anyonr know about ptv contact?

[ADRENLN]

would ptv contact happen in neutral during free reving, or would the tapping only happen under load while you are driving the car? when would you be able to hear it? one or the other or both? thanks

 

[Gearbanger 101]

You won't have piston to valve issues with your stock modular engine no matter how much you rev it in neutral. There is more than enough clearance, even were you to add cams. The "ticking" noise you describe is likely attributed to something else. Piston slap, wrist pin noise, valve train noise, exhaust leak....etc, etc. It could be any number of things, but not an issue of clearance.

 

[bdcardinal]

if you have flattop pistons and aftermarket cams on a 2v then ya you can get ptv contact. it just comes from having the valves lift too much versus a taller piston. on a stock motor there wont be any.

 

[ADRENLN]

i have a stock motor, but aftermarket heads and cams. i get tapping when i go 3 quater throttle or morewhile driving while under the hood if reved while in nuetral i dont hear the tapping.

this is what im trying to figure out.

 

[DropTopPony]

did you check the spark plugs/wires? sometimes they click or pop when loose...wouldn't want one to blow out on those expensive heads.

 

[tomustang]

could just be the gas.. air/fuel mix

 

[ADRENLN]

i dont know i guess ill just have to get it back to the tuner to let him take a listen.

 

[tomustang]

i get tapping when i go 3 quater throttle or morewhile driving while under the hood if reved while in nuetral i dont hear the tapping.

i use to have the same problem in the 98 (stock) it turned out to be the gas, so i just went to premium

 

[ADRENLN]

i have a chip and have been dyno tuned, ive been using premium for a while. thanks for the reply though.

 

[tomustang]

tell him to back off the timing once it's in

 

[ADRENLN]

gearbanger, are you saying that with aftermarket cams you dont have to worry about ptv contact? i thought some people were havin problems with certain comp cams?

for the sake of the thread, lets say you do have ptv contact. would you hear it both driving the car and just recving it in neutral?

 

[Gearbanger 101]

gearbanger, are you saying that with aftermarket cams you dont have to worry about ptv contact? i thought some people were havin problems with certain comp cams?

for the sake of the thread, lets say you do have ptv contact. would you hear it both driving the car and just recving it in neutral?

That I know of, none of the street grinds are creating PTV contact issues. The stock 18cc dish with the PI heads provides enough clearance for this. The only feasible way that I could see there being a problem, is if the valve springs weren't upgraded with the cam (if so required) and you're getting "valve float". In which case, you wouldn't have the issue very long, because if this were the case, it wouldn't take long at all to bend a valve. Whether you'd hear it or not under all conditions depends on how close the clearance is. Usually, with the engine not being under load is when it's at it's closest (IE: revving in neutral, or a missed shift). But as I said, in your case, I just don't think this is your problem.

It's really impossible to diagnose without hearing it in person, but my gut tells me that it's not a clearance issue. Why don't you contact your cam manufacturer and see what they've got to say about clearance issues with that particular grind.

 

[Red2000GT]

Sounds like ping to me. Almost positive on that.

 

[ADRENLN]

thanks gear banger. what does pinging sound like? people always describe it like marbles in a tin can. that would lead me to think it has sort of a high pitch to it.

also does pinging happen sparaticly or does it have an even pulse. hard to explain sorry!

i mean the ticking i get is not random it is very even sounding like whatever in the engine is making the noise as it turns it is at an even pace. it just speeds up as i lay into the gas.

im thinking gearbanger is right about the ptv. i have comp springs so i should not be having a prob with that. i need to know more about pinging. from what i know i didnt think it was this, but if it is i have to get it fixed. why would i be having a pinging problem? the car is tuned on the dyno on the rich side. wouldnt i have to be running lean to get pinging?

 

[mogs01gt]

what duration are the cams? The comp 270s and 272( I think that is the number) can cause PtV contact because of the duration and the fact that Comp adds a few points of degree into their cams. Its NOT THE .550 lift, its the duration. PtV issues happen at ALL RPMs not just in the upper or Mid. If you are hearing something that sounds like marbles in a can, that is pinging/detonation. Either have timing pulled or you need to run a higher octane.

Did you degree the cams on install? Did you do the install? If they are off a tooth, you can run into PtV issues also. The only comp cams that have no had PtV have been the 262s for the 2v mod engines.

 

[ADRENLN]

they are 212intake 218exhaust @050. 114center

they were put together by foxlake, i just had them bolted in. i do NOT hear marbles in a can, im just wondering what pinging sounds like. im running rich on the dyno, so i didnt think it was possable for me to get pinging

 

[mogs01gt]

Only way you are going to have PTV with those cams is incorrect installation. Meaning the timing is off. If the timing is off, you can have PTV.

 

[MaxedGT]

Sounds like ping to me. Almost positive on that.

 

[ADRENLN]

can someone please elaborate on PINGING...PLEASE.

give me more on the sound, is it random or timed?

can i get pinging with a rich tune?

i was dyno tuned with 94 octane in the tank. ran a tank of 93, would this effect it?

 

[mogs01gt]

pinging will not sound like PtV contact. PtV will sound like metal on metal and pinging/detonation will sound like marbles or metal in a tin can. A rattle type sound. It could be slight or heavy.

not only does the a/f ration effect detonation but timing is a much bigger factor.