with a LQ4 and 243 heads you should be at 10.5 not 10.0

 

Stock 6.0 (LQ4) is 9.4 to 1, no? If so, bumping the chamber size from 71 (317 heads) to 64 (243 heads) brings it to 10.2 changing nothing else.

 

Whatever you get will be better than what you've got........

 

9.5cr....and 72 cc head, Iron LQ4 were 9.4

just like if you put on 243 heads on a LQ9 you are now at 11.1

 

http://www.c5frc.com/calculators/Com...Calculator.htm

That's what I was using. Set for .0001 deck (believe the piston is out of the deck .008"), .055" gasket, -7cc dish on the pistons, it comes back with 9.4 to 1, which is where everything I've ever read has stated for the 6.0 LQ4. (The 5.3 is 9.5 to 1). Bump the chamber to 64cc on an LQ4, get 10.3.

Not arguing, just trying to get this ironed out so I *know* for certain. There is so much misinformation out there that I don't want to be peddling, you know?

 

im just recalling numbers from the ls1 books for specs of heads and compression ratios....you know those two LS1/GenIII books they sell

 

Ah yes... We need a sticky with this stuff. If the engine wasn't actually running, I would measure it just to be sure.

 

if your running a comp grind cam heres a cool little tool found. just change the stuff up to match your motor. its set up for a LS1 at the moment

Step 1 put in your cam/ if you dont know the lift falues to put in go to the lobe source tab, find your lobe and follow it to the duration. the number to the right is the one you want to use(if you dont have your cam card handy).

http://www.alantripp.com/VE%20calcul...okup%20LS1.xls

 

Quote:
Originally Posted by kirtondog23
The 6.0 will also be a much easier swap in terms of accessories and stuff like that.

you will be maxing out that engine more often and this is important if you ever plan on towing anything.


explain these two statements....


I am just trying to remember things as it was explained to me when I made the decision to go with a 6.0. Starting with the second question. Both engines are great but the 6.0 stock is set up for less HP at 300-325 and a little more torque at 360 than the ls1 at something like 350HP and 345-350 TQ. I know the TQ ratings are not that different but the 6.0 will do more power a little lower and not rev as high to do it which makes for more reliable towing over the long term. This is one of the reasons a stock LQ4 only has 300hp. This also eliminates the need to swap intakes as well.

I elected to go with the 6.0 for price, future buildup options (displacement and Iron) and because I have to turn 38.5 inch tires which takes having more torque in the lower rpm range pretty important.

Back to the first question, and I have not swapped an ls1 so I am not ab expert her nor do I pretend to be but I understand that the ls1 accessories are in different places and that might mean that he has to modify his harness or shift things around while with the 6.0 his current harness should just plug into everything. Again without clarification on what his project truck is specifically this is a bit of a guess on my part.

If I am wrong in my assumptions please let me know. I am the last person who wants to contribute to the spread of misinformation as it occurs over the web today.

Thanks

 

the ls1 and 6.0's are essentially the same exact motors. the 6.0 was actually designed off of the ls1. your right about having more room to grow with the 6.0 boring and all that. being that the motors are the same minus cubes/material all the accessories bolt up the same exact way. no wiring harness differences assuming you use the truck intake. you can bolt the car accessories up to a 6.0, and the truck accessories up to a ls1. its all interchangable.

as for the power differences...im not really sure myself. from everything i heard GM under-rated the "claimed" power of the LS1 in the camaros at 310hp/340tq. why would they do that? one reason is so your avg person could afford insurance on the cars, and the other reason is so the power of the camaro didnt match/exceed the chevrolet flagship car....the corvette. the ls1 was the same exact motor as the vettes but it was tuned down and little factory restrictions were added that are easily removed. the vettes of the time were rated around 350hp with the same exact motor.

this is why i say choose whichever motor you can get for cheapest. chances are youll find a 6.0 for cheaper but in rare cases like mine a ls1 can be stole ($250 longblock including accessories etc /bragging) haha.