cam shaft swap help

[IsaacHayes]

After 2000+ 3100 heads are the same as 3400. Some 99 3100's got the 3400 heads/intakes.

But the older 3100 heads have smaller intake valves.

[Rootie524]

but yeah going back to the other question.

are 3400 heads the same as 3100 heads?

[Rootie524]

thanks for pointing that out..it does say 168 in/lb..that sucks. why would they have most in ft/lb then a few in in/lbs..that really screwed me up..now i know to really pay attention to that.

[pocket-rocket]

It probably said inch/lbs. I'm pretty sure it's less than 20 ft/lbs. If you come across inch/lbs and you don't have an inch/lbs torque wrench just divide the figure by 12 (because there are 12 inches per foot). It's not as accurate, but it works.

[Rootie524]

i was looking in the haynes to see torque specs for rocker arms and it says 160ft/lb plus an additional 30 degree turn.

is that true?! that seems very excessive.

and just for future references are the heads and valves on a 3400sfi grand am the same on a 3100sfi..

[Rootie524]

well i mean all the other valves are used technically..they just werent removed. so i may be technical..since it got replaced with the exact same valves on the same cylinder..its like it was never replaced. i understand what you guys are saying..i just hope it will be ok or wont be bad enough until i can do my heads in a few months during the summer.

[SappySE107]

Loss of power and it could throw off the MAP sensor if its bad enough. It might seat in after some use but you should have lapped a used valve for sure. If its already together, I don't know if I would tear it apart just for that, especially if you plan on upgrading heads this year.

[Rootie524]

well would a leaking valve cause damage or just loss of some power because i really want this car running again and i already put the heads back on.

so do you think i might be ok? i went to a junk yard..pulled the intake valve off the same car..pulled it out..went to my car..took the bent valve out and put the junkyard one in..the valve looks sealed well around the head of it..so you think i can live without? i know i shouldnt but this summer im planning to finish off the valve train with ported heads, 3500 valves, new retainers and seats and seals and all that good stuff. so hopefully it will be good till then.

[SappySE107]

A valve job where a cutter is used would also seal the valve to the seat. If the seat isn't pitted, you should be ok with a new valve in there.

[Superdave]

im new to this stuff..lap? lol. call me dumb but this is allll new to me. never had the engine apart more than the UIM before. so im not too familiar with different valve train things. lap the valve? the old one slid right out and the new one slid right in..what is there to "lap"?

To get a proper valve seal you need to do what's called lapping the valve.

http://www.v6z24.com/howto/valvelapping

Without doing that there is a good chance that intake valve is going to leak, basically causing a loss of compression on the 1cyl and that's never good.

[1988GTU]

I didnt read the whole post . Thought you just replaced the rocker and rod and left the valve in.

Now you know.

[Rootie524]

http://www.answerbag.com/q_view/7386

Off timing is a simulation of a broken timing chain/belt to a lesser extreme.

oh ok..that makes sense..but the damage has already been done..it turns out the timing wasnt off..just the rods were swapped. so only the one valve was bent and it has been replaced..and it has a new chain on

so am i missing something why you mentioned this? because please tell me..i dont want this to get screwed up.

[Rootie524]

im new to this stuff..lap? lol. call me dumb but this is allll new to me. never had the engine apart more than the UIM before. so im not too familiar with different valve train things. lap the valve? the old one slid right out and the new one slid right in..what is there to "lap"?

[1988GTU]

http://www.answerbag.com/q_view/7386

Off timing is a simulation of a broken timing chain/belt to a lesser extreme.

[Superdave]

did you lap the new valve in?