DOHC 3.1

[skeeterone2]

okay i dont know if this was touched on at all before... but... since the 3.4 and the 3.1 are the same engine block... but the 3.4 is bored out... how hard would it be to make a 3.1 hybrid DOHC? ... the difference with the bore cant significant for the 3.4 heads to bolt up. i mean sh*t if that chould be done... but some of you might be laughing while reading this so just lemme know how far out my thinking is.

sorry about the double post but this is where this topic was ment to be.

[TurboZ24]

RE: DOHC 3.1

The 3.4 DOHC is the "Same" block, but there are several things on the 3.1 OHV that arn't machined on the 3.4 DOHC, for one the lifter bores.

[skeeterone2]

RE: DOHC 3.1

that wouldent matter... you would use a 3.1 block and 3.4 topend.

[Guest]

Re: RE: DOHC 3.1

that wouldent matter... you would use a 3.1 block and 3.4 topend.

No actually you won't, there is too much that is different between the blocks.

I've looked extensivly at ding a DOHC hybrid, it's just not worth the effort, you'd be better off destroking the 3.4 to a 3.0L.

[skeeterone2]

RE: Re: RE: DOHC 3.1

F... okay. well that stinks.. are the mounts dfferent?... oil lines?... coolant lines? i have access to a machine shop... eh oh well i'll take your word for it... back to a 3x00 hybrid swap.

[Anonymous]

I hear the oil passeges are also very different.

Why not just use a 3.4L DOHC?

[Guest]

Re: RE: Re: RE: DOHC 3.1

F... okay. well that stinks.. are the mounts dfferent?... oil lines?... coolant lines? i have access to a machine shop... eh oh well i'll take your word for it... back to a 3x00 hybrid swap.

It goes much deeper than just oil and coolant lines being different. Oil drain back from the DOHC heads is very different than the OHV version.
You would need to make lifter plugs to close off the lifter bores, otherwise you'll get no oil pressure and worse yet, no oil to the crank.

There are many other differences that are easier seen, by placing a DOHC head on an OHV block.

[skeeterone2]

RE: Re: RE: Re: RE: DOHC 3.1

yeah... well thanks it was just a thought... looks like a regular hybrid swap would be more worth the time... it would be cool to do an entire engine swap + a 5 speed... but i dont have the resouces to do that...<<<sigh>>> there is always that tight 2.8 turbo VVT on the horizon... i have to admit that engine makes me warm and fuzzy inside.

[Juglenaut]

RE: Re: RE: Re: RE: DOHC 3.1

The way the whole head bolts on is different.

you would need a untapped block. Basically a bare block casting is needed because the taps will not line up right that and the oil thing, coolant or water jacket is slightly different.

You would need a block that is prep'ed for a 3.1 bottom end, just that the top-end is left for you to tap or have a machinist tap them with proper specs. As long as oil get to the cams and floats down back to the pan would make a decent hybrid proto. And yes what was just previously said above in the post before.