Rollmaster +.002 - My set has no markings.....

[Blazer406]

Trying to put my motor together after a long time being disassembled.... block was line bored after 2 center steel caps were installed. I was told a .004 didn't fit so I ordered a .002...... well.... other issues caused me to pull the engine out twice.... in 60 miles of driving...... now that that has been fixed... I am re-assembling my 60 mile motor.... The timing chain has about .380" slack...so if you press on the chain where the stock tensioner does.... it moves a total of about 3/8" ..... so I get to looking at my timing set.... and there are no markings on the timing set other than Rollmaster..... obviously there is multiple keyways in the bottom gear....and two dots.... and one dot on the top gear.... and "rollmaster" inscribed into the gear...... but best I can tell.... there is no identifying marks that tell me it is an +.002" gearset.

Anybody else run into unmarked timing gears?

Frustrates me.... because they are very clear on T/A's catalog that say the gears are a matched set.....but yet I have no way to know if mine are actually .002 or not.......

BTW... it is not T/A's fault.... I ordered it from another vendor on here some time back.....but had a T/A catalog handy when I went to look up what set I needed to order next.... IMHO... Rollmaster should have put some identifying numbers or marks to let me know that both gears are .002" line bored gears....

Oh... I didn't assemble the engine initially... so I don't know if there was any slop... or if there was.... how much... I can't say.... I just know now.....that it is too sloppy for my liking.....

 

[bison]

Mine wasnt marked either. I wound up with a .006 set. Im not sure if both gears are different of just one is different. Seems like it would be a bitch for them to make different crank gears and cam gears.The box was unopened and had the .006 designation on the sticker. It fit a lot tighter than the std ones i compared it to. There is no for sure way to know where you are till you try at least one new set and see how it fits. Looser is better than too tight.

 

[Blazer406]

So... if I currently have a near new (only 1 hour run time) +.002" timing set.... and I have about 3/8" of slop.... i.e. total chain movement perpendicular to chain.... like pushing on it like the stock tensioner would... if it were installed. I want to clearly ID where the 3/8" slack is...

What set do I need now?

My guess is try an +.005 ??

 

[Blazer406]

Well... I found this on the Romac Website.... might be of some use to somebody.....

Tunnel Bore Sizes
How to Determine Tunnel Bore Sizes


After fitting your standard Rollmaster Timing Chain Set to the engine you need to pinch the chain with two fingers halfway between the crank and the cam sprocket on the right hand side. Without forcing or pushing hard move the chain back and forth and note the amount of movement.

Use this formula:

1/4" = .002" to .004"
5/16" = .004" to .006"
3/8" = .006" to .008"
1/2" = .008" to .010"

These sizes are the amount of the oversize you need to order to obtain the best possible results for chain fitment.

If I have a near new .002 set now..... and have 3/8" slop...... rekon I need the .008 or .010?

 

[charlief1]

Thanks for the info Blazer. I never thought of looking at the site to see how it's measured.