New cam and lifters installed, now it sounds like a diesel!!!!!!!
03-14-2003, 03:45 PM
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New cam and lifters installed, now it sounds like a diesel!!!!!!! I installed a new comp cam and 850 lifters. Heads are milled 0.038 and have 7.35" pushrods.
I soaked the new lifters in engine oil like the instructions said.
I installed a new cam because my old T1 and lifters surfaces came apart.
I let the car run for about ten minutes in hopes that the lifters needed to pump up. After ten minutes I still here the loud clack, clack.
What should I check now?
Before I took the old cam and lifters out there was a rattling noise coming from the passenger side. Now with the new cam and lifters in there is a loud clack, clack diesel engine sound coming from the same location.
Anyone have any ideas of what to check?
Get this, I pulled the passenger valve cover. Rolled the engine over to get the lobes on cylinder #2 on their heel. I loosened the rocker bolts while watching the valve spring. It didn't move. Ok, I tighten the same rocker bolts back down (without turning the engine any) and the valve springs are pushed down as I tighten the rocker bolt. What gives?
I soaked the new lifters in engine oil like the instructions said.
I installed a new cam because my old T1 and lifters surfaces came apart.
I let the car run for about ten minutes in hopes that the lifters needed to pump up. After ten minutes I still here the loud clack, clack.
What should I check now?
Before I took the old cam and lifters out there was a rattling noise coming from the passenger side. Now with the new cam and lifters in there is a loud clack, clack diesel engine sound coming from the same location.
Anyone have any ideas of what to check?
Get this, I pulled the passenger valve cover. Rolled the engine over to get the lobes on cylinder #2 on their heel. I loosened the rocker bolts while watching the valve spring. It didn't move. Ok, I tighten the same rocker bolts back down (without turning the engine any) and the valve springs are pushed down as I tighten the rocker bolt. What gives?
03-14-2003, 05:55 PM
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! I heard in a recent post that it took a few days of driving for the valvetrain noise to quiet down. Good luck.
03-14-2003, 06:24 PM
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! Could it be detenation? Could you possibly have an air leak?
<small>[ March 14, 2003, 06:25 PM: Message edited by: DaleMX ]</small>
<small>[ March 14, 2003, 06:25 PM: Message edited by: DaleMX ]</small>
03-14-2003, 06:25 PM
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! did you but the hole in the side of the lifter towards the back? if not, i heard it makes a difference.
03-14-2003, 06:59 PM
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! How many minutes of run time do you have on the motor so far? I have seen new lifters take like 15 minutes to pump up and in the meantime the car sounds like crapola.
Did you drain the old oil out, how did it look?
Did you drain the old oil out, how did it look?
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03-14-2003, 07:11 PM
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Pro Stock John:
<strong> How many minutes of run time do you have on the motor so far? I have seen new lifters take like 15 minutes to pump up and in the meantime the car sounds like crapola.
Did you drain the old oil out, how did it look? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I've done only two cam installs and the first time the clacking didn't last too long. But the second time it was about 15-20 minutes because the lifters were out of the car for a longer period of time. I installed as mentioned above; holes toward back and even soaked them in oil.
I would give it some time.
<strong> How many minutes of run time do you have on the motor so far? I have seen new lifters take like 15 minutes to pump up and in the meantime the car sounds like crapola.
Did you drain the old oil out, how did it look? </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I've done only two cam installs and the first time the clacking didn't last too long. But the second time it was about 15-20 minutes because the lifters were out of the car for a longer period of time. I installed as mentioned above; holes toward back and even soaked them in oil.
I would give it some time.
03-14-2003, 10:20 PM
#10
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! For what it's worth:
The aftermarket cams being installed today will usually have a smaller base circle than the stock LS1 cam they are replacing. Base Circle is actually the distance accross the cam's lobe. This is 90 degrees from the top of the cam's lobe at the point of highest lift.
You can easily measure this base circle distance with a micrometer. Measure across the cam's lobe (the lobe's smallest distance across). You will find that it is 1.552” on a stock LS1 cam. You will need to cut this distance in half in order to get the cams "centerline to lobe heal" distance. The stock LS1 cam has a .776" centerline to lobe heal distance (19.7mm).
This centerline to lobe heal distance is what is important to you in determining lifter preload.
A TR-220 cam has a 1.502” across the lobe base circle. Cutting this number also in half will equal a 0.751” centerline to heel distance. This is a 025" smaller centerline to lobe heal distance than the stock cam.
To be very accurate, you would then need a pushrod that is .025" longer than stock to achieve the same spec lifter preload as you had with your stock cam.
These aftermarket pushrods come in .050" length increments, so in this case, a stock 7.40” pushrod would be ok.
Remember, hydraulic lifters, due to there design have a + - preload variance that the lifter can operate within. It don't need to be exact. Just get it as close as possible with the various pushrods that are available (in .050" increments)
Be advised, milling the heads will change all this and require shorter pushrods equal to how much is milled off the heads (see below).
So, to re-iterate all this:
1. If your cam has a .025" smaller centerline to lobe heal distance than stock, you would need a .025" [longer] rod.
2. If you just milled the heads .025", you would need a .025" [shorter] rod.
3. Combine the two, and your stock 7.40" pushrod would be perfect … It then becomes tit for tat
_________________________________________________
CHECKING LIFTER PRELOAD:
1. Turning the engine, bring the EXHAUST valve on one of the cylinders down until it is at peak lift (valve fully open). The pushrod will be pushed all the way down and the valve spring will be compressed.
2. Now, fully loosen the rocker arm bolt on the INTAKE of that cyl. (this valve will be fully closed).
3. Then turn that INTAKE rocker arm bolt down until the lifter is at "zero lash". You will be able to tell it is at zero lash when the rocker bolt gets very hard to turn. It gets hard to turn because the valve spring starts to compress. Again, stop turning the bolt as soon as you feel resistance to turning.
4. Mark the bolt with a marker.
5. Now count how many turns it takes to completely tighten the rocker bolt to 22 FT/LB.
The bolt should have turned between 1 3/4 to 2 turns for the acceptable GM lifter peload.
If you don't get the 1 3/4 to 2 bolt turns of preload, you need a different length pushrod. (IE: longer rod if it takes much more than 2 turns, and a shorter rod if it takes much less than 1 3/4 turns).
NOTE: You really only need to do this on one cylinder. The rest will be the same.
NOTE: If you have aftermarket Comp Cams “Type R” lifters, I understand that those like less preload than stock lifters. Instead of 1 3/4 to 2 full turns as indicated above, 1 to 1 1/4 turn may be more acceptable
Hope this helps.....
<small>[ March 14, 2003, 10:27 PM: Message edited by: Kimchee and Rice ]</small>
The aftermarket cams being installed today will usually have a smaller base circle than the stock LS1 cam they are replacing. Base Circle is actually the distance accross the cam's lobe. This is 90 degrees from the top of the cam's lobe at the point of highest lift.
You can easily measure this base circle distance with a micrometer. Measure across the cam's lobe (the lobe's smallest distance across). You will find that it is 1.552” on a stock LS1 cam. You will need to cut this distance in half in order to get the cams "centerline to lobe heal" distance. The stock LS1 cam has a .776" centerline to lobe heal distance (19.7mm).
This centerline to lobe heal distance is what is important to you in determining lifter preload.
A TR-220 cam has a 1.502” across the lobe base circle. Cutting this number also in half will equal a 0.751” centerline to heel distance. This is a 025" smaller centerline to lobe heal distance than the stock cam.
To be very accurate, you would then need a pushrod that is .025" longer than stock to achieve the same spec lifter preload as you had with your stock cam.
These aftermarket pushrods come in .050" length increments, so in this case, a stock 7.40” pushrod would be ok.
Remember, hydraulic lifters, due to there design have a + - preload variance that the lifter can operate within. It don't need to be exact. Just get it as close as possible with the various pushrods that are available (in .050" increments)
Be advised, milling the heads will change all this and require shorter pushrods equal to how much is milled off the heads (see below).
So, to re-iterate all this:
1. If your cam has a .025" smaller centerline to lobe heal distance than stock, you would need a .025" [longer] rod.
2. If you just milled the heads .025", you would need a .025" [shorter] rod.
3. Combine the two, and your stock 7.40" pushrod would be perfect … It then becomes tit for tat
_________________________________________________
CHECKING LIFTER PRELOAD:
1. Turning the engine, bring the EXHAUST valve on one of the cylinders down until it is at peak lift (valve fully open). The pushrod will be pushed all the way down and the valve spring will be compressed.
2. Now, fully loosen the rocker arm bolt on the INTAKE of that cyl. (this valve will be fully closed).
3. Then turn that INTAKE rocker arm bolt down until the lifter is at "zero lash". You will be able to tell it is at zero lash when the rocker bolt gets very hard to turn. It gets hard to turn because the valve spring starts to compress. Again, stop turning the bolt as soon as you feel resistance to turning.
4. Mark the bolt with a marker.
5. Now count how many turns it takes to completely tighten the rocker bolt to 22 FT/LB.
The bolt should have turned between 1 3/4 to 2 turns for the acceptable GM lifter peload.
If you don't get the 1 3/4 to 2 bolt turns of preload, you need a different length pushrod. (IE: longer rod if it takes much more than 2 turns, and a shorter rod if it takes much less than 1 3/4 turns).
NOTE: You really only need to do this on one cylinder. The rest will be the same.
NOTE: If you have aftermarket Comp Cams “Type R” lifters, I understand that those like less preload than stock lifters. Instead of 1 3/4 to 2 full turns as indicated above, 1 to 1 1/4 turn may be more acceptable
Hope this helps.....
<small>[ March 14, 2003, 10:27 PM: Message edited by: Kimchee and Rice ]</small>
03-14-2003, 10:24 PM
#11
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Glenn98ZM6:
<strong> did you but the hole in the side of the lifter towards the back? if not, i heard it makes a difference. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I looked at that when I removed the lifters from my bone stock engine. Some holes faced foreward, and some to the rear. My conclusion was that it made no difference which way the holes were oriented.
<strong> did you but the hole in the side of the lifter towards the back? if not, i heard it makes a difference. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I looked at that when I removed the lifters from my bone stock engine. Some holes faced foreward, and some to the rear. My conclusion was that it made no difference which way the holes were oriented.
03-15-2003, 02:15 PM
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Re: New cam and lifters installed, now it sounds like a diesel!!!!!!! As you tighten certain rockers, you are gonna compress some of the springs. That's fine. FWIW, my car took about two days to settle down. Ask anyone who was there and they'll back me up on my claim that my sounded like it was coming apart!! It was incredibly loud and then the rockers seemed to work themselves out and it is almost gone. Some noise but it is now to the level I expected and not like ball bearings in a glass jar!!
