231 Buick V6 timing chain and fuel pump Qs

[joesregalproject]

It's been a while since I've been on the forum but I still have my regal and it's close to being back together. Currently I have the engine apart to replace the fuel pump and I put my finger through the hole for the cam on the engine side and when I felt the timing chain there is about an inch or so of slop in the chain. What is an acceptable tolerance for the timing chain? The engine currently runs very very well but I don't want to wrap a lot of money up in it being a base engine which I may eventually swap. I also don't want to destroy the engine because I neglected to change a severely worn timing chain. Should I bother changing the chain or just leave it?

My second question is, how do I know the cam on the fuel pump is properly seated inside the engine before I bolt it up? I could get it to one spot that felt ok, but it did give me a little resistance when trying to tighten the bolts. Any answers help, thanks!

 

[joesregalproject]

 

[jetsetw31]

Change the timing chain. There is not supposed to be hardly any slack what so ever on a Buick V6 chain because it has a chain tensioner. Any looseness means the tensioner is either worn out or the spring broke. Since you said it was running ok, then It most likely is worn. Just change the chain to have peace of mind.

The fuel pump is suppose to have a little tension before it tightens up.
T

 

[81Regal]

On the later models there was a chain tensioner but the 3.8's in these cars had nylon gears if they still have the stock timing chain. Almost all the RWD 3.8's Ive had apart had some play in the chain but the gears themselves were shot. Cheap insurance to replace the timing set if you are planning on daily driving it.
There is a lobe on the front of the cam that the fuel pump arm sits against, the arm rides on the bottom of that lobe.
I have a few of these engines sitting around for parts if needed.

 

[jetsetw31]

On the later models there was a chain tensioner but the 3.8's in these cars had nylon gears if they still have the stock timing chain.

You're right about the nylon gears, But all but one of the V6s that i've worked on didn't have a tensioner and that one was missing. Those motors ranged from 1978 to 90. My '78 Skyhawk 231 had one and I put an 84 motor in it that also had one. My '81 Cutlass 231 had one. Maybe they were removed from the motors you have.

 

[joesregalproject]

I got the fuel pump replaced and the engine back together. Runs beautifully. I honestly don't think I'm going to change the chain. I have more than enough money and time wrapped up in this engine as it is, and currently my main goal is to get the car painted. It isn't going to be driven daily so i don't have to rely on it. From this point on all I'm doing to this engine is oil and filter changes until it blows up.

 

[jetsetw31]

Lol, It probably won't blow up but, at least you have a plan.
T

 

[565bbchevy]

I had an Buick 231 that came in one of my Gbodies that was waiting on a SBC swap and from what I am guessing the timing chain skipped a tooth and for about a week it felt like it had the power of a V8 roasting the tires from a stop (I'm guessing it advanced the cam? ) until it jumped again and ran like crap.