Timing Chain

[78SilvAnniv]

Below is a pic of my timing chain. Is that slack normal and/or desireable?

Kenny removed the timing chain/gears from that pic and has installed a Cloyes double roller timing chain/gears. The new chain is taut all the way around. Is this better?

Another question:
Why is a double roller timing chain desireable?
Heidi

ps...waiting for new piston to arrive next week to begin putting block back together.

 

[billyvette]

timing chain

chain should be snug and not tight, the pic looks ok to me.

what all are you having to do?

double chain is "better" than stock with the single chain
keeps valves and pistons from getting together.

did your entire dash and console have to come out when you done the heater core?

billyvette

 

[Canuck]

The chain in your pic is fine. The chain should always have some slack. No slack is no good. If the chain is too tight on the sprockets it will wear the chain quickly and prematurely.

TOM

 

[78SilvAnniv]

heater core

...did your entire dash and console have to come out when you done the heater core?
billyvette

Kenny was using very colorful language when he did the heater core so I mostly stayed in the house.
I do believe the center console and the dash needed to be removed, or at least loosened to give him access to the heater core.
Heidi

 

[billyvette]

thanks for the imfo.

 

[Bob Chadwick]

Re: timing chain

did your entire dash and console have to come out when you done the heater core?

billyvette

I think it needs to come out only if you have ac.

 

[Jack]

Heidi & Kenny:
IMHO ... the old single row chain shows slack that is normal for miles/age. But, it is not so desirable. It probably has a good bit of service life left ... If I was in a pinch I'd use it if I HAD to ... but not otherwise. A new chain ... single or double ... will be taut. A double is better in the sense that it has greater tensile strength so it is more resistant to stretch ... is better because its rollers run with less friction ... runs a bit cooler ... less likely to break also. A double will probably be a tiny bit noisier than a single ... but you probably won't even notice it.

Slack in chain will cause errant cam and/or ignition timing.

Seems a valve hit a piston ... & you're replacing piston. Sometimes such a hit could stress the rod too. Do have your machinist check your rod for bend & twist before he presses on the new piston.

Did y'all opt for another cam ... if so, what?
JACK:gap