[Verdoro 68]

Put the 236/242 cam in the block last night. Spins nicely and free. The Sims cam retainer and timing set is really nice with very explicit instructions.

The timing chain sprockets on the other hand are too tight. The crank in particular won't go on at all. I'm assuming they need to be honed for an easier slip fit. What's the best way to do that? Could I use a brake cylinder hone?

[HWYSTR455]

Originally Posted by Verdoro 68

.....The timing chain sprockets on the other hand are too tight. The crank in particular won't go on at all. I'm assuming they need to be honed for an easier slip fit. What's the best way to do that? Could I use a brake cylinder hone?

Hm. Well, you can hit the gears with some emery/wet sandpaper to make sure there's no edges/flash. Can do the same on the end of the crank snout too. Can clean after with WD-40.

And the cam one goes on fine? I know sometimes the crank snout on aftermarket cranks are at-spec, and little to no room for gears/balancer in some cases.

I would still only hit the inside of the gears, and only sand the crank snout at the end where the transition areas are. Check balancer fit too.

Keep checking fit of gears wo the chain, and get a 'feel' for the fit. If it still just isn't going to go, you could use a brake hone, but would be wary of doing too much.



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[HWYSTR455]

Test fitting the gears helps seat the keys too.

Even the slightest debris on the parts can make them hard to install, and I usually install dry. Lube can make it more difficult to install as well.

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[HWYSTR455]

I also doctor the keys, so the one end is a little pointed and narrowed, to allow for slight variations of alignment.


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[Stan Weiss]

I guess I am just different. I would like a little interference to the fit.

Stan

[HWYSTR455]

I know the Ohio cranks the snouts were so tight at one time, many started checking (and machining) prior to further machine work.

The Romac balancer were really tight too, and those no WAY would go on without doctoring them.

It sux when you try to uninstall a balance and/or gears and you have to use pullers/removers on them.

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[HWYSTR455]

AH, ok, so they comment on it, that's good.

It may vary from gear set to gear set too don't trust anything out-of-box.

If it's tight on the cam too, and all surfaces are clean, I would be looking at the gears personally. Knock down all sharp edges, etc. On the keys too.

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[Verdoro 68]

The cam is tight too, but not as tight as the crank. I can't get either gear anywhere close to keys, they go on maybe 1/8" or so. The crank sprocket keyways are pretty sharp, but I'm not sure they're even making it to the crank. I'll try gently deburring and wetsanding. I did lube them up which may not be helping. The Butler site says they may need to be honed which is new to me.

Pontiac timing set/ crank gears were “slip-fit” from the factory. The crank sprockets in these billet gear sets may need to be honed to fit as desired (some builders prefer a tighter fit and some want a stock slip-fit) depending on the crank shaft snout size as they vary from stock as well as different brands of aftermarket cranks.

[Verdoro 68]

I prefer a snug fit, but I don't love the idea of using a puller or installer as I degree in the cam. It's a big enough PITA to get the gears lined up without having to deal with a puller. My last Rollmaster set was really tight on the stock crank. I muscled it on and never felt good about it.

[HWYSTR455]

There's 'snug', but then there's also 'too tight'.

I had one that was 'too tight' one time, needed to use puller/installer. Without knowing it, or feeling it, I pushed a key out and had to pull the cover again. Not fun.


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[Verdoro 68]

Got the replacement rings today and was able to get the last piston installed. Milestone! Re-checked the torque of all the mains and rods then installed the lower dipstick tube, windage tray spacers and stock windage tray which was previously modified to clear the main studs.

I fiddled with the timing set some more. I used a brake cylinder hone to make the cam gear fit more comfortable. That one was pretty easy. The crank gear was a pain. I dressed the woodruff key and used some fine sand paper to knock down some of the edges on the crank gear. I found a couple burrs on the crank snout from my first few test fits so I knocked those down with some emory cloth. I was reading through an old thread where Cliff mentioned heating the crank gear to expand it so I busted out the propane torch, heated it up and it slipped right on. I had to work fast though.

I have things lined up dot to dot for starters. The .005 short chain fits like a glove. If I end up needing to advance it, the crank gear will probably need a puller to come off. The one I have isn't thin enough to get between the block and the chain, but I'll cross that bridge if I get there.

Now to go refresh my memory to setting up a cam. It's been a few years...

[HWYSTR455]

Nice! Yeah I have a hot plate in the garage for just those type of occasions. Could slightly warm it with a heat gun too.

Wish I had access to my notes, but think the rollmaster sets are off a couple degrees, if my memory is serving me right! Know it depends in a number of factors, but that's what I remember. (think it's 3 degrees retarded in my experiences)

You can mic the snout and balancer, see if that's going to be stubborn too or not. If you look at the one pic of my mishap, you can see I lightly peened the snout end where the key 'line' is, which helps when lining up the key/keyway during install.

In my case, I think since I was using an installer, the turning of the nut/hat of the installer my have turned the balancer along the way, not sure. But the marks helped initially.


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[Stan Weiss]

Originally Posted by Verdoro 68

I have things lined up dot to dot for starters. The .005 short chain fits like a glove. If I end up needing to advance it, the crank gear will probably need a puller to come off. The one I have isn't thin enough to get between the block and the chain, but I'll cross that bridge if I get there.

If you have to pull the gear you don't want the timing chain to be on the gear.

Stan

[johnta1]

The cam snout should be sticking out of the gear?
Do you have the cam plate on?

Probably need to pry the cam forward and slide the gear on more.

[Verdoro 68]

Originally Posted by HWYSTR455

You can mic the snout and balancer, see if that's going to be stubborn too or not. If you look at the one pic of my mishap, you can see I lightly peened the snout end where the key 'line' is, which helps when lining up the key/keyway during install.

Good idea. Lining up the gear with the key is a pain. I marked the snout with a sharpie but it wears of quickly. Will check the balancer.

Originally Posted by Stan Weiss

If you have to pull the gear you don't want the timing chain to be on the gear.

Good call. I don't want to damage or stretch the chain. The chain is a very tight fit so I can't remove it off the cam gear without moving the crank sprocket in tandem. Any recommendations?

Originally Posted by johnta1

The cam snout should be sticking out of the gear?
Do you have the cam plate on?

Probably need to pry the cam forward and slide the gear on more.

Yes, it should and I will.

[25stevem]

I believe you are right with the rollmasters being off, because Cliff has posted many times that he refuses to use them.

[Dragncar]

Originally Posted by 25stevem

I believe you are right with the rollmasters being off, because Cliff has posted many times that he refuses to use them.

I believe Cliff does not like them because they stretch out too quick for his liking but they are accurate when new.
Mine was pretty much dead on. I would have used a Morse if my block was not aligned bored.
With all these timing chain issues I am about to get into Milodon gear drives and be done with it.

[Verdoro 68]

I'm a little rusty at cam degreeing, but initial indications show I may have gotten lucky here. It was a little too easy so I'm skeptical.

Found top dead center on #1 using a dial indicator, and the degree wheel. Put a lifter in and a pushrod on the #1 intake lifter and set up the dial indicator.

Next, I centered up the cam on the apex of the lift. Since it's a roller, it dwells a little bit, so I used the same method you use to find TDC to find the exact top of the cam. This actually put the pointer at 110 on the degree wheel (makes sense as it's the same process as below, just with less distance), so either my measurement is really good or I flubbed a step. Rolling it forward .020 came out to 80 degrees, going back .020 came out to 140. 80+140 = 220. 220/2 = 110, which is the ICL the cam is ground on.

110 degrees came up too many times too easily for me to feel like I did this right. Did I miss something or am I good to go? This felt harder to do last time I did it, but I did it in the car with the head installed.

[Stan Weiss]

Originally Posted by Verdoro 68

I'm a little rusty at cam degreeing, but initial indications show I may have gotten lucky here. It was a little too easy so I'm skeptical.

Found top dead center on #1 using a dial indicator, and the degree wheel. Put a lifter in and a pushrod on the #1 intake lifter and set up the dial indicator.

Next, I centered up the cam on the apex of the lift. Since it's a roller, it dwells a little bit, so I used the same method you use to find TDC to find the exact top of the cam. This actually put the pointer at 110 on the degree wheel (makes sense as it's the same process as below, just with less distance), so either my measurement is really good or I flubbed a step. Rolling it forward .020 came out to 80 degrees, going back .020 came out to 140. 80+140 = 220. 220/2 = 110, which is the ICL the cam is ground on.

110 degrees came up too many times too easily for me to feel like I did this right. Did I miss something or am I good to go? This felt harder to do last time I did it, but I did it in the car with the head installed.

I am not so if I understand this correctly or not. When I degree a cam I only rotate in one direction. Clockwise.

Stan

[Formulajones]

Correct
Only rotate the engine clockwise.
As a side note, I know too late now but I usually only assemble the number one piston then degree the cam. Sure makes it a lot easier to rotate the engine. Especially when you're trying to move it that last degree. Overshoot and you have to go around again lol