[wbnapier]

Hello,

Does anyone have a nice diagram of the keyways for a melling timing set, #40408?

Thank you.

[Cliff R]

I don't use those but the keyways and upper sprocket should be well marked for all three positions. Going from memory they used a "O", "triangle and a square for the corresponding keyways and upper sprocket orientation.

That is one of the "low" end sets but uses a little better chain that the "bottom of the barrel" stuff. The sprockets are cast iron, not billet steel. I think the chain has solid bushings that actually roll and not "fixed" but it's not nearly as good as a stock Melling 3/4" wide Morse chain set-up, and from what I've seen those stretch out pretty quickly and the timing mark will "bounce" around some after it's been in place for a few hundred miles.

I bought a completely rebuilt 455 a couple of years ago from a guy who was getting out of the hobby. He had installed one of those timing sets and only ran the engine couple of times a month in his garage as the vehicle was "under construction" and never got finished. He pulled the engine, trans and parted out the rest of the car. I bought the engine and several more "parts" 455's plus a bunch of other stuff from him. When we tore the engine down for inspection and to get rid of the hypereutectic pistons and cast rods that same timing set already had an alarming amount of slop in it so we "round filed it"........FWIW........Cliff

[wbnapier]

Thank you Cliff.

What timing set would you recommend? It's a 455, 0.040" over, 4.25" stroke, Stump Puller II, pump gas, tri-power build.

[Cliff R]

I would use a stock type 3/4" wide Morse chain timing set. The Rollmaster is popular for double roller higher end sets. I tried one once and it lasted for about 4 years then had to be replaced. My next build got the Melling set and it's still fine now since 2009 and has a LOT of running time on it.

From what I've seen the 3 keyway type are next to useless for moving the cam around in small amounts with any accuracy. The bad news with stock type sets is that Mopar discontinue the offset keyway set a few years ago so options are limited there as well......

[TedRamAirII]

If I use a Stock Type chain, and the Cam timing is off, whats the remedy?

[wbnapier]

Offset cam or crank keys (woodruff keys) I think. + or - 2 degree increments. ???

[1968GTO421]

Originally Posted by wbnapier

Offset cam or crank keys (woodruff keys) I think. + or - 2 degree increments. ???

Here's a set at reasonable price (quality?)

https://www.jegs.com/i/JEGS/555/W5343/10002/-1

[Cliff R]

Mopar used to sell an offset cam key set, but they have been discontinued for some time. They look like the keys in the link below:

https://www.summitracing.com/parts/dcc-5249600

I'm pretty sure MrGasket still makes a few of the offset keys, and I was told that the keys in the link below will also work but I haven't tried them.

https://www.partsgeek.com/catalog/19...?brand=genuine

A few years ago I bought two sets of NOS Mopar keys off Ebay so good to go for the time being.......

[lust4speed]

Originally Posted by Cliff R

...https://www.partsgeek.com/catalog/19...?brand=genuine...

From the prices I gather they are rather proud of them. Guess the bright side is they are available somewhere. This is another one of those items we should have stocked up on when they were readily available in the Mopar kit.

I have a few large offset keys for the crankshaft, but haven't seen them available for years either.

[tooski]

Originally Posted by TedRamAirII

If I use a Stock Type chain, and the Cam timing is off, whats the remedy?

Butler site has 2* and 4* offset cam keys. Got one in my last order from them.

[Cliff R]

To be perfectly honest I haven't had the need to move very many camshafts using the stock timing sets. Most come in where they need to be at. The few exceptions have been some of the Crower flat camshafts but I haven't used in since going to roller cams back around 2004 so they may even be coming in closer these days.

As many of you know I am NOT a fan of double roller timing sets, and for good reason. Most of those sets are "low" end, so you've got to step up to top shelf variety to get a decent part.

Even with that said the way these vehicles are being used these days even the bottom of the barrel stuff will last a while. This is also the reason we don't see much negative feedback on double roller timing sets. If folks were out there putting 10,000 miles a year on these engines we'd find out quickly that there are a lot of parts that don't make the grade, staring with timing sets. Since most of these vehicles are lucky to get more than a few hundred miles a year put on them just about anything being sold for a timing set will be fine........FWIW......

[TedRamAirII]

I may be way out of line, but can I ASSUME that it would be good practice to advance the cam 2 degrees, to take in account of some initial timing chain stretch, and will settle in where it should be? I like the idea of a tensioner type of rubbing block. like some 4.3 GM engines use. Anyone ever try that?

[1968GTO421]

I guess from what Cliff said my best bet wold be to use the stock Melling 3/4" wide Morse chain when I do my cam job.

Is Melling the best Morse chain to use or are there other brands that I can/should consider?

Thanks.

Also Ted's question abut a two dgree advance is interesting to condider.

[Cliff R]

I can't speak or current production factory Morse type chains. I have two older sets left that still used the good heat treated metal gears and high quality Morse chain.

They may be doing some outsourcing these days so don't hold me to the fire that what you buy now is top quality.

Even so the Morse chain design is quiet, smooth, constant tooth contact and a LOT stronger than any type of roller chain set-up. If you don't think so look in every single chain driven transfer case used on 4 X 4's in the last half a century and see what type of chain/gears are used. A roller chain in that scenario wouldn't make it to the bottom of your driveway let alone tens of thousand with that kind of load on it!

I attached a pic of the two I have left here, one has the heat treated gears the other is a later variety but I wouldn't hesitate to use either one of the as they are pretty old stock and very well made......Cliff

[wbnapier]

The Melling set is actually made by SA Gear, and their chain is NOT Morse.

I just received a new set from Paul Spotts (eBay), username fbpaul.

It IS a Morse chain and has a very different appearance to the Melling chain (SA Gear). They are totally different chain designs. I'll try to post a photo later.

[LKLusza]

I took a look at the Melling chain (Part: 3-350S). There is another one at Summit Racing from Mahle https://www.summitracing.com/parts/m...tiac/model/gto

wbnapier, is this the different type you were talking about? I tried to find your vendor on eBay but no success.

[Cliff R]

The older sets come up from time to time on Ebay, but I don't stock too many these days as I got out of the engine building business several years ago.

Some early production chains were actually made in Japan and excellent. I think Morse had an interest there at one time decades ago.

Most of the currently available stock type 3/4" wide link belt sets will look like the one in the pic below and use an iron top sprocket. I suppose this negates the need to heat treat it as iron with the right nickel content is an excellent wear surface.

Over the years I've used a wide variety of these timing sets and noticed that some actually say MORSE right on the chain, others say JAPAN, some say nothing at all and just have some sort of symbol on the links. In the big scheme of things it really doesn't matter, never had the first issue once with any of them.

The only timing chain failure I've had to date was with my own engine assembled around 1999-2000 and the chain failed in 2004. I would note that at that time I was racing the car at least 2-3 times a week and street driving it almost every day. I racked up a LOT of time on that engine, and all seemed well until one night it started running like chit after a hard 1/4 mile run. It didn't want to idle when I got back to my pit sight, so I trailered it home and pulled the engine. The ONLY thing I found wrong with it was the Rollmaster timing chain had LOT of slop in it! That surprised me because I had the timing cover off and moved the cam 4 times earlier the same year and although the chain was starting to get a little loose everything appeared fine otherwise and each cam movement put the ICL right where it should have.

I did read someplace that if these roller chains reach a certain point in looseness that they will start whipping pretty hard on the loose side at speed and wear out very quickly from the harmonics created by that deal. Not sure about how accurate all that is but I will say I went back to the stock type set and put one in my new engine and have had zero issues. Even had the timing cover off last summer to repair a coolant leak and aside from light "witness" marks on the sprockets the chain is pretty tight and all appeared fine.......Cliff

[400 Lemans]

https://www.ebay.com/itm/Pontiac-V-8...oAAOSwvAhbW0nU Link to Paul Spotts.

[1968GTO421]

Originally Posted by 400 Lemans

https://www.ebay.com/itm/Pontiac-V-8...oAAOSwvAhbW0nU Link to Paul Spotts.

Thanks, appreciate the info. Went ahead and ordered one.