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Re: VR6 engine stays the same from mk3 to mk4? (billgti)

Roughly...yes. Everything is interchangeable from one to another if that's what you mean. Intake manifolds are completely different of course, but head and block are the same stuff.
-DVScott
 

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Re: VR6 engine stays the same from mk3 to mk4? (djsilvera)

quote:[HR][/HR]I think the head changed from OBD1 to OBD2. The secondary air pump was added, etc. So a 95's head isnt the same as a 2001's head. [HR][/HR]​
I have a 93 Passat with a VR6 (OBD1). I have a secondary air pump.
 

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Re: VR6 engine stays the same from mk3 to mk4? (Ken93P-GLX)

Hmmm...well just trust me on this. I'm gonna ask paul (need_a_vr6) bt I'm pretty darn sure something is different from OBD1 to OBD2 on the heads.
I dont want the originato of the post to go buy an OBD1 head for his OBD2 car on this information just yet
 

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Re: VR6 engine stays the same from mk3 to mk4? (djsilvera)

The only thing that I can think of that might be different between OBD1 and OBD2 cars is the gaping hole in the front of the head for the smog pump. That would only apply to OBD1 non smog pump cars though, and it's a 92-early93 thing only. A later head can be used on those cars by tapping a freeze plug into the "hole" left by the pump.
Other than that though, I can't think of anything related to the motor/head. All the other changes are in the manifolds and peripherals.
 

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Re: VR6 engine stays the same from mk3 to mk4? (billgti)

Early VR's used a dual upper timing chain and sprockets, later VR's use a single. You can convert over from either, but it's pricey.


[Modified by SLC4EVER, 7:57 AM 10-2-2002]
 

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Discussion Starter · #10 ·
Re: VR6 engine stays the same from mk3 to mk4? (M this 1!)

so horsepower ratings or at the crank remain the same?
i was also wondering how much lighter the mk3 gti vr6, compared to mk4 gti vr6.
 

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Discussion Starter · #12 ·
Re: VR6 engine stays the same from mk3 to mk4? (M this 1!)

200 lbs is quite a lot. how come it seems like the mk4 vr6s are as fast as the mk3s? gearing? the extra torque?
 

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Re: VR6 engine stays the same from mk3 to mk4? (billgti)

quote:[HR][/HR]200 lbs is quite a lot. how come it seems like the mk4 vr6s are as fast as the mk3s? gearing? the extra torque?
[HR][/HR]​
well....my opinion, based partly on racing, physics, and made up stuff:
1) the mk4 manifold gives it a hefty torque advantage between 2500 and 4000 over the mk3. Probably enough to compensate for the weight.
2) at speed (70+ mph) drag dominates the difference in weight between the two cars as far as forces go. The faster you go, the harder it is to go faster (ke = m*v^2 and drag = v^2/2 *Cd*A*density) so they'll seem more "equal" on the highway
3) theyre both fwd cars, so at a drag race, either driver is capable of making a tiny launch mistake that messes up the whole race.
4) in the end, the mk3 is faster. A good bit faster, but still well within the limits of marginal drivers like me.


[Modified by djsilvera, 6:29 PM 10-3-2002]
 

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Re: VR6 engine stays the same from mk3 to mk4? (billgti)

Also, there is an extra motor mount attachment point on the MK4's. So, and Mk4 block would work in an Mk3, but not vice versa.
Actually, the split is in '97. A '97+ block will work in Mk4's.
HTH,
Jeremy
 

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Re: VR6 engine stays the same from mk3 to mk4? ([email protected])

Sorry to inform you, but the extra mounting point as you called it go'es back to 94.
The early passat and corrado's do not have the 3 threaded holes in the pass side of the block.
Other than this point you can very easly swap these motors.
The cam chain is no big deal if you have a dual chain motor than just use the cam sprockets for dual chain's and if you have a single chain motor same deal, just use the single chain sprockets.
The upper side cover is diffrent from mk3 to mk4 the cam sensor mounts just a little different.
The cam sensor pick up is also different but can be swaped.
i guess what i'm trying to say that if you want to install a mk4 motor into a early car , you just swap over some small things and it's done.
If you want to swap a early motor into a mk4 and want a factory fit you will need to make sure about the bolt holes and air pump hole , if those are there than same thing some small crap and your in like flint.
 

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Re: VR6 engine stays the same from mk3 to mk4? (-=VdubGuY=-)

Sorry to inform you, but the extra mounting point as you called it go'es back to 94.QUOTE]
David,
Not to argue here, but we haven't seen them on anything BUT '97+ vehicles. All the '95s/96s we've seen and built motors for haven't had them.
Best,
Jeremy
 
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