Is it possible to bore 3.4 v6 to higher displacement?

[run3]

My 3.4 seems dying now, need a rebuild, maybe engine shop can bore it to higher displacement?

BTW, i know 3.4 is been bore from 3.1, perhaps it's not that easy

[Marty85]

Anything can be bored...its just a matter of how much you have to work with. And im not too sure in our case with the 3.4's. If i were you though I would spend the money you would have spent on getting the block machined and put in a decent cam and valvetrain. It wouldnt be that hard to have it done if you buy the parts since the only diff would be installing new parts intead of the old parts. Also I think any gain you would see with a slight increase in cu.in. would be attainable if not beatable with a good cam, supporting mods (better flowing intake and exhaust) and maybe a tune. A little extra cash when you get it rebuilt will go alot further than just getting it bored in my opinion.

[viper98885]

It can be bored, but only to about .030" over safely. Anything more than that would be unsafe due to cooling issues.

One main issue on the 3.4's (or any 60 degree V6) is that we use a flat tappet cam/lifter setup whereas the 3.8's use a roller cam. The flat tappet lifters will grind away at the camshaft lobes which, over time, will reduce the lift produced by the camshaft. When I removed my stock camshaft, the lift on some of the intake lobes was just rediculous.

My suggestion, rebuild the top end of the engine with a new, more powerful valvetrain system and camshaft. It will really bring the power back and much more.

[Marty85]

^basically what I said only in english.

[StudlyCamaro]

Originally posted by viper98885:
One main issue on the 3.4's (or any 60 degree V6) is that we use a flat tappet cam/lifter setup

thats not true, all the 3X00 motors have roller cams

[andrew.brandon]

I have a somewhat similar question. I can tell my 3.4 is just starting to fade on me. I am seriously looking into the 3400 setup. my question is how much would it cost to have someone look at the block to see if it needed to be machined and how much to machine it if needed?

[StudlyCamaro]

you wont need to have the block machined most likely, with the exception of having the cylinders honed, which most people can do a decent job at home with a rather inexpensive tool

but jsut for reference, i had a 3.4L punched .020" over honed, painted, freeze plugged, and had new cam bearings installed for around 200$ .... but from what ive been told, that was a hell of a deal

[teal99camaro]

if I were you, i'd rebuild the motor with parts off the 3400.. one guy on here has his to 200hp on all factory GM parts. He used the pistons, heads, and intakes off the 3100/3400. That seems like the most cost effective and smartest thing to do. look into it. I'll see if i can find the post.

http://www.fullthrottlev6.com/forums...?t=8935&page=1


Read that in its entirety. You will have one of the fastest NA 3.4s at a low cost if you're going to rebuild the thing anyway. good luck

[teal99camaro]

just use parts off the FWD 3.4l cars