3.1l motor interferance or not

dalejr88money

does anyone know if the 3.1L is or is not an interferance motor for sure 100%

corvette

I don't know for sure, but Google suggests that it is. If your timing chain has skipped teeth, probably need to borescope it.

oldfarmer50

If you Google it you get an AI answer that suggests it is but not 100%. I would assume that almost all modern engines are interference designs unless proven otherwise.

kyfdx

I'm not 100% sure, either. But, from everything I can Google, it IS an interference engine. It seems the related 3.4 engines were NOT.

thecardoc3

Checking service information, the timing chain replacement does not have a caution about turning the crankshaft while the timing chain is off with the 3.1l. Service information does mention turning the crankshaft approximately 90 degrees before TDC on the 2.3l to prevent hitting the valves when the camshaft is rotated which makes sense because the 2.3 is definitely an interference engine. Without that caution on the 3.1 it is not considered an interference engine.

However.

There have been occasions where a non-interference engine still managed to bend some valves and pushrods if the engine gets out of time. Did this jump time and is that the reason for the question?

ronsteve

Isn't the 3.1 a pushrod engine with a chain driven cam? IIRC timing chains are known to make a bit of a racket to warn you of their impending failure, at which point it's good to get checked out and maybe changed, whether it's interference or not.

nyccarguy

@dalejr88money said:
does anyone know if the 3.1L is or is not an interferance motor for sure 100%

Can we ask what the problem is?

dalejr88money

thecardoc3 said:

Checking service information, the timing chain replacement does not have a caution about turning the crankshaft while the timing chain is off with the 3.1l. Service information does mention turning the crankshaft approximately 90 degrees before TDC on the 2.3l to prevent hitting the valves when the camshaft is rotated which makes sense because the 2.3 is definitely an interference engine. Without that caution on the 3.1 it is not considered an interference engine.

However.

There have been occasions where a non-interference engine still managed to bend some valves and pushrods if the engine gets out of time. Did this jump time and is that the reason for the question?

thanks makes sense,with that said i agree that its most likely not an interference motor and after a [non-permissible content removed] ton of googling i found that the 92 gm 3.1 has dished pistons therefor giving more clearance,im about to get the cain guide ,chain and both sprockets changed next week,ill let you know for sure next week

dalejr88money

oldfarmer50 said:

If you Google it you get an AI answer that suggests it is but not 100%. I would assume that almost all modern engines are interference designs unless proven otherwise.

that ai is garbage,if you ask if it is interferance it says yes,then if you ask if it isnt it says yes,lol,crazy ai

dalejr88money

nyccarguy said:

@dalejr88money said:

does anyone know if the 3.1L is or is not an interferance motor for sure 100%

Can we ask what the problem is?

chain jumped off

dalejr88money

nyccarguy said:

@dalejr88money said:

does anyone know if the 3.1L is or is not an interferance motor for sure 100%

Can we ask what the problem is?

chain jumped off

ronsteve said:

Isn't the 3.1 a pushrod engine with a chain driven cam? IIRC timing chains are known to make a bit of a racket to warn you of their impending failure, at which point it's good to get checked out and maybe changed, whether it's interference or not.

yup it gave me a warning with the occasional racket,didnt know what it was,i do now,lol