio, though are getting rare and therefore expensive in any kind of decent condition. this could be the weak link of any conversion and so worth investing in if you can. Aidan is the rebuild man and can probably give more advice if sought
linkage for 5speeds are all the same, usually seen on for sale section now and then
you will need to purchase and install a needle bearing for the end of the crank so that your gearbox input shaft is supported or it will wreck stuff in no time (your passat engine won't have one of these installed)

modification to oil dipstick so you can measure the level in the now 'tipped over' passat engine (4.5L of oil)
For longevity you will likely need an external oil cooler as these engines run hot when pushing 2tonnes uphill (especially with a bigger turbo which will add a lot of heat to the oil) - brickwerks do a good kit for this

plenty more to do i'm sure but that's top of my head, plenty of posts on this so get a cup of tea and have a search :ok

Regards,
Brent
'82 TDI project camper
'85 AAZ Panel daily drive

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Re: T25 Engine Swap HELP...

Post by ajsimmo »

WHS^^^
agree with all of that, especially questioning the need to change from the original AAZ turbo.

Just another suggestion as an alternative for you. If you are looking for an easy "drop straight in" conversion then the 1.9 1Y (non-turbo) would be much more straightforward than the AAZ. Your original 4-speed box is stronger than a 5-speed petrol one, so if your box is good I'd think about sticking with that.
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Re: T25 Engine Swap HELP...

Post by peteabbott »

I think you are a good ol boy for taking on an engine swap and going that far with it........altering the sump......different turbo and maybe a bit of body/chassis alteration AND maybe manifold changes. I tend to agree with the above comment that a 1Y is quite a simple swap with fairly good results and good reliability. Very interested in what you propose to do so please keep us updated during your progress.
Pete Abbott

monsterVW1982
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Re: T25 Engine Swap HELP...

Post by monsterVW1982 »

Many thanks for your replies,

I am just awaiting my brother (the mechanic is all this) to have a read of these posts to see what his thoughts on this is.

So a few questions about the running of the van with the different options suggested if I may: -

Option 1
1.9TD Diesel (AAZ)
5 Speed Gearbox
Bigger Turbo

This seams like a lot of work and expense with alterations such as turbo oil return connection, exhaust manifold, engine mounts, exhaust fabrication, oil dipstick, Oil Cooler & needle bearing etc...

Option 2
1.9TD Diesel (AAZ)
5 Speed Gearbox
Standard Turbo

Less modifiation (a little anyway) but the main thing that has jumped up is langb20 & ajsimmo saying the standard turbo is ok
What will the van do on the motorway and up them hills? (with the current engine was screaming at 55/60mph on motorway and slow slow up hills)
I dont want to break any speed records and I am happy to plod along but not be overtaken by trucks.

Option 3
1.9 1Y Diesel
Existing 4 Speed Gearbox

Now this sounds a lot less work to me... and I am all up for that along with the good reliability :D
My gearbox is fine I thnk (I might have it checked over while I am down there)
However, it comes back to what it will do on the motorway with a standard 4 speed box (the current 1.7 and 4 speed box starts to scream a bit too much for my liking on the motorwway at 60mph)
Any input on MPH in 4th and approx engine revs/noice at 60mph and what it will pull up hills would be useful
My theory on the revs is that its a little bigger engine so the revs should be less at 60mph?

Will Let you know what progress I make on this when my brother has had a look at things

Cheers again

Andy

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Re: T25 Engine Swap HELP...

Post by langb20 »

Hey Andy,
RPM exactly that, revolutions per minute - no matter what engine you put in, if you have the same gearbox it'll be turning round exactly the same RPM at the same vehicle speed. best get your gearbox code and check out the ratios to be sure if it's 'short'...
So to give you a bit more insight on gearboxes (have you read the WIKI yet?) there are different ratios on these gearboxes mainly because of the power output of the engine. If you have low power - take the 1.6/1.7D engines for example, then you need lower ratio gearboxes (which is what VW put on those vehicles) in order to pull 2tonnes up hills. If you increase the power of the engine e.g. 1.9D plus turbo, then you don't need the ratios in the gearbox to help with power at the wheels - so you can have a longer ratio gearbox.

Try to imagine it like the gears on your mountain bike, exactly the same thing - you try peddling up a hill in 4th gear and the number of revolutions is low, but damn it's hard work - if you got the power in the legs to do it then no problem. But then flick down to 1st gear and you're peddling like crazy (not going very far with each rotation mind you) and it's much easier on your 'engine' (legs)

there is the small matter of rolling radius also - the wheels - if you increase the circumference by fitting taller tyres, then for the same distance travelled, the number of revolutions goes down - so your engine speed goes down (provided you have the power to push it there) you can't gain too much here in terms of rev reduction.

I have an AAZ with standard turbo, running a 4 speed petrol 'ABB' gearbox (oh, another thought - you will need to keep your diesel bellhousing for the conversion - easy to swap onto a petrol gearbox, change input shaft seal while you're there) it will do 60 all day long, bit noisy-er on motorway at 70 but will sit there ok, plenty of torque going up hills slowest it'll do up most hills is 40-45 which ain't too bad considering aerodynamic tendencies of the brick. Am running a panel van with r&r bed so it's not exactly heavy. Will need an oil cooler if boosting for a long time up a hill - it does get warm.

1Y is probably less work you are right there, don't be too put off by the AAZ route tho - especially if you get your hands on a decent donor engine. I haven't yet retro-fitted a 5speed linkage to a 4 speed van yet mind, how hard can it be? :roll:
hope that helps,
Brent
'82 TDI project camper
'85 AAZ Panel daily drive

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ajsimmo
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Re: T25 Engine Swap HELP...

Post by ajsimmo »

Hi Andy,

Before you decide on your engine, make sure you have read all of this on AAZ
http://wiki.club8090.co.uk/index.php/Al ... gine_1.9TD

and here's some useful stuff on the 1Y
http://wiki.club8090.co.uk/index.php/Li ... .29_engine

Whilst the AAZ is widely regarded as the one to have (and I loved mine, but that was in a heavy Syncro), my own recommendation would be the 1Y if cost and ease of swap are considerations.
You could always PM Weldore if you want another review, he's got a 1Y in his van.

1Y Advantages:
Cheaper
Easier swap (keep original exhaust, everything is a straight swap really)
Easier to find parts (lots of Golfs and Caddy vans in the scrappies with this engine)
No turbo to go wrong
More economical than AAZ

Disadvantages:
Not quite as powerful as AAZ (but you'd hardly know it - 67bhp against 75 @ 4200rpm, and more importantly only 7% less peak torque at 2400rpm)

On the AAZ side, I have recently fitted one for Brandygangster. He had a blown 1.6D, swapped his 4speed for a 5speed while we were at it, so you could give him a shout for his opinion.

Whichever engine you choose - DON'T FORGET TO FIT THE SPIGOT BEARING! :wink:

As for your gearbox, see the code list here http://www.brick-yard.co.uk/VehicleSpec ... fo/gbx.htm

Done some calculations for your gearbox question (very quickly, correct me if I'm wrong Aidan!):
Based on your van being an 89 1.7D 4-speed, the most likely box code for that model is an APF box, 4th gear ratio 0.85, final drive 5.5, giving a speed at max 4000rpm of 65mph.

If you went for an 8L 5-speed. 5th gear 0.816, FD 5.43, speed @ 4k = 69mph.
Or you could look for a higher geared box (hard to find and expensive), such as a 3H, which is a 5-speed with 0.816x4.83 giving (a theoretical but unlikely due to power limitations) 77mph @4k.

I assume you have standard 185/80R14 wheels & tyres. Just moving up to 195s on standard wheels makes a small but appreciable difference, and putting 15" wheels on with something like 215/75R15 tyres makes a big difference (eg with the 8L box, this would give an extra 5mph at 4k rpm, or cruise at 65 at the optimum 3500rpm).

BTW why do the engine and gearbox at once? You could do engine now, see how you go, and swap box later if you feel there's a need to.

Best of luck with the swap. :ok
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monsterVW1982
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Re: T25 Engine Swap HELP...

Post by monsterVW1982 »

Hey Folks

Sorry I didnt did I how rude of me, many many thanks for the above posts which have been most helpful in my selection, just hope I get a good engine this time and it all works out

Well it looks like I am going to go down the AAZ route with hopefully with a JX T25 Turbo but sticking with the original APF gearbox for now.

If anyone can help with sourcing a good condition JX T25 Turbo and a JX Exhaust Manifold, drop me a PM.

Also, as this is a fair bit of money to be spending, what's the feeling with getting you money back if I ever sold the van with an aaz engine in?

Andy
Last edited by monsterVW1982 on 27 Apr 2011, 11:02, edited 1 time in total.

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ajsimmo
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Re: T25 Engine Swap HELP...

Post by ajsimmo »

:D You're welcome, :ok

Hope it all goes well, you'll love the difference with an AAZ.
Any probs, just shout. I'll be glad to try to help.
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skell
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Re: T25 Engine Swap HELP...

Post by skell »

AAZ is a good route.
I'm running AAZ and DU gearbox.
Oil Cooler and Rover Boost Pin, JX turbo and manifold, AAZ inlet manifold, slightly taller tyres but not much.
is happy at 70 every day, gets to 80 easy and feels like has plenty more, think I've seen 90 when showing off.
(tin top twin slider with heavy rock and roll bed so probably similar weight to yours)
skell
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mrhutch
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Re: T25 Engine Swap HELP...

Post by mrhutch »

or...


swerveball


Fit a petrol GTi (2E) engine from a golf/jetta/passat

Donor car will should cost you less than £300 to buy - you can weight it in afterwards for over £100

Better MPG, you've already got ALL the bits you need with the 1.7D, engine will rev to 6K so gearbox no issues and 30+ mpg on cheaper fuel (or gas it and get over 50mpg)
1981 Vanagon Westy Burning oil as fuel...  

kit
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Re: T25 Engine Swap HELP...

Post by kit »

30 mpg + on a petrol pulling 2.5 tonnes, you serious?
1y Tin top rust collector.

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mrhutch
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Re: T25 Engine Swap HELP...

Post by mrhutch »

absolutely
1981 Vanagon Westy Burning oil as fuel...  

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weldore
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Re: T25 Engine Swap HELP...

Post by weldore »

how does that work Mr Hutch...my agg golf only used to get around 35 mpg .? Not saying your wrong but just interested in your findings

E D I T...just went through the brickyard thread ..and ....mmmmmmmm
the word 'pissing' is safe

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mrhutch
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Re: T25 Engine Swap HELP...

Post by mrhutch »

hahahaha

really happy with the conversion and I'm one who thought that I'd never leave the diesels!

OK, I bought 2 B3 passats that have the 2E engine. One had MOT for 6 months so I ran that one round. Bear in mind I don't do much round town driving as I work from home. In the passat from Hereford - Dover (EXACTLY 250 miles on GPS) the trip computer showed 46 MPG - real world (brimming tank) showed 42.2

Same trip now one of the motors is in the T3 Panel - driving at between 65 -70 steady away, relaxed right foot gives 30.9 mpg - if i give it some beans over those same 250 miles I get between 26 - 28 mpg

I do this journey very often!

ABL gearbox, 67mph @ 3600 rpm Merc 15" steeles with AT Cooper tyres 205/70/15

engine redlines at 5-6K!!


No bullshit, the wife has a 2,0 8v new beetle with an AGG and we stuggle to get over 25 MPG on petrol, I've set her gas system up so we get 27MPG on gas! The panel van is now LPG'd as well, but need further tuning as the economy drops to low 20's on LPG, can someone give me some time to do this ? :D


** edited as checked tyre size and RPM's **
Last edited by mrhutch on 27 May 2011, 23:27, edited 2 times in total.
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