I see some of the I-6 240/300 CID engines have timing chains and some have timing gears. Does anyone know when Ford changed them? Does one have an advantage over the other? Can I change my timing chain to timing gears easily? Thanks.

 

as far as i knew none of the I6s ever had timing chains?

you dont want chains, they stretch and break...gears dont...but gears do make more noise, small price to pay

the stock timing gears in a 300 are not metal i forget what they are called but its some synthetic material made to reduce noise, as a result they cannot stand up to much more than the factory build of the engine...if you want to build one (especially depending on your cam choice) you will probly need ot og to metal timing gears, again the noise...minor detail

as i stated you should already have gears

i think they are called phoelenic??? that jsut rings a bell dont quote me

and i have heard many times that timing chains cannot be used in the 300 for some reason never read much into that

 

Thanks. I believe you are correct. I was confused by EBay listings for timing "chain" covers for the 300, but they should really be listed as timing "gear" covers.

 

Ford started using a fiber reinforced phenolic resin cam gear at some point in the 70's or 80's. Prior to that they were a steel crank gear and an aluminium cam gear. There is no way to use a chain without a reverse cut cam as that would turn the cam in a reverse rotation.

I have talked to a few machinists and they say there are realy no advantages or disadvantages to the resin gear other then it is quieter.

 

The 300 never came with a timing chain...it wouldn't work anyway as the cam would rotate backwards.

 

Some of the OLD I-6's (216, 232) used timing chains. I have one apart in my garage, the chain is about 1" wide.

In theory the phenolic gears are quieter and wear better, however they're more prone to losing teeth and chipping when abused. Regardless of the material, something else in the motor will require attention before the cam gears unless the engine is just totally and completely abused.

 

170,200, and 250 sixes used chains too.

 

Ford did supply metal gears in the P500/600 300's. Having dealt with quite a number of these engines I can tell you they were quiet. You had to use the proper crank gear with them, if you tried to mate a metal cam gear with the steel crank gear used with the fiber gear it would drive you out of the shop. They also made the metal gears in two different pitches one was somewhere around 8 teeth to the inch and the other was about 16. Never saw one fail. The phenolic setup did give leave you on the roadside ever now and then. My experiences and observations. Kotzy

 

hey i was close! i knew it started with a ph and sounded fancy

yeahhhh thats why they dont work...well if you really terribly wanted to you could probably make it work, reverse cut cam...

 

170, 200, and 250 sixes used chains too.

In ford terms, different "family" (includes the 144 too) from the 240/300. All great motors if U apply each to the intended engine need.

 

My 79 Had stock steel gears on cam and crank? Original owner motor never taken apart

 

My 72 F250 has the original steel timing gears in it, even after a rebuild at 135000 miles. I don't hear them at all. Both gears were steel. I now have a timing problem, and thought it might be the timing gears, but a mechanic told me 'no', he'd never seen those gears wear out. Break maybe, but not wear out. Turns out my distributor has about 20 degrees rotational play in the shaft, which isn't as solid as I thought. No wonder I couldn't time it!