Jump to content

hi-po3.1 vs 3.4


ThunderBat

Recommended Posts

check out this link about the 3.4DOHC...

http://www.angelfire.com/ca2/34Performance/dohc.html

 

its a bit of a lengthy read but a good one...obviously someone who knows his cookies about the LQ1...this one really seperates the men from the boys and I'm afraid I fall into the latter category here...I do love a hi-performance car and I do like modding them and doing the occasional tinkering and maint... but this is definitely one racy hi-maint baby!

So given this info, does anyone here have a hot rod 3.1 under the hood of their "W"?...and if so what mods did you make to it?

Link to comment
Share on other sites

someone posted a scanned pic of the prototype Lumi Z34s

285HP and like 285 - 300ft/lbs of torque

 

 

it was a 5.0L V8

not a super V6...

 

guy likes to over exaggerate the maintenance, though :D

Link to comment
Share on other sites

im sorry but hot rod and 3.1 dont mix. i have a 3.1 and have done some serious work to it but that is not the one in the car. i got a 3.1 from the junkyard and im buildin it up. port and polish heads,intake,exhaust, had the heads shaved and i have 23lb. injectors in her. thats just the start of the list but i wouldn't say the 3.1 is a hot , it is a beast

Link to comment
Share on other sites

Jesus I wish i had access to that guys traffic!

 

Old website and many of those things have been debunked MANY times before

 

*Edit* I just notice that it has been changed AGAIN! Well, that's good because some of the stuff it was promoting was junk.

 

One thing I remember was about the sodium-filled valves. ANother about NOT putting headers because the exhaust manifolds were perfect and "i couldn't imagine putting headers into this beast"

Link to comment
Share on other sites

That guy is generally conceived to be a dumbfuck. Nearly everything he said was wrong.

 

I'll take a few right now...

 

Trannsmission the cause of 210 not 285hp-Not at all. GM can build a tranny for anything. If they wanted it to have 285hp, it would have, just not in 1991, but in the later years after they have developed a tranny. it was becuz a 5-speed 285hp Z34 would have beaten their Corvettes. How does your company look when your V6 family grocery getter can beat your 2 seater sports car?

 

The oil cooler only came on rare 3.4s, not nearly all.

 

He still says the valves are sodium filled.

 

IIRC, downpipe is 2.5", not 3".

 

Our intake is a tuned tunnel ram? Yah right. Tuned maybe, for 5500rpm max power and 200-210 of it. Tunnel ram? I guess...But by those standards any intake on a car is a tunnel ram in one way or another.

 

7,000rpm screamer? No, more like 5500. They dropped off bigtime after 6, the 5-speeds can barely redline 3rd gear stock becuz power falls off. This becuz of the "tuned intake"

 

EH then says it has a 6500rpm redline, its 7. And he says the 70hp cutback was in fuel tables and spark, which we have proven could only take out about 10hp, not 70.

 

91 models aren't really scarce by any means...

 

the intake manifold DID NOT change every year after 1992. There were 3 setups, not 5. 91-93(MAP), 94-95(No MAP but same design), and 96-97.

 

 

At this time I think i have proved my point and am sick of reading his article. He knows his general motor information, but not in terms of the 3.4L.

Link to comment
Share on other sites

it was becuz a 5-speed 285hp Z34 would have beaten their Corvettes. How does your company look when your V6 family grocery getter can beat your 2 seater sports car?.

 

I AGREE WITH AARON!!!!!!!!!!!!!!

 

....same reason the GM killed the Fiero, the 1990 prototype put the vette to shame....

Link to comment
Share on other sites

actually aaron, the intake runners are tuned, and tunnel ram. Its the plenum area and the transition from TB to plenum, then plenum to runners that is choking the motor. The runner length is tuned for 7200 RPM, hitting the 3rd and 4th harmonics at lower RPM.

 

The 3.1 can be built up, but the majority of people on this site don't know how to do anything to it other than swap it out for something else.

Link to comment
Share on other sites

Guest TurboSedan

The oil cooler only came on rare 3.4s, not nearly all.

 

 

i've seen oil coolers on 3.1 W-bodies before in the j/y, and they looked exactly like the DOHC W-body oil coolers to me. the oil coolers weren't a DOHC only thing.

Link to comment
Share on other sites

given the fact that I have no personal experience with the 3.4 I cant refute anything thats been said here...I'll assume that you guys do know better since many of you do own and have turned the wrenches on these cars. While I can easily see how a lot of the particular tech points (redline,intake runners,valves) can be in error, I noticed nobody disputed the amount of maint this engine requires or the difficulty in performing that maint...which to me would be the major discouraging points of owning one...I suppose I just dont it being worth the time and effort when there are other engines that make just as much power, more bottom end torque and are more reliable. There also seems to be a fair amount of aftermarket for the pushrod 60degree engine and if the stone stock 3400 makes 185 then 225-250 doesnt seem like a huge stretch...I wish GM would try their hand at say a 4.0L 60degree V8...I think that would be a compact engine that would make great power, be light in weight and reliable to boot (didnt someone say the Z34 prototype was a V8?)

Link to comment
Share on other sites

I havent read that site in a long time and the maintenance to me isn't difficult. Other people bitch and moan about having to change their oil so it really depends on who you ask. If you pay a shop to do your work, don't get a DOHC. The power potential of the DOHC is far greater than the pushrods right now, minus the 3900 coming out which may come with a 3 valve per cylinder setup down the road.

 

60 V8 is no good, same as 90 V6. Yeah, you can do it but I wouldn't want it. The V8 lumina was just for testing. There was an AWD beretta as well I think. If you want a 4.0, get the 3900 and bore it out to a 4.0.

Link to comment
Share on other sites

the maintenance isn't really any harder on a 3.4 than a 3.1, it just takes a little extra time.... the only real major difference is the timing belt and alternator... the rest is pretty much the same... at least it was in my brothers 3.1...

 

hell, the longest part about changing the water pump on the 3.4 is draining the coolant :lol:

Link to comment
Share on other sites

So given this info, does anyone here have a hot rod 3.1 under the hood of their "W"?...and if so what mods did you make to it?

 

I've got a factory "hot rod" 3.1 in my TGP. :wink: Search the Turbo part of the forum if you want to see how to make itl

Link to comment
Share on other sites

it was becuz a 5-speed 285hp Z34 would have beaten their Corvettes. How does your company look when your V6 family grocery getter can beat your 2 seater sports car?.

 

I AGREE WITH AARON!!!!!!!!!!!!!!

 

....same reason the GM killed the Fiero, the 1990 prototype put the vette to shame....

 

yeah i'll agree to a point here as well, thats one of the reasons the grand national was killed.

Link to comment
Share on other sites

ok...for the record the n/a 3.1 is not in any way a hot rod!

 

the 3.4 DOHC is by far a more advanced engine and has alot more potential than the 3.1 ever will

 

the n/a 3.1 is sluggish, slow, and pretty much nothing more than a really reliable engine

 

now the 3100 and 3400 have more to say about being a hot rod if your going that route

 

but anyways...woohoo for the 285HP Z34...I wish GM woulda had their $hit together and actually produced it, that woulda been kick ass!!!! 8)

Link to comment
Share on other sites

 

the n/a 3.1 is sluggish, slow, and pretty much nothing more than a really reliable engine

 

yup. i don't think it's enough engine for a heavy w-body.

 

i've drove an iron duke lumina, it is seriously not enough engine for the car.

Link to comment
Share on other sites

I do believe they orignially were able to get 300 HP out of the 3.4 DOHC engine, but because of transmission building costs (making all new tooling, and a sepperate transmission for ONE car) the costs far outweighed the need/want for it. There's ALSO the problem of it kickin' the shit outta the corvette's I don't know if it'd have gone as far as to kick the shit outt them, but even if it could've kept up with them, it'd have been a huge red mark against GM for that manuver.

 

I found a listing somewhere of the GM prototype engines, and some of their designs - I'll see if I can't find that book again.

 

Aaron ... I'm suprised you didn't call this guy an idiot for his headers comment - he says the cast manifolds are good enough to move the exhaust ... where this is true, it does not mean that the manifolds are good at sepperating the exhaust pulses to offer the best available performance.

 

--Dave.

Link to comment
Share on other sites

I know that GM has or used to have an "unofficial" rule that no GM car could have a higher power rating than that year's Corvette. Hence the reason that the '89 25th anniv TTA with turbo 3.8 was only rated at 250HP (more like 300 in actuality). Guess what the HP rating of the Vette's TPI was that year? :wink:

 

I would hardly consider the 3.4 DOHC to be anything in the Vette's league however.......

Link to comment
Share on other sites

Well, in 91 they had 245 hp and 345 torque torque. Had GM made a 285 hp V6 that year, how hard would it be to run with the corvette at a fraction of the cost? Sure, the torque wouldnt' be there but with the close ratio 5 speed, it wouldn't be getting its ass kicked either at the 285 hp/tq mark. Granted the rest of the car wasn't going to be on teh same level, but the motor surely could put out more hp than their V8. In 91, what other motor in a GM car was over 200 hp? Im just curious...but you say it wasn't in the same league...only if you compare it to the LT5.

Link to comment
Share on other sites

I think the manufacturers have come to realize that the performance car purists almost always demand RWD/AWD...thats why cars like the Miata have survived all this time...they arent particularly powerful but they are lightweight and fun to drive (and they get huge aftermarket support) The Miata is the very reason Pontiac green-lighted the Solstice.

Getting back on topic tho...a couple of previous posts stated that the n/a 3.1 is no hot rod...I have no arguement with that at all...what I was after was there anyone who had modded a n/a3.1 to make comparable power. Kind of like the old Chryco 318, in stock trim it was a reliable engine with ho-hum performance...but a few simple mods could make it a serious performer...am I correct in assuming that the top end of the 3100/3400 will swap onto the 3.1 short block?...the turbo idea sounds interesting but cobbling together the parts could be a major task all its own...Lastly I think the one thing I dread most about the idea of owning a 3.4 is the timing belt...especially since the cams aren't clearly marked or keyed. Granted I've never done this job before and maybe if I did it one time with someone who knew his stuff I wouldnt be so intimidated by it...I was reading over on 60degreeV6 that a simple cam adjustment (6 degree advance on the intake, 7 degree retard on the exhaust...I think) brings a pretty substantial power boost...I gotta admit, go fast mods dont get much cheaper than that!

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...