Pre VVT Head swap options onto V70

[Camaro37]

Hi there, second post today so go easy


I'm looking at buying a 2001 V70 with the B5244S motor (2.5 n/a), its cheap, "well" maintained and looks pretty good.

I've done a fair bit of work on the swedes, owning an S70 2.5, 850 S and two 740's (Yay one was a TiC 4spd manual!)


Catch is tho that the uni student who owns it had the timing belt skip a few teeth, enough to bend valves. Knowing the 2.5 motor fairly well and knowing it was introduced in Aus about 1993 I rang up a wreckers yard to source a good 1998 S70 2.5 head. They confirmed yes and a $250 price tag.

So far all good until I realised volvo changed to VVT in about 2000. I've read of VVT long motor swaps into 90's 850's, but my question is has anyone heard of a pre-vvt (1998 2.5) head being swapped onto a 2.5 VVT block successfully? What other heads work?
Basically do the oil and coolant passages line up? Do they use different head gaskets?
What will be the challenges?
My fabrication skills are a little weak but I have a MIG and tons of grinding experience from british classics

Thanks, and to answer any fears I'm pretty sure the piston crowns are fine, I can vouch for their durability. I think the belt slipped when it was a cold start.

[precopster]

It's your lucky night!!

FYI The older 850 blocks will go in to a later car with some add on welds and later sump though I know this isn't what you're chasing

I have a 850 square port head which is going in to a project car. While I had my 1999 V70 motor apart I did some testing.

The 850 cam will not go into the 1999 head because there is a ridge in it which will have to be machined in (I can take photos if you like)

However there is physically no reason why you can't put an early head on a later block. Later pistons don't alter in dimensions or compression (though the oil control ring is situated a little lower on later pistons) Even the coil pack threads are there on the old heads!!

You will need the early metal top engine mount (instead of the aluminium one)

The metal bracket under the inlet manifold which supports its weight will line right up to the block.

You can put the CVVT cams in to the old head and the threads for the newer Denso cam sensor (which is on the inlet side) will be your old distributor threads. On the old cam sensor side you simply use the plug which you can purchase from FCP or Volvo.

The only problem I see (and it is a big one) is that the ECM will be trying to control the CVVT which can't be added to the older head. Performance may suffer as a result.

[Camaro37]

Wow man thanks so much, I actually saw a really nice 850R for sale in Victoria that was kinda tempting but 16K was way too steep for me.


Yeh I suspected it was pretty interchangeable, I was told by a mate you could stroke the early non VVT n/a by using a turbo 2.4 crank with different pistons but he may have been mistaken?

The other thing, is it worth matching the port size to the gasket, or is it just extra work without gain?
I was a little worried that maybe newer manifolds wouldn't fit older heads due to possible design changes. Oh and thanks for the heads up about the metal top engine mount, bit hard to bargain that into the deal after its been bought

Great photos too, I read a thread on here that actually said VVT was only really an economy feature on n/a motors, disconnecting it made no difference except a possible CEL, however they soon after went aftermarket ECU so hard to tell.

[Camaro37]

As it turns out its ok to swap on a early head, but there can be slight running/ idle issues.

[SVTGuy02]

So what came of this? Can you just disconnect the VVT and remove it from the tune and be done with it?

[abscate]

Creaky old thread alert

[precopster]

Title of thread says "pre VVT head swap options" so even if you had VVT it can't be disconnected unless somehow locked in place. This particular head from a 1999 non turbo was non VVT. Turbo cars inclusive of 1999 and post this era are VVT

The intake gasket you see in the above pic was a VVIS intake gasket (used before 1994 in the USA) with a much larger port size than the usual 850, V70 or S70