Anyone hear of the 3.4dohc having 275hp originally?

[JH]

I saw something written on the internet about the 3.4dohc having 275 hp when it was first designed but was taken to 200hp by cutting the fuel delivery and spark advance curves because of tranmission warranty problems does anyone know if this was true?

[SappySE107]

Maybe it did, but it wasn't released that way and it certainly didnt have that much power with all the parts that it was released with. The site you read this shit from used to have even more crap on it it, and still has quite a few lies. No, the computer alone wont give you ungodly amounts of power. No, the exhaust valves aren't filled with sodium. No, the stock exhaust manifolds are not defying the laws of common sense and somehow NOT restricting the exhaust gases.

Who knows what GM originally had designed this motor to have, with different cams, heads, pistons, intake manifolds, exhaust manifolds/headers, and then....tuned for all those parts.

[Rhedalert]

This question is almost as common as "Will the L67 drop right in....."

[TheProfessor]

yeah that was a relly hyped up version of the 3.4 never released
probably GM just trying to see what was possible

[dbtk2]

Just like the original Turbo 3.1 was 305hp, not 205. The test engines are always more powerful than the ones they release.

Shawn

[JH]

Lol that sounds exactly like the site i saw. Just wondering if it was true i guess it isn't

[blk92z34getrag]

It may have been true. There have been Desktop Dyno runs with defferent cam specs, and using the "Official" GM specs I think there was an enormous gain. You'd have to dig up the thread. I'm sure they didn't release this because of reliability reasons.

Or maybe they didn't want FWD "family" cars smoking the Camaros and Corvettes of the day.

[SappySE107]

The official cam specs were wrong. GM decided to rate the duration at .2...or something like that. I corrected the site page with the specs months ago.

[TheProfessor]

thats kinda like the quad 4 that they tuned the shit out of and got like 1000hp out of it
im sure that badboy didnt last more than a couple of minutes

[PlatinumZ34]

i dunno i can easily see 280 hp out of these motors. Im not saying they did or didn't, but its very possible... and it damn well should be...

its a 4 cam 24 valve 6 cylinder 207 CI monster. 210hp seems pretty low, if it was a 12V pushrod it could probably be making around 210 quite easily.

I personally believe there is an unbelieveable amount of untapped power in these bad boys, im going to take it to a tuning shop here in town that specializes in imports and see what they can do. Since the domestic shops are like "DOHC, ya they make pretty good exhaust". (the import shop has also done several 32V northstar swaps... into old golfs)

I have some old magazines that did previews for the Z34... and they talk about the "throaty 4 pipe exhaust" and "mustang smoking power... in a v6"...

this is coming out of the magazines that didn't get picked up by ford, chevy or chrysler (such as motortrend and car and driver, which are sickeningly biased)... which is why they're no longer around.

[Anonymous]

You are right, and there is untapped power.

IMO, and proved by a dyno sheet, it can be achieved easily with a better intake manifold, headers, and cams. Not to mention what head work, higher compression, borexstroke, etc would do to it.

[blk92z34getrag]

Speaking of untapped power and what-not. I'm going to be needing to rebuild my engine within the next year. For boring over, I've heard .020 is fine. What kind of power gains are we talking about with any sort of boring over? I also want to deck the heads, but I forget what is safe without causing the engine to become interference.

Also, since I am boring it over, I would like to destroke slightly, to raise max RPM and cut down slightly on mass with shorter connecting rods. All of this will (obviously) have to be custom made, which I can probably find someone to do. What is the PROPER way to destroke? And is this even worth it? I know there is an optimal bore:stroke ratio.

[Anonymous]

Well you aren't going to gain much from a .020 over bore. That is a pretty small bore, basically it is good for cleaning the cylinder walls. As for the stroke, you can use a 2.8L crank, it had a lower stroke than the 3.1/3100/3.4 TDC/3400. But why not keep the stroke up? The 3.4 already can hit 7k without problems, and its been proven that it can hit 7600 with a new intake manifold, and mine will be hitting 8. And these are all on stock stroke, maybe higher. The weight gains you'll notice by shortening stroke will not be worth the power loss.

[blk92z34getrag]

I was just looking at the chart, it says .060 is the most you can do safely.

Would it even be worth it to bore that much? After the cost of pistons, rings, etc. I don't think it would be.

[Anonymous]

Well I am using Wiseco for my pistons, and the price is nearly the same if I go stock, 20, 30, or 60 over. There is like a $10 difference per piece from stock to .060 over. And since my rings are going to be custom Total Seals anyway, the price is also nearly the same. True its $5 here, 5 there, but all in all a .060 bore makes up for $100 extra.