can aftermarket cams ruin stock vlave train

[miller97tsi]

ok i am thinking that my cams might have ruined my valve train is this possible? i have the equivalant 272 version of comp cams. any suggestions

 

[salisbury]

let me guess another delta cams horror story?

 

[forcdndukshun]

Normally aftermarket cams will specify if they are compatible with stock valve train. Can aftermarket cams mess up your valve train? I'm sure they can. What brand of cam do you have and do you know if they are meant to run on stock valve train, need to be shimmed etc.

 

[BogusSVO]

if your running the OE factory installed springs, I bet they were wore out BEFORE the new cams got slammed in the head.

forcdndukshun is right, if the springs are not the ones for the cam, then damage will occur.

think about how many times the springs have been bounced... and how many miles at what RPM.

I would advise anyone dropping cams in that the springs tested at a min or just replaced.

http://www.dsmtuners.com/forums/newbie-forum/341287-how-test-valve-springs.html

and here is some spring info too

http://www.dsmtuners.com/forums/newbie-forum/341209-4g63t-valve-spring-info.html

you always need to check with the cam manufacture to see what seat preassure and what open pressure they want on the cam.


BTW salisbury... what horror stories are you talking about?

 

[Calan]

Any cams can fubar the valve train if you rev the motor too high. If you keep it within reason, aftermarket cams will work just fine with a stock valve train, unless:

a). The cam profile requires something heavier (which the manufacturer should specify), or
b). Your stock valve train is weak...in which place it probably isn't the cam's fault in the first place, or
c). You rev it past it's limits.

I've been running FP2 cams (basically 272's) on a stock valve train both in my stock 2.0 and now the 2.3l stroker rebuild with no issues for around 15,000 miles combined. But I did go through the head to check for worn components and replaced the seals and some valves. And I keep the revs to about 7.2K max.

 

[miller97tsi]

they are comp cams they could have been bad would yall suggest a compression check

 

[BogusSVO]

whats the issue your having?

if you think the cams are bad, pull the VC and look, you would have excessive wear on the cam lobes.

 

[miller97tsi]

not that the cams are bad just trying to figure out if i might have jacked the valve train up by installing these cams. its not running thinking something is going wrong in there

 

[Calan]

So back up a minute. Did you install the cams and now the car won't run, or did it run for a while and then quit? And what are (were) the symptoms?

If you installed new cams and it immediately won't run now, the problem is most likely that the timing belt is not tensioned properly or installed incorrectly...assuming it's not something simple like forgetting to plug something back up.

 

[miller97tsi]

no i installed the cams it ran a a few minutes i shut it down. the a couple of days later i started it back up and it wont even turn over. it cranks over but no detonation i have spark and fuel figure the cams might have ruined somethingmdont know though i am stumped

 

[BogusSVO]

I have seen one issue of the valves being bent from a cam install..... the customer bolted the cams in, then rotated the cams, and when he did he bent the valves by hitting the other valves. basicly say #3 cylinder, INT valves were at full open, and when he rotated the exh cam and #3 cyl EXH valves came to full open, he hit all 4 valves together bending them
but he was also equiped with +1mm valves



Calan........ what vendor are you with?

 

[Calan]

When it first ran... did you notice anything out of the ordinary? Especially noises?

I don't think you ever said exactly which cams we are talking about here. But if they are 272 clones, it still sounds like a t-belt or timing issue.


Bogus: PM sent

 

[miller97tsi]

i guess that i can recheck it. the only noises that i noticed were lifter tap noises. thing is that it ran idled between 750 and 1000 rpms. i let it warm up then i shut it down. a couple of days later i tried to restatrt it and i got nothing. not really sure what is going on. going to try a compression check and hopefully figure it out maybe bent valve hopefully this is really the only thing that i am counting on. always open to more suggestions, anybody?

 

[Delta Cam]

let me guess another delta cams horror story?

Been doing cams for 26 yrs, never had 1 HORROR story, please send link to post or at least make up a good story if there is no post in fact.

 

[adamtsi]

272's typically are ok with stock springs if you don't plan to rev past 7000, anything past that your gonna be floating your valves which could cause piston to valve interference causing valve train damage

 

[Delta Cam]

salisbury........ waiting