[SSandman]

So I have been doing the research and talking to those who are in the know as I have been debating swapping over to an LQ9 setup to run boosted via procharger.
Obviously the LS is the motor of the Gods and it has no issues...or at least the internet seems to think so. Speaking to my machinist (Jeff Lawrence of Lawrence Racing Engines Inc and a few other machinists I know they all pretty much had the same two gripes with LS motors

valvetrain first oiling and 10 head bolts vs SBC's crank first oiling and 17 head bolts. Now obviously there are guys still making huge power with these drawbacks but the surefire way around it would be to go with an LSX block, 6 bolts per head and crank priority oiling. But that's big money and overkill for what I plan to do.

Anyway, it just kind of surprises me that my machinist, the engine builder at my shop and his friends shop (Merkel) all seem to urge me to keep the SBC (LT1) for my 750hp+ boosted project. I mean these are the guys in the know, I know jeff has done many LS builds and he practically flat out talked me out of spending more money with him in scrapping my already paid/machined/balanced LT setup for a new LS setup. Hell, after talking to AI about their LS head combination, they told me that the 200cc LT1 heads I have from them now should support the power levels I wish to make.

What do you guys think? I am kind of on the fence here. I was all set to go LQ9 for the big power it can make...but I hate to think i'd be going with a setup that may have more weaknesses even though it'll have the ability to make more power. Ideally I would go LSX, but then im getting into big money for an LSX block and aftermarket heads.
Obviously, there ARE guys out there making big power with LQ setups....but likewise there are guys out there making big power with LT1 and SBC setups too on factory blocks.

 

[55belairgasser]

SSandman, I am in a totally different boat then you, so my answer may not really apply. I still have a stock bottom end and mostly stock top end, so with very little money invested I will more then likely go the LSx route. I have seen some very impressive numbers from the LT1's so you never know....and with the LT1 you don't have to change the harness. I have seen a lot more help with the LSx motors from the aftermarket with everything and a better and more friendly tune crowd. If you already have the "perfect" setup for the LT1, give it a try first. If it does not work as you wish sell it off whole or piece it out to make some of your money back. Good luck in what ever you choose! - Lance

 

[SSandman]

SSandman, I am in a totally different boat then you, so my answer may not really apply. I still have a stock bottom end and mostly stock top end, so with very little money invested I will more then likely go the LSx route. I have seen some very impressive numbers from the LT1's so you never know....and with the LT1 you don't have to change the harness. I have seen a lot more help with the LSx motors from the aftermarket with everything and a better and more friendly tune crowd. If you already have the "perfect" setup for the LT1, give it a try first. If it does not work as you wish sell it off whole or piece it out to make some of your money back. Good luck in what ever you choose! - Lance

Thanks for the reply Lance! It does make sense to try out the LT1 setup first, as for all I know it could accomplish my goals and then some. My only issue is the car is all apart now, frame off, doing new everything pretty much and I will probably never have the money, time or motivation to do something radically different with this car again. I have my fathers 70 challenger that was passed on to me some time ago and the Impala has pretty much not allowed me to do anything to that car but keep it running. I'd like to get back into that car someday. If a motor blows on the SS, I'll take it out and repair it...but with all the time I am putting into paint, powdercoating and all that other stuff...once it goes back together as an LT1, it will probably stay an LT1.

It just worries me of how many guys actually practically talked me out of spending money with them in telling me to keep the LT setup. It seems like the guys 'in the know', while still impressed of the head flow numbers of LS stuff, aren't nearly as impressed with the rest of the motor as the internet is. These aren't part time engine builders or back woods machinists I am talking to either...I would understand then that some guys just like to stick to what they know. These are guys that run big scale machine shops, build competitive pro racing motors, are always trying different things ect...

I wanted to go LQ because I figured it would be the SAFER option for boost, make more power which nobody denies but will hold up as well. The extra money i'd have to spend on ditching my old setup would be worth it if that was all true...but I am not so sure now.

...wishing for an LSX block lol

 

[big_tugg'SS]

SSandman... If you read back in my post, I always defended LT1's, they are not that bad of a motor even compared to Lsx... I've also been told by MANY creditable people with my money invested to stick with the LT-1 and that the "gains" are not worth it for my goals. I mean I've had in my hands LSX 427 built shortblock (2500hp) but talked out of it because for my goals it was over kill!

Doing the finishing touches on my build...I would ditch LT1 pcm and opti and with those upgrades faith might be restored for you and LT1's.

If it is tough decision, after the new year I will post some vids of my car, maybe you will look back and what I said a long time ago and vids would just motivate the hell outta ya

 

[greenturtle05]

To the OP if i were you, i would go with the lower compression lq4 which is the same as an lq9, but with dished pistons as opposed to the lq9 with flat tops. You can find lq4's a whole lot cheaper than lq9's.Most people running boost uses lq4. Not knocking the Lt-1, but the ls line has a ton of after market parts out there, and tuners. there aren't much people out there that still tunes the opti, so you won't be limited. To me it's a hell of alot easier to make more power with an LSx motor. 450rwhp n/a is nothing for an 6liter to make. Just my 2.cents. Its all up to you.

 

[big_tugg'SS]

To the OP if i were you, i would go with the lower compression lq4 which is the same as an lq9, but with dished pistons as opposed to the lq9 with flat tops. You can find lq4's a whole lot cheaper than lq9's.Most people running boost uses lq4. Not knocking the Lt-1, but the ls line has a ton of after market parts out there, and tuners. there aren't much people out there that still tunes the opti, so you won't be limited. To me it's a hell of alot easier to make more power with an LSx motor. 450rwhp n/a is nothing for an 6liter to make. Just my 2.cents. Its all up to you.

you believe it is worth starting over for a lq4? You mentioned tuning and opti, so say if those became LSX for the LT1, you believe for a 700hp car lq4 is worth starting over?

 

[greenturtle05]

I don't know how much cash he has tied up in his current motor, i was just stating my opinion as i'm entitled to. For me i was going to build a 406 to go in my car but that changed after doing more research. In my case those ls engines are more reliable,and gas friendly with the latest technology of today. i want to be able to drive my car with out having to stop at every gas station. It aslo takes alot to get a gen 1 or 2 sbc to those power levels that's all i was saying. But to the OP the Choice is yours.

P.S He could always sell what he have to help generate cash for a new build.

 

[juicedimpss]

what do the lt heads flow vs the lq heads?

 

[SSandman]

Tugg, hell yea man. Definitely looking forward to some videos of that beast running. I agree that an LTCC setup and FAST and i'd be on my way to an ideal LT1 setup. The reason why I was leaning towards LS was because I figured if I went to LTCC for the blower setup, after that money spend I might as well just put it towards and LS setup because it would be 'better'. But now I am not so sure.

Green Turtle, LQ9 or 4 wouldn't really matter for me as i'd be using a Callies rotating assembly with JE pistons....i'd be doing a 408 stroker out of it anyway so nothing but the block would remain. As far as WHY the LS makes more power, it's no mystery. Plain and simple it is head flow specs. Most 23 degree chevy stuff doesn't come close. Of course there is 18 degree racing stuff that can match LS power no problem. We all know that flow isn't everything, which is why I believe that AI LT1 heads seem to make more power than other heads with similar flow numbers...but for the blower port velocity doesn't matter so much as raw cfm's.

With that said, I already have AI 200cc LT1 heads. They don't flow like a set of ported L92/LS3 castings would but they are still pretty good. I believe 290-295 cfm's vs the 340-350 cfms that guys are getting from ported L92/LS3 castings. I was talking to Phil at AI about doing a set of LS3 heads for me, and they told me that their LT1 heads that I already have should be able to produce 600-800rwhp with the blower. I believe i'd need somewhere in between those numbers to get my pig heavy car into the 10's.

They admit as do I that the LS stuff could MAKE more....and even though there are plenty of guys supporting big power with factory LQ9 blocks the inherent flaws that all the machinists have been pointing out to me make me wonder if going LQ9 may not be an upgrade at all. It would be nice to have the potential to MAKE more power, but the whole point is to make more power WITHOUT sacrificing durability/longevity. When comparing the downfalls to the factory LQ9 to SBC...it seems that the only way I'd be able to accomplish that is to go with an LSX block and do away with the valvetrain first oiling and add some head bolts.

 

[big_tugg'SS]

Sandman, did we talk to the same people! LOL!!
What I got was if I wasn't gonna do my 427 LSX build (and was ready to write another 15k check) then stick to LT1. I hear the whole better gas mileage, reliability etc, etc, but it is starting to seem like a broken record. I mean I guess for a bolt on car swap (and your LT1 is not completely decked) then why not. But if your talking 800hp and gas mileage? Or 800hp and reliability?? Now granted I drove from Fayetteville to Charlottesville on 1 tank of gas in my impala... w/ 4.10 gears on stock tires! That's about 5 hours on the hwy, and I'm sorry but that is beyond good for me!

Sandman do u already have LTCC, if not I say go one step further and do the conversion!!! That's what I did!

 

[ProTools4]

From first hand "I tuned it" and "my shop put it together" experience

at a SAE corrected 1000RW your going to have a hard time holding thick deck after market heads on even the legendary LSX block with even the largest head studs

at 900RWHP an LS3 alum block with deform underneath thick deck aftermarket heades with the largest head studs
that is if you get lucky and dont split the webbing in half!

water consumption and minor leaks under boost are kinda a given at this hp level at the track
but on the street this becomes a major issue

the additonal clamping force and structure of the older block is a big advantage on the outter limits of street power.

guys like Tom Nelson seem to have the right stuff in the righ quanities for massive street HP.

Fact is if one cell is tuned bad on a 400ish cubed motor making 1000wheel it is doomed and WILL GO VERY BAD in a Hurry!

But your builder has a point,
tuned correctly
set up correctly
in the big power game holding the lid on the block is a major concern

 

[SSandman]

Thanks Tad, as always your advice/first hand experience is much appreciated! I wish my shop did more late model so I could see some of these things first hand, we do a lot of 1000hp cars but they are always big cube big blocks.

I am not looking to make any more than 700-750rwhp. I don't know if my fuel system would support it, I wouldn't have a drivetrain that could support it and my chassis sure as hell wouldn't hook worth a damn. I know there are LQ setups that are living at this power level...even if they have inherent weaknesses on paper. It will no doubt cost me a few more grand to build a new LQ setup (machine work, parts ect...) especially considering that I probably wont fetch a premium for my old LT1 stuff. At this point I am thinking that it just isn't worth spending any more money to go LQ when there may be no advantages to be had other than a bit more power that I probably wont need. Maybe i'll keep my eyes out for a cheap LSX block but if I don't find one cheap I think I should stick LT1 vs spending more money on a platform that MAY be less able to handle big boosted power.

What are your experiences with high hp boosted LT1's Tad? Talking reliability, streetability, power ect...

 

[ProTools4]

What are your experiences with high hp boosted LT1's Tad? Talking reliability, streetability, power ect...

have done one good stand out
Joe Mejia / Race-Prep forged / built 383 D2SC LT1 in the 850RWTQ range
engine has broken everything else but the motor
this car eats money

right now the customer had me set it on soft mode to keep his wallet intact
21 degrees of spark advance and low 11s AFR make it soft
still makes 8000+ TQ but kills the HP to only 650s

If the FUEL system is nice and the tune is nace 2bar
Boosted LT1s LIVE!

I have a customer will a FULLY STOCK LONG BLOCK f-body t56
**vavle covers and manifold have never been off!**
V2 / Fab9" / LTs / 3" Ypipe / twin intank dual pumps / 12 AN / tiged up rails / dual feed / dual return
..the Kicker...
500RWP on the stock long block streetable stupid sidewayes in 3rd, 22" of idle vacuum 91 pump gass street fun!

I would love to build;
-stock 4bolt Y-body motor & cam
w/ ported heads and ARP hardware /242Toil pan
-2x volvo 850 T5s turbos fed from Long tube 4:1 headers
-twin symetrical dual feed dual return fuel system
-2bar PCM / LTCC
600RWHP and TQ all day long!

 

[defdaboss]

you could choose lt1 over lsx. my MAIN reason for swapping the lq4 engine in mine is for the value. it's not a real impala ss but a caprice with that motor would cost MORE than a stock impala around here so it's just better money invest. and im not paying anyone to do the swap.. im taking the excitement of doing it myself. rebuilding from bottom to the top. it cost money but im not planning on dying too soon so it's plenty of time to finish this project.

FWIW. my engine is currently on a engine stand. im still running around in the LT1 till my engine is completely ready to go with every parts to complete the swap. it's my DD.

 

[ProTools4]

at 5-600RW the LS / LQ motors are a better value. IMHO
but the added cost and difficulty of a platform swap in a b-body will offset that...

Now if your starting with a new bare chassis or vintage there is no reason NOT to go LS / LQ in the 5-600RWHP range

If your a hard core racer and spend lots of time on track and tweakin with the car HPTUNERS realtime tuner suite can be a deal breaker on Gen2 vs Gen3!

 

[big_tugg'SS]

Tad what other problems have u seen with 1000rwhp builds? I just wanna keep my eye open to see how many will pop up my way

 

[ProTools4]

Tad what other problems have u seen with 1000rwhp builds? I just wanna keep my eye open to see how many will pop up my way

-head / block clamping force and deformation issues
-G-force oil sump starvation 1000hp is drysump & vacuum pump territory
-inadiquate oil filtration and cooling combined with sc/turbo drainback / feed flow issues
-under designed under specd fuel systems that over heat pumps and fuel pump cavitation issues
-too small exhaust sytesm leading to pre detination / hindering the quest to big big numbers due to heat and pressure stacking in chamber and exhaust valve
some time duel 3" is not enough!
-nasty habbits of breaking fresh drive line parts that were claimed to handle X-HP level via the orignal venor / mfg

My mottos are
if you use a zip tie you did it wrong
if you used a butt splice you did it wrong
hose is bad, AN is good, hard line is better
dont use a sheet metal screw were you can put a bung or a thread
attent to detail, clean clean clean, simple is better
the best work looks like it came that way

 

[SSandman]

-head / block clamping force and deformation issues
-G-force oil sump starvation 1000hp is drysump & vacuum pump territory
-inadiquate oil filtration and cooling combined with sc/turbo drainback / feed flow issues
-under designed under specd fuel systems that over heat pumps and fuel pump cavitation issues
-too small exhaust sytesm leading to pre detination / hindering the quest to big big numbers due to heat and pressure stacking in chamber and exhaust valve
some time duel 3" is not enough!
-nasty habbits of breaking fresh drive line parts that were claimed to handle X-HP level via the orignal venor / mfg

My mottos are
if you use a zip tie you did it wrong
if you used a butt splice you did it wrong
hose is bad, AN is good, hard line is better
dont use a sheet metal screw were you can put a bung or a thread
attent to detail, clean clean clean, simple is better
the best work looks like it came that way

Amen! We do a lot of 900hp+ bigblock old school builds and the one thing you'll notice about it is we are using HUGE primary headers, HUGE exhaust system, big money oil systems ect... Meanwhile it seems the late model crowd thinks they can get away with 1000hp on 1 3/4 primary headers and a 3" exhaust with factory style oil control. Yea, I guess you can make it work but it's kind of like trying to run through the woods barefoot. You can do it but you'd be much better off/safer with shoes!

the one key advice I have learned in working at my shop (especially when we do late model builds) is that !!!!!SERVICEABILITY!!!!! cannot be stressed enough on ANY setup but especially on high hp setups. Things needed to be taken apart, changed, fixed ect... is a frequent occurrence. You want something that is simple and clean and can be taken down to the last nut with the least amount of trouble. I have worked on so many cars that we didn't build that are just downright STUPID. People want to hide this, or put that over there or wire it without planning. It makes things downright painful to work on.

Second thing I learned is it always pays to do it right. If you want 10000hp....it'll be cheaper in the long run to use an aftermarket block. Don't think your saving money on factory stuff because after it breaks and takes out your big money rotating assembly you'll be wishing you didn't.

Another thing we do a lot is have customers have us cut up the front of their car to install a rack+pinion and for clearance of oil pans. Then they have us cut up the back of the car to do a backhalf. In the end, you would have had a MUCH nicer chassis if you just went out and bought a chassis engineering frame and worked from there. Guys think they are saving money by cheaping out on stuff...often time the labor costs in trying to make round pegs fit in square holds end up causing them to spend almost as much as just doing it the 'right' way.