Very quick and easy question. Are our 2.8L V6 engines an interference engine? So if the timing chain were to break for any reason would the pistons be able to slap the valves?

 

No.

 

Sweet I love that, thanks.

 

are you sure that's a no? i could be wrong but i would think its possible

 

unless you have an ultra high lift cam and heads that have been shaved to bare minimum, there is no possible way for the pistons to contact the valves on a 660 motor. There is too much clearance to be an issue. Ask me how I know...lol.

 

not even with a broken timing chain like he said? like, if a piston comes to TDC and a valve is open (obviously at the wrong time because of a broken timing chain), they won't contact each other?

 

no, if you take the timing chain off and roll the crank over (i have done that) nothing touches anywhere, it spins free, well till you hit a combustion stroke, lol.

 

Nope, that's exactly how I know. I was driving one day, got on it hard, shifted into 3rd and the chain snapped right around 4000 rpm. Tore the front apart, slapped in a new chain and gears, started and has been fine since. Over 25K miles now on this chain.

 

ok, that seems a little surprising to me but if you all have done that stuff...guess you're right! However, I'd be scarred to try that with my cam!

 

I think the only 2.8's that were interference engines are the Gen II motors (FWD, aluminum head, splayed valves, heart-shaped combustion chambers)...

 

Yeah, with a no tso stock cam like what I've heard you're running, it'd be a little scary. I don't know the exact clearence numbers, but I think there's enough that even with a radical cam in there you'd be ok.

Now, I don't know what kind of valvetrain you have, but I think you'd have to be running special valve springs and have over .750" of valve lift.

 

I've got domed pistons in it, too. with everything "in line", i've got over .125" clearance between the valves and pistons but I don't imagine I'd have that if something out of the ordinary happened.