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  #16 (permalink)  
Old 12-30-2011, 06:55 PM
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Thanks Inspector !!! Valuable info !
Here's the Super T10 Codes :
My friend doesn't really care about the cam sound , i was there trying to
pull it off , but he says now he wants more out of what he has.
And i think when he floor it the car tends to shut off.
So the smaller combo will be better for him and all around driving.
He definetely does not race. Daily street use only.

Codes:





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Old 12-30-2011, 07:53 PM
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If he crazy for the rumpity-rump(I know I am!) sound tell-em about Isky cams. They are ground on a 108LSA(thats where the rumpity-rump comes from...a tight LSA) Comp and alot of the others use a 110* "normally"..for their street/strip grinds. Tight LSA 106-108*...not a huge amount of lift.....duration in the 230ish area...may work for'em.
6sally6
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  #18 (permalink)  
Old 12-31-2011, 05:03 AM
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First off, dont use a thumper cam. Those are fad cams, all bark and no bite. Standard high performance cams lope at idle just fine. But it seems now days many guys install a standard performance cam and it wont lope at idle. This complaint seems to be so big and thats why comp jumped on the band wagon and seen it as a way to make money off a simple sound. Truth is, and I did a post about this not long ago, if your running a cam with good duration figures with plenty of overlap and it dont lope at idle it means its not tuned correctly. In the past I had plenty of time to play with this so Ill explain it. Many guys will install all there pieces then theyll time it to 12 degrees before top dead center for base timing. They test drive it and find out two things, it dont lope at idle, and its a complete slug on low end power. So they think something is wrong with the cam. So they complain to the cam company about it and so on. So why wouldnt the cam lope at idle? Simple. Not enough base timing. 12 degrees is what it should be set to with vacuum advance disconnected and plugged. Then reconnect the vacuum advance and make sure its connected to a full time manifold vacuum source (any source that pulls vacuum full time, INCLUDING idle) then recheck the timing. It should be 18 to 24 degrees before top dead center. Now the higher timing has made the idle go up, so now we lower the idle speed and the engine has a nice nasty lope and sounds mean. We test drive it to find it picked up what feels like 50 horsepower in the low end so were pleased, we got the lope and we got good low end power. Now lets rewind back to 12 degrees base timing without vacuum advance. Why wouldnt it lope and why did it have such sluggish low end power? Two reasons. The 12 degrees setting alone isnt enough spark advance, so to get it to idle around 700 RPM like its supposed to, the idle has to be opened up a good ways. What happens is, its opened so far the carb is now off the idle slots so its pulling fuel from the main boosters instead of the idle circuit. Now we know why it wont lope. Now why is the low end so sluggish? This is due to the mixture. Idle and off idle mixtures are lean, and leaner mixtures burn slower than do richer ones. Since the lean mixture burns slower means we need to lite it off sooner, hence the reason for more base spark advance. Now heres where it gets interesting. When you order a cam, in the instructions itll say connect the vacuum advance to a ported source. Magazines say use a ported source. MSD ignition says use a ported source. I dont know where they got there information but its wrong. Ported vacuum gets its vacuum when the throttle blades are opened because its above the butterflies and since its above the butterflies the vacuum signal isnt very strong so it doesnt have enough pull to open a vacuum advance. When a cam is used thats so large it doesnt have enough vacuum to operate a vacuum advance then we start with base timing 18 to 20 degrees. Sorry for the long post, but I wanted to make sure you knew the facts before hand. Theres no telling how many Ive told this on this board and they act like Im speaking a different language or Im giving them bum information as after all, if a magazine, the cam company and the ignition company say use ported advance then by all means they must be right and Im wrong. In that case I tell them try it both ways and youll quickly be able to tell it has more power with vacuum advance in use on a manifold source. For those who still dont believe me I say what Fbird already said, you can lead the horse to water but you cant make him drink. This is also why I say knowing how to tune one seems to have become a lost or forgotten art.
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  #19 (permalink)  
Old 12-31-2011, 05:44 AM
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Quote:
Originally Posted by DoubleVision
First off, dont use a thumper cam. Those are fad cams, all bark and no bite. Standard high performance cams lope at idle just fine. But it seems now days many guys install a standard performance cam and it wont lope at idle. This complaint seems to be so big and thats why comp jumped on the band wagon and seen it as a way to make money off a simple sound. Truth is, and I did a post about this not long ago, if your running a cam with good duration figures with plenty of overlap and it dont lope at idle it means its not tuned correctly. In the past I had plenty of time to play with this so Ill explain it. Many guys will install all there pieces then theyll time it to 12 degrees before top dead center for base timing. They test drive it and find out two things, it dont lope at idle, and its a complete slug on low end power. So they think something is wrong with the cam. So they complain to the cam company about it and so on. So why wouldnt the cam lope at idle? Simple. Not enough base timing. 12 degrees is what it should be set to with vacuum advance disconnected and plugged. Then reconnect the vacuum advance and make sure its connected to a full time manifold vacuum source (any source that pulls vacuum full time, INCLUDING idle) then recheck the timing. It should be 18 to 24 degrees before top dead center. Now the higher timing has made the idle go up, so now we lower the idle speed and the engine has a nice nasty lope and sounds mean. We test drive it to find it picked up what feels like 50 horsepower in the low end so were pleased, we got the lope and we got good low end power. Now lets rewind back to 12 degrees base timing without vacuum advance. Why wouldnt it lope and why did it have such sluggish low end power? Two reasons. The 12 degrees setting alone isnt enough spark advance, so to get it to idle around 700 RPM like its supposed to, the idle has to be opened up a good ways. What happens is, its opened so far the carb is now off the idle slots so its pulling fuel from the main boosters instead of the idle circuit. Now we know why it wont lope. Now why is the low end so sluggish? This is due to the mixture. Idle and off idle mixtures are lean, and leaner mixtures burn slower than do richer ones. Since the lean mixture burns slower means we need to lite it off sooner, hence the reason for more base spark advance. Now heres where it gets interesting. When you order a cam, in the instructions itll say connect the vacuum advance to a ported source. Magazines say use a ported source. MSD ignition says use a ported source. I dont know where they got there information but its wrong. Ported vacuum gets its vacuum when the throttle blades are opened because its above the butterflies and since its above the butterflies the vacuum signal isnt very strong so it doesnt have enough pull to open a vacuum advance. When a cam is used thats so large it doesnt have enough vacuum to operate a vacuum advance then we start with base timing 18 to 20 degrees. Sorry for the long post, but I wanted to make sure you knew the facts before hand. Theres no telling how many Ive told this on this board and they act like Im speaking a different language or Im giving them bum information as after all, if a magazine, the cam company and the ignition company say use ported advance then by all means they must be right and Im wrong. In that case I tell them try it both ways and youll quickly be able to tell it has more power with vacuum advance in use on a manifold source. For those who still dont believe me I say what Fbird already said, you can lead the horse to water but you cant make him drink. This is also why I say knowing how to tune one seems to have become a lost or forgotten art.
Beautifully explained!
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  #20 (permalink)  
Old 12-31-2011, 11:48 AM
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Quote:
Originally Posted by Scandinavian
Beautifully explained!
I agree.....
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  #21 (permalink)  
Old 12-31-2011, 11:56 AM
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Quote:
Originally Posted by 6sally6
If he crazy for the rumpity-rump(I know I am!) sound tell-em about Isky cams. They are ground on a 108LSA(thats where the rumpity-rump comes from...a tight LSA)
If you think this through completely, you may realize that there is insufficient cylinder pressure at overlap to make the rump-rump of the piston shoving the fuel/air mixture back up the intake tract with the intake valve still open. The fact is that when a cam is ground on a tight LSA, it is also ground with an extended intake closing point and that's what makes the rump-rump, the mixture being shoved back past the venturis.....and the venturis will add still more fuel to the mixture because they cannot sense that the mixture is going the wrong way. They see movement and sense a low pressure area, so they add fuel. Once the motor gets up in the rpm range a little, it "gets up on the cam" and the motor smooths out with mixture going only one way.
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  #22 (permalink)  
Old 01-02-2012, 02:53 PM
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Impressive post Doublevision, thanks for taking the time to put this valuable information ! Nice to start the year learning !
I didn't know thumper cams were "poser" cams, i learned it here. I might ask you for advice when we get there to tune it correctly because i really want to see my friend with a permagrin ! The Carb and Intake were pulled off today
and my friend is ready for replacements, he will keep the stock cam for now,but he wants something that he might be able to grow up in the very next future with new heads and cam and plenty of power for the street.

600 CFM Performer Carb is a must , we had that in the past and it's real real good.
Intake choice is pending...
Thanks Guys !

Bye Bye Victor !
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Old 01-03-2012, 10:06 AM
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What you guys think of this kits ?


http://www.summitracing.com/parts/EDL-20214/
or
http://www.summitracing.com/parts/EDL-20224/
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  #24 (permalink)  
Old 01-03-2012, 11:41 AM
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355 Gen I Chevy street motor, budget build....
Block: '68-'86 Chevy 350 Gen I bored +0.030". Align-hone or align-bore the main bearing bore, then cut the block decks to whatever block deck height you need to fit your stack of parts and set the piston deck height where you want it. This will square everything up and allow you to build on a solid block. If you will also equalize the chambers, you will come closer to having a motor that makes equal power from cylinder to cylinder.
Crank: Stock 350, 3.48" stroke, 2.450" main journal diameter. I would cut it 0.010"/0.010" just to make sure the journals are parallel with each other and round.
Rods: Stock 350 5.7". Recommend ARP bolts, re-size big end.
Pistons: Keith Black hypereutectic, part #KB193, 12cc D-cup, 5/64,5/64,3/16 rings. 1.561" compression height. Gap top ring 0.026", second ring 0.018".
http://www.kb-silvolite.com/kb_car/p...tails&P_id=155
Heads: RHS Pro Torquer Vortec 170-64 (part number 12407), 1.94" intake, 1.50" exhaust.
http://www.competitionproducts.com/p...407&variation=
These heads will accept either conventional or Vortec type intake manifolds. They are drilled and tapped for both types. Fill 'em with valves, springs, retainers and keepers from Competition Products. They have inexpensive kits.
Intake manifold: Dual-plane, high-rise such as the Edelbrock RPM #7101, or Professional Products Typhoon.
http://www.amazon.com/s/ref=nb_sb_no...7101&x=12&y=13
http://www.amazon.com/Professional-P...5616644&sr=1-6
Carburetor: Vacuum secondaries 750 CFM.
Headers: 1 3/4" primaries, long-tube, equal-length. Install "X" pipe between collectors and mufflers. Run 2 1/2" pipe to the rear through mufflers of your choice.
Camshaft: CompCams flat tappet hydraulic 260H: [1], installed straight up.
http://www.crankshaftcoalition.com/w...ips_and_tricks
Rocker Arms: 1.6 ratio on both intake and exhaust.
Static Compression Ratio: 9.6:1
Dynamic Compression Ratio: 8.4:1
Squish: 0.035" to 0.045". Zero piston deck height with 0.035" to 0.045" head gasket or 0.010" to 0.020" piston deck height with Victor Reinz #5746 head gasket that compresses to 0.025".
RPM HP TQ
1000 59 310
1500 103 361
2000 150 395
2500 192 402
3000 246 431
3500 306 459
4000 360 473
4500 407 475
5000 442 464
5500 453 433
6000 450 394

Stock converter and stock rear gear will work, but would be more fun with a converter that stalls at 2000 to 2200 rpm's and a 3.73 gear. Check out the 395 ft/lbs of torque at about 2000 rpm's. In my opinion, this makes the perfect street 350.

Last edited by techinspector1; 01-03-2012 at 11:56 AM.
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Old 01-03-2012, 11:47 AM
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Looks GREAT !!!!
But the Iron heads would make shipping real expensive because we are overseas, is there a Alum version for those heads or something similar ?
Thanks !
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Old 01-03-2012, 12:00 PM
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Quote:
Originally Posted by Calderone
Looks GREAT !!!!
But the Iron heads would make shipping real expensive because we are overseas, is there a Alum version for those heads or something similar ?
Thanks !
What you save on the iron heads over aluminum will pay for the freight and then some. Buying bare heads and the valve kits and assembling them yourself, you will have around US$800 invested in two complete, ready-to-bolt-on heads. Freight can't be that costly. Check with a freight forwarder in L.A. or Miami. There might be a container coming your way and the shipper might let your parts ride along for cheap.

Forgot to add this tips and tricks article for flat tappet cams....
http://www.crankshaftcoalition.com/w...ips_and_tricks

Last edited by techinspector1; 01-03-2012 at 12:26 PM.
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Old 01-03-2012, 12:41 PM
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This combo will be hard pressed to make 375hp. 390ft/lbs torque
going down a steep hill.

Don't know where you get this stuff. But its pure BS.
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Old 01-03-2012, 01:01 PM
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Quote:
Originally Posted by F-BIRD'88
This combo will be hard pressed to make 375hp. 390ft/lbs torque
going down a steep hill.

Don't know where you get this stuff. But its pure BS.
What you mean ?
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Old 01-03-2012, 01:04 PM
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Quote:
Originally Posted by techinspector1
What you save on the iron heads over aluminum will pay for the freight and then some. Buying bare heads and the valve kits and assembling them yourself, you will have around US$800 invested in two complete, ready-to-bolt-on heads. Freight can't be that costly. Check with a freight forwarder in L.A. or Miami. There might be a container coming your way and the shipper might let your parts ride along for cheap.

Forgot to add this tips and tricks article for flat tappet cams....
http://www.crankshaftcoalition.com/w...ips_and_tricks
Inspector , thanks !
My friend does not want bare heads , neither Iron, the bare head price is unbeatable but he wants to save time as well and have alum heads.
Sorry,it's not that i don't like your suggestion,i appreciate it , but it's my friend's car and he wants that. Around 400 hp would be just fine.
Thanks once again !
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Old 01-03-2012, 01:12 PM
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Quote:
Originally Posted by F-BIRD'88
This combo will be hard pressed to make 375hp. 390ft/lbs torque
going down a steep hill.

Don't know where you get this stuff. But its pure BS.
Thank you for your comment. I get the same feeling about your locked-out ignition timing for a street motor.
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