72tutone

First post. Long time lurker.
@Summitracing Just bought a used LQ9 and I'm torn between the Stage High lift truck cam 8720r1 and the torkinator. Its backed with a 80e, 3.42 gears, and LT's. Std 317 heads round it out. Although, I've been tempted to throw on my 706 head laying around. But, not sure if I can get away on pump gas. It has a Circle D converter 3000-3200 is the stall. All of this is in a 72 C10 truck.

My old combo , 5.3 BTR cam, same components was absolute turd down low. I dont want to make the wrong decision this go around.

So, having said that, looking at those two model of cams, the BTR TN cam, and even the TSP chopacabra. I dont track this thing. Street/cruising is all. But, I want some power down at 2500, through the power band. But will still pull nicely to say 6000/6200 RPM.

Between your two cams what would you recommend? I also have BTR dual spring .660 lift that I will be putting on as well if that was a question.

Thank you for your time.

G Atsma

706 heads will raise the compression too much for what you want.
The 8720R1 is a much improved version of the old GM Hot Cam. Power around 2500 should still be enough to be responsive at that speed.
The Torkinator has much more stock-like characteristics but would still be a nice boost over a stock cam

72tutone

Thank you, G. Would the 8720R1 and the BTR TN be a fairly good comparison. I like the chop at idle. I usually set my idle around 750-800 so I can play around with it a bit to get a chop sound. But, just wanted thoughts. Any TSP cam? Their stage 2 looked appealing -

https://www.texas-speed.com/p-8557-t...-camshaft.aspx

G Atsma

Both the 8720R1 and Truck Norris will have a bit of a rough idle. Too hard a chop loses low end responsiveness.
The TSP St. 2 Truck Cam is a bit milder but will perk up your engine nicely
Keep in mind, "chop" is an intermittent miss and an indicator of inefficiency.
Make performance your priority, not sound. Are you a runner or poser?

72tutone

I'd prefer to be both But, my knees hurt. I digress.

So, I'm thinking between the 8720r1 and the TSP Stage 2.

218/227 .600/.600 lift vs 212/218 .600/.600 Both, are on a 112

Summit cam 299$ TSP 389.00

The big truckinator specs out at 212/218 but is on a 110 with a slightly lower exhaust lift at .585.

G, are you saying roudy idle based on the overlap? I dont see TSP full specs. So I cannot speak on that.

99 Black Bird T/A

iTrader: (4)

Most tuners can make any cam lope and sound aggressive etc. I wouldn't pick a cam based on sound but for the intended application. One of my car's has a cam with more overlap ( 4 degrees) than any of these and it's tuned to idle smooth and usually passes for a stock LS.

212/218 on a 112 is -9 degrees overlap, very smooth, a good tuner should be able to make it behave in traffic very close to OEM stock in a 6.0.

212/218 on a 110 is -5 degrees overlap, a good tuner should be able to make it behave and drive well. Maybe a little trickier to fully sort out with the 110 LSA than the more common 112 to 115's depending on the tuner.

218/227 on a 112 is -1.5 degrees overlap, (assuming a modern lobe etc) a good tuner should be able to make it behave reasonably and very driveable.

72tutone

Yea it’s not so much the sound as performance. I just love to hear a loped cam.

but having said that I don’t even know if what I’m suggesting is right for me.

the cam i was running in my 5.3 was a btr turbo cam as I planned to boost it.
looking at the valve events through valve closed I believe around 43.
which in a 72 truck 5.3 with a 80e and 3.42 gears it absolutely sucked.
I know my gearing has a lot to do with the above. But again I planned on boosting.

So now I want to get a cam that’s right. I want to punch it off the line if need be and mid MPH. I don’t tow, I don’t track this.

I just want a nice steet truck with just the right amount of oomph if someone rolls next to me.

stockA4

​​​​​​So if he had an LS2 instead You would tell him to put 317 heads on it because that's too much compression for pump gas!? What is wrong with you stop giving bad advice. I swear to God every time I breeze through here I see one of your posts and I want to rip my hair out. How much different is an LS2 and an LQ9 with 706 heads. It's not much different at all.

Op, usually the first person that posts on here after you start a thread has no idea what they are talking about and no real experience get used to it.


if You'd like as much low end as possible then put the 706 heads on that b****

You know that you can get a custom grind cam perfectly specked for your application for $430 from comp right
If that's too much trouble then pick something that's said to run well in an LS2, as that's basically what you'll have only with more torque.

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G Atsma

He'll have 11.44 compression with 706 heads. IF he has 93 gas available it might be OK. Otherwise too close to call.
StockA4, you have no idea of what I know or not. Until you do, kindly STFU.

stockA4

How many people are on here struggling with detonation issues with NA combinations?

72tutone

for what it’s worth I do have 93 here in MO.

im not sure if any thicker head gaskets are available than 0.51 to drop compression a couple of ticks. Or if it even wouldn’t matter.

but not worried so much in detonation than I am with p to v.

G Atsma

With the cams discussed P to V should not be an issue.

72tutone

i suppose I can look for some 243/799 heads to as I’m not running as high as compression. This might be the best of both worlds for me. A bigger bump in compression and better heads than the 317.

still undecided on cam. I’ve read so much I’m going in circles lol

99 Black Bird T/A

iTrader: (4)

72tutone, the comment about having a custom cam spec'd for your specific combo and goals is excellent advice. Hopefully @Summitracing can comment on cam selection for your project.

Talk with your tuner about compression and see what they say. I know two excellent tuners that have tuned LS's with ~12 to 1 on 93.

BTW - I have a 416 that runs ~11.7 to 1 on 93 octane with ZERO issues. Likewise a 383 that runs ~11.4 to 1 etc with proper cam selection you can go pretty high on compression.

Typically ~12 to 1 compression is doable in an LS if you're working with an expert tuner, have 93 available with proper cam selection. Weight and gears can have an impact etc as well. One can always get bad gas so I like to stay under ~11.8 on compression with 93 for my cars

Che70velle

iTrader: (6)

The cutoff with 93 octane is 12.45:1. I run 12.42 with no detonation on pump 93. The LS chamber is very efficient. Chamber design has 99% to do with what works and what doesn’t. Compression is just a squeeze. The harder you squeeze a gallon of gas, the farther you can go on it. Efficiency.

72tutone

All good points here and making me feel better with running higher comp on 93 octane. So, I might put on those 706 heads just to see what it does.

Assuming the comments above about p-2-v aren't an issue here.

With 799/243 heads I'd be right around a LS2. And I'm pretty sure there isnt even a restriction on running 87 on those? I'd have to check. A friend of mine rolls a G8 and I'm pretty sure he throws 87 in his.

So, really it all comes down to cam Come on @Summitracing waiting to hear your thoughts.

stockA4

If you're waiting for them to come on here and help you out you're going to be waiting for a very long time. They have phone operators that would answer your questions on the phone right now.

One of my setups is an iron block bored over and fitted with LS3 flat top pistons and stock 706 heads. It's about 11.9:1 compression.

I've ran four different camshafts in this particular set up alone and I've been messing with these engines for about 20 years

Measured at 0.006" these cams closed The intake valve as early as 65° and as late as 86°

Measured at 0.050" these cams close the intake valve has early as 33° and as late as 49°

None of these cams caused any detonation issues however you're leaving a lot on the table closing the intake early with higher compression.

With your setup, heavy truck 3000 stall 3.42 gears I'd look for any camshaft mild or wild that closes the intake somewhere between 44°- 51° @ 0.050" and it will run its *** off. However you won't find many cams on the shelf that close the intake much after 45° so a custom grind from comp would still be cheaper and run better than a generic shelf cam and an adjustable timing set, You don't need that headache.

PM me if you want to know the valve events I would pick if I was going to run your setup





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72tutone

@stockA4 Hmm, I have no option to send a PM. Not sure if its because I just created an account and rights havent been granted? But i have no send PM anywhere within this post. Or, in my CP.
If I select your name there isnt a send PM option for you either. Am I missing something?

stockA4

It doesn't really matter, I hardly come on here anymore It's not like anyone else that posting here is going to care about my way of doing things anyway, that being said, with 4" flat top Lq9 Pistons and 706 heads You will have an engine that can tolerate aggressive valve timing and still drive very very well, You can have your cake and eat it too with the setup (Great sound and excellent drivability) because it will still start it up and go after it's tuned and the idle is bumped up a bit.

I really recommend grinding this cam on the old comp extreme RPM high lift lobes, and just use the regular proven and reliable gm LS6 springs. Double springs and a super high lift cam are waste of money on the 706 heads IMO. The comp "extreme RPM high lift" lobes and LS6 springs will easily go over 100,000 mi without any maintenance. If when you pull out the stock cam it looks good you can reuse the stock lifters no matter how much mileage is on them just don't worry about it and don't worry the cam bearings are supposed to look like s*** with copper scraped all around It doesn't matter. Just slap the heads on there with some felpro blue head gaskets and throw some 7.450" push rods in it and you are good to go.

Have them grind you:

228/236 115 + 0

With long tube headers and a good exhaust this will sound excellent, It will have an agressive performance idle and yet it will still have excellent manners and make awesome power compared to a shelf grind with two early of an IVC.

This cam spec has plenty of PTV with your setup It would be incredibly flexible nothing to worry about there. You could even advance it 4° for a rougher idle and better lower end throttle response or back it off 4° for a smoother idle and more top end power and better high RPM throttle response.

grubinski

I run 11.8:1 on 92. Just need a late enough IVC to keep dynamic compression in check, and not too aggressive timing. No issues.