2.8l engine vs 2.9l engine also are they the same?

[malaki 0]

I have a 2.9 rado that I am restoring, I want to get hold of a second engine short or complete to bore out and rebuild before I remove the other one. Does any 1 know what the differences between these 2 engines? is it the same just different bore and pistons? can a 2.8 be bored to the same as a 2.9 could be? I just want to get it all sorted before the rotrex is fitted cheers.

[malaki 0]

bump

[junkie 0]

Im not fully clued up on the VR6 but i have heard for def that the 2.8 can be rebored to 2.9.

[malaki 0]

perhaps i didnt make it as clear as it could be, i want to bore out to 3.0 or 3.1 as ive seen this done a few times in the quest for big power ! money isnt that much of an issue but ive been offered a 2.8 for peanuts and just wanted to know if there are any inherant differences between the blocks themselves ??? if not then it wont hurt for me to bore the 2.8 instead of shelling out for a 2.9 which is obviously harder to get hold of ? any info would be appreciated 8)

[junkie 0]

As far as i know the 2.9 came from the 2.8 so essentially whatever you do to the 2.9 yes you can do to the 2.8 in theory, i may be wrong though mate.

 

If your going FI then do not go 3.1, chesewire did along with others and there is not enough material left in the cylinder bores to cope with the heat, but whether thats turbo only i dont know but he was only running around 12psi. Destroyed the block in not so many miles.

[malaki 0]

nice 1 has any 1 else got any info ar facts on this cheers from malc

[dr_mat 0]

2.9 block is a rebored 2.8, straight from the factory, they are otherwise identical.

3.1 is pushing your luck a little though, by all accounts.

[malaki 0]

are all the other components ie the crank and the conrods and head the same between the 2.8 and the 2.9 is it only the bore and pistons that differ between the 2 engines cheers from malc

[dr_mat 0]

AFAIK yes, though there may be minor differences in the cams and the inlet manifold, depending on what car you source your 2.8 from.

[cata 0]

I'm pretty certain about these differences:

-Bore

-Pistons

-Upper intake manifold

-Throttle body

 

The only thing left is the ECU and I'm not very sure but a remap would eliminate that problem. I wish we got remaps on this side of the pond, there's only one place that I know of which does it.

[H8RRA 0]

3.1 is pushing your luck a little though, by all accounts.

.....unless you have a long stroke crank :-)

 

I've also possibly got a 2.9 block suitable for rebore open to offers

[junkie 0]

And when you stroke engines yes you get more capacity but it will not be as rev happy.

[Kevin Bacon 5]

Indeed.

 

3.1 isn't possible with bore alone. You would need 85mm pistons (3074cc) and there just isn't enough meat in the block for that.

 

As H8RRA says, you need to do it with crank throw instead. A 95mm crank throw with 83mm pistons would give you a tidy 3084cc.....but you'd need to use special pistons with 4.7mm shorter crowns. It gets expensive and complicated. Not worth it!

 

Just stick to 83mm bore (2931cc) with a blower ;-)

[malaki 0]

has any 1 got a 2.9 engine short or tall suitable for this thart i can get from them cheers

[VRTrickster 0]

I think bigpants baby may have a couple of 2.9 engines.