Cam ?

[Chefritenour]

Hello
Have been drag racing 02 t/a stock except cat back.going to do headers and cat less y pipe with a cam.what is best cam to add without changing valuve springs .what is expected hp with full exhaust and bolt ons .

[98TransAmWs-6]

Hello
Have been drag racing 02 t/a stock except cat back.going to do headers and cat less y pipe with a cam.what is best cam to add without changing valuve springs .what is expected hp with full exhaust and bolt ons .

Pretty much no cam. Even the ls6 cam requires more spring. You should change the springs with any cam, the last thing you want is a spring to break because a cam was technically under the max lift or it should be good and have to pull the motor and clean it all out or rebuild it because the springs jacked it up. Honestly the springs are added insurance it's not worth the risk to save $200. Get some nice springs like Brian Tooley Racing .660 springs with titanium retainers.

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[SMWS6TA]

Also plan on chrome-moly pushrods and new set of lifters. If your going to go thru the hassle of cam upgrade you gotta do it right. Otherwise like Will said you're making a ticking time bomb on your motor.

Now staying with stock heads a 228 cam is about the best bet. MS3/4 will be choked out with 241 heads, even if you port & polish them you're still not going to get the full benefits of a cam like MS3 or 4. Those benefit more with aftermarket heads.

[Chefritenour]

Well motors at 160k already making some top end noise so was thinking cam and bolt ons plus a little spray and replace things in the order they break lol had a couple lt1 cars but don't know spefic of the ls type motors can you do anything with the 6l truck engine they seem plentiful but I read more about 5.3s so.... originally was thinking of buy a lower mile 5.7 / lsi cam swap and tune , but ffor the price I'd probably by a short block and work some heads.also thought about gambling with just rebuild ing the top 1/2 either way objective is modest 7.90 in 1/8;still a street car .

[SMWS6TA]

can you do anything with the 6l truck engine they seem plentiful but I read more about 5.3s so....

Oh yeah I know the 6 liters well......



My engine is a LQ4 block 4.005" bore with a 4" K1 Forged stroker crank making it a 403ci.


My signature has most of the details. IMHO the LQ4/9 blocks are the best go to block to get. Has more options in building up then the 5.3's and all Aluminum blocks. The only negative is they are about 60-90lbs heavier then aluminum blocks. They can handle more boost, more nitrous and can be bored safely to 4.030" and with some cylinder wall testing they can be bored out some more. They can use ls1 or ls3 style heads and intakes.

99-04 yrs are what you want but even if you get a newer block with some things that need to be swaped out you can make them work with your car.

Will also has a 6 liter block that with his crank has a 421ci. Can't wait to see it run.

[Chefritenour]

Which cylinder heads have the best compression ratio

[SMWS6TA]

Depends on what your build is and if your talking stock vs aftermarket.

There are a lot of factors for figuring out the CR. Head chamber, pistons (dome, dish, flat, w/relief cuts, etc), rod length, head gasket thickness, and cylinder diameter.

Stock LS1 heads - for Natural Aspiration Builds - 243/799 heads (Usual CR is around 10.5-11.1 on stock LS1's) you can pick up a used set for $400-500 a set. I did on mine and had a shop install new valve guides and install my BTR springs for $100 more.

Boosted - 317 heads (Usual CR is around 9.4-10.1 on dish pistons, these are found in 4.8 5.3, 6.0 engines)

With aftermarket you have too many options to list. TrickFlow and PRC pretty much dominate on LS1 builds.


Now if you get a 6 liter block and decide for LS3 style heads - Stock, these perform very well out of the box compared to any LS1 style head. But there's always improvement to be made. TrickFlow has awesome set for LS3 style heads, but the top dog would be the same TF heads but P&P by Frankenstein Heads.

[Whamhammer]

Depends on what your build is and if your talking stock vs aftermarket.

There are a lot of factors for figuring out the CR. Head chamber, pistons (dome, dish, flat, w/relief cuts, etc), rod length, head gasket thickness, and cylinder diameter.

Stock LS1 heads - for Natural Aspiration Builds - 243/799 heads (Usual CR is around 10.5-11.1 on stock LS1's) you can pick up a used set for $400-500 a set. I did on mine and had a shop install new valve guides and install my BTR springs for $100 more.

Boosted - 317 heads (Usual CR is around 9.4-10.1 on dish pistons, these are found in 4.8 5.3, 6.0 engines)

With aftermarket you have too many options to list. TrickFlow and PRC pretty much dominate on LS1 builds.


Now if you get a 6 liter block and decide for LS3 style heads - Stock, these perform very well out of the box compared to any LS1 style head. But there's always improvement to be made. TrickFlow has awesome set for LS3 style heads, but the top dog would be the same TF heads but P&P by Frankenstein Heads.

So what's the performance difference and cost difference between a set of used/ported&polished 243's vs a set of Trick Flow Cathedrals?

[SMWS6TA]

Depends on what your build is and if your talking stock vs aftermarket.

There are a lot of factors for figuring out the CR. Head chamber, pistons (dome, dish, flat, w/relief cuts, etc), rod length, head gasket thickness, and cylinder diameter.

Stock LS1 heads - for Natural Aspiration Builds - 243/799 heads (Usual CR is around 10.5-11.1 on stock LS1's) you can pick up a used set for $400-500 a set. I did on mine and had a shop install new valve guides and install my BTR springs for $100 more.

Boosted - 317 heads (Usual CR is around 9.4-10.1 on dish pistons, these are found in 4.8 5.3, 6.0 engines)

With aftermarket you have too many options to list. TrickFlow and PRC pretty much dominate on LS1 builds.


Now if you get a 6 liter block and decide for LS3 style heads - Stock, these perform very well out of the box compared to any LS1 style head. But there's always improvement to be made. TrickFlow has awesome set for LS3 style heads, but the top dog would be the same TF heads but P&P by Frankenstein Heads.

So what's the performance difference and cost difference between a set of used/ported&polished 243's vs a set of Trick Flow Cathedrals?

Quite a bit. Air flow is higher. More air + fuel = more hp.

Also most have the valves at 13° angle which allows bigger cams and avoid ptv issues you have with same cam with stock heads.

[98TransAmWs-6]

Aslo have thicker decks so you can mill them more without having ptv clearance issues and allowing higher compression. Also you have room to port and polish more with the trickflow heads so their full potential isn't done right out of the box.