Tapping noise after 206/212 cam install.

[mazdatech78]

I just got my car back together this weekend. I did the cam break-in procedure since it is a flat tappet. After doing that I shut the car down and changed the oil. After restarting I noticed that it developed a metallic tapping sound that sounds like it is coming from the drivers rocker area. I also notice that it comes and goes. The tapping goes with the RPM's too. I used a stethescope and when I pull the oil fill breather off the drivers valve cover and place it on the rocker shaft. The noise seems to be the loudest there. I can also here it pretty well if I put it on the drivers header tubes. Im just trying to get an idea where to start before I start tearing this engine back down. I reused the pushrods and rocker shafts. I also torqued the shafts down to factory spec. When the motor was out I also put on a set of big valve ported 8445's with 110lbs springs. I am leaning toward the lifter preload being off but knowing my luck this cam and lifters decided to eat eachother. Just looking for some ideas. Thanks.

James

 

[Louie L.]

From my experience that sounds like a lot of spring pressure for a flat tappet. But if the cam is fine i would think its preload related.

 

[mikebart101]

lash maybe?

 

[mazdatech78]

Just my f*cking luck!!!

After pulling the valve covers and cranking the motor I found my problem. #3 exhaust rocker is not moving as much as the others. I used a measuring stick to measure the max lift from the cyl. head to the rocker. All the other exhausts are at 2 inches. The #3 is only about 1.80 inches. This f*cking sucks. Comp cams garbage. I should have left the stocker in there. Now I have to decide to fix it or part this POS out!!!


James

 

[JDSfastGN]

fix it, its not a lot of money if you got lucky and you can just stick a new cam in there. Try a speedpro 204/214 cam... runs good and ive heard of very few if any wiping

 

[PEACHS]

Way too much spring pressure, 85-90#s would have been enough. Whenever i install a new flat tappet cam i use old weak valve springs to break in the cam. A small 208 Erson cam would be a great replacement cam.

 

[rob86gn]

How long did it run all in all with the noise? My car sat for about 2 months, I changed the oil, started it, and it made a noise on one rocker for about 30 minutes at idle. I just let it run and I think the lifter finally filled up with oil or something but it's been fine since.

I did notice that particular rocker was loose until the lifter pumped up again.

 

[mazdatech78]

I ran it for a while. I drove it 8 miles. It also was idling alot while I was trying to find the noise.

 

[John Wilde]

Don't feel bad I have lost about 3 cams in the last 10 years.
Two flat tappet and one "buget" roller.

 

[Louie L.]

#3 exhaust is the typical problem in these motors.Like I said above, 110 lbs is too much for that cam even more so during break in. It is important that you break flat tappets in following the instructions on GNTType.org using lots of EOS GM additive.I have only done one myself a long time ago and we used old weak valve sprigs to break the cam in. Then the motor was not allowed to idle any lower than 2500 rpm for the 1st day of driving.Been doing rollers ever since.

The price of a roller cam doesnt look so bad after this happens. Good Luck

 

[SITHV6]

JUST when I thought I was safe...

Reading about valve spring pressure being a killer of flat tappets has me worried now...I JUST rebuilt my TR with a PTE 218/218 flat tappet and if memory serves the valve springs on GN1's are over 100...(110 or 125?) and if it IS 125 does this mean my 218 cam may be toast? Because even after breaking it in I hear far more valve train tapping than I ever had with this car. (had been told the 218/218 is a NOISEY CAM to begin with). Guess I'll know for sure after a long drive and remove th valve covers to retorque the heads and i can do the same to check lift hieghts, God I'm NOT looking foward to this...

 

[rodman99999]

Hey Louie- Where do I find these instructions? Is there a URL available?(couldn't find it with, "search" on gnttype.org) I'm about to reassemble my engine, and need the info. Thanx

 

[Louie L.]

http://www.gnttype.org/techarea/engine/cam_tips.html

 

[rodman99999]

Thanx Louie- I had the right plans, but it's good to have them confirmed!!

 

[JDSfastGN]

Reading about valve spring pressure being a killer of flat tappets has me worried now...I JUST rebuilt my TR with a PTE 218/218 flat tappet and if memory serves the valve springs on GN1's are over 100...(110 or 125?) and if it IS 125 does this mean my 218 cam may be toast? Because even after breaking it in I hear far more valve train tapping than I ever had with this car. (had been told the 218/218 is a NOISEY CAM to begin with). Guess I'll know for sure after a long drive and remove th valve covers to retorque the heads and i can do the same to check lift hieghts, God I'm NOT looking foward to this...

don't worry about it for now, the 218s ive heard with non factory lifters are very very noisy motors. You may want to check to make sure all the pushrods are going up the same height just to be sure but i wouldn't worry about it too much

 

[RUQWKNF27]

Oh Well!!

Just getting my motor broke in with my 218/218 with 512 m.i. an no problems @ all. I love this cam it really comes alive !!!! I can tell there may be a lil more noise but nothing extreme @ all. An oh man what a idle people think I gotta cammed SB. Must be this 4" exhaust we built . As long as you break it in right an use a lot of assembly lube an all the clearances are right you should be fine.. I'm leary of wanting things too when breaking in a motor!! I have already changed my oil 5 times an thats a loota oil since I got this RJC pan..

 

[rodman99999]

So would a 100lb spring be right for a flat tappet cam? I'm going to use a 214/214, and thinking about Kirban's (100lb) replacement springs(so I can buy the removal tool at a discount). Anyone have experience with those springs?

 

[mazdatech78]

Well, I finally tore this thing down to find out what really happened. The #3 exhaust lobe is gone and the bottom of the lifter is dished. I checked every other lifter and lobe. They broke in perfect. I know this had nothing to do with spring weight. This was a defective cam that was cut wrong! With the amount of metal that has probably went through my motor im looking at a total rebuild! Unfortunatly with all the money I spent to get this car back together right I dont have any left to do this. Now I get to look at a 3600# paper weight till spring. What a f*cking crock!!!

James

 

[Super6]

roller

this is why i went to a roller...i got enough crap to worry about when and if i ever get this thing fired up.........save up and go roller mazdatech78........Bob

 

[Louie L.]

Well, I finally tore this thing down to find out what really happened. The #3 exhaust lobe is gone and the bottom of the lifter is dished. I checked every other lifter and lobe. They broke in perfect. I know this had nothing to do with spring weight. This was a defective cam that was cut wrong! With the amount of metal that has probably went through my motor im looking at a total rebuild! Unfortunatly with all the money I spent to get this car back together right I dont have any left to do this. Now I get to look at a 3600# paper weight till spring. What a f*cking crock!!!

James

How did you arrive at the fact that the cam was cut wrong. Was it by looking thru the lifter bore???

From the 1st post the spring pressure you stated was for a high for a flat tappet. Second the cam not cut wrong. What you have is the lifter bore is in the wrong spot.This was clearly visible if you looked thru the #3 exhaust lifter bore. Very common to the 109 block. Some blocks have this condition worse than others. Because of the misaligment, the lifter will not spin in the bore and kill the lobe.

Lots of info on this issue on the boards.

With that said the cam was most likely going to wipe no matter what, the spring pressure just sped it up.

We call these blocks "cam wipers" no matter what cams wont last in them. The only easy fix is to use a roller cam.