So as usual, I've become bored with my car, and if you're reading this thread in this section you probably are too haha.

So long story short, I bought a 98' LS1 that was incorrectly re-assembled for very cheap. I'm selling off some parts I wouldn't need with either direction I go and am almost even on the deal plus I have a shortblock that would run.

The 5.7 will need a crank and a set of rings because I was an impatient idiot and broke a ring using a jenky piston ring compressor, but that's not a big deal.

My car made 406rwhp/367rwtq on a Dynojet dyno with the following combo:
Stock bottom LQ4
231/234 .617/.612 112LSA EPS cam
Fast 102 intake w/ NW 102 tb
36lb injectors
PRC 243 heads (unsure what stage I sent them my cores during a porting sale)
1-7/8 longtube headers
2.5in exhaust with an x pipe
4000 yank stall in a 4l60e

The car ran 11.28 and I think I trapped 117mph, had a 1.50 60'


My question is, if it were your car, what would you rather do:

Squeeze out a 10 second pass by gutting the interior, adding some lightweight parts, try some different drag radials, double adjustable shocks in the rear, tighten up the front drag shocks, cutouts etc etc

OR

Pull the 6.0 out and transfer everything over to the 5.7, maybe gain a little power with the added compression and save over 100lbs vs the iron block


I have no idea what I will do if I will really do anything and right now I don't have time for either, but I just wanted to see what everyone else thought.



I really want to build something other than NA, maybe a small nitrous plate setup or an ebay turbo deal but everything in the car was built with NA in mind (trans, rear end) and I would rather get a cheap roller off of CL and do that.


Sorry for the long thread but when you are bored but don't have the time or money to do something to your car this is what happens

 

The weight difference isn't 100 lbs. 75 lbs tops. I would think if your looking for flat out fast as you can go, then call tick and get the polluter v2 and a 4500+ converter.
The 5.7 will not make more power than a 6.0 with the same top end. The added cubes will out perform the smaller engine. I'm sure some Internet guru will debunk me on that though.....

 

The ls1 would be a lot lighter but with a full frame car I would just stick with the 6.0 for more low end...buy another car and carb the 5.7, even stock it would make any car fast...add a cam to it and you got something real fun...I would suggest the aluminum block if it was in a light car just to keep the weight balanced for handling...you can buy a third gen Camaro for cheap now a days

 

LOL if anyone argues that a 5.7 will make more power and go faster than a 6.0 with the same top end, same compression everything the same down to the last nut and bolt...that person needs their computer privileges taken away.

 

well key there is compression...I see more lq builds that are turds than properly built ones and the primary problem tends to be compression

I would take a stock compression ls1 over a stock or even slightly higher than stock compression lq any day of the week for a N/A build

So has no one really weighed an iron block and an aluminum block on the same scales? It seems no one on tech can agree on the real weight difference. People have spouted off everything between 60lbs and 120lbs. Most common seems to be 80lbs.

 

I told you the Internet engine building society would have something to say.

 

10-4. Roger that

 

I guess the easier question would be will the added compression and weight savings make up for .3 liters

I'm the block weight sticky someone posted saying the aluminum was lighter by 100+ lbs

 

With my camshaft, my CR calculates out to 10.03 with the LQ4 and 64cc heads

Using the same cam specs and heads and putting in the specs for an LS1 I got 10.40

So lets say rule of thumb is for every point of compression, a 4% power gain. Seeing the car makes 406rwhp, and I would only gain .4 of a point of compression, that would probably equate to a 1.6% gain in power. It doesn't seem like much but doing the math it comes to a 8rwhp gain.

Now surely it's not worth all of that work for that little bit of gain, but what would happen if I had the heads milled .020 or .030

 

You're using the wrong intake valve closing event for your calculations. Use the advertised @.006" duration numbers to find your IVC@.006" lobe lift not @.050".

I bet your DCR is closer to 7.8-8.4:1 and not 10:1.

 

Definitly agree with Martin on you Dynamic compression Ratio Calculation. To answer your intial question however if it were my car and I had a lower compression IE close to 10:1 static compression car I would look into forced induction IE wet nitrous kit on a wide ope throttle with a window switch and progressive controller if your gunna do it do it right or your gunna mess stuff up. Also there is alot more to breaking into the 10's than just raw power! There is a big factor called traction and if you over power your setup your gunna run slower you may see a faster trap speed but a slower ET. So you may see better gains but spending your money to get your weight transfer right and the traction needed to put the power to the ground. Also I noticed your signature says 4l60e and 3.73 what is your overall tire height? you may look into tire selection and if you want an all out race car pull the 3.73 and go with a 4.10 or 4.56 with the 4l60 you dont want to hit overdrive though before you go threw the lights in my experience.

 

The 1/2 point or so of compression between the ls1 and lq4 isn't that big of a deal. The 18 cubes can be a big deal if the camshaft is ground correct as Martin is so graciously helping in explaining. Check this thread and see how a not so optimal camshaft performed great IMO and think what this car could run with a camshaft that is optimal for an lq4.
http://www.yellowbullet.com/forum/sh...d.php?t=517325

Oh, and the comment about "most 6.0 builds I've seen have been dogs" or turds or what ever I call BS. My lq4 with boltons,converter and tune has made quite a few haters and is in the thread I li med to you can see the lq4 engines are just as good a candidate for heads and cam or just cam-only.

 

That weight difference is going to be like 10-15 hp worth...all things being equal the extra cubes will easily offset the difference

 

You're taking my comment out of context, misquoting it, and then getting offended by it because you're taking it personal. A lq build done right is perfectly fine.

Point I was making was a lot of people throw their ls1 parts onto a lq engine and then get confused why it doesn't make more power or it isn't faster just because it has a few extra cubes. I'm not claiming to be an expert just pointing out what seems to be a common mistake of people swapping to a 6.0l longblock.

And it also depends on the uses of the car. I don't want any weight back on the nose of my car if I can help it, especially not ~80lbs. The aluminum block was part of the draw of the ls1 for me.

 

around here the several that have switched to lq4 with the same top end as they had, their car was at the least as fast. Those with nitrous picked up substantially. I will take 18 cubes over 1/2 a compression point for pump gas any day.
Agin
http://www.yellowbullet.com/forum/sh...d.php?t=517325
Typical 5.7 "top end" on lq4 and imagine what a cam for the engine combo would do.

Good luck! Have fun! I hope it all works out the way you want!