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ASA cam swap trouble

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Old 11-26-2007, 09:13 AM
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Why did you put the 7.450" pushrods in for this swap? The stock pushrods are only 7.325".
Old 11-26-2007, 04:21 PM
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Originally Posted by 69LT1Bird
Why did you put the 7.450" pushrods in for this swap? The stock pushrods are only 7.325".
Stock Pushrods are 7.4" and the reason for the longer pushrod is the cam has a smaller base circle.

Also if the cam is 180* out the car will run for a few seconds just like his did. Obviously the #1 piston must be at TDC on the comprrssion stroke, Not the exhaust stroke.
I had a similar problem with a Pontiac 400 years ago. After the cam was installed correctly it ran perfect.
Old 11-26-2007, 04:56 PM
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Stock pushrods are not 7.4", I double checked the blueprints today.

I will check the specs tomorrow but I am almost positive that the base circle is not smaller than a normal LS1 camshaft, it only has .525 lift. The only thing GMPP says you need to upgrade is the springs, not the pushrods.
Old 11-26-2007, 05:11 PM
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Originally Posted by 69LT1Bird
Stock pushrods are not 7.4", I double checked the blueprints today.

I will check the specs tomorrow but I am almost positive that the base circle is not smaller than a normal LS1 camshaft, it only has .525 lift. The only thing GMPP says you need to upgrade is the springs, not the pushrods.
Well its my understanding that the LS6 heads have the longer valve stems to compensate for a smaller base circle on the LS6 cam, which also has .525 lift.
This is why I went with the 7.425".
Old 11-26-2007, 06:11 PM
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You know I never thought I could put it 180 out but I will check it. That is one hell of a way to find you are 180 out. I am used to just having a car not even run and backfire if that is the case. It fired right up when I turned the key and had the coil packs plugged in. So in order to check if it is 180 out I would just need to pull the plug on cylinder one (which is driverside head front?) and make sure the piston is on the tdc when the dots are lined up?
Old 11-26-2007, 08:12 PM
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I don't believe you're a full 180 out. Let's talk about the Rollmaster. It has 7 keyways. That's a lot of room for error. When you installed the Rollmaster sprocket at what clock position was the crank key when you slid the Rollmaster sprocket home. You not getting any hints on this one. If your answer is wrong then the process started off wrong from the beginning and went down hill from there. That's why it is important to put your cam and crank sprockets in the DOT to DOT relationship BEFORE you start to take the timing set apart and to be sure you don't move the crank while the swap is taking place. Most tutorials don't bother to tell you this little tidbit because they assume your knowledge base is beyond the basic level and that you already have a good grasp on the what 4 stroke cycle theory is all about. Trying to explain how to properly use one of the advance or retard Rollmaster keyways is so complicated it gives me a headache just thinking about it so you should just stick to straight up timing. Using the center keyway the DOT on the crank sprocket(there is only one DOT) should be at 12 o'clock when the cam DOT is at 6 o'clock. If the key in the crank doesn't line up with the center keyway in the Rollmaster sprocket when the DOTs are lined up you better get it there or more bent valves could be the result.

Last edited by eallanboggs; 11-28-2007 at 06:42 PM.
Old 11-26-2007, 08:15 PM
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If you had #1 cylinder at TDC, then its next to impossible to get it 180 out. To do that, the dots wouldn't have lined up. There may be multiple dots on the crank gear, but there should only be one on the cam gear.
Old 11-26-2007, 08:50 PM
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I know that I did not line up the dots on the T chain before I took it off. I did not think I could screw it up with not lining it up at first. I am not sure what I was think it would be an issue. I dont need to tell you how many cars i have worked on but I have done my fair share. The best part is I thought oh I should line it up first then I said to myself nah it wont be a problem. Yikes. I am still not positive on it but it makes sense and I remember reading about a guy that put it 180 out, fixed it but could not get it started. When I lined up the rollmaster I used the dot that is closest to you when you put it on and lined that dot with the key way. Thanks for all of the help.
Old 11-27-2007, 07:01 AM
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The same pushrod, pn 10238852, has been used since 1997 in the LS1 that they use today in the LS3 and the other LS derivatives (except LS7).

The LS6 intake valve (4.83") is only .02" longer that the LS1 valve (4.81"). Putting in a pushrod with the stock unmilled heads and stock headgaskets that is 1/8" longer just doesn't make sense. The ASA cam has the same base circle as the LS1 cam.
Old 11-27-2007, 10:36 AM
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There's your problem. You do NOT line up the DOT on the Rollmaster sprocket with the key on the crankshaft. You line up the center keyway on the Rollmaster sprocket with the key on the crankshaft. At that point the DOT on the Rollmaster sprocket should be at 12 o'clock or you better get it there BEFORE you install the timing chain. The cam sprocket is at 6 o'clock at this point, right? I think you're confusing the terms key and keyway which many people do. The terms are NOT interchangeable and you need to know the difference so you can give a succinct explaination of your problem and to be able to understand the replys given back to you. If you had put the sprockets in the DOT to DOT relationship as I suggested before you tore this thing apart you would have avoided all these heads aches. I think you realize that now, but you're not the only one who could benefit from this one extra step in a cam swap. It only takes a couple minutes extra to place it DOT to DOT at the beginning of the process, but the payoff can be priceless.
Old 11-27-2007, 11:50 AM
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Originally Posted by 69LT1Bird
The same pushrod, pn 10238852, has been used since 1997 in the LS1 that they use today in the LS3 and the other LS derivatives (except LS7).

The LS6 intake valve (4.83") is only .02" longer that the LS1 valve (4.81"). Putting in a pushrod with the stock unmilled heads and stock headgaskets that is 1/8" longer just doesn't make sense. The ASA cam has the same base circle as the LS1 cam.
You're retarded. Its pretty common knowledge that the ASA cam has a .025" smaller base circle, this is why so many people that put the ASA cam in get a lifter tick with stock length pushrods, .025" longer pushrods get to the proper lifter preload.
Old 11-27-2007, 02:10 PM
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Drew,
Retarded? Nice.

.025 is one thing, a .125 (1/8") is another. If you are going to call me names at least learn to do the math.

If the base circle is .025 smaller, why go with such long pushrod? Correct pushrod length is critical to the overall geometry of the valve train movement.

Since GMPP themselves say you only need the LS6 springs and you apparently can out engineer GM, who am I to argue with you.

Some people complain about tick, some don't have any problem.
Old 11-28-2007, 12:07 AM
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1. I never said he had the correct length pushrods, this can only be verified by wipe pattern on the valve tip
2. I never said I can out engineer GM, The ASA cam can be installed without .025" longer pushrods if you don't mind a little valve train noise.

The ASA cam is very well engineered, yes many companies have made cams that out perform the ASA cam with similar durations due to more agressive ramp rates. The ASA cam however is not nearly as hard on valve springs as these. I also have yet to see a dyno graph of any cam on a 347 other than TR224 that has a torque curve near the ASA.

Didn't mean to come off as an *** earlier, I just hate when false information gets put on forums as "fact". I can say however that I have researched the ASA cam almost exclusively since I am putting one in early spring along with long tubes and a few bolt ons.

Last edited by Drew04GTO; 11-28-2007 at 12:17 AM. Reason: Tried to sound like less of an ass
Old 11-28-2007, 05:40 PM
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You could not have put it in 180 deg off unlees the "0" on youre crank sprocket was on the bottem side of the crank centerline.

So as long as the dot on the crank gear was upside and the "0" on the cam gear was down you could have not have put it in wrong.

The key is machined in the crank in relationship to the throws on the crank. the only way it could be 180 is like i said if the dot was on the lower side of the crank. and then how could you line up the dot's

The whole 180 off deal came from old school chevy's that you could drop the dist in 180 off due to the oil pump drive that was the only 2 ways it would drop in . either in right or 180 off

good luck
Old 11-28-2007, 06:10 PM
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someone tried to say i was wrong but the deleted it before i could get a quote on it.

Yes the cam spins 1/2 the speed of the crank. even so that would put the cam gear dot on the top side of the center of the cam.

again the zero on the crank gear is in the same place no matter how many times you spin the crank over. well unless you stamp a new "0" or machine a new key
Old 11-28-2007, 07:45 PM
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Originally Posted by THE CHOP SHOP
I know that I did not line up the dots on the T chain before I took it off. I did not think I could screw it up with not lining it up at first. I am not sure what I was think it would be an issue. I dont need to tell you how many cars i have worked on but I have done my fair share. The best part is I thought oh I should line it up first then I said to myself nah it wont be a problem. Yikes. I am still not positive on it but it makes sense and I remember reading about a guy that put it 180 out, fixed it but could not get it started. When I lined up the rollmaster I used the dot that is closest to you when you put it on and lined that dot with the key way. Thanks for all of the help.
sometime's it is not easy to figure out. the "0" keyway may be a way's from the "0" dot to line up with the cam gear.I have a slp t-chain set and my engine is out i will go take a look.

OK my zero to line up with cam gear is exactly 3 and 1/2 teath counter clockwise from the zero keyway in the crank gear .

so if you have it dot to dot crank gear dot straight up it would be 3 1/2 teath to the right to the keyway in the crank

Last edited by quick346; 11-28-2007 at 07:51 PM.
Old 11-28-2007, 09:23 PM
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Originally Posted by 69LT1Bird
.025 is one thing, a .125 (1/8") is another. If you are going to call me names at least learn to do the math.

If the base circle is .025 smaller, why go with such long pushrod? Correct pushrod length is critical to the overall geometry of the valve train movement.
Speaking of math...
The stock pushrod length is 7.4". 7.4" + 0.025" = 7.425"
Can you please explain to me how he is using a pushrod that is 0.125" to long?
Is he using a 7.525" pushrod?
Old 11-29-2007, 08:36 AM
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Quick346 has the crank sprocket DOT and crank keyway position correct when the crank DOT is at 12 o'clock. I was trying to see if Chop Shop would get it right himself by giving him enough hints. The Rollmaster can be confusing if you let it because of all the keyways it has, but if you stick with the center keyway you'll find the the only DOT on the Rollmaster sprocket should be at 12 o'clock when the cam DOT is at 6 o'clock. Just look at how the terms key and keyway have been used interchangeably here in recent posts. It illustrates how the two terms get confused. This might seem like a small thing, but when someone is already confused about his timing set(which can result in engine damage if he gets it wrong) it just makes things worse when the explaination he receives uses incorrect teminology. You can think of it this way: A key goes in a keyhole and a key goes in a keyway. Maybe that helps.
Old 11-29-2007, 08:59 AM
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If the base circle on that cam is 0.025" smaller in diameter, then you would need a pushrod that is 0.0125" longer because the pushrod is working off the radius of the cam circle. The pushrod change needed will be 1/2 of the change in the base circle diameter.

Originally Posted by 5.3LJimmy
Speaking of math...
The stock pushrod length is 7.4". 7.4" + 0.025" = 7.425"
Can you please explain to me how he is using a pushrod that is 0.125" to long?
Is he using a 7.525" pushrod?
He is using a 7.425 rod that is 0.0125" too long, not 0.125" too long.

Last edited by Weezzer; 11-29-2007 at 09:07 AM.
Old 11-29-2007, 09:02 AM
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I just happen to have my rollmaster double roller sitting in my garage and here is a pic of the crank sprocket
this is 0* key for the crank


this is the dot to line the cam sprocket up with


Quick Reply: ASA cam swap trouble



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