Going with a 3.4 DOHC Twin boosted

[Aaron]

Or, since you're only wanting 3-400, just boost a stock 3.4 with a good tune and intercooler. The full build would be more reliable, sure, but there's nothing showing the DOHC is unreliable. Mine is well over 400 on a stock lower end turning past 7 regularly.

[Series8217]

Good point. I think Matt Hawkins put down 418 whp on a stock motor and did it for years. It sounds like the OP may be starting with a Motor of Unknown Pedigree (MOUP) though.

[Aaron]

Ya if I didn't have first hand knowledge of the motors history, at the very least driven it, I'd probably do hone/rings/bearings and a valve job.

There's no doubt it'd be more durable with a proper low end build, but I literally have seen a single lower end blowed up due to power. Or even a bad tune or high IAT's for that matter. The only blowed lower ends I've seen have been spinned bearings, and a hydro locked motor that bent a rod I came across.

[draven]

I agree, I did a fair amount of searching on failed LQ1's prior to sending mine off to the machine shop, and found time and time again, spun bearing after spun bearing... should've databased my findings but it was pretty prevalent.. but very little to no failure on those that were properly maintained, oil, belt, etc... I basically mimic'd much of what steven did to his lq1 just altered a bit for forced induction..

The one performance level failure that sticks out is the one from Ferrari Fan (355 rebody) who put down 430ish on only 12psi (97 LQ1) running $8F OBDI ecu tuned by Engineered.net here locally.. he turned the wick up to 17psi, without a VE re-map, and spun a bearing shortly thereafter. Thinking detonation or over sped the crank...

From the abuse steven has been putting on his LQ1 it looks like proper cooling and oiling block modifications have paid off..

[Aaron]

I don't abuse mine near what Steven does, but do have the turbo. Stock block with casting flash, I wish I had removed it but oh well. 7.5 quart oil pan.

Can we even say Ferrari Fan's spun bearing was a power failure? It could've been coincidence. And I don't believe increasing power would make the bearings any more failure prone would it? I guess his oil temps could have gotten too high because of the turbo, we'll never know that for sure though.

[Shaun41178(2)]

higher hp creates more loads on the bearings. Being as the bearings are small to begin with, you start putting more power to them, and you can push the oil right out from the bearing surface creating metal to metal contact. A synthetic oil as well as a thicker weight can help. I was making near or over 500 tq on my old iron head turbo setup and used a 50 weight oil. Never had an issue with rod or crank bearings. I am using 0w40 full synh mobil one in the new setup.

Dohc revs higher which might have been Ferrari fans issue. He might have also ran the pan dry. I don't know anything about what happened though, just read it for the first time here.

[draven]

Can we even say Ferrari Fan's spun bearing was a power failure? It could've been coincidence. And I don't believe increasing power would make the bearings any more failure prone would it? I guess his oil temps could have gotten too high because of the turbo, we'll never know that for sure though.

The $8F ECU was strictly MAP and with no fuel trim correction from a MAF. If he indeed jumped from 12psi to 17psi without remapping his enrichment VE, he very well could have detonated and wasted a bearing. Not as much an issue of increasing power but rather needing to pull timing (don't know if the $8F has knock control) or add fuel due to the onset of a dangerous AF ratio. But who knows if he had used block out some college kid's car with 80K+ miles on it too..

All I know is I read that he upped the boost on a mad mechanic forum I believe and I coincidentally saw it at Jeff's shop with a new crate GEN I LQ1 crate "made in canada" waiting to go in. I'll ask Jeff one day what he found when he tears down the block..

[Aaron]

Makes sense. I run Mobil 1 0W30 synthetic in my Fiero and my BMW.

[Series8217]

The only damaged rod bearing I have personal experience with was caused by my engine's intermediate shaft front bearing delaminating and sending trash into the rod bearings. That is what prompted my rebuild.

When Blue Shift took his motor apart the front IMS bearing was about to go too.

I think the difference between timing belt and timing chain tension causes the intermediate shaft to squeeze out the oil film when the motor is stopped, and then it gets a lot of cold/dry startup wear.

All water-cooled Porsche motors up until recently had an intermediate shaft also, which they opted to use a ball bearing on the front of, probably to avoid this very problem. However, that ended up being the Achilles heel of Porsche's engines. The seals fail on the ball bearings, the grease gets washed out, and then the bearing fails and explodes, ruining the motor case.

[draven]

The IMS front bearing on the abused 15K LQ1 I pulled recently was coming apart as well. The debris found in my main and rod bearings were probably from that, however, it did endure 3-4 jumped belts and a broken timing chain so I'm sure all manner of non-typical loads were present..

I wonder if, on a fresh belt, the load between it and the chain are more or less equalized and belt slop due to poor maintenance seriously exacerbates the issue...

hehehe, Yes, and the "remedy" for the boxster IMS bearing is to install a heavy duty ball bearing for longer life (inspections every 40K-50K) or they tap an oil line and run a standard pressurized bearing in its place, irony eh? Wife wants an early 2000s boxster so I've been investigating this very issue. Oddly enough, even with the destructive nature of the bearing letting go, there are "very" few in the yards, at least here in the SE.

But getting this thread back on track for the OP, for an LQ1.. start fresh from a rebuild or get ahold of a crate and perform a mild refreshening.. the average american driver doesn't maintain their engines enough to keep an LQ1 happy.. nothing this forum doesn't already know...

[Identity Crisis]

Well the story of this LQ1 is kind of interesting.

I got a 96 GTP in a straight trade for a 93 Ford Probe (hated that car), back in 07.

As soon as I got the car I was very meticulous with it and made sure to to go over the engine to see if there were any issues. Thankfully the original owner took very good care of the car (55 year old woman bought it new), then she sold it to a young man in her church for next to nothing he said and he only had it about six months and then he wanted something a little more sporty (his words not mine).


In the Fall of 2008 After loosing a race to a honda civic, I was lets say very unimpressed with the cars power to weight. January of 2009 I picked up a 98 GTP, pulled the engine and did a rebuild on it with some power mods.
I pulled out the old engine and dropped in the new one.


I then gave the engine to a good friend of mine that does work on the 3.4 TDC/DOHC as a gift for his help over the years.

Fast forward to 2013. I finally get my 87 Fiero GT and I want to upgrade the power plant. After lots of discussions and decisions I finally decided to go with a 3.4 DOHC and low and behold my buddy asked me if I wanted my old engine back. Only catch..... He tore it down for easier storage.
I now have my old engine and tranny back and I will use it for my Fiero GT.

[Aaron]

Interesting. The 96 GTP was one of my favorite LQ1 cars, I love them. How that kid could say it wasn't sporty enough is besides me lol. I'm also surprised you were unimpressed with the power, even with the auto the LQ1 always felt real strong to me.

That's a sweet looking GTP. Love it.

[Series8217]

Did you have the Getrag 284 or the 4T60E?

[The Dark Side of Will]

284 was only in '91-'93 cars.

[Identity Crisis]

4T60e. I plan on keeping the car auto. But will be looking at a higher stall.

[Series8217]

Oops, missed that it was a 96.