timing a 3.1l

[birar]

I have a 91 grand prix gt with the 3.1 in it. it recently just broke a timing chain and bent some valves so im putting new valves in and wondering which way the timeing should go. i have read theres 2 ways that it can go on a 3.1 i think its the cam and the crank should be at 12oclock and num1 piston is at tdc is this correct?

[tblake]

I thought for some reason the 3100 was a free-wheeling (non-interference) motor... I guess not.

I've never had to time one. So I cant help you there. Sorry! Someone will know though.

[birar]

yea ik its strange i thought it was a none interference engine to but apparently it is in certain instants o well i guess thanks anyway

[lefty1120]

Per my '93 FSM, Go with #1 TDC. Camshaft mark at 6 oclock, Crank at 12 oclock.

[richtazz]

"Technically" these motors are not an interference design. But due to the short skirt pistons, as they get older and develop the common piston slap issues, the valve clearances close due to the pistons rocking in the bores. It's not uncommon for them to hit valves at higher mileages due to this.

[birar]

the pic is kind of confusing so u have to have the cam at 6 and the crank is 12 i was told different before so that's why im getting other opinions

[birar]

and in the pic it looks like num 1 should be at tdc and the crank and cam r at 12oclock were u just refering to ur car?

[lefty1120]

Ignore the pic...is it still showing? I removed it.

Crank at 12, cam at 6 with #1 at TDC.

Here's another investment well worth the money.

http://cgi.ebay.com/ebaymotors/1991-...sQ5fLiterature

[birar]

alrite thanx man ik i should have went with my gut, cuz i put the chain in and thats how i found out i had bent valves and the haynes book said i was 180 off with the cam when i checked that afterword for torque specs, thanx for the quick reply!(: